The holotype of the basal archosauromorph Prolacerta broomi revisited

Abstract: Prolacerta broomi is one of the most important of fossil reptiles. First considered as one of the earliest members of squamates, this basal archosauromorph has been used as a model for diapsid morphological evolution ever since its discovery, playing a pivotal role in hypotheses on the origin of diapsid reptiles. The holotype of Prolacerta broomi (UCMZ 2003.41R) is known from a mostly complete skull, but the original description is limited to the superficial features of the skull roof and palate. Since then, many other specimens of Prolacerta broomi have been recovered that potentially account for this limited access to anatomical information, but it remains unclear whether these aspects correspond well to the known material of the holotype. Here, the skull morphology of the holotype of Prolacerta broomi is revisited through the use of μCT scans. The identifications of some cranial elements have been corrected, such as the left prefrontal and lacrimal, and several new elements are revealed, including the epi- and ectopterygoids, prearticular, coronoid, and braincase bones. The orbitonasal region is described in detail and significantly shows a contribution of the lacrimal to the dorsal alveolar canal. Finally, the addition of the holotype as an independent OTU in recently published analyses indicate conflicts with the current knowledge on Prolacerta broomi phylogenetic affinity and taxonomy. First, it points to potential taxonomic inconsistency since the holotype does not form a monophyletic group with other Prolacerta broomi OTUs in any of the analyses and, second, it suggests a more basal position for the holotype than that recovered in some studies, more basal than rhynchosaurs and close to the origin of Crocopoda. Together, these findings indicate areas of future research interest in the study of early evolving archosauromorphs.

reptilia
diapsida
archosauromorpha
crocopoda
triassic
south africa


Biomechanical analysis and new trophic hypothesis for Riojasuchus tenuisceps, a bizarre-snouted Late Triassic pseudosuchian from Argentina

Abstract: Ornithosuchids are a Late Triassic pseudosuchian archosaur group, consisting of four species (three from South America, and one from Scotland). All of them have triangular skulls with a protruding premaxilla, large nostrils, an extensive diastema in their narrow snout, a short jaw that does not reach the anterior end of the skull, and serrated posteriorly curved teeth. For this clade, carnivorous and scavenger habits have been previously proposed. Within the Ornithosuchidae, Riojasuchus tenuisceps (from Argentina) has the most morphologically extreme characteristics. Based on CT scans of the preserved skulls we generated a 3D model, and over this, we estimated the volumes of the adductors and abductor muscles and the force exerted by each. From these data we built the finite element model and measured the bite force (1.8–2.3 kN). Lateral, tractive, and torsional forces were applied to the end of the snout to evaluate the structural response of the skull during feeding. The results show that R. tenuisceps could resist tractive and torsional stresses better than lateral stress. Additionally, we analysed the peculiar morphological characteristics of the skull and their functional implications. We observed that the upper and lower dental rows were laterally separated from each other, preventing the generation of a cutting line during occlusion, and therefore, R. tenuisceps would have fed on small-sized prey that it could swallow whole. The curved premaxilla and the short mandible would not allow it to bite with the tip of the snout (ruling out the scavenging hypothesis), but were instead more adequate to capturing prey suspended in a fluid. This set of results allows us to propose that R. tenuisceps could have had a zoophagous diet and a wading habit, being able to feed on fish, amphibians, or any small animals that they could catch from the shoreline.

archosauria
biomechanics
feeding habits
finite element model
bite force estimation


New artiopodan euarthropods from the Chengjiang fauna (Cambrian, Stage 3) at Malong, Yunnan, China

Abstract: The artiopodans, consisting of trilobites and their relatives, were a major euarthropod group in the Paleozoic. Since the first discovery of Naraoia from the Chengjiang fauna, a significant number of artiopodans have been subsequently found in China. Here we describe three new artiopodan species from the lower Cambrian Chengjiang fauna (Cambrian Series 2, Stage 3) at Malong, Yunnan, China. Zhugeia acuticaudata gen. et sp. nov. is defined by a semielliptical cephalon with long genal spines, nine overlapping thoracic tergites, and a pygidium with an elongated needle-like median spine. Its cephalic shield covers multiple anterior thoracic tergites. Tonglaiia bispinosa gen. et sp. nov. is defined by a suboval cephalon, seven thoracic tergites, and a micropygous pygidium with a pair of parallel posteriormost spines. Sidneyia malongensis sp. nov., a new occurrence of Sidneyia from South China, is defined by a crescent-shaped cephalon, eight imbricated tergites, and an abdomen consisting of two cylindrical segments and a tail fluke. The evolutionary affinities of these new taxa are reconstructed and discussed in a phylogenetic context. Phylogenetic analyses resolve Z. acuticaudata among the xandarellids and T. bispinosa gen. et sp. nov. as a trilobitomorph with an uncertain placement, The discovery of three new species improves the biodiversity of artiopodans from the Cambrian and the Chengjiang fauna.

arthropoda
trilobitomorpha
vicissicaudata
burgess shale-type fossils
exceptional preservation
lagerstätten
cambrian
yu’anshan formation
chengjiang


Parmalean and other siliceous nannofossils from the Oligocene of Polish Flysch Carpathians

Abstract: Well-preserved fossil assemblages provide valuable insights into the evolutionary history of biota and their environments. Here, we report on Rupelian (early Oligocene) siliceous nanoeukaryotes from diatomites in the Carpathian Mountains, southeastern Poland. These sediments yielded novel forms of parmaleans and parmalean-like fossils. Their cell wall structure differs from that of described genera. Instead of the generically specific separate dorsal plate and set of girdle plates, some of our taxa contain one upended, hollow, subspherical, perforated cup. To accommodate these differences, we propose a new division Parmaphyta, a new family Parmoligocenaceae, a new genus Parmoligocena and a new species Parmoligocena janusii. Other remains are reminiscent of the extant genus Pentalamina and for this we propose a new genus and species, Pentalaminamorpha radiata. The taxonomic affinity is less certain for other nannofossils found, as they are only somewhat similar to parmaleans, and so we only tentatively associate them with this group. All these fossils occur together with a diverse assemblage of diatoms (mostly from Leptocylindrales, Rhizosoleniales, Coscinodiscales, Cymatosirales, and Hemiaulales), silicoflagellates (mostly species from the genus Corbisema) and archaeomonads. Together they suggest the palaeoenvironmental context for the parmaleans, a neritic marine environment, thus similar to where silicified parmaleans can be found today.

parmoligocena
pentalaminamorpha
diatomites
siliceous nannofossils
parmaleans
oligocene
polish flysch carpathians


New records of marsupials from the Miocene of Western Amazonia, Acre, Brazil

Abstract: The Amazonian region covers a significant part of the South American continent and harbors outstanding biodiversity. However, much of its history is still unknown. This situation has begun to change with paleontological field efforts over the last decades, which have been proving that fossils can be common in this region. Despite their great current species richness and abundance in the area today, marsupials have a sparse fossil record, restricted to a few specimens from handful Cenozoic Amazonian localities. Here we present new records of fossil marsupial teeth from the Solimões Formation (lower Eocene–Pliocene), on the Juruá and Envira riverbanks (Acre, Northwestern Brazil). The localities investigated yield at least four distinct didelphid didelphimorphians at PRE 06 (Ponto Rio Envira: Marmosini ?Marmosa sp., Didelphis cf. D. solimoensis, Thylamys? colombianus, plus unidentified didelphids), and two paucituberculatans from the Juruá River localities (Ponto Rio Juruá: the palaeothentid Palaeothentinae indet. at PRJ 25 and PRJ 33’, and Abderitidae indet. from PRJ 33). In agreement with the associated mammalian faunas, most of the didelphids, except for Thylamys? colombianus from PRE 06, indicate a (?early) Late Miocene age for this locality. Conversely, the abderitid specimens found in situ at PRJ 33 would match a Middle Miocene age. The palaeothentids found at PRJ 25 and PRJ 33’ localities cannot be considered for biostratigraphic inferences, since they were found outside a stratigraphic context. Nevertheless, these paucituberculatans considerably add to our knowledge, as they are the first ever recorded in Brazilian Amazonia.

mammalia
metatheria
didelphimorphia
paucituberculata
systematics
historical biogeography
miocene
brazil


A new diminutive fossil ziphiid from the deep-sea floor off northern Chile and some remarks on the body size evolution and palaeobiogeography of the beaked whales

Abstract: The evolutionary history of the beaked whales (Ziphiidae), odontocetes nowadays adapted to deep diving, is well known thanks to a significant fossil record mainly from the deep ocean floors. A partial cranium of a ziphiid recovered from Plio-Pleistocene deep sea deposits (about 1000 m) off the port of Pisagua, northern Chile, during fishing activity is here described and referred to the new species Ihlengesi changoensis. Ihlengesi changoensis differs from the type species Ihlengesi saldanhae, from the sea floor off South Africa, by having a more elongated premaxillary sac fossa and consequently a more anteriorly located premaxillary foramen; dorsal margin of each premaxillary crest sloping markedly ventrolaterally and generating an acute dorsal profile of the vertex in anterior view; less anterolateral extension of the right nasal forming part of the premaxillary crest; lateral margins of the nasals not anteriorly diverging but weakly convex; nasofrontal suture anteriorly pointed. The phylogeny supports a sister-taxon relationship between I. changoensis and I. saldanhae, both members of the crown ziphiids Hyperoodontinae. Ihlengesi changoensis shares with I. saldanhae and other fossil ziphiids a small body size (estimated length 3.5 m) supporting the hypothesis that in the past small beaked whales (<4 m) were more common than today. Such recent shift of the ziphiids towards a larger size could be the result of a progressive change of diet from fish to cephalopods, to the competition with the delphinids, and the predatory impact of the white shark Carcharodon carcharias and/or of the killer whale Orcinus orca. This new Chilean ziphiid further supports the hypothesis that crown beaked whales originated and firstly dispersed in the oceanic waters of the Southern Hemisphere. Their radiation and geographical distribution could have been driven by the southern oceanic circulation and related localized concentration of trophic resources in high productivity upwelling areas.

mammalia
cetacea
ziphiidae
cenozoic
southeastern pacific
south america


A comparison of teeth in Tithonian, Late Jurassic, predatory actinopterygian fishes from Owadów-Brzezinki Lägerstatte and its palaeoecological implications

Abstract: The Owadów-Brzezinki palaeontological site is known for its very well-preserved fossils of Late Jurassic vertebrates, such as numerous fossil fish teeth and occasional dental bones. Some of these represent well-studied taxa, including the most common large predatory fish, with notable examples of caturoids (such as Strobilodus sp.) and pachycormids (Orthocormus teyleri). The current study presents the microstructure and histological features of the teeth of the selected specimens of the above taxa. They are determined through examinations of tooth cross-sections under thin microscopic observations and by the usage of scanning electron microscopy (SEM). The above inspections, combined with aspects of external tooth morphology, allowed us to determine the palaeoecology of the aforementioned taxa of large predatory fish. It is concluded that examined Caturoidea displayed a rather homogenous dentition belonging to the intermediate cut/slash guild, characterized by an internal orthodentin histology with prominent incremental Andresen growth lines of differing form, indicating living in a highly variable, unstable environment. The teeth of pachycormid specimen (O. teyleri) can be characterized as having denteon-based orthodentin histology, with a rapid rate of tooth eruption and a heterodont, elongated specialist dentition of the piercing guild. The observed structural differences in the teeth suggest a different niche distribution between the taxa studied. They help to explain how these predatory ray-finned fishes may have coexisted both in the local environment of the Owadów-Brzezinki and in the wider, more global context of Late Jurassic shallow marine environments. In addition, the tooth samples are characterised by pronounced surface bioerosion with traces of Mycellites ossifragus durophagous fungal activity, indicating an intense bioerosion caused by these microorganisms after the death of the fish.

key words: actinopterygii
caturoidea
teeth
predatory
microstructure
histology
niches
late jurassic
poland
owadów-brzezinki quarry


A new Early Devonian antiarch placoderm from Belarus, and the phylogeny of Asterolepidoidei

Abstract: A new asterolepidoid antiarch, Sherbonaspis talimaae sp. nov., is described based on the disarticulated skeletal elements from several boreholes in Belarus, from the Lepel Beds of the Vitebsk Formation, which has been assigned to an Early Devonian, late Emsian age. New information is provided on the structure of the paranuchal plate previously unknown in Sherbonaspis. Data on the remains of the other fossil vertebrates, and the characteristics of the fossil-bearing rocks are provided. These data add information on the taxonomic composition of the late Emsian–early Eifelian fish fauna from the western part of the East European Platform. The new cladistic analysis of the Euantiarcha provides results more reliable in comparison with the analysis of all antiarchs together, and supports traditional subdivision of the group into Bothriolepidoidei and Asterolepidoidei. However, further analysis demonstrates unresolved polytomy close to the base of the Asterolepidoidei, and supports the hypothesis that the family Pterichthyodidae is polyphyletic. Until the phylogenetic relationships of Asterolepidoidei are more clearly resolved, Sherbonaspis is attributed to Pterichthyodidae. Comparison of the sections of the Lepel Beds of Belarus with the age-equivalent deposits in Estonia, Lithuania, and Latvia supports a late Emsian or possibly early Eifelian age for the Lepel Beds.

placodermi asterolepidoidei phylogeny devonian belarus


The tarphyceratid cephalopod Trocholites in the Middle–Upper Ordovician of the Prague Basin —the Baltican element in peri-Gondwana

Abstract: The vast majority of cephalopods of the order Tarphyceratida are known from regions that were located at mid- or low palaeolatitudes during the Ordovician (mainly Baltica, Laurentia, and Chinese palaeoblocks). Only a handful of tarphyceratid specimens are known from high palaeolatitude regions of peri-Gondwana and Gondwana. Here, we describe the two best-preserved trocholitid cephalopods known to date from the Ordovician of the Prague Basin. The first is from the late Darriwilian/early Sandbian Dobrotivá Formation and is assigned to Trocholites fugax, a species previously recorded from roughly coeval strata of Iberia, France, and Bohemia. The specimen thus strengthens previous hypotheses regarding the interchange of non-benthic faunas between Baltica and different regions of peri-Gondwana during the Middle/ Late Ordovician boundary interval. The second specimen, assigned to a new species of Trocholites chaloupkai sp. nov., is from the late Sandbian–early Katian Zahořany Formation and thus represents one of the stratigraphically youngest Trocholites in the Ordovician of peri-Gondwana. Internal structures of the shell of the holotype of the new species were studied using micro-CT tomography. This revealed that T. chaloupkai sp. nov. closely resembles the stratigraphically older (Darriwilian) species Trocholites depressus from Estonia.

tarphyceratida
trocholites
micro ct
darriwilian
sandbian/katian
prague basin
baltica
peri-gondwana
bohemia


On Triassic Murchisonia-like gastropods—surviving the end-Permian extinction to become extinct in the Late Triassic

Abstract: High-spired Murchisonia-like slit-band gastropods are an important component of late Paleozoic gastropod faunas. Twenty-seven genera of such gastropods have been reported from the Permian, most of which representing the caenogastropod family Goniasmatidae. Only four genera, Trypanocochlea, Wannerispira, Laschmaspira, and Altadema crossed the Permian/Triassic boundary. Based on the study of newly collected specimens and material from natural history collections, we studied the surviving genera as well as the Triassic recovery of this group. Two new species (Laschmaspira lirata sp. nov. and Altadema hausmannae sp. nov.) and one new subfamily (Cheilotomoninae) are introduced. Murchisonia-like caenogastropods, chiefly Goniasmatidae, were diverse and abundant until the Permian, barely survived the end-Permian extinction, regained a certain generic diversity within the Triassic with the evolution of several new genera but failed by far to regain their Permian generic diversity. This once successful and diverse group shares a similar fate (surviving the end-Permian extinction, a reduced Triassic diversity and extinction during Late Triassic crises) as conodonts, orthoceratids, conulariids, and others. This diversity pattern does not qualify for the “Dead Clade Walking” phenomenon, i.e., the extinction shortly after a major mass extinction event (survival without recovery) because they have survived for ca. 30 Ma (at least until the Norian) and even produced a number of new genera. The exact time of their extinction is unknown but there are no safe Rhaetian occurrences. Their extinction is part of a long-term selective trend against the character “shell-slit”.

gastropoda
goniasmatidae
diversity
recovery
end-permian extinction
triassic
italy
austria


Palaeoclimate and fossil woods—is the use of mean sensitivity sensible?

Abstract: The growth rings of fossil wood provide valuable data on tree ecology. As many of the parameters controlling width are climatic, it is tempting to use these rings as an indicator of climate. This is what has been done, with great success, by dendrochronological studies of archaeological wood. For wood dating from before the Pleistocene, however, the task is more uncertain. Since around 1980, researchers have relied mainly on a statistical parameter, the mean sensitivity, an average of the difference in width between two consecutive rings. However, there has never been a critical examination of utility and significance of this parameter for fossil wood. I compiled 63 studies that used mean sensitivity for palaeoclimatological inferences. An analysis of this compilation is presented here. Despite its ups and downs since the 1980’s, mean sensitivity is increasingly used by palaeobotanists. However, it has been used in very different ways. The values obtained for the same fossil can vary greatly from one researcher to another, but also according to the radii of the woody axis considered. Within fossil wood assemblages, average sensitivity varies widely, but rarely consistently. Overall, mean sensitivity values are continuously, normally and unimodally distributed, and therefore are unsuitable for characterising discrete climate classes. Finally, it seems that the most recent studies are also the least cautious when it comes to interpreting the values obtained.

climate proxy
growth ring
palaeobotany
palaeoecology
tree


A new thalassematid echiuran worm from the Middle Ordovician Castle Bank Biota of Wales, UK

Abstract: Echiurans (spoonworms) are a very distinctive group of polychaete annelids that had long been considered to constitute a separate phylum. Their fossil record is extremely limited, although trace fossils that have been suggested to be attributable to them date back as far as the Cambrian Period. The oldest body fossils are from the Carboniferous Mazon Creek Biota, and preserve only limited morphological detail. New material from the Middle Ordovician (Darrivilian, Didymograptus murchisoni Biozone) Castle Bank Biota of Wales shows fine detail of the morphology of a new taxon, Llwygarua suzannae gen. et sp. nov., including several details that indicate an assignment to the derived family Thalassematidae, allied to the speciose genus Ochetostoma. These details include proboscis morphology, anterior setae, and muscle organisation within the trunk. An additional specimen is described in open nomenclature, as it may be either a distinct species, or a juvenile of Llwygarua suzannae gen. et sp. nov. with a relatively elongated proboscis. These worms demonstrate a very early and previously unrecognised diversification of the echiuran grown group, further supporting an early diversification of Annelida as a whole.

annelida
echiura
thalassematidae
darriwilian
middle ordovician
united kingdom


Early Tremadocian cephalopods from Santa Rosita Formation in NW Argentina: the oldest record for South America

Abstract: We describe early Tremadocian (Kainella meridionalis Biozone) cephalopods from the Cordillera Oriental, Jujuy, NW Argentina. They consist of numerous small specimens collected at the Quebrada de Arenal, Trancas section, near the town of Tilcara, in the Alfarcito Member of the Santa Rosita Formation. All but three specimens were assigned to a new species of Ellesmeroceras (Family Ellesmeroceratidae), E. humahuacaensis sp. nov., based on its slightly endogastric curvature, the characteristics of the siphuncle and chambers dimensions. Micro CT scanning of one specimen aided in the description of the apex and facilitated the construction of a 3D model of the species. A single, similar specimen was assigned to Ellesmeroceras sp. pending the availability of additional material. Two specimens differ from the rest, being exogastric with a lower angle of expansion. They are tentatively assigned to Bassleroceras sp. This material indicates that Cambrian and early Tremadocian cephalopods are not as different as previously thought. “Diversification” and “extinction” events during the late Cambrian may be attributed to taxonomic “over-splitting” and taphonomic and/or sampling biases, respectively. These specimens are currently the oldest recorded in the Central Andean Basin and of West Gondwana, and probably represent the first migration of cephalopods into the region, when the water column was still poorly colonized. During the middle Tremadocian, subsequent immigrations and originations of several cephalopod orders accounted for a rise in diversity and expansion into new niches during this interval. Some of these taxa persisted into the middle Floian, at which time, a second increase in diversity is recorded. Ellesmeroceras humahuacaensis sp. nov. is interpreted as a sub-vertical nektobenthic organism.

cephalopoda
ellesmeroceratidae
ellesmeroceras
stem cephalopods
tremadocian
ordovician
santa rosita formation
cordillera oriental


Enamel microstructure and dental histology in a heterodontosaurid dinosaur: Heterodontosaurus tucki

Abstract: Among non-avian dinosaurs, Heterodontosaurus tucki is unique for possessing complex dental features including both morphological and proportional heterodonty, sub-hypsodonty, tooth occlusion, and extensive low-angled wear facets—a collection of derived traits made additionally noteworthy by their appearance in one of the earliest-branching ornithischian lineages. In many taxa with similar dental characteristics, complex suites of modified dental tissues shape functional occlusal surfaces through wear. It remains unknown if H. tucki possesses similar histological complexity. Here, we investigate the histology and enamel microstructure of H. tucki maxillary cheek teeth from the Early Jurassic upper Elliot Formation of South Africa. Despite possessing a superficially complex dentition, the maxillary teeth exhibit a thin, relatively simple, three-layered enamel schmelzmuster (basal unit, columnar unit, and parallel crystallite) with enamel tubules. On the labial face, the enamel thins out drastically (<6 μm) and is discontinuous with a more simplified enamel microstructure. Surprisingly, a thick band of wear-resistant, histologically distinct dentine arises concurrent with the thinning enamel and appears to form the primary cutting crest of the functional occlusal surface, a role typically filled by enamel. This represents both the phylogenetically and chronologically earliest known acquisition of this form of modified dentine within Ornithischia.

dinosauria
heterodontosauridae
heterodontosaurus tucki
enamel
microstructure
histology


New Pleistocene bird fossils in Taiwan reveal unexpected seabirds in East Asia

Abstract: The island of Taiwan, with its diverse microclimates and key position on the East Asian-Australasian Flyway, attracts numerous bird enthusiasts due to its diverse avian fauna. Nevertheless, due to the scarcity of fossil records, there is a significant knowledge gap between modern and ancient avifaunas in Taiwan. Currently, there is only a single described Pleistocene fossil; it is attributed to Phasianidae. To address this gap, this study describes two new bird fossils, a left humerus and a left tibiotarsus, and discusses them in detail herein. The fossils were collected from the Liuchungchi Formation (Early Pleistocene, 1.95–1.35 Ma) in Niubu, Chiayi, southwestern Taiwan, which represents a neritic environment. The fossils are identified as from species of Gaviidae (loons), with the humerus belonging to an undetermined species of Gavia and the tibiotarsus to Gavia stellata. Loons are seabirds that are primarily distributed in high- and middle latitudes of the Northern Hemisphere. In addition, these birds are extremely rare in modern Taiwan: records are scarce and most are limited to northern and northeastern Taiwan since the 1860s, indicating that the modern Gavia birds only occasionally visit Taiwan. All known Pleistocene fossils of species of Gavia from the northern West Pacific come from Japan. The Taiwan fossils of Gavia provide valuable bird evolutionary and paleobiogeographic information for the subtropical West Pacific and may imply the presence of a distinct avifauna in the region during the Early Pleistocene.

aves
gavia
loon
seabird
early pleistocene
taiwan


Muscle attachment scars in helcionelloids from Denmark cast light on mollusc evolution in the Cambrian

Abstract: Multiple, small (diameter <20 μm) swellings on the apex of internal moulds of the laterally compressed helcionelloids Eotebenna viviannae and the new species Eotebenna danica from the middle Cambrian (Miaolingian) of Bornholm, Denmark, are interpreted as a muscle attachment scars. The scar pattern is unique amongst currently known helcionelloids both in the abundance of attachment sites and in crossing the median plane of symmetry on the supra-apical (dorsal) surface. Sites of typically two pairs of dorsal muscle scars in other helcionelloids are distributed symmetrically on the dorso-lateral areas. The recognition of four groups of muscle scar patterns in helcionelloids suggests a degree of anatomical diversity within the group that is obscured by the morphological simplicity of the enclosing cap-shaped shells, although evolutionary links to mollusc crown groups are unresolved. In addition to the muscle scars, traces of shell micro‑structure are described.

mollusca
helcionelloida
muscle scars
miaolingian
cambrian
denmark


Dimorphism in Late Cretaceous ammonites—evidence from early Turonian ammonite faunas of the Brießnitz Formation in Saxony, Germany

Abstract: Systematic palaeontological and biometric-statistical analyses (classical clustering and linear discriminant analysis) of statistically significant populations of three early Turonian ammonite species from offshore marls of the Brießnitz Formation (Saxonian Cretaceous Basin, eastern Germany) were used to evaluate a formerly just visually suspected hypothesis of a size dimorphism within the taxa. The studied faunas can in fact be regarded as contemporaneous late early Turonian fossil assemblages derived from a palaeobiogeographic and depositional entity. However, only one of the three species passed the statistical tests. Neither in Lewesiceras peramplum nor in Mammites nodosoides can a dimorphism be proven. In both taxa, no other features than size can be recognised that differ significantly between the overlapping groups. Furthermore, adulthood cannot be proven due to the absence of unequivocal mature modifications. Thus, a combination of large intraspecific variability and commonly incompletely preserved (i.e., small) specimens dissembles dimorphic populations at a first glance. On the other hand, the suspected dimorphism in Spathites (Jeanrogericeras) reveliereanus was confirmed by the statistical analyses of numerous biometric parameters. Not only the maximum diameters but also the distinct apertural cross-sections and ornament show significant differences between the statistically clearly separated two groups. Furthermore, a decline in ornament and widening of the body chamber in fully grown macroconch specimens, regarded as a mature modification of the shell, demonstrate that the antidimorphs really differed in adult morphology. Thus, it can be shown that there are in fact two forms in the fossil assemblage of S. (J.) reveliereanus that, based on their morphological differences and lack of any overlap, represent micro- and macroconchs (inferred males and females) of an evidently dimorphic ammonite species. Finally, we conclude that simple visual inspection is commonly insufficient for the reliable proof of dimorphism in ammonoids.

ammonitina
biometric-statistical analyses
dimorphic pairs
elbtal group
cretaceous


In vivo and post-mortem bioerosion traces in solitary corals from the upper Pliocene deposits of Tunisia

Abstract: The polychaete borings Caulostrepsis taeniola, Caulostrepsis cretacea, Caulostrepsis avipes, Caulostrepsis penicillus isp. nov., Maeandropolydora elegans, Maeandropolydora sulcans, Sulcichnus sigillum, the bryozoan boring Pinaceocladichnus onubensis and the phoronid boring Talpina cf. hackberryensis occur in coralla of the solitary scleractinian coral Ceratotrochus (Edwardsotrochus) duodecimcostatus in the upper Pliocene middle/lower neritic to upper bathyal fine-grained deposits of NE Tunisia. This very rich assemblage of borings is produced in vivo as suggested by (i) their occurrence close to the surface and mostly in the upper part of coralla (Caulostrepsis ispp., M. elegans), even if they are known to penetrate deeply in the substrate, or (ii) evidence of corallum deformation in response to the boring action (Sulcichnus sulcans). The remaining borings were probably produced post mortem; they penetrate deeply into the corallum (M. sulcans) or always occur shallowly in the substrate (Talpina) and, in addition, cross cut other borings (Pinaceocladichnus). The polychaete borings are dominant. The abundance of the borings is probably caused by ecological pressure from shallower zones in subtropical waters. This resulted in the colonization of hard, small-sized substrates located in relatively deep (offshore) waters. The interpretation of age and palaeoenvironment was elucidated by the analysis of benthic and planktonic foraminifers.

anthozoa
palaeoecology
ichnotaxonomy
commensalism
pliocene
mediterranean basin


Floian, Early Ordovician, trilobites from the Olongbluk Terrane, northwest China

Abstract: Floian, Early Ordovician trilobites are systematically described and revised based on new material from the middle part of the Duoquanshan Formation of the Shihuigou area, northern Qinghai Province, northwest China. The fauna that lived on the shallow-water carbonate platform comprises three species belonging to two families, i.e., Tsaidamaspis diarmatus, Zhiyia tsinghaiensis, and Liexiaspis sp. indeterminate. It exhibits a strong endemicity to the Olongbluk terrane. The new isoteline genus Zhiyia is established on the basis of the material from the Olongbluk terrane and South China palaeoplate, and is characterized by its: (i) almost obsolete cephalic and pygidial axial furrows; (ii) flattened anterior border and narrow (sag., exsag.) occipital ring; (iii) bilobed hypostome with a shallow median notch and a small triangular median projection; (iv) subsemicircular pygidium with wide pygidial axis and border. Faunal evidence indicates that the palaeogeographic position of the Olongbluk terrane may have been situated closer to the South China palaeoplate rather than the North China palaeoplate during the Floian.

trilobita
palaeogeography
floian
ordovician
olongbluk terrane
northwest china


An early Eocene pan-gekkotan from France could represent an extra squamate group that survived the K/Pg extinction

Abstract: In this paper we describe a new lizard from the early Eocene of the Cos locality in the Quercy region (near the Caylus village, Southwest France). The age of the Cos deposit has been proposed as the MP 10–11 interval, close to the transition of the late Ypresian to early Lutetian. The fossil material includes a nearly complete right maxilla and a large section of the right dentary, both elements attributed to Pan-Gekkota. These specimens are morphologically different from crown gekkotans, therefore, we describe them as a new species. Some aspects of the maxilla are very atypical regarding geckos (e.g., the shape of the facial process). The posterior margin of the facial process slopes down gradually dorsoventrally towards the jugal facet, reaching the posterior end of the maxilla, in contrast to gekkotans, where the facial process ends anterior to the posterior end of the maxilla. A similar maxilla is present in the Late Jurassic–Early Cretaceous pan-gekkotan genus Eichstaettisaurus. This suggests that the new fossil taxon represents either a lineage that persisted from the Mesozoic to the early Eocene in Europe, or perhaps a morphology otherwise unrepresented in crown gekkotans. We allocate this taxon provisionally to Pan-Gekkota, and contribute to increase the diversity of this clade in Western Europe during the Paleogene, which now includes the stratigraphically similarly aged Laonogekko lefevrei from France (MP 10), and older Dollogekko from Belgium (MP 7).

squamata
pan-gekkota
mesozoic
k/pg extinction
paleogene
phosphorites du quercy
france


Novel pneumatic features in the ribs of the sauropod dinosaur Brachiosaurus altithorax

Abstract: Pneumatic dorsal ribs are known for many sauropods, but to date costal pneumaticity has received relatively little attention. In particular, the pneumatic ribs of the holotype specimen of Brachiosaurus altithorax have been largely overlooked, although they present a unique configuration of pneumatic features. One rib, with a pneumatic foramen some distance down the shaft, was briefly described and illustrated in the early 20th century by Elmer S. Riggs. A second rib with a pneumatic foramen in the tuberculum of the rib has not previously been described or illustrated. This previously undescribed foramen is similar in location to those in some dorsal ribs of Brontosaurus excelsus and Giraffatitan brancai, but differs from them in both size and shape. The contrasting sites of costal pneumaticity in the holotype individual of Brachiosaurus altithorax emphasize the generally opportunistic mode of postcranial pneumatization, in both sauropods and other ornithodirans, but conform to models of pneumatization following vascularization.

sauropoda
dinosauria
brachiosauridae
pneumaticity
costal pneumaticity


A new gigantic titanosaurian sauropod from the early Late Cretaceous of Patagonia (Neuquén Province, Argentina)

Abstract: A new gigantic titanosaur Bustingorrytitan shiva gen. et sp. nov. is described. The four specimens upon which this species is erected come from Neuquén Province, Argentina, from levels of the Huincul Formation (Cenomanian). Bustingorrytitan shiva gen. et sp. nov. exhibits some autapomorphic characters such as posterior dorsal vertebrae with spinodiapophyseal laminae bifurcated in two, very well developed anterior and posterior spinodiapophyseal lamina rami, which limit a deep, vertical, socket-like fossa; posterior dorsal neural arches with forked centropostzygapophyseal laminae; hyposphene in anterior caudal vertebrae; humerus with deltopectoral crest strongly expanded distally; and femur with a low longitudinal crest on the lateromedial half of the anterior face, bifurcated in two minor crests, which are directed to their respective condyles. The phylogenetic analysis performed recovers B. shiva gen. et sp. nov. as a lithostrotian, the sister taxon of Saltasauridae. The estimated body mass is 67.297 metric tons (with a standard error of ±17.228), which makes B. shiva gen. et sp. nov. one of the largest sauropods ever recorded. The record of this new sauropod corroborates the idea that gigantism (evolution of forms over the 50 metric tons) would have evolved many times within Eutitanosauria.

dinosauria sauropoda titanosauria cretaceous neuquén patagonia


A new Baurusuchidae (Notosuchia, Crocodyliformes) from the Adamantina Formation (Bauru Group, Upper Cretaceous), with a revised phylogenetic analysis of Baurusuchia

Abstract: Baurusuchidae is a group of notosuchian crocodyliforms ubiquitous to South American Upper Cretaceous deposits. They are distinguished by having dog-faced skulls, reduced tooth rows, and hypertrophied caniniforms. Here, we describe a new baurusuchid from the Adamantina Formation (Bauru Group), in Southeast Brazil. The new taxon consists of a right portion of the skull, cranial roof elements, fragments of the secondary palate and the lower jaw, as well as six isolated teeth. The specimen is assigned to the genus Aphaurosuchus due to the presence of a posterior depression on the nasal and upturned infraorbital jugal ridge. A new species, Aphaurosuchus kaiju, was erected based on characters that distinguish it from Aph. escharafacies, such as a large and deep depression occupying most of the dorsal surface of the frontal, a midline longitudinal depression on the anteriormost portion of the frontal, a well-developed crest concealed in the frontal depression, and a smooth parietal near the supratemporal fenestrae. We investigated the affinities of Aphaurosuchus kaiju and recently described/revised putative baurusuchians by performing an updated phylogenetic analysis that combined information from the three most up to date datasets available. We recovered the two main lineages of Baurusuchidae, Pissarrachampsinae and Baurusuchinae, with its traditional subset of taxa, but also recovered Ogresuchus furatus (Maastrichtian of Europe) and Razanandrongobe sakalavae (Batesian of Madagascar) as non-baurusuchid baurusuchians. In the light of our results, the inclusion of these two taxa in an otherwise well stablished Baurusuchia suggests that this clade had much broader spatial and temporal distributions than initially thought.

aphaurosuchus
baurusuchidae
baurusuchia
adamantina formation
bauru basin


Redescription of the key specimen MACN-Pv-N 35: Laminar anatomy and hyposphene–hypantrum in an early rebbachisaurid (Dinosauria, Sauropoda) from Patagonia, Argentina

Abstract: The purported basal rebbachisaurid MACN-Pv-N 35 specimen from the La Amarga Formation (Lower Cretaceous) is re-described. It is represented by a single mid to posterior dorsal neural arch and it was considered as a basal rebbachisaurid based on the well-developed hyposphene. Here I provided a re-description and a phylogenetic analysis including a new combination of morphological characters. The peculiar ovoidal hollow hyposphene, particularly recognizable in this specimen, is completely different from the massive and rhomboidal hyposphene present in Diplodocidae or Histriasaurus. The presence of a laterodiapophyseal fenestra on the transverse process recover the specimen MACN-Pv-N 35 as a Rebbachisaurinae closely related to Katepensaurus. The reassessment of the specimen MACN-Pv-N 35 as a Rebbachisaurinae improves our knowledge about the evolutionary history of Rebbachisauridae, opening the field for future investigations into how hyposphene evolved within the group.

sauropoda
diplodocoidea
rebbachisauridae
la amarga formation
argentina


Integrated biostratigraphy (orbitolinids, calcareous nannofossils, and palynomorphs) of the Lower Cretaceous Sarcheshmeh Formation, western Koppeh-Dagh Basin, NE Iran

Abstract: An integrated biostratigraphy using orbitolinids, calcareous nannofossils, and dinoflagellate cysts was conducted on the Lower Cretaceous Sarcheshmeh Formation in two stratigraphic sections from the western Koppeh-Dagh Basin (NE Iran). The analyzed successions consist mainly of deep-marine shales and marlstones with intercalations of thin-bedded orbitolinid-bearing limestones. These strata yielded common to abundant and fairly well to well-preserved calcareous nannofossil assemblages. The aforementioned assemblages led to the identification of parts of the NC6 and NC7a biozones that can be correlated with parts of the CC7a and CC7b zones. The organic-walled dinoflagellate cysts also show well-preserved and relatively diverse assemblages in the studied sections that corresponded to the Odontochitina operculata Zone. Additionally, within the limestone intercalations of the Sarcheshmeh Formation, two index species of orbitolinids, Praeorbitolina cormyi Schroeder, and P. wienandsi Schroeder, were recorded, indicating the presence of the Praeorbitolina cormyi Zone. According to the literature, these recognized biozones are compatible with the ammonite zones of Deshayesites forbesi, Deshayesites deshayesi, and Dufrenoyia furcata, as well as the Globigerinelloides blowi and Leupoldina cabri planktonic foraminiferal zones. By the compilation of all acquired data, an age of late early Aptian (late Bedoulian) is deduced for the Sarcheshmeh Formation in the studied sections.

aptian
orbitolinids
calcareous nannofossils
dinoflagellate cysts
biostratigraphy
koppeh-dagh basin


Stratigraphic distribution and importance of some imperforate benthic foraminifera from the upper Campanian–Maastrichtian of the Tauride Carbonate Platform, Türkiye

Abstract: Many parts of the Tauride Carbonate Platform were exposed to subaerial exposure from the Turonian to the Santonian. However, the record of the upper Campanian–Maastrichtian in shallow-marine facies is relatively continuous, except for short-term platform emergences. The present study focuses on the stratigraphic distribution and importance of some selected benthic foraminifera from the upper Campanian–Maastrichtian of the Tauride Carbonate Platform. Mainly Accordiella conica, Moncharmontia apenninica, Fleuryana adriatica, Murciella cuvillieri, Pseudocyclammina sphaeroidea, Rhapydionina liburnica and Pachycolumella acuta recorded from different parts of the TCP were studied. On a local and/or regional scale, some of these benthic foraminifera can be regarded as chronostratigraphically significant. Murciella cuvillieri, whose first occurrence is in the upper Campanian, and Rhapydionina liburnica, which has a narrow stratigraphic range (upper Maastrichtian), are two examples. Their occurrences and abundance vary throughout the upper Campanian–Maastrichtian. The presence of Accordiella conica, which is represented by a small number of specimens, and Moncharmontia apenninica, of which numerous characteristic specimens have been found, characterizes the upper Campanian strata. The upper Maastrichtian is marked by Rhapydionina liburnica, which co-exists with Pachycolumella acuta, known from the upper Maastrichtian–Paleocene interval. Murciella cuvillieri, Fleuryana adriatica, and Pseudocyclammina sphaeroidea occur throughout the upper Campanian–Maastrichtian strata. Fleuryana adriatica is represented by larger, typical specimens in the upper Maastrichtian but by smaller, atypical ones in the older strata. The stratigraphical importance of these species for the Campanian–Maastrichtian intervals in the Tauride Carbonate Platform is discussed.

upper cretaceous
platform carbonates
benthic foraminifera
stratigraphic ranges
taurides


First discovery of large-bodied dromaeosaurid fossil materials (Dinosauria: Theropoda) from the Upper Cretaceous Quantou Formation, Songliao Basin, Northeast China

Abstract: This paper reports the first discovery of large-bodied dromaeosaurid fossil materials (Dinosauria: Theropoda) from the lower Upper Cretaceous Quantou Formation, in Changchun area, Jilin Province. The specimens include a manual ungual and a pedal penultimate phalanx. The manual ungual is the larger of the two and laterally flattened, curved and sickle-shaped from the middle to the distal end; the pedal penultimate phalanx is strongly constricted centrally with the subcircular fossae on both sides of the trochlea located in the upper part of the geometric center of the articular arc. The available evidence indicates that these specimens likely belong to an eudromaeosaur. This new discovery provides important reference materials for studies of dromaeosaurid evolution and distribution, as well as a deeper understanding of the paleocommunity and diversity of northeast Asia during the Cretaceous Period.

theropoda
large-bodied dromaeosaurid
cretaceous
songliao basin
jilin province


Paleobiology of Rinconsaurus caudamirus and Muyelensaurus pecheni (Sauropoda, Titanosauria) from the Neuquén Group, Upper Cretaceous of Argentina: inferences from long bone histology

Abstract: Titanosauria is the most successful and diverse clade of sauropodomorph dinosaurs, with some of the largest and smallest sauropod species known to date. Rinconsaurus caudamirus and Muyelensaurus pecheni were two small-sized titanosaurs recollected from the Neuquén Group (Upper Cretaceous) of Argentina. The bone remains of both specimens include axial and appendicular elements corresponding to several individuals. These taxa have been anatomically and phylogenetically studied, but did not analyzed from paleohistological viewpoint yet. This contribution focuses on the description of the long bone histology of both species including several aspects of its paleobiology. For this, thin transverse sections were made at the diaphysis level and were analyzed under microscope. The histology of M. pecheni and R. caudamirus shows a uniform bone microstructure similar to other titanosaurs, with changes in bone tissue types being mostly related to the different life story. The major difference between the taxa is in the type of bone matrix. Whereas woven fibered bone predominates in the cortex of M. pecheni, R. caudamirus shows parallel-fibered bone. The presence of this last primary tissue is consistent with the reduced size of R. caudamirus. The long bone histology of M. pecheni resembles that of large basal neosauropods. Contrary to the reported for other noesauropods, the data obtained in this study does not reveal a correlation between the ontogenetic stage and the body size in R. caudamirus and M. pecheni. Finally, as was mentioned previously to others titanosaurs, both specimens show a high rate of secondary remodeling.

osteohistological study
life history
rinconsauria
south america


The problem of landscape evolution across the Cretaceous/Paleogene boundary revisited at Madrid East, southeastern Colorado, U.S.A.

Abstract: Faulting at the well-known Madrid East K/Pg boundary locality in the Raton Basin of southeastern Colorado, U.S.A., recently has been interpreted to be the result of remote triggering by the Chicxulub impact in the Yucátan Peninsula, Mexico. However, a similar fault at the neighboring, correlative Madrid West locality recently has been attributed to overloading by a rapidly or catastrophically deposited crevasse splay in a sedimentological study. Therefore, this investigation seeks to provide additional insight on this problem. By focusing primarily on the timing of faulting and deposition of the crevasse splay at Madrid East and neighboring localities, this study presents evidence that faulting at Madrid East and neighboring localities post-dated the K/Pg boundary.

seismicity
k/pg boundary
chicxulub
asteroid impact
crevasse splay


Pachytraga gracilis sp. nov. (Hippuritida, Caprinidae) from the Barremian of the Sub-Alpine region (SE France). Evolutionary and biogeographic implications for the genus Pachytraga Paquier

Abstract: A new species of Pachytraga (family Caprinidae) is described from the Forêt de Coulmes (Northern Vercors, Subalpine region of SE France) and dated from the Taveraidiscus hugii- Nicklesia nicklesi ammonite Zones (lowermost Barremian). Pachytraga gracilis sp. nov. has an undivided posterior myocardinal cavity on the left valve and an anterior myophore supported by a single row of rectangular canals. The right valve bears a row of anterior canals, a partitioned posterior perimyophoral cavity and a network of minute pallial canals on the dorsal side. The new species represents an evolutionary link in between the Hauterivian Pachytraga tubiconcha and the Late Barremian–early Aptian Pachytraga paradoxa, so shortening the West European Barremian Lazarus phase of the genus Pachytraga. The possibility of a Barremian p.p. ecological rather than geographical refuge is proposed. We consider the new species as a potential biostratigraphic marker of the West European lowermost Barremian. It is the oldest member of canaliculated Caprinidae. Number of traits of Pachytraga gracilis sp. nov. (shape, mode of canaliculation), are absent in its assumed descendant P. paradoxa, but present in other advanced taxa, Praecaprina, Caprina, hence the new taxon was a precursor in more ways than one.

rudists
lower cretaceous
se france
new species
caprinidae


Farlowichnus rapidus new ichnogen., new ichnosp.: A speedy and small theropod in the Early Cretaceous Botucatu paleodesert (Paraná Basin), Brazil

Abstract: The Botucatu Formation (Paraná Basin, Brazil and the southern neighboring countries) comprises one of the richest tetrapod ichnological deposits of the Lower Cretaceous in South America. The ichnofossils are found in reddish sandstones lithofacies -interpreted to be dune and interdune deposits. The sandstones of Botucatu Formation originally covered a surface estimated in at least 1,300,000 km2, the largest known fossil desert in the Earth's history. The distribution area of the Botucatu paleodesert presents one of the world's largest megatracksites. The tetrapod ichnofauna from the Botucatu Formation comprises minor bipedal dinosaur tracks (almost all attributable to theropods, with one exception, a doubt ornithopod trackway) along with many thousands of footprints of early mammals, and a single trackway of a lacertiform reptile. Among the bipedal dinosaur footprints, the most common and typical are considered theropod tracks, with long strides and high step angle and always with an acuminate termination. These trackways are straight and very narrow, with long strides and step angles showing high values. The footprints have a relatively large and very wide III digit and small, short, pointed, bladelike outer digits. The most special characteristic is that the II digit is longer and more important than the IV digit. Because of this morphology, the general outline of the footprint often reminds that of a waterdrop and, although it is structurally tridactyl, it usually looks like functionally monodactylous. These tracks are herein assigned to small theropods adapted to desert life with a prevalently cursorial gait, probably ancestors of clades such as noasaurs and velocisaurs. Due its unique morphological aspects it is defined a new ichnogenus and ichnospecies, Farlowichnus rapidus new ichnogen., new ichnosp.

farlowichnus rapidus new ichnogen.
new ichnosp.
botucatu formation
paraná basin
brazil
lower cretaceous
dinosaur tracks


A new Mesozoic record of the pseudoscorpion family Garypinidae from Upper Cretaceous (Santonian) Ajkaite amber, Ajka area, Hungary

Abstract: Pseudoscorpions have a sparse fossil record although they are among the oldest terrestrial lineages with origins extending to the Devonian (ca. 390 Ma). Amongst the 25 extant families of pseudoscorpions, only 14 are known from fossils, most of which are preserved in European ambers from the Eocene. Fossil pseudoscorpions from the Cretaceous of Europe have only been reported from three localities, Archingeay amber (France), from the Rhenish Massif (Germany), and from Álava and Teruel amber (Spain), but only one of these has ever been formally described. Here we add a new fossil pseudoscorpion genus and species, Ajkagarypinus stephani gen. et sp. nov., from an Upper Cretaceous (Santonian, ca. 86.3–83.6 Ma) amber deposit in the Ajka Coal Formation (Ajka area, Hungary), the so-called Ajkaite. This fossil extends the spatial range of the pseudoscorpion family Garypinidae and suggests that they might have been widespread in the whole Eurasian landmasses under humid, subtropical climatic conditions.

santonian
ajkagarypinus
pseudoscorpiones
amber inclusion
late cretaceous


New evidence on the previously unknown gynoecium of Araripia florifera (Araripiaceae, fam. nov.), a magnoliid angiosperm from the Lower Cretaceous (Aptian) of the Crato Konservat-Lagerstätte (Araripe Basin), northeastern Brazil

Abstract: The angiosperm Araripia florifera was originally described based on a fossil specimen including a few lobed leaves and floral buds. Although nothing was known of the internal structure of the flowers, based on the external similarity of the flower buds, it was compared with Calycanthaceae (Laurales). A new fossil from the type locality provides the first morphological evidence for the gynoecium of A. florifera. An androecium was not found, but new evidence is still needed to determine whether the flowers are unisexual. The gynoecium of this fossil species is syncarpous or monomerous, the ovary is superior, globose and distinctly stipitate, and the style is elongated and relatively thick. This new floral information disagrees with suggestions that Araripia belonged to the family Calycanthaceae, because this extant family is characterized by perigynous flowers, with apocarpous gynoecium and ovaries that are never stipitate. We also question the leaf arrangement, originally proposed as opposite, but alternate in this new fossil. We provide a phylogenetic hypothesis combining morphological and DNA sequence data using Bayesian inference. Our phylogenetic analyses indicate that A. florifera is more likely an extinct lineage of Laurales, and is hereby placed in its own family Araripiaceae.

araripiaceae
calycanthaceae
crato formation
gynoecium
laurales


Report on the 7th International Meeting of the IUGS Lower Cretaceous Ammonite Working Group, the Kilian Group (Warsaw, Poland, 21st August 2022): State of the art on the current Standard Ammonite Zonation of the Western Tethyan Mediterranean Province,

Abstract: The 7th meeting of the IUGS Lower Cretaceous Ammonite Working Group the ‘Kilian Group (KG)’ was held in Warsaw, Poland, on 21st August 2022. Need of major changes for the Jurassic/Cretaceous transition, namely to the uppermost Tithonian and lower Berriasian, and for the upper Aptian and Albian schemes is a long-known issue, which are finally conceptualized and hereby introduced into the Standard Mediterranean Ammonite Zonation (SMAZ, Western Tethys). Besides, refinements were added to the Valanginian and Hauterivian stages, discussion on some zonal indices and units are also provided. The KG highlights again the exclusive use of interval zones and subzones. Most important changes of the uppermost Tithonian–Berriasian stages are the followings: i) use of two folded Berriasian is agreed, to be in better accordance with ammonite turnovers and microfossil framework; ii) uppermost Tithonian Lopeziceras chaperi, top-uppermost Tithonian to lowermost Berriasian Praedalmasiceras progenitor and lower Berriasian Pseudosubplanites grandis Zones are accepted to be introduced into the SMAZ, these three zones to cover the former ‘Berriasella’ jacobi Zone auctorum which is formally abandoned; iii) lower Berriasian Delphinella delphinensis Subzone is accepted as a reliable marker level of the upper Praedalmasiceras progenitor Zone; iv) Strambergella jacobi Zone is established and discussed. Tirnovella occitanica Zone and Tirnovella subalpina Subzone are discussed. Modifications on the Valanginian zonation are the followings: i) Neocomites premolicus Subzone is re-defined, ii) Neolissoceras (Vergoliceras) salinarium Subzone is introduced; iii) Neocomites neocomiensiformis Zone is divided into two subzones, the lower N. neocomiensiformis and the upper Busnardoites campylotoxus Subzones. Modifications on the Hauterivian stage are the followings: i) all horizons are deleted; ii) Olcostephanus (Olcostephanus) variegatus Subzone is introduced; iii) Balearites angulicostatus Subzone is introduced; iv) all subzonal index-species of the B. balearis Zone are assigned to genus Balearites; v) Pseudothurmannia mortilleti is considered as a senior synonym of P. catulloi, therefore its nominal subzone also changed its name to mortilleti. No change in the Barremian scheme, however the base of Toxancyloceras vandenheckii Subzone and Zone is defined by the first appearance of the genus Toxancyloceras. Most important changes of the upper Aptian zonation are the followings: i) Nolaniceras nolani and 'Hypacanthoplites jacobi' zones are retained from the SMAZ; ii) re-introduction of Diadochoceras nodosocostatum Zone is given. For the Aptian–Albian transition interval, introduction of ‘Hypacanthoplites’ elegans Zone is accepted, where the Aptian/Albian boundary lies within. Most important zonal changes of the Albian stage are: i) the Leymeriella-based succession is abandoned from the SMAZ and replaced by the cosmopolitan Douvilleiceras-based succession; ii) Douvilleiceras leightonense Zone is introduced; iii) middle Albian Hoplites dentatus, Euhoplites loricatus, Euhoplites lautus Zones and Hoplites spathi Subzone are retained from the SMAZ and restricted to the Boreal ammonite scheme; iv) Lyelliceras lyelli Subzone arisen to zonal rank defining the basal middle Albian; v) Oxytropidoceras (Oxytropidoceras) roissyanum Zone is introduced; vi) upper Albian zonation based on the phyletic lineage of Mortoniceratids is kept, however generic names of the indices are modified to Pervinquieria; vii) Pervinquieria pricei Zone is divided into three subzones of Hysteroceras varicosum, H. binum and H. choffati from the oldest to youngest; viii) Pervinquieria inflata Zone is divided into two subzones of Hysteroceras bucklandi and Cantabrigites spp. The KG tributes to our recently deceased ammonitologist colleagues in the Supplement, a discussion on the future work is provided. The next Kilian Group meeting will be held in Hannover, prior to the first day of the 12th International Symposium on the Cretaceous System.

lower cretaceous
ammonites
mediterranean standard zonation
berriasian
aptian
albian


Evolution of the Upper Jurassic and Lower Cretaceous vulcano-sedimentary record – Southeast portion of the Paraná Basin, Brazil

Abstract: The period between the Late Jurassic and Early Cretaceous on the southernmost part of the Paraná Basin was characterized by the accumulation of the aeolian system from the Botucatu Formation, which was entirely preserved by the volcanic flows of the Serra Geral Formation. To a lesser extent, intense basic and acid magmas covered an extensive aeolian continental environment. However, in the central region of the state of Rio Grande do Sul, in the southernmost part of the Paraná Basin, data from 29 outcrops, 13 vertical stratigraphic profiles, and 334 paleocurrent measurements exposed fluvial–aeolian deposits of the Guará Formation in contact with volcanic rocks of the Serra Geral Formation. This study considers new temporal and spatial relationships between the fluvial–aeolian, aeolian, and volcanic systems developed in this temporal range. For this purpose, facies analysis and architectural elements were used to reconstruct the evolution of this volcano-sedimentary record. Nineteen facies grouped into five facies associations (braided fluvial channel, ephemeral braided fluvial channel, aeolian sand sheets, aeolian dunes, and volcanic plain) were identified according to their architectural elements in the Guará, Botucatu, and Serra Geral formations. The contacts between the deposits of the Guará and Botucatu Formations and their boundaries between Serra Geral Formation flows demonstrate that these sedimentary environments remained active during the onset of volcanism, and there was no hiatus between these units. Therefore, the Guará and Botucatu Formations present ages between Late Jurassic and Early Cretaceous.

botucatu formation
serra geral formation
guará formation
fluvial–aeolian systems
aeolian systems


Upper Cenomanian caprinulid-radiolitid rudists (Bivalvia) from the Gattar Member of Jebel el Kebar (central Tunisia): Stratigraphical implications and palaeobiogeographical relationships with coeval rudist-assemblages from carbonate platforms of the southern Tethyan margin

Abstract: The Gattar Member (upper part of the Zebbag Formation) is a prominent dolomitic limestone unit in Tunisia, the age of which was ascribed either to the Turonian, the Cenomanian, or the Cenomanian−Turonian. Here, we present the discovery of a Caprinulidae-Radiolitidae rudist asssemblage in the Gattar Member of Jebel el Kebar (central Tunisia). This consists of Caprinula cf. boissyi, Sauvagesia cf. sharpei, Durania arnaudi, Neocaprina sp. and Eoradiolites sp. The detailed description of two sections of the Gattar Member in Jebel el Kebar allows us to define the sedimentological and palaeoecological attributes of the rudist-bearing carbonates and their sequential relationships with the Zebbag and Rouana stratigraphical units respectively. The caprinulid-radiolitid assemblage is age-calibrated, based on the ammonite standard zonation of the Cenomanian stage from Portugal, South-Eastern France, and Oman, where rudist, benthic foraminifera and ammonite Zones have been correlated. Its age is late Cenomanian. The correlations of the Gattar Member between central Tunisia and the Gafsa-Chotts area are established on the base of ammonite and rudist biostratigraphical markers. The age of the Gattar Member of southern Tunisia and of its stratigraphical counterpart in western Libya is discussed. At last, we analyze the palaeobiogeographical distribution of the upper Cenomanian caprinulid-radiolitid assemblages from coeval carbonate platforms of the North African margin (Algeria, Morocco) and of the North Arabian margin (Levant region: Syria, Jordan, Lebanon, Israel, North Sinai).

rudists
stratigraphy
cenomanian-turonian
carbonate platforms
tunisia
north africa
levant


Caenagnathids (Theropoda, Oviraptorosauria) from the uppermost Maastrichtian of the Scollard Formation of Alberta, Canada

Abstract: Recent work has greatly improved our understanding of the diversity and paleobiogeography of caenagnathids in North America. However, the late Maastrichtian caenagnathid record remains poorly understood, with only two species established from this time interval. Here we describe three isolated elements of caenagnathids recovered from the base of the upper Maastrichtian portion of the Scollard Formation of Alberta, Canada. Two specimens, a metatarsal II and a pedal ungual, represent large-bodied species and are most similar to the same elements in Anzu wyliei (upper Maastrichtian Hell Creek Formation) and Caenagnathus collinsi (upper Campanian Dinosaur Park Formation). The third specimen, a pedal ungual from an immature individual, is most similar to Leptorhynchos gaddisi (upper Campanian Aguja Formation). Preservation of only isolated elements from the Scollard Formation and a scarcity of relevant comparative specimens from the upper Maastrichtian in general, hinders taxonomic assignment of these specimens to the genus level. Regardless, these specimens provide evidence for the widespread and northerly occurrence of caenagnathids, including large-bodied forms, in North America during the last one million years of the Cretaceous.

theropoda caenagnathidae maastrichtian biogeography biodiversity


Bite traces of a large, mosasaur-type(?) vertebrate predator in the lower Turonian ammonite Mammites nodosoides (Schlüter, 1871) from the Czech Republic

Abstract: A specimen of the acanthoceratid ammonite Mammites nodosoides from the lower Turonian of the Bohemian Cretaceous Basin shows signs of having been preyed upon by a reptile, probably with a mosasaur-like dentition. Based on these traces, a new ichnotaxon, Nihilichnus quadripertitus Mikuláš, isp. nov., is erected. Several bite traces are arranged into two convergent, straight rows, which would rule out sauropterygian reptiles or fishes as agents. Jaw margins appear to contour the ammonite aperture, suggesting an attack directed at the apertural part with the head and arm crown. The lethal nature of the bite(s) inflicted is supported by the crushed anterior, albeit not anteriormost, portion of the body chamber. Spacing, size and angle of these traces, as well as the angle of convergence between both rows would suggest that the agent was a medium-sized (up to 6 m) member of the marine lizard family Mosasauridae, and more specifically, of the subfamily Tethysaurinae. However, a representative of another closely related subfamily, the Yaguarasaurinae (which includes the genus Romeosaurus), cannot be ruled out. The bite marks on the present ammonite shell contribute to a palaeoecological evaluation of tethysaurines (in particular with regard to food adaptations) and to a better picture of the palaeogeographical distribution of early Turonian mosasauroids across central European shelves.

amniote predation
upper cretaceous
central europe
new ichnotaxon
cephalopods


A new genus of whip scorpion (Arachnida: Thelyphonida: Thelyphonidae) from mid-Cretaceous Kachin amber of northern Myanmar

Abstract: Familiar animals today, whip scorpions are rather rare in the Mesozoic and only three species are recognized from the Cretaceous. Here we describe a new genus and species, Crethypoctonus kachinus gen. et sp. nov. from mid-Cretaceous Kachin amber, clearly belonging to Thelyphonidae. It is characterized by its stout and long patellar apophysis of the pedipalps with attached microteeth and setae, and the absence of an ommatoid on tergite XII of the opisthosoma. Significantly, it lacks a keel and its abdomen is not divided. It not only augments the rare Mesozoic occurrence of whip scorpions with their distinct morphology, but reveals the long history of their evolution.

kachin amber
cretaceous
whip scorpions
thelyphonidae


Changes in bivalve assemblages at the onset of the OAE2 event in the Peri-Tethyan area (Bohemian Cretaceous Basin)

Abstract: The Ocean Anoxic Event (OAE2) at the Cenomanian-Turonian boundary presents a unique record of gradual global warming and its effects on benthic organisms. The present research considers a palaeoecological, systematical and statistical evaluation of bivalve assemblages from the Pecínov Member in the Bohemian Cretaceous Basin. The well-exposed succession of Cenomanian through lower Turonian strata contains one of the most complex records of the OAE2 in central Europe. In total, 392 specimens have been studied and assigned to 24 genera within 21 families and 9 orders. The bivalve association prior to the positive shift of the δ13Corg (peak “a” sensu global carbon curve; lower part of the Metoicoceras geslinianum Zone) is strongly dominated by infaunal suspension feeders, followed by semi-infaunal suspension feeders. The near-absence of free-living epifaunal bivalves may be linked to a very fine, muddy substrate and water turbidity, a limiting factor for many epifaunal species. Infaunal deposit feeders are also present but comparatively rare, indicating a nutrient-rich environment with energy levels sufficiently high to keep organic matter in suspension. The Cucullaea glabra – Pseudoptera anomala assemblage of this level is considered to have formed during normal, shallow (15–20 m, supported by abundant material of Pinna) marine conditions. The association inhabiting the area above this level (upper part of the M. geslinianum Zone, S. gracile/E. septemseriatum Subzone) is characterized by the Panopea gurgitis – Rhynchostreon suborbiculatum assemblage suggesting considerably shallower depths and higher energy. Clusters of Modiolus and small oysters characterize the upper parts directly prior to the prominent positive δ13Corg peak “b” (the major peak of OAE2 CIE; ? base/lower part of the N. juddii Zone). No benthic fauna occurs above this level.

late cenomanian
central europe
bivalves
palaeoecology


Discovery of a new species of Eomysmauchenius from mid-Cretaceous Kachin amber (Araneae: Archaeidae)

Abstract: Maybe extant Archaeidae are only distributed in southern hemisphere, but all of their fossils are from the northern hemisphere. Here, we report a new well-preserved fossil specimen from Kachin amber, which was identified to be a new species, Eomysmauchenius cretaceominimus, through a series of morphological characteristics comparison, including a strongly raised cephalic part, a sclerotized ring around the spinnerets and a pedipalpal-cheliceral stridulatory organ absence, cheliceral peg teeth in an irregular position, the distal lateral margin of chelicera with a small triangular projection, length and height almost equal opisthosoma. The discovery of this new species once again increases fossil record diversity of the family Archaeidae in the Cretaceous, and unique palp structure enrich our knowledge of juvenal male pedipalps.

archaeidae
new species
eomysmauchenius
kachin amber
cretaceous


New amber records of Burmusculidae (Hymenoptera) from mid-Cretaceous Myanmar

Abstract: Two new species, Burmusculus flexus sp. nov. and Burmusculus mutatus sp. nov. of Burmusculus Zhang and Rasnitsyn, 2018 in Burmusculidae, are described from the mid-Cretaceous amber of northern Myanmar. A key to all seven species of Burmusculus and detailed comparisons among the species are provided. Veins 1-Rs, 1-M, 1cu-a, 2m-cu and 2-Rs with different states suggest interspecific diagnostic characters within Burmusculus.


Middle Miocene trace fossils from the Tenes area (NW Algeria) and their palaeoenvironmental implications

Abstract: The Miocene succession (Allala River Sandstones and Tenes Blue Marls Formation) that crops out in the Tenes area, situated in the northeast of the Lower Chelif Basin in NW-Algeria, contains a low-diversity assemblage of trace fossils. Fifteen (15) ichnogenera were identified: Arenicolites, Beaconites, Cylindrichnus, Diplocraterion, Macaronichnus, Ophiomorpha, Palaeophycus, Parahaentzschelinia, Planolites, Rosselia, Skolithos, Taenidium, Teichichnus, Thalassinoides and Zoophycos. Ethologically, these ichnogenera chiefly display dwelling and feeding activities. The presence of thick, deep-tier, scattered, mainly vertical dwelling burrows attributed to the Skolithos ichnofacies indicates high energy conditions, normal oxygenation and soft substrate. Moreover, elements of the Cruziana ichnofacies show more varied behavioural strategies and higher inchnodiversity with the dominance of horizontal burrows of deposit-feeders. This ichnological study supports the palaeoenvironmental interpretation based on sedimentological analysis of a wave-dominated siliciclastic platform (backshore to offshore), allowing a more precise zonation of the shoreface zone (middle/upper and lower shoreface). In addition, this study allows evaluation of variable degrees of storm influence in response to the contrasting palaeogeomorphology of the coastline.

ichnology
tenes
lower chelif basin
shallow-marine
storm influence


Fringing reef growth in the Mid-Devonian: An example from the southern Rhenish Massif, Germany

Abstract: The Givetian Balduinstein Reef developed upon mixed felsic lavas and volcaniclastic tuffs. The Givetian age of the reef is proven by conodonts (Polygnathus rhenanus/varcus Zone to the Polygnathus ansatus Zone) and the occurrence of the brachiopod Stringocephalus burtini. Remains of land plants and subaerially ejected volcanic bombs in the vicinity of the outcrops document that the volcano was an emerged island surrounded by a fringing reef in an unstable tectonic environment. Reef development is characterised by a complex interaction of volcanism, erosion and the rate and pattern of sea-level change, which resulted in a variety of facies settings and rock-types. Microfacies analysis and rock-types prove that the fringing reef was backed by a shallow lagoon. A lime mudstone/alkali rhyolitic breccia represents a lava flow, or more probably a dome collapse breccia, which flowed into the lagoonal mud and confirms a contemporaneous occurrence of volcanism and reef growth. Reefs flourished during several episodes of inactivity of the volcano, particularly in the upper part of the sections, suggesting that the reef development kept up with sea-level changes and/or local events. Lithofacies of the upper part of the youngest section point to a regressive phase. The distinctive depositional architecture and evolution of the Balduinstein Reef are interpreted as having been controlled mainly by regional tectonics and volcanism with contributions from eustasy.

middle devonian
fringing reef
lahn syncline
microfacies
volcanism


Early Cretaceous Equisetites from Slovakia

Abstract: A new find of terrestrial plant Equisetites cf. lyellii is reported from the Early Cretaceous of Slovakia. It comes from the Mráznica Formation of the Rajec Basin in Fatricum, Zbyňov locality, Rajecké Teplice (Žilina district). The presence of a 53 mm long horsetail axis provides good evidence of terrestrial environments during sedimentation of the studied strata. According to our interpretation, such a plant strongly indicates a moist to wet habitat (even swampy environments) on the presumed dryland from where it was transported. This dryland could represent an isolated unknown small island(s) in the vicinity, or the Vindelician-Bohemian Massif that was active as a dryland for the entire period of time from the Triassic through the Late Cretaceous. However, the exact palaeogeographic position of the Fatricum during the Mesozoic in relation to the Vindelician Landmass is not entirely clear, and such an interpretation needs a bit of caution.

equisetites
terrestrial fossil plants
early cretaceous
slovakia


Benthic graptolites (Graptolithina, Pterobranchia) in the Miaolingian (Cambrian Series 3)

Abstract: Benthic graptolites (Graptolithina) were surprisingly common and diverse in the Miaolingian (Cambrian), but have rarely been described in detail. Encrusting and erect growing colonies already evolved and can be differentiated in early Miaolingian faunas. The Rhabdopleuridae with their encrusting colonies provide few fossils, but members of the erect growing, bushy colonies of the Dithecodendridae are more common, at least as fragments indicating considerable fragmentation and transport. In the Wuliuan, the benthic graptolites reached a considerable diversity at the genus level with at least 6 genera appearing in this interval. The most common taxon is the encrusting genus Sphenoecium with its robust colonies, showing a worldwide distribution. Most taxa, however, are known from few records and their biostratigraphical and palaeogeographical distribution cannot be established yet. Erroneously, the widely distributed Tarnagraptus with its conical thecae has often been misidentified as the Ordovician Mastigograptus, but differs considerably in its tubarium construction and both might not be closely related.

graptolites cambrian miaolingian rhabdopleuridae dithecodendridae evolution diversity


First evidence of the Upper Jurassic deposits in the Middle Atlas (Marmoucha syncline, Morocco) and connections to the Tethyan Domain

Abstract: The Marmoucha syncline is located in the eastern part of the Middle Atlas. In this syncline, the "Gypsum marls" (Bathonian-Callovian) are covered by red detrital deposits which outcrop in Ait Bazza locality. The upper limit of these detrital deposits is below the transgressional unconformity of the Albian-Cenomanian marine series. The present work introduces a synthesis of stratigraphical, sedimentological and micropalaeontological studies, which has led to new dating and to the identification of different depositional environments. These results have allowed us to define a new chrono-lithostratigraphic unit, the "Ait Bazza Formation", which comprises three superimposed members AB1-3 separated by two sedimentary discontinuities. This formation, exceeding 300 m in thickness, is formed by conglomerate, sandstone, sand and varicoloured marls. Micropalaeontological bulk sampling in marly horizons revealed associations of charophytes and ostracods, particularly in Member AB2. The charophytes are represented by oogonia of small Porocharaceae, Clavatoraceae such as Hemiglobator rectispirale, Dictyoclavator ramalhoi, and Nodosoclavator bradleyi that characterise the Tithonian. The ostracod microfauna is diverse, consisting of non-marine and lagoonal- shallow marine species at several horizons, associated with sea urchin spines and rare foraminifera, which indicate fluvio-deltaic sedimentary environments subjected to marine influences. This new age constraints of AB2 Mb to the Late Jurassic, and the discovery of marine influences in this eastern part of the folded Middle Atlas, consequently indicates the existence of palaeogeographical connections with the Tethyan domain located to the NE in the Rif foreland.

charophytes
ostracods
tithonian
marmoucha syncline
middle atlas
morocco


Euboeus mimonti Boieldieu, 1865, the oldest record of an extant species of Tenebrionidae (Coleoptera) and notes on other species identified as darkling beetles from the Late Pliocene of Willershausen (Germany)

Abstract: Several fossil beetles from the Late Pliocene (Piacenzian) of Willershausen (Lower Saxony, Germany) previously identified as Tenebrionidae and Staphylinidae are reviewed. One species, formerly determined as “Staphylinoidea” is identified as Euboeus mimonti Boieldieu, 1865 (Tenebrionidae: Helopini). This species is the oldest record of an extant species of darkling beetles, which occurs now in the Balkans and Anatolia. The discovery of Euboeus mimonti in the Late Pliocene of Germany indicates that the range of this species was much wider, and the climate in the Late Pliocene in the modern territory of Lower Saxony was much milder. One species formerly determined as “Alleculidae gen. sp.” belongs to the subfamily Alleculinae (Tenebrionidae) and it is identified here as Pseudocistela aff. ceramboides. Two species, misidentified by a previous author as Tenebrionidae belong to Elateridae and Cerambycidae respectively. Generic and species composition, as well as the ratio of extinct and extant beetle taxa in the Willershausen Fossil Lagerstätte are discussed.

tenebrionid beetles
elateridae
cerambycidae
fossil
willershausen lagerstätte
piacenzian


Environmental, vegetational and climatic investigations during the Plio-Pleistocene in SW-Anatolia: A case study from the fluvio-lacustrine deposits in Uşak-Karahallı area

Abstract: The Plio-Quaternary fluvio-lacustrine sediments located in the Uşak-Karahallı area (SW- Anatolia) have been investigated with multidisciplinary approaches to highlight their depositional processes and palaeovegetational history. For this purpose, samples from seven different core sites drilled in the area have been used besides field observations. According to sedimentological analysis, three depositional environments were determined: alluvial fan, fluvial and lacustrine. The first two of them are mainly composed of Pliocene aged coarse-medium grained clastics. In the meantime, lacustrine deposits mainly composed of Pliocene aged fine-grained clastics (mudstone, coal), and carbonates (clayey limestone, marl) were deposited. Later, (?)Early-Middle Pleistocene aged clayey limestone, marl, and travertines were precipitated in this lacustrine system. The 230Th measurements on travertines obtained from core samples indicate that these terrestrial carbonates continued to precipitate during the Middle Pleistocene (~288 ka). Moreover, Pliocene palynoflora is mainly represented by hydrophytic plants and gymnosperms, according to palynological investigations. These palynomorph association could be indicated the swamp environment and low-middle altitude area souround the deposition area. The Middle Pleistocene (MIS 10) microflora unlike the Pliocene palynoflora is characterised by widespread open vegetation areas consisted of herb plants in general. The palaeoclimatic signals in the Uşak-Karahallı area during the Middle Pleistocene show that temperate climate mainly prevailed, and also the humidity has changed from dry to wet. All findings suggest that the sedimentation of clastic and carbonate deposits is influenced by topography, tectonic activity, and climate. Tectonic structures such as growth faults have very important role in the lake infill, causing subsidence, which affected the sedimentation rate. Additionally, hydrothermal water influx played an important role in forming travertine precipitation and this could be strongly concerned with the active fault systems in the study area.

plio-pleistocene
palynology
depositional systems
uşak-karahallı
sw-anatolia


Global palaeobiogeographic distribution patterns of the Cenozoic pleurotomariid gastropods (Family: Pleurotomariidae Swainson, 1840)

Abstract: The palaeobiogeographic distributions of the pleurotomariid gastropods (Family Pleurotomariidae) are investigated from Maastrichtian (Latest Cretaceous) to Holocene to understand the global distribution patterns of this gastropod group during the Cenozoic. Although the diversity of the pleurotomariids considerably declined during the Late Cretaceous, they survived the K-Pg mass extinction and thrived in the Cenozoic. The Tethyan group of localities hosted the greatest diversity and thus, can be considered the central hub for the pleurotomariid gastropods throughout the Paleogene. However, with the closure of the Tethyan seaway during the early Neogene, their abundance significantly dropped in the Mediterranean. In the present times, this group has entirely disappeared from the Mediterranean Sea. The distribution became bicentric from the Middle Miocene onwards with one cluster in the Caribbean group of localities and the other in the Western Pacific group of localities. Latitudinal distribution of the fossil pleurotomariids shows that during the end-Cretaceous and Paleocene these gastropods were mostly confined to the polar and temperate latitudinal zones. However, they become more abundant in the temperate latitudinal zone during the Eocene and gradually expanded their habitat towards the tropical latitudinal zone from the Pleistocene onwards. Thus, a typical unidirectional shift from higher to lower latitudes is observed during the Cenozoic revealing habitat tracking in pleurotomariid gastropods.

pleurotomariidae
palaeobiogeography
cenozoic
latitudinal distribution
habitat tracking


Organic carbon isotope stratigraphy of Devonian-Carboniferous boundary sections in the Rhenish Mountains

Abstract: The boundary between the Devonian and the Carboniferous has been drawn using ammonoids, conodonts and miospores, while geochemical data have only rarely been used. The sampling of eight sections (Aprath, Apricke, Effenberg, Wocklum, Stockum, Drewer WJ, Drewer WA, Marsberg) at the northern margin of the Rhenish Mountains demonstrates the potential of the isotope ratio of organic carbon to regionally correlate sections in different facies areas. With the help of the carbon isotopes, a distinct stratigraphic succession is documented, which is characterised by several positive and negative excursions; this succession was recorded in all examined sections. The carbon isotopes can therefore make a significant contribution to the stratigraphic subdivision of sections and complement the biostratigraphic methods.

devonian-carboniferous boundary
hangenberg event
rhenish mountains
organic carbon isotopes
stratigraphy


Lithofacies variability and facies analysis of a Givetian reef in the southwestern Lahn Syncline (Rhenish Massif, Germany)

Abstract: A 200 m thick drill core penetrating the Givetian Hahnstätten Reef in the southwestern Lahn Syncline (Rhenish Massif) was investigated. A range of different depositional environments is described based on lithofacies and microfacies analysis. All in all, nine lithofacies types (FTs) are distinguished, which can include subfacies types. The majority of lithofacies of these ultrapure carbonates is represented by lime mudstone and fenestral microbialites, all pointing to shallow subtidal, intertidal to even supratidal low-energy palaeoenvironments. In contrast, more high-energy parts of the reef were dominated by bioclastic rubble deposits (e.g. rudstone). Autochthonous, reef-building carbonates are represented by bafflestone and framestone. Diversity of reef building organisms (stromatoporoids and corals) is low and is dominated by Stachyodes, Actinostroma, Stromatopora, and Thamnopora and alveolitids, respectively. Other bioclasts are brachiopods, gastropods, ostracods, foraminifera, echinoderms, trilobites, and conodonts in descending order. Development of the Hahnstätten Reef is interpreted as having been controlled mainly by synsedimentary tectonics and volcanism with contributions from eustasy. The occurrence of Stringocephalus burtini in the entire section and conodont findings, which provide more precise biostratigraphic data confirm an early to middle Givetian age (Polygnathus rhenanus/varcus Zone to Polygnathus ansatus Zone) of the succession. The average quality of the ultrapure carbonates lies at 97.68% CaO (excl. loss of ignition), with 70% of the core ranging between 98% and 99% CaO. This extremely high purity makes it difficult to identify correlations between lithofacies and geochemical data.

middle devonian
rhenish massif
reef limestone
facies
biostratigraphy


Where’s dinner? Variation in carnivoran distributional responses to the mid-Vallesian faunal turnover

Abstract: The Catalan locality of Can Llobateres 1 (early Vallesian, MN9) shows a remarkably rich diversity just prior to the mid-Vallesian crisis, including 23 species of Carnivora. Similarity maps using the Raup-Crick index and covering the Middle to Late Miocene (16–5.3 Ma) show that the origin of this carnivoran chronofauna lies to the north of the Iberian Peninsula, gradually making its way south. The chronofauna built up through migrations during the Aragonian, but shows a major influx during the early Vallesian, leading to a biodiversity hotspot. At the end of MN9, the mid-Vallesian turnover, the chronofauna collapses. This is mainly because of the extinction of parts of the fauna, and the retraction of some species to the north, disappearing from Spain. Thus, the rich fauna is an amalgamation of persisting older elements, northern elements having a brief temporary presence and new elements coming in. All these were supported by the unique rich ecosystem of the Vallès-Penedès Basin during the early Vallesian.

late miocene
palaeobiogeography
carnivora
vallesian crisis
mammals
iberian peninsula


Early Paleogene precipitation patterns over East Asia: Was there a monsoon after all?

