A new primitive hadrosauroid dinosaur from the Early Cretaceous of Inner Mongolia (P.R. China)

The right dentary of a new hadrosauroid dinosaur, Penelopognathus weishampeli, has been discovered in the Bayan Gobi Formation (Albian, Lower Cretaceous) of Inner Mongolia (P.R. China). This new taxon is characterised by its elongated, straight dental ramus, whose lateral side is pierced by about 20 irregularly distributed foramina. Its dentary teeth appear more primitive than those of Probactrosaurus, but more advanced than those of Altirhinus, both also from the Lower Cretaceous of the Gobi area. Non-hadrosaurid Hadrosauroidea were already well diversified in eastern Asia by Early Cretaceous time, suggesting an Asian origin for the hadrosauroid clade. To cite this article: P. Godefroit et al., C. R. Palevol 4 (2005).     

A new stem-sperm whale (Cetacea, Odontoceti, Physeteroidea) from the Latest Miocene of Peru

A finely preserved skull with mandible and teeth associated, from the Latest Miocene beds (ca. 6 Ma) of the Pisco Formation, Sud-Sacaco, Peru, represents a new physeteroid genus and species, Acrophyseter deinodon. This moderate size sperm whale is characterized, among others, by: the short rostrum, the mandible distinctly curved upwards, large teeth very close together (12 on each upper tooth row and 13 on each lower tooth row), the lateral margin of the maxilla along the rostrum base much lower than the orbit roof, a wide supracranial basin dorsally overhanging the right orbit and limited to the cranium and a large temporal fossa dorsomedially elevated. A preliminary cladistic analysis provides a phylogenetic position of Acrophyseter nested within the stem-Physeteroidea, more basal than the clade Kogiidae + Physeteridae. The morphology of the oral apparatus and of the temporal fossa suggests that Acrophyseter was able to feed on large preys.     

The last hadrosaurid dinosaurs of Europe: A new lambeosaurine from the Uppermost Cretaceous of Aren (Huesca, Spain)

A new hadrosaurid dinosaur, Arenysaurus ardevoli gen. et sp. nov., from the Late Maastrichtian of Aren (Huesca, South-central Pyrenees) is described on the basis of a partial, articulated skull, mandibular remains and postcranial elements, including vertebrae, girdle and limb bones. Arenysaurus is characterized by having a very prominent frontal dome; nearly vertical prequadratic (squamosal) and jugal (postorbital) processes, and deltopectoral crest of the humerus oriented anteriorly. Moreover, it possesses a unique combination of characters: short frontal (length/width approximately 0.5); midline ridge of parietal at level of the postorbital-squamosal bar; parietal excluded from the occiput; squamosal low above the cotyloid cavity. A phylogenetical analysis indicates that Arenysaurus is a rather basal member of Lambeosaurinae and the sister-taxon to Amurosaurus and the Corythosaurini-Parasaurolophini clade. The phylogenetic and biogeographical relationships of Arenysaurus and other lambeosaurines suggest a palaeogeographical connection between Asia and Europe during the Late Cretaceous.     

A new baurusuchid crocodyliform (Archosauria) from the Late Cretaceous of Patagonia (Argentina)

A new baurusuchid, Wargosuchus australis gen. et sp. nov., coming from the Bajo de La Carpa Formation, Neuquén Province (Argentina), is described. This new taxon is based on a fragment of snout and a portion of the cranial roof. Wargosuchus differs from other crocodyliforms by possessing a deep median groove on the frontals, a contact between nasals and frontals extremely reduced, a large depression for the olfactory bulbs, three large foramina surrounding the large, smooth perinarial depression, and a hypertrophied, conical last premaxillary tooth followed by a large paracanine fossa. The finding of Wargosuchus in Patagonia (Argentina), a taxon with a strong resemblance to Brazilian baurusuchids, reinforces the hypothesis of a similar biota between both regions by the Late Cretaceous. Wargosuchus and Cynodontosuchus represent the only Argentinian mesoeucrocodylians to be included within Baurusuchidae. This finding extends the number of crocodyliforms from the Bajo de la Carpa Formation, which, in turn, corresponds to the most taxonomically diverse one in Argentina.     

New data on perittocrinids and hybocrinids (Crinoidea, Echinodermata) from the Middle Ordovician of the Baltic region

Age variation of radial plates of perittocrinids and aberrant cups of the hybocrinid genus Hoplocrinus from the Middle Ordovician of the St-Petersburg region are examined. Three patterns for the development of folds on the radial plates of perittocrinids are recognized. The differences between patterns are of species level. It is proposed here that the folded structures of perittocrinids (as well as the pore-structures of other pelmatozoans) were not only used for respiration, but also very likely for feeding. Tetracionocrinus transitor is a young individual of a species of the genus Perittocrinus or a paedomorphic species of this genus. The study of aberrant cups of Hoplocrinus suggests that its ancestor could have had biserial arms. Phylogenetic implications of this interpretation are discussed, and homologies within the phylum Echinodermata, reassessed. The three-armed genus Baerocrinus may be an aberrant form of a species of the genus Hoplocrinus.     

Faunes et paléoenvironnements des principaux sites archéologiques plio-pléistocènes de la formation de Nachukui (Ouest-Turkana, Kenya)

Faunas and paleoenvironments from main archaeological Plio-Pleistocene sites of the Nachukui Formation (West Turkana, Kenya). The Nachukui Formation is currently under archaeological investigation, especially within the Kalochoro (2.35 – 1.9 Myr) and Kaitio (1.9 – 1.65 Myr) Members. Six main archaeological sites have been excavated from this time period, which yield rich vertebrate faunas collected in situ or in close vicinity to the site. Paleontological studies help to precise the specific diversity for each site and increase our documentation for each Member with the discovery of new taxa. They allow to provide new informations about the biotope diversities exploited by Hominids and show a climatic tendency towards more humid environment between the Members. To cite this article: J.-P. Brugal et al., C.R. Palevol 2 (2003).     

A Late Campanian sphenodontid (Reptilia, Diapsida) from northern Patagonia

The fossil record of sphenodontids in the Southern Hemisphere is much longer than in Laurasia, where they became extinct after Early Cretaceous times. Recent works demonstrated the persistence of at least eilenodontine sphenodontids until the ‘mid’-Cretaceous of Patagonia. Focused examination of the Los Alamitos Formation collections provided remains of Late Campanian sphenodontids. Although the phylogenetic position of these remains is still uncertain, they belong to a new, unrecorded species of sphenodontid perhaps related to opisthodontians or primitive, toothed sapheosaurs. To cite this article: S. Apesteguía, C. R. Palevol 4 (2005).     

Two new species of seahorses (Syngnathidae, Hippocampus) from the Middle Miocene (Sarmatian) Coprolitic Horizon in Tunjice Hills, Slovenia: The oldest fossil record of seahorses

Two new and the only known extinct seahorse species Hippocampus sarmaticus and Hippocampus slovenicus are described from the Middle Miocene beds (Lower Sarmatian) in Slovenia, representing the oldest known fossil record of seahorses. Hippocampus sarmaticus was most similar to the extant seahorse species Hippocampus trimaculatus, while H. slovenicus can be most easily compared to the extant pygmy seahorses H. bargibanti, H. denise, and H. colemani. These Sarmatian seahorses lived among seagrasses and macroalgae in the temperate shallow costal waters of the western part of the Central Paratethys Sea.     

Systematics and functional morphology of Molarochoerus yuanmouensis (Suidae, Mammalia) from the Late Miocene of Yunnan, China

The discovery of a propotamochoerine suid with unique features of the dentition and skull led to the naming of Molarochoerus yuanmouensis Liu & Pan [6]. Further study of the material reveals that this species was better adapted than Sus scrofa for the ‘rooting’ behaviour and that its dentition has morphological features indicating that it was eating hard food items. The posterior premolars are completely molarised, hence the generic name, the first time that any suid has been shown to possess almost perfectly molariform P4/s and p/4s. In lateral view the curvature of the occlusal surface of the upper cheek teeth is convex ventrally, the opposite of the usual situation in suids. The origins of the rostral musculature are exceptionally well developed, and the nasal bones are much more robust than is usually the case in Suinae, indicating powerful musculature and fortified osseous structures presumably for ‘rooting’ in hard ground or for extended periods of time. The masseteric musculature appears to have been more massive than it is in Sus, Microstonyx and Propotamochoerus. To cite this article: M. Pickford et al., C. R. Palevol 3 (2004).

Résumé

Systématique et morphologie fonctionnelle de Molarochoerus yuanmouensis (Suidae, Mammalia) du Miocène supérieur de Yunnan, Chine. La découverte d”un Suidae Propotamochoerini présentant des caractères dentaires et crâniens uniques a conduit à la création de Molarochoerus yuanmouensis Liu & Pan [6]. Une étude du matériel montre que cette espèce était bien mieux adaptée au fouissage que Sus scrofa. Par ailleurs, les caractères morphologiques de sa dentition indiquent qu'il se nourrissait d'aliments coriaces. Les prémolaires postérieures sont complètement molarisées, d'où le nom générique, et c'est la première fois qu'un Suidae présente des P4 supérieures et inférieures presque parfaitement molariformes. En vue latérale, la courbure de la surface occlusale des dents jugales supérieures est convexe ventralement, différant ainsi de la morphologie classique des Suidae. La musculature rostrale est exceptionnellement bien développée et les os nasaux sont beaucoup plus robustes que chez les autres Suinae, suggérant des structures musculaires et osseuses puissantes, probablement liées au fouissage, soit dans des sols, soit sur une longue durée. Les muscles massétériens sont plus puissants que dans les genres Sus, Microstonyx et Propotamochoerus. Pour citer cet article : M. Pickford et al., C. R. Palevol 3 (2004).     

A large Percrocutid Carnivore from the Late Miocene (ca. 10–9 Ma) of Nakali, Kenya

The presence of a large hyaenoid (Hiperhyaena sic leakeyi) from the Late Miocene (Vallesian equivalent) deposits at Nakali, Kenya, was first recorded in 1974, but the fossil on which the announcement was based was not described or figured, nor was a type specimen or type species nominated. The generic and specific names are thus nomina nuda. Howell and Petter (1985) described Hyperhyaena leakeyi, and credited the generic and specific names alternatively to Aguirre and Leakey (1974) and Aguirre and Crusafont in 1974 (the latter paper was never published). Howