Showing papers in "Palaeontologische Zeitschrift in 2015"

Fish otoliths from the Konkian (Miocene, early Serravallian) of Mangyshlak (Kazakhstan): testimony to an early endemic evolution in the Eastern Paratethys

Abstract: Reconstruction of fossil teleost faunas can provide important information on palaeoenvironments, palaeogeography and evolution, and otoliths are particularly useful for that purpose. Here we present an otolith-based fish fauna from the middle Miocene of the Eastern Paratethys, i.e. the Karagaily section of the Mangyshlak Peninsula in Western Kazakhstan, and report on the accompanying nannoplankton, foraminifera, molluscs and ostracods. A total of 30 teleost species are described and figured, including ten new species: Alosa paulicrenata n.sp., Morone? bannikovi n.sp., Centracanthus pobedinae n.sp., Genyonemus? karagiensis n.sp., Trewasciaena suzini n.sp., Parablennius prokofievi n.sp., Aphia djafarovae n.sp., Neogobius udovichenkoi n.sp., Ponticola zosimovichi n.sp., Pomatoschistus bunyatovi n.sp. Nannoplankton and gastropods indicate a Konkian (late Badenian, early Serravallian) age for this fish assemblage. The dominance of Gadidae and Gobiidae, together with the composition of the nannoplankton, indicates an inner-neritic to coastal environment with high productivity. The Konkian fish fauna of the Eastern Paratethys shows a high degree of autonomy relative to approximately contemporaneous fish faunas from the Central Paratethys and other European basins. This confirms that the Konkian was a time of limited faunal exchange between the Central and Eastern Paratethys, while a marine connection may have persisted between the Central Paratethys and the northern Mediterranean. We conclude that the fish fauna reported here records an early endemic development in the Eastern Paratethys during the middle Miocene (Konkian). The disappearance of Bregmacerotidae and Gonostomatidae (Bonapartia) during the preceding stage of the Karaganian and the first appearance of Palimphemus minusculoides in the Konkian are important biostratigraphical markers.

New finds of anguines (Squamata, Anguidae) from the Early Miocene of Northwest Bohemia (Czech Republic)

Abstract: New material on anguines is described from two Lower Miocene localities in Northwest Bohemia in the Czech Republic: Merkur (MN 3) and Dolnice (MN 4). Although the material is disarticulated, it was possible to assign several elements to one species based on similar ornamentation of the skull roof bones and similar morphology of the teeth. Two new species, Ophisaurus holeci nov. sp. and Pseudopus rugosus nov. sp. are described. Pseudopus rugosus becomes the second species of the genus Pseudopus described from the Merkur locality. In addition to the new Ophisaurus species above, the species O. spinari is described on the basis of the parietal and Ophisaurus sp. 1 and Ophisaurus sp. 2 on the basis of the frontal bones. A further five anguines, designated Anguine morphotypes 1 to 6, are described on the basis of the marginal teeth bearing elements (premaxilla, maxilla and dentary) and on the pterygoid, the angular bone and elements forming the posterior portion of the lower jaw. The described specimens present a relevant contribution to our knowledge of the diversity of anguines in the Early Neogene of Europe.

Postcranial material of Nothosaurus marchicus from the Lower Muschelkalk (Anisian) of Winterswijk, The Netherlands, with remarks on swimming styles and taphonomy

Abstract: The postcranial morphology of Nothosaurus from Winterswijk is described on the basis of three partially preserved skeletons. Because of the association with a diagnostic cranium, two of these can be confidently assigned to N. marchicus. Preserved humeri are recognized as morphotype II, which confirms the relationship between this humeral morphotype and N. marchicus. The occurrence of an additional nothosaur taxon in the Lower Muschelkalk, strong sexual dimorphism, or a broader size range of N. marchicus is evidenced again. The postcranial morphology of Nothosaurus is compared to published and new data on the basal pistosauroid (cf. Cymatosaurus) from the same locality. Numerous shared morphological characters of N. marchicus, Nothosaurus sp., and the basal pistosauroid from Winterswijk hamper assignment of isolated bones, which is presently only possible if a combination of features on multiple bones from a single individual can be assessed. Ontogenetic stage of the described skeletons is discussed as well. Differences between N. marchicus, the basal pistosauroid, and the morphologically similar, but smaller pachypleurosaur A. heterodontus are mainly related to the morphologies of the humerus, ulna, and the clavicle-interclavicle complex, and thereby indicate different modes of locomotion i.e., swimming styles. The pachypleurosaur and the basal pistosauroid were most likely anguilliform swimmers, whereas Nothosaurus also employed its forelimbs during swimming (paraxial swimming). Taphonomical observations on material of the Winterswijk locality indicate the presence of scavengers, although most disarticulated skeletons were transported by water and decayed and disintegrated in shallow water.

New toxodontid (Notoungulata) from the Early Miocene of Mendoza, Argentina

Abstract: We describe a new toxodontid species, Nesodon taweretus sp. nov., from the Aisol Formation in Mendoza Province, central-west Argentina. Nesodon is a frequently found Toxodontidae, member of the Notoungulata, an extinct endemic group of Cenozoic South American mammals that are ecologically similar to current hoofed ungulates. The holotype of N. taweretus sp. nov. is a skull, and we tentatively assign some mandibular fragments and postcranial bones. N. taweretus sp. nov. differs from the other Nesodon species in several cranial and dental features, and close comparisons were made with the Patagonian Nesodon imbricatus, common in the Santa Cruz Formation (Santacrucian Age, Early Miocene). The material is of a similar size to N. imbricatus, with a body mass estimation of about 550 kg. The phylogenetic analysis groups N. taweretus sp. nov. with other species of Nesodon. The absolute age of the Aisol Formation has been established at ca 19.480 ± 0.025 Ma (Burdigalian; Early Miocene) by means of U–Pb zircon dating. The vertebrate association is encompassed by the Santacrucian Age. Latitudinal separation between Mendoza and Patagonia in the south would have favored taxonomic differences, as reflected in the species of Nesodon.

The Paradoxides puzzle resolved: the appearance of the oldest paradoxidines and its bearing on the Cambrian Series 3 lower boundary

Abstract: The Moroccan Atlas ranges provide sections that help reconstruct the earliest evolution of Paradoxides s.l. A fine-scale analysis of the basal part of the Jbel Wawrmast Formation in the eastern Anti-Atlas and comparisons with other sections in southern Morocco not only shows the abrupt appearance of Acadoparadoxides in nearly monofacial successions, but also illustrates a rapid diversification of the genus. This remarkable evolution of the clade includes material that can be assigned provisionally to the frequently described species Acadoparadoxides mureroensis (Sdzuy, 1958), to A. nobilis (Geyer, 1998) and also to the new species A. pampalius, A. levisettii and A. ovatopyge, of which A. pampalius can be shown to be the oldest described species of Paradoxides s.l. presently known. A fine-scale biostratigraphic and depositional development analysis permits a precise evaluation of suggested correlations within West Gondwana and into other Cambrian continents, and shows that attempts at precise correlations based on Acadoparadoxides species, and particularly A. mureroensis as a key taxon for global correlation, suffer from deficiencies that become obvious. In addition, the often subtle differences between species of the A. mureroensis clade illustrate that a confident identification of these species is only possible for well-preserved and largely undistorted specimens. Thus, many reports of A. mureroensis may be based, in part, on unfavourably preserved specimens of other species. The concept of a fairly variable species and even the idea of a dimorphism seem to have led to problematic identifications. In this context, material from the Taurus Mountains, southern Turkey, identified as A. mureroensis is identified herein as Acadoparadoxides deani n. sp. Paradoxides s.l. species appear to have been quite provincial in their palaeogeographic distribution, and an analysis of early appearing species shows that A. harlani (Green, 1834) was restricted to the Avalonia palaeocontinent, is incorrectly reported from West Gondwana and cannot be used as a basis for lower Series 3 correlation or chronostratigraphy. Finally, the so-called Valdemiedes Event described from the Iberian Chains in Spain obviously is a regional feature based on the abrupt appearance of an early, but not the earliest, Series 3 trilobite assemblage above a barren interval. This “event” appears to be a local stratigraphic artefact and does not reflect regional West Gondwanan or global geological history.

New insights into the anatomy and systematic of ‘Papoulemys’ laurenti, a representative of Neochelys (Chelonii, Podocnemididae) from the early Eocene of the south of France

Abstract: Neochelys is a European Eocene genus of turtles well represented by various species. It is one of the few members of Pleurodira identified during the Cenozoic of this continent. However, it has generally been recognized only by shells, and too few skulls are known to provide useful data for comparative diagnosis and relationships. The European Eocene ‘Papoulemys’ had been proposed as a junior synonym of Neochelys, the species ‘P.’ laurenti becoming N. laurenti, but this hypothesis was insufficiently justified. A second skull of this species, from its type locality (the French locality of Saint-Papoul), is analysed here together with several unpublished skulls of other Neochelys spp. from various countries and ages, providing new arguments to refute the validity of the characters used to diagnose ‘Papoulemys’ as a genus distinct from Neochelys. They are exclusively cranial characters since only its holotype (a skull) was known. Several shells from the type locality, on which the reattribution to N. laurenti had been proposed (but only synthetically), are also studied in detail here, as well as other unpublished Neochelys spp. shells. We propose a new diagnosis for ‘Papoulemys’ laurenti, reallocating the species to Neochelys. We also expand the available information on this genus and on several of its representatives.

Three bird taxa (Aves: Anatidae, Phasianidae, Scolopacidae) from the Late Miocene of the Sea of Azov (Southwestern Russia)

Abstract: European Late Miocene avian faunas are very insufficiently known. Until now, no Mio-Pliocene birds have been described from the eastern part of the Eastern Paratethys, and the entire record of birds from the Eastern Paratethys is restricted to several poorly described taxa from Ukraine and Moldova. Here we describe the remains of three bird species from the recently discovered Late Miocene vertebrate locality Morskaya-2, which has yielded the first known avian fauna of this age in the European part of Russia and also the easternmost Neogene avian fauna in Europe. The three taxa represent the families Phasianidae, Anatidae and Scolopacidae, which have not been documented from the Miocene of the Eastern Paratethys before. A small quail from Morskaya is assigned to Plioperdix hungarica comb. nov., which was previously known from the Late Miocene of Hungary. We show that the morphology of the acrocoracoid process of the coracoid is very diagnostic in phasianids and fits the molecular phylogeny of the family relatively well. Apomorphic characters indicate that Plioperdix is a sister taxon of the extant genus Coturnix. A medium-sized duck is assigned to the genus Anas s.s. and described as a new species, A. kurochkini sp. nov. Although metrically close to S. clypeata, this duck is morphologically distinct from all extant dabbling ducks. The presence of the quail and the duck indicates a certain degree of similarity between the avian faunas across the northern borders of the Central and Eastern Paratethys in the latest Miocene. The third reported taxon is a large snipe, which is described here as Gallinago azovica sp. nov.

Giant rodents from the Neotropics: diversity and dental variation of late Miocene neoepiblemid remains from Urumaco, Venezuela

Abstract: Caviomorphs constitute a large evolutionary radiation of South America rodents, exhibiting a wide range of body size and ecomorphological disparity. The geological history of caviomorphs has been recorded mainly from high latitudes, besides isolated discoveries from the Neotropics. The late Miocene fauna from Urumaco, Venezuela, is noteworthy for its location and for preserving the giant rodent Phoberomys pattersoni. Previous studies of isolated postcranial remains suggested that the rodent diversity from Urumaco was higher than is currently recognized. Based on new remains we document dental variation that indicates the presence of at least two giant rodent taxa in Urumaco, including Neoepiblema. Quantitative analysis of dentition of the different neoepiblemid species supports the differentiation between Neoepiblema and Phoberomys and suggests that several recognized species of Phoberomys could represent different ontogenetic stages of one or few taxa within the genus.

Enamel microstructure and mastication in Pyrotherium romeroi (Pyrotheria, Mammalia)

Abstract: The South American ungulate Pyrotherium romeroi provides a new enamel type, “Pyrotherium-enamel”. It is characterized by vertically oriented bands that differ from vertical Hunter–Schreger-bands in being wider and having a specific internal feather-like structure. The enamel is formed exclusively by prisms with keyhole-shaped cross sections. This prism type occurs in Proboscidea, Taeniodonta and some Primates and thus evolved independently several times. A slight differentiation between trailing and leading edges was found in the schmelzmuster. In addition to scanning electron microscope examination, the “reflecting light method” was applied, especially for the investigation of more extensive structures in the enamel microstructure. The mastication of Pyrotherium is dominated by phase I, which is directed mesially and steeply inclined. An insignificant lingually directed phase II without inclination was deduced from striations. The transverse lophs are very resistant to wear and retain their shear-cutting function for most of the lifetime. Whereas mastication in Pyrotherium is functionally comparable to that of other mammals with bilophodont dentitions, the enamel microstructure provides evidence for new unique morphological specializations in Pyrotheria and does not support connection to any other mammalian order so far discussed.

Graptolite reconstructions and interpretations

Abstract: Graptolites can be identified as a group of clonal, colonial pterobranchs with numerous extinct members and a few extant ones, secreting a characteristic housing structure, the tubarium. The zooids of the extant genus Rhabdopleura can be regarded as a general model to reconstruct graptolite zooids, but may not represent precisely the soft-body anatomy of extinct taxa. The life cycle of fossil graptolites can be interpreted from the ontogeny of the zooids of the extant Rhabdopleura and the astogeny of the fossil colonies. The planktic graptoloids (Graptoloidea) lived un-attached in the oceans and were actively moving through the water column, filtering the water column to gather food. Fossil evidence of attachment to seaweeds or other floating materials does not exist. The benthic graptolites are attached with their sicula to a firm surface either rocks, sediments or other organisms. Some of the early graptolite reconstructions are still widely distributed in the scientific literature and in palaeontology textbooks and show a considerable longevity. They are visually appealing, but in conflict with the available evidence.

Early Toarcian (Jurassic) belemnites from northeastern Gondwana (South Riffian ridges, Morocco)

Abstract: A belemnite fauna collected in the lowermost Toarcian succession that crops out near Moulay Idriss (northern Morocco) is studied in this article. This is the first palaeontological study of Early Toarcian belemnites from Northern Africa, i.e., the northeastern margin of the Gondwana, in connexion with Tethys. Four species of the family Passaloteuthidae Naef, 1922, have been identified: Passaloteuthis bisulcata (de Blainville, 1827), Pseudohastites longiformis (Blake, 1876), Parapassaloteuthis zieteni (Mayer-Eymar, 1884) and Parapassaloteuthis sp. A. All species have been collected in lowermost Toarcian beds dated to the ammonite Polymorphum Chronozone (=Tenuicostatum Chronozone), which coincides with the belemnite Passaloteuthis bisulcata biozone. The discovery of a syntype of this zonal index is discussed. The identified species are common with Europe, thus suggesting that the onset of the belemnite provincialism in the Toarcian could post-date the earliest Toarcian Polymorphum—Tenuicostatum Chronozone. However, records of Early Jurassic belemnites are still too sparse to recognize the establishment of provincialism and the timing of its onset.

High-latitude Chondrichthyans from the Late Devonian (Famennian) Witpoort formation of South Africa

Abstract: New material from the Late Devonian Witpoort Formation (Witteberg Group, Cape Supergroup) of Waterloo Farm (Grahamstown, South Africa) includes teeth, spines, and rare endoskeletal remains of early chondrichthyans. Plesioselachus, formerly described from Waterloo Farm, is redescribed and reinterpreted on the basis of new specimens. A new species of Antarctilamna is reported and described for the first time, adding significantly to the range of skeletal anatomy covered by fossils attributed to this genus. Notably, it reveals new details of the jaws and braincase. Juvenile chondrichthyan material is also reported; although this provides only limited anatomical detail; it might be attributed to Antarctilamna. The record of Devonian chondrichthyans is poor compared with that of early osteichthyans, and these fossils are a significant addition to the data set. Thus far, the Waterloo Farm locality preserves a unique, high latitude, shallow marine (estuarine) biota dated to the latest part of the Devonian. The Waterloo Farm vertebrate assemblage thus provides a biogeographically outstanding comparison with better-known, contemporary vertebrate assemblages from much lower latitudes. Faunal lists from these localities have already been used to estimate the magnitude of an acute turnover of vertebrate diversity across the Devonian-Mississippian boundary. Waterloo Farm chondrichthyan diversity, albeit limited, is, at least, consistent with hypotheses of an End Devonian biotic crisis. Rather than providing an early glimpse of the increasingly well documented post-Devonian evolutionary radiation of modern gnathostome clades, it seems that Waterloo Farm vertebrates are mostly related to groups that flourished earlier within the Devonian record.

The trace fossil Lepidenteron lewesiensis: a taphonomic window on diversity of Late Cretaceous fishes

Abstract: The trace fossil Lepidenteron lewesiensis (Mantell 1822) provides an exceptional taphonomic win- dow to diversity of fishes as shown for the Upper Creta- ceous of Poland, in the Middle Turonian-Lower Maastrichtian deposits of the Opole Trough, Miechow Trough, Mazury-Podlasie Homocline, and SE part of the Border Synclinorium. Lepidenteron lewesiensis is an un- branched burrow lined with small fish scales and bones, without a constructed wall. It contains scales, vertebrae, and bones of the head belonging to ten taxa of teleostean fishes: two undetermined teleosteans, six undetermined Clupeocephala, one Dercetidae, and one undetermined euteleostean. The preservation of fish remains suggests that fishes were pulled down into the burrow by an animal, probably by eunicid polychaetes.

A gap in digging: the Talpidae of Petersbuch 28 (Germany, Early Miocene)

Abstract: In the Miocene, the talpid diversity was much higher than today. Especially the semifossorial and ambulatory moles were farther distributed and more common. Here, the talpids from the Bavarian fissure filling Petersbuch 28 (Early Miocene, MN 3) are described. The uropsiline Desmanella engesseri Ziegler, 1985 is the most frequent species, followed by Myxomygale hutchisoni (Ziegler, 1985), an urotrichine less specialized towards burrowing. The fossorial talpids Talpa sp. and Proscapanus intercedens Ziegler, 1985 are represented by humeri, P. intercedens by a few teeth. Some teeth could not be determined to species level. Among the rich postcranial material, the humerus of Desmanella engesseri was found for the first time. Compared to other Miocene localities, Petersbuch 28 is unique in the dominance of only superficially burrowing and semifossorial talpids. In the time from MN 2 to MN 7 + 8 (Early to Middle Miocene), the fossorial talpids were less dominant during MN 2 and most of MN 3, became more frequent during MN 4 and were predominant from MN 5 onward.

Fish-otoliths from the marine-brackish water transition from the Middle Miocene of the Belgrade area, Serbia.

Abstract: We describe here the first fossil otoliths from the Middle Miocene (Badenian and Sarmatian) of Belgrade, Serbia. They were obtained from Lower Badenian outcrops at Slanci and from upper Badenian and Sarmatian sediments recovered from four shallow wells near the village of Barajevo. The otoliths from the Lower Badenian of Slanci represent fishes typical for an open marine environment, characterized primarily by the mesopelagic families Myctophidae and Bregmacerotidae, a faunal composition that is also well known from other time equivalent locations in the Central Paratethys. The upper Badenian and Sarmatian composition of the fish fauna, in contrast, is dominated by otoliths of the family Gobiidae, indicating a sharp environmental shift from open marine to shallow water, probably slightly brackish environments, which is also confirmed by the faunal composition of mollusks, foraminifera, and ostracods. Most of the gobiid genera identified in the samples from Barajevo represent small fishes of the so-called sand gobies with Ponto-Caspian affinities, such as Economidichthys, Knipowitschia, or Pomatoschistus, or are entirely endemic to the Ponto-Caspian Basin, such as Hyrcanogobius. Another group of endemic Ponto-Caspian gobies is the first fossil record interpreted to represent the genus Proterorhinus. These and other finds currently being investigated indicate that the origin of the extant, rich, endemic gobiid fauna of the Ponto-Caspian Basin dates back to a crucial time in the development of Paratethys during the Middle Miocene when it segregated from the Mediterranean with the onset of phases of low salinity in the basin. In addition, we briefly discuss the distribution of certain gobiid species during Late Badenian and Sarmatian as it begins to emerge. The following new taxa are described based on fossil otoliths: Hyrcanogobius hesperis n.sp. and Proterorhinus vasilievae n.sp.

Skeleton of a Late Pleistocene steppe mammoth (Mammuthus trogontherii) from Zhalainuoer, Inner Mongolian Autonomous Region, China

Abstract: In 1980, in the Lingquan Strip Mine of Zhalainuoer, Inner Mongolian Autonomous Region, China, two partial skeletons of Mammuthus trogontherii were unearthed and subsequently stored at the Inner Mongolian Museum in Hohhot. In March 1984, an almost complete skeleton of M. trogontherii was recovered in the same coal mine. This third steppe mammoth skeleton (Zhalainuoer III) is now exhibited at the Zhalainuoer Coal Mine Museum. It is the best-preserved skeleton of M. trogontherii ever found. A previously identified dropping and the enclosing sediments where the Zhalainuoer skeletons were found were dated to the Late Pleistocene. The almost complete third skeleton (Zhalainuoer III) is that of a fully grown male. The age at death of this individual was estimated at c. 53 years. It had a shoulder height of 389 cm in the flesh and a body mass of 10.5 tons. The completeness of the Zhalainuoer III skeleton provides new information about the morphology and the osteology of M. trogontherii. Especially noteworthy is the complete preservation of the caudal vertebrae.

The fossil pulmonate snails of Sandelzhausen (Early/Middle Miocene, Germany): Ellobiidae, Pupilloidea, and Clausilioidea

Abstract: Sandelzhausen is an Early/Middle Miocene (Mammal Neogene zone MN5) fossil site near Mainburg, S Germany, that despite its small size harbors a rich fossil record. Thousands of fossil continental mollusks, almost exclusively pulmonate snails, were recovered during the excavations, but did not receive much attention from researchers. Here, the first part of a formal taxonomic treatment of Sandelzhausen’s fossil pulmonates is presented, dealing with the superfamilies Ellobioidea, Pupilloidea, and Clausilioidea, and including the description of a new species. The following species were found in the material: Carychium eumicron and Carychium galli sp. nov. (Ellobiidae); Granaria cf. grossecostata and Granaria sp. (Chondrinidae); Gastrocopta acuminata and Gastrocopta nouletiana (Gastrocoptidae); ?Pyramidula sp. (Pyramidulidae); Strobilops sp. (Strobilopsidae); Vallonia lepida (Valloniidae); Vertigo callosa (Vertiginidae); Pseudidyla moersingensis (Clausiliidae); Triptychia sp. (Filholiidae).

On the validity of Pteraichnus palacieisaenzi, Pascual Arribas and Sanz Pérez 2000: new data from the Huérteles formation

Abstract: The original definition of the ichnospecies Pteraichnus palacieisaenzi Pascual Arribas and Sanz Perez (Estudios Geologicos 56:73–100, 2000) failed to comply with some of the norms proposed in the most recent version of the ICZN (International code of zoological nomenclature, fourth edition 1999) for the definition of new taxa. This was an undesired consequence of the long process of its publication. Furthermore, the progressive growth of lichens in the tracksite made it difficult to see the tracks, as a result of which some authors have called the validity of P. palacieisaenzi into question. After being completely cleaned, the tracks are of a better quality than at the time of their discovery, making it possible to describe the characters of the ichnotaxon in greater detail. Moulds of the type specimens have been prepared with a view to housing them in a public institution (Museo Numantino, Soria). The present paper redescribes the ichnospecies P. palacieisaenzi and compares this ichnotaxon with other tracks from a variety of pterosaur ichnospecies. Finally, a hypothesis is proposed on the trackmaker of the ichnospecies.

The eomyid rodents (Mammalia) from the Oligocene and Miocene of the Valley of Lakes (Central Mongolia)

Abstract: We report new discoveries of eomyid rodents from the Valley of Lakes (Central Mongolia) yielded by diverse layers ranging in age from the Early Oligocene (local biozone A) to the Late Miocene (local biozone E). The remains of eomyid rodents are relatively rare compared to other groups of fossil rodents found in the same region. All together, eight taxa have been identified: Eomys cf. orientalis (biozone A), Eomys aff. orientalis and Eomys sp. (biozone B), cf. Asianeomys bolligeri (biozone C), Asianeomys dangheensis (biozones C1 and D), Eomyops/Leptodontomys sp. and Keramidomys sp. (biozone D1/2), and Omboomys builstynensis gen. nov., sp. nov. (biozone E). A progressive change of dental morphology and size indicates that the genus Asianeomys represents a local evolution of the genus Eomys in Asia, but also suggests the possible existence of a lineage including Eomys cf. orientalis, Eomys aff. orientalis, cf. Asianeomys bolligeri, and Asianeomys dangheensis.

Skeletal material from larger Eusauropterygia (Reptilia: Eosauropterygia) with nothosaurian and cymatosaurian affinities from the Lower Muschelkalk of Winterswijk, The Netherlands

Abstract: Eusauropterygian elements from the Lower Muschelkalk (Vossenveld Formation) of Winterswijk, The Netherlands, comprising three mandibles and a selection of postcranial material, are described. The new mandibles correspond to crania larger than eusauropterygian cranial material previously known from this locality. The postcranial material represents a selection of isolated and associated material of comparably large size. Two of the mandibles conform to the morphology commonly recognized in Nothosaurus from the Lower Muschelkalk, but the third mandible accommodates five fangs per ramus in the symphyseal domain and exhibits a symphyseal ratio of 1.04, a condition not yet described for Eusauropterygia from the Vossenveld Formation. Body length for the animals represented by the finds was estimated through dimensional comparison with MB.R.27, a nearly complete skeleton from the lower Middle Muschelkalk locality of Rudersdorf (Germany) assigned to Nothosaurus marchicus. Body length estimates for the individuals represented by the largest mandible and by a selection of associated postcranial material exceed 1,500 mm; approximately 50 % larger than the eusauropterygian taxa from Winterswijk described so far. Furthermore, certain morphological characters identified in one mandible and in the postcranial elements suggest a cymatosaurian affinity over a nothosaurian affinity. The present study indicates eusauropterygian diversity during the Lower Muschelkalk was greater than traditionally believed. This challenges the concept of a slow paced, gradual biotic response to the origination and expansion of the Muschelkalk Sea, which commenced only 5 million years after the Permian–Triassic mass extinction event.

Mollistephaninae and Frebolditinae, new subfamilies of Middle Jurassic stephanoceratid Ammonoidea

Abstract: Two new Bajocian stephanoceratid subfamilies are distinguished based on morpho-structural criteria and phyletic patterns. At the Aalenian/Bajocian transition, Stephanoceratinae of the genus Albarracinites are the source of the earliest species of Mollistephanus and of the new Mollistephaninae lineage that includes three successive genera: Mollistephanus, Paramollistephanus gen. nov. and Phaulostephanus. The Mollistephaninae span across the Mediterranean-Caucasian Subrealm during the lower Bajocian, but Paramollistephanus is pandemic to both the Mediterranean-Caucasian and East Pacific subrealms during the Propinquans Zone. The Frebolditinae evolved from Paramollistephanus in the lower Bajocian, beginning with Freboldites and giving rise to diverse genera such as Parabigotites, Patrulia, Bajocia, Subcollina and Parastrenoceras that occur into the upper Bajocian of both the East Pacific and Mediterranean-Caucasian subrealms. Palaeobiogeographical and phylogenetic data of these two subfamilies support an active Bajocian Central-Atlantic Seaway, the so-called Hispanic Corridor, as a bidirectional, biodispersal route driven by changes of the relative sea level. Several bioevents of appearance, immigration and dispersal, associated with the range expansion of ammonoid taxa, were effective (Paramollistephanus in the latest Laeviuscula Zone, Subcollina in the latest Humphriesianum Zone, and Parastrenoceras in the earliest Niortense Zone). Based on life-history strategy, morpho-structural and functional criteria, the dimorphic Caumontisphinctes-Infraparkinsonia pair seems to be the origin of the Parkinsoniidae. The Mollistephaninae and Frebolditinae show small adult size, scarcity of fossils, and low stratigraphic persistence and constancy; however, they present some pandemic genera of the Tethys-Panthalassa Realm and display high resolution for time correlation between the western Tethyan and eastern Pacific marine basins of separate bioprovinces.

A vertebrate trackway from the Twyfelfontein Formation (Lower Cretaceous), Damaraland, Namibia

Abstract: A trackway of 22 footprints is the first definite evidence of vertebrate life from the Main Aeolian Unit of the Twyfelfontein Formation (Lower Cretaceous), Kunene region, Northwestern Namibia. Footprints were left on the lee slope of an ancient dune in a hyper-arid, erg-dominated paleo environment. The new material is reminiscent of the Mesozoic ichnotaxon Brasilichnium, which is exclusively found on the slip face of sand dunes, from both South and North America. The Twyfelfontein Formation is considered a lateral equivalent of the Brazilian Botucatu Formation in which Brasilichnium is a common trace fossil, but correlation was formerly based exclusively on sedimentologic and lithostratigraphic homologies. Aside from being the first vertebrate evidence from the Cretaceous of Namibia, and possibly the first African Brasilichnium, this new find enforces the correlation between the Botucatu and the Twyfelfontein formations.

The Carnian/Norian boundary succession at Berlin-Ichthyosaur State Park (Upper Triassic, central Nevada, USA)

Abstract: The Upper Carnian-Lower Norian (Upper Triassic) Luning Formation at Berlin-Ichthyosaur State Park (BISP) in central NV (USA) has been sampled using for the first time the bed-by-bed approach for ammonoids, pelagic bivalves, and conodonts, more than 60 years after its first description by Silberling (U.S. Geological Survey Professional Paper 322: 1–63, 1959). BISP is historically important for the definition of the uppermost Carnian of the North American Triassic chronostratigraphic scale and is known worldwide as one of the most important ichthyosaur Fossil-Lagerstatte because of its extraordinary record of 37 articulated, large-sized specimens of Shonisaurus popularis. Nearly 190 ammonoids were collected from two stratigraphic sections, documenting all the latest Carnian to Early Norian ammonoid faunas previously described by Silberling. Halobiids were collected from five levels, and the first report of conodonts from BISP includes faunas from 13 levels. The ~340-m thick Brick Pile section, the most complete in the study area, includes the uppermost Carnian Macrolobatus Zone, which provides conodont faunas of the lower primitia zone and Halobia septentrionalis. The 200-m thick lowermost Norian Kerri Zone, which begins 52 m above the Macrolobatus Zone, yields conodonts of the upper primitia zone in its lower part, together with H. cf. beyrichi and H. cf. selwyni. The ichthyosaur-bearing interval, whose stratigraphic position has been interpreted quite differently by previous authors, is documented in the uppermost Carnian Macrolobatus Zone and is characterized by rich Tropites-dominated ammonoid faunas and by the onset of Halobia. All models proposed by various workers to explain the unusual ichthyosaur record are discussed and an additional explanation for the main ichthyosaur-bearing bed is proposed. The new hypothesis is that a harmful algal bloom (HAB) may have been the trigger for the mass mortality recorded in this level. Although the C/N boundary in the Brick Pile section lies within a 52 m interval that presently lacks paleontologic data, this succession is included in a small group of sections that are expected to contribute to the definition of the GSSP of the Norian stage. Correlation of the Brick Pile section with the best Carnian/Norian sections in northeastern British Columbia is discussed. Compared to the British Columbia Juvavites Cove and the GSSP candidate Black Bear Ridge sections, the Brick Pile section exhibits an ammonoid and Halobia record that is slightly more similar to that of the Tethyan sections. Correlation of the Brick Pile section with the second GSSP candidate Pizzo Mondello (Sicily, Italy) well demonstrates the significant problems encountered in calibration of the Tethyan and North American scales.

Two new species of Prolagus (Lagomorpha, Mammalia) from the Late Miocene of Hungary: taxonomy, biochronology, and palaeobiogeography

Abstract: The present study describes two new species, Prolagus pannonicus sp. nov. and P. latiuncinatus sp. nov., from the Late Miocene Hungarian localities Sumeg (MN10/11) and Polgardi 2 (MN13). These species are closely related, probably by a direct ancestor–descendant relationship. They share characters common to Late Miocene–Pliocene eastern European species (e.g., the retention of the entoconid enamel in p3 contrarily to coeval western European ones), attesting to an eastern European group of Prolagus that evolved independently from western European species at least since MN10/11. Nevertheless, the two Hungarian species of Prolagus here described follow particular evolutionary trends: contrarily to other European Late Miocene species, their p3 does not undergo a substantial size increase after MN12, whereas the crochet size enlarges noticeably. Special emphasis is given to the comparison of P. pannonicus sp. nov. and P. latiuncinatus sp. nov. with the Gargano insular endemic Prolagus species. Their common morphological traits are related to convergence due to endemism. Prolagus pannonicus sp. nov. and P. latiuncinatus sp. nov. probably were continental isolated species.

Cranial ontogenetic variation in Mapusaurus roseae (Dinosauria: Theropoda) and the probable role of heterochrony in carcharodontosaurid evolution

Abstract: The carcharodontosaurid theropod Mapusaurus roseae (Cenomanian of Neuquen Province, Argentina) is represented by at least seven disarticulated individuals from a monospecific bonebed, all of different sizes and presumably different stages of maturity. We report a series of anatomical differences between repeated skull bones of Mapusaurus, which we interpret as produced by peramorphic heterochronic processes. The materials analyzed include maxillae, lacrimals, dentaries, and isolated teeth. Most of the differences were recorded in the maxilla, the most noticeable change being the reduction of the pneumaticity. We found that some of the synapomorphic characters of derived carcharodontosaurids appear to be the result of peramorphic heterochronies, as in the strongly ornamented facial bones, and the single opening in the anteroventral corner of the antorbital fossa in the maxilla.

The middle Eocene European “ratite” Palaeotis (Aves, Palaeognathae) restudied once more

Abstract: Palaeotis weigelti is a flightless, “ratite”-like palaeognathous bird, which occurs in the Middle Eocene of the German fossil sites Messel and the Geisel Valley. The species is known from several specimens, most of which are, however, very fragmentary or poorly preserved. Its phylogenetic affinities are controversial, with earlier authors especially considering close affinities to Struthionidae and Rheidae, and some skeletal features were only briefly described. Moreover, recent molecular analyses congruently indicate that a “ratite” morphology evolved multiple times within palaeognathous birds. The skeletal morphology and phylogenetic affinities of Palaeotis are therefore reanalyzed, and the taxon is subjected to a phylogenetic analysis based on one of the most comprehensive published data sets for palaeognathous birds. In addition to the primary analysis, further analyses were run that were constrained to a backbone topology reflecting the results of sequence-based studies. In none of these analyses was a well-supported placement of Palaeotis obtained, and it is concluded that current data do not convincingly resolve the affinities of this taxon. Palatal morphology of Palaeotis most closely resembles that of lithornithids, another group of palaeognathous birds from the Eocene of the Northern Hemisphere, and there remains a possibility that the “ratite” features of Palaeotis evolved independently from those of the extant taxa.

The corkscrew-shaped trace fossil Helicodromites Berger, 1957, from Rhenish Lower Devonian shallow-marine facies (Upper Emsian; SW Germany)

Abstract: Corkscrew-shaped horizontal burrows are reported from the Rhenish Lower Devonian (Upper Emsian) of the Lower Mosel area. The trace fossils most probably represent dwelling burrows of vermiform organisms and are attributed to the ichnotaxon Helicodromites aff. mobilis Berger, 1957. The palaeoenvironmental setting of this occurrence is briefly discussed, and a shallow-marine, storm-influenced deposit is inferred. All spirally coiled trace fossils with a horizontal longitudinal axis are briefly compared to Helicodromites.

Dinosaur teeth from the Jurassic Qigu and Shishugou Formations of the Junggar Basin (Xinjiang/China) and their paleoecologic implications

Abstract: The Middle and early Late Jurassic Qigu and Shishugou Formations of the southern and central Junggar Basin yielded teeth of theropods (Theropoda indet.), sauropods (Eusauropoda indet.), and stegosaurs. The dinosaur assemblage of the southern Junggar Basin is less diverse and is represented by smaller forms than in the central part of the basin. The microwear of the teeth of Eusauropoda indet. resembles that observed in Camarasaurus and may have formed as a result of biting through resistant woody materials. Carbon and oxygen isotope data of the sauropod and theropod teeth indicate feeding within a C3-plant ecosystem in a continental setting. Differences in enamel δ13C and δ18O values between Eusauropoda indet. and the theropod teeth are comparable to those observed in other herbivorous and carnivorous vertebrates, and suggest at least partial preservation of original dietary signals.

Exotic trilobites from the Lower–Middle Cambrian boundary interval in Morocco and their bearing on the Cambrian Series 3 lower boundary

Abstract: The Moroccan Atlas ranges provide sections which not only permit fine-scale biostratigraphic analysis of the basal part of the Middle Cambrian by means of typical West Gondwanan faunal elements, but also include exotic trilobites well known from other Cambrian continents or at least extremely rare in West Gondwana. Such trilobites often permit intercontinental correlation that significantly improves the framework for the traditional Lower–Middle Cambrian boundary interval and leads to a fairly robust correlation table. Other “exotic” trilobites are rare findings of new taxa with mosaic patterns of morphological characters, which therefore remain problematic in consideration of their systematic position. This case study illustrates and (re)describes the trilobites Granularaspis bommeli n. sp., Shergoldiella vincenti Geyer, Palaeoworld 15: 348–359, 2006, Onchocephalites permingeati (Termier and Termier, Paleontologie marocaine. Tome 2. Invertebres de l'Ere primaire. Fasc. 4: Annelides, Arthropodes, Echinodermes, Conularides et Graptolithes. Notes et Memoirs de la Service geologique du Maroc 79, and Coll. Actualites scientifiques vol 1095 Hermann & Cie, Paris, pp 282, 1950), Eoptychoparia tafilaltensis n. sp., Oreisator tichkaensis Geyer and Malinky, J Paleontol 71(4): 620–637, 1997 and Cambroproteus lemdadensis n. gen., n. sp. from the Moroccan Atlas ranges. These species partly belong to genera previously known from outside West Gondwana only, and all of them provide new and unexpected clues for faunistic relationships from West Gondwana into other Cambrian continents and distinctly supplement the picture of the organismic diversity for the basal Middle Cambrian in the region.

Rodents from the Upper Miocene Tuğlu Formation (Çankırı Basin, Central Anatolia, Turkey)

Abstract: The upper Miocene assemblages of rodents collected from two layers of the type section of the Tuglu Formation (Cankiri Basin, Central Anatolia, Turkey) are described. The assemblage from the lower level is considerably less diverse than that from the upper level. It contains Progonomys together with Megacricetodon, which is a very unusual association. The assemblage from the upper layer shows a relatively high diversity with four species of Gliridae instead of only one in the lower layer. Apart from the more diverse Gliridae, Byzantinia sp., Spermophilinus, Keramidomys and Myocricetodon appear in the upper layer. The absence of Murinae in the assemblage from the upper layer is very unexpected, because they usually become dominant soon after their arrival. Their unusual subsequent absence may be either due to a significant change from an open and humid environment to a more dry and wooded environment or to taphonomic bias. Both rodent faunas are assigned to local zone I, which is correlated to the lower Vallesian (MN9).