Abstract: Early Paleogene latitudinal precipitation gradients and patterns along the Pacific coast of Eurasia are studied in time and space using the Coexistence Approach, for the first time applied on an extensive regional palaeobotanical record. The palaeobotanical data used in this reconstruction are compiled from literature resources on 110 reasonably well-dated floras, including terrestrial deposits of 73 sites located in the Far East of Russia, Eastern Siberia, China, and Japan, and covering the early Palaeocene to early Eocene. Our reconstructions of precipitation for the Pacific side of Eurasia in the early Paleogene demonstrate a clear division (especially pronounced in the early Eocene) into two zones at ca. 50° N palaeolatitude on all precipitation parameters. Our results reveal very weak latitudinal precipitation gradients during the early and late Palaeocene. In the early Eocene, the gradient became more clearly pronounced, and a larger “arid” zone can be distinguished in the mid-latitudes. Our data suggest that in the early Paleogene, the global atmospheric circulation consisted of two well-defined cells, Hadley and Ferrell, while the polar cell was either absent or located over the Arctic Ocean and was very weak. Based on our reconstructions, the records could not be interpreted in terms of a monsoonal type of climate. The regional distribution of hygrophilous and xerophilous taxa in our early Eocene record largely coincides with the reconstructed precipitation pattern and generally corresponds to the distribution of coals and/or oil shales and red beds and/or evaporites, respectively.

coexistence approach
spatial precipitation gradient
temporal climatic trends
precipitation seasonality
monsoon
global atmospheric circulation


The identity of the Silurian retiolitine genera Paraplectograptus and Sagenograptoides (Graptoloidea, Retiolitinae)

Abstract: The genus Paraplectograptus includes a small number of retiolitine species with an identical development of the main thecal and ancora sleeve lists. A complete virgella-virga-nema development with connecting lists is formed on the obverse side of the tubarium, while the only thecal lists on the reverse side are the lateral apertural lists, connected through the pleural lists of the ancora sleeve. Obverse and reverse sides of the tubarium are connected by the thecal lips on the ventral sides. The characteristic zigzag thecal lists of the reverse side of many early retiolitines are not present in the genus. The development and extent of the reticular ancora sleeve lists on the obverse and reverse sides of the tubarium are quite variable and range from lacking entirely to dense. The genus Pseudoplectograptus is regarded as a junior synonym of Paraplectograptus. Pseudoplectograptus sagenus is transferred to the genus Sagenograptoides. Its type species ‘Sagenograptoides arctos’ was known only from small, immature or fragmentary specimens of the associated Sagenograptoides sagenus. This species bears a characteristic reticulum on the ventral thecal walls, not found in the genus Paraplectograptus, but which is present in other Cyrtograptus lundgreni Biozone retiolitines.

graptolites
retiolitinae
paraplectograptus
pseudoplectograptus
sagenograptoides
tubarium construction
biostratigraphy


Late Early to late Middle Pleistocene medium-sized deer from the Italian Peninsula: implications for taxonomy and biochronology

Abstract: The taxonomy of Quaternary medium-sized deer from Europe rests mainly on antler morphology, while adequate dental and postcranial diagnostic features are lacking. When complete antlers are not available, the taxonomic identifications are often attempted on chronological ground. A considerable number of mostly unpublished craniodental and postcranial remains of fallow deer from selected Italian sites from the late Early Pleistocene to the late Middle Pleistocene is here presented and discussed. The aim of this work is to test the validity of the diagnostic characters proposed in literature and to explore the variability of the fallow deer taxa. In addition, the analysis of the two reference samples from Riano and Ponte Molle allows to refine the features of Dama clactoniana. Finally, biometric comparison has been performed in order to investigate possible oscillations across time and/or differences among taxa.

early-middle pleistocene transition
mediterranean area
morphology
cervids


The shark and ray teeth of the Lower Miocene (Upper Marine Molasse) from Ballendorf, Baden-Württemberg, Southern Germany

Abstract: In an abandoned sand pit near Ballendorf (Alb-Donau District, Baden-Württemberg), sediments of the Upper Marine Molasse (Lower Miocene) are present. In these sediments, 39 shark and ray species belonging to 29 genera were identified (Aetobatus, Alopias, Araloselachus, Carcharhinus, Carcharias, Centrophorus, Chaenogaleus, Dasyatis, Galeocerdo, Hemipristis, Iago, Isistius, Keasius, Notorynchus, Pachyscyllium, Paragaleus, Physogaleus, Pristiophorus, Raja, Rhinobatos, Rhinoptera, Rhizoprionodon, Rhynchobatus, Scyliorhinus, Sphyrna, Squalus, Squatina, Taeniurops, Triakis). However, in this paper we only illustrate and describe the 23 taxa not already discussed in previous publications on the Upper Marine Molasse deposits of Äpfingen, Rengetsweiler and Ursendorf, apart from two exceptions: teeth from jaw positions not previously illustrated, and specimens that are better preserved than those in previous publications. Specimens only determined as “sp.” were illustrated because it cannot be ruled out that they represent different species to the ones published earlier. Nearly all of the taxa found have Recent relatives; only Araloselachus, Keasius and Physogaleus are extinct. Most of the recovered taxa lived on or near the bottom in the shelf region. Alopias and possibly also Keasius lived higher in the water column. With Isistius, a taxon living in the oceanic realm was present, and the Recent representatives of Centrophorus live in deeper waters. Nearly all taxa fed on invertebrates and/or fishes; Isistius also fed as an ectoparasite. Additionally, two generalist feeders (Galeocerdo, Notorynchus) and one filter feeder (Keasius) were identified. The species Carcharias crassidens, which is not common in the Upper Marine Molasse, was also verified. Other fossils found in this deposit include remnants of odontocete cetaceans, molluscs, balanid barnacles, algae, and teeth of terrestrial mammals. The palaeoenvironment was a warm, shallow-water habitat. Based on greater proximity to the palaeo-coastline, the water depth was probably less than in other Upper Marine Molasse deposits.

elasmobranchii
teeth
lower miocene
upper marine molasse
paratethys


Eocene sediments and a fresh to brackish water biota from the early rifting stage of the Upper Rhine Graben (west of oil field Landau, southwest Germany): implications for biostratigraphy, palaeoecology and source rock potential

Abstract: The Eocene biota from the pre-rifting stage of the Upper Rhine Graben (southwest Germany) is, with exception of the world-famous fossil sites Messel and Bouxwiller, poorly known. While from these localities exclusively terrestrial and freshwater fossils were recovered, here we present floral and faunal assemblages from the middle Upper Rhine Graben which clearly indicate a temporarily brackish water environment and consist of a diverse palynomorph association, calcareous nannoplankton, foraminifers, ostracods and some fish and reptile remains. Based on the occurrence of Trochastrites hohnensis, a Lutetian age is assumed. Organic-walled dinoflagellate cysts, in particular Phthanoperidinium comatum, Phthanoperidinium echinatum, Apectodinium homomorphum and Apectodinium quinquelatum, suggest a late Ypresian to Lutetian age. The pollen and spores assemblage includes typical mid Eocene species, such as Tegumentisporis villosoides, Tricolporopollenites crassostriatus and representatives of Bombacaceae, but a late Ypresian to Priabonian age cannot be excluded. Foraminifers and ostracods do not further refine the biostratigraphical assignment. Hence, a Lutetian age is most probable. The mass occurrence of Neocyprideis, various foraminifer taxa and an organic-walled dinoflagellate cyst assemblage of very low diversity are indicative of a brackish water environment. Disarticulated vertebrate remains include fish teeth of Lepisosteidae, turtle plates and alligatoroid teeth of Diplocynodon and Hassiacosuchus. The present palaeogeographical scenarios do not consider a connection from the Upper Rhine Graben to the North Sea Basin, Alpine Sea/Paratethys or Paris Basin during the mid Eocene. Provided that the middle Upper Rhine Graben was land-locked and definitely not reached by a marine ingression during this time interval, we tentatively suggest that the brackish water taxa may have been accidentally introduced into a brackish inland sea by wind (anemochory), rain, highly mobile insects or vertebrates such as fish, birds and mammals (endozoochory/ectozoochory). The presumably freshwater calcareous nannoplankton species Nannoserratolithus minutus Martini is newly described.

calcareous nannoplankton
palynomorphs
microfossils
vertebrate remains
palaeoecology
organic geochemistry
paleogene


Chronological features of Heinrich Stadial 2 based on a high-resolution analysis of δ18O stalagmite records from China, and possible links to changes in Atlantic Meridional Overturning Circulation

Abstract: The Heinrich Stadial 2 (HS2) event is poorly defined in the Greenland δ18O ice core record; however, it can be identified in stalagmite records from China. In this paper, we reconstruct an absolutely-dated and high-resolution calcite δ18O record from Shima Cave, central China, covering the interval from 26.0 to 23.9 ka BP, with a temporal resolution of  16 years. By integrating our newly reported record with all available δ18O records of Marine Isotope Stage 2 from China, which are securely 230Th/U-dated, we calculate the timing of the onset, termination and duration of HS2. The statistical results show that the prominent HS2a phase started at  24.4 ± 0.1 ka BP and ended at  23.6 ± 0.1 ka BP, lasting approximately 0.8 ± 0.3 ka. If the onset of the Dansgaard-Oeschger 2 event in the Greenland δ18O record is synchronous with the termination of HS2a, then the GICC05 chronology should be adjusted by +230 years to align it with stalagmite results. Further investigation of HS2 shows that Chinese cave records exhibit a distinct two-fold structure, corresponding to HS2a and HS2b, as observed in marine sediment cores, particularly those recovered around the Atlantic Ocean. These records show comparable changes in relative amplitudes during the HS2a and HS2b phases, which could possibly be related to different weakening episodes in the Atlantic Meridional Overturning Circulation.

east asian summer monsoon
stalagmite
th/u dating
heinrich stadial 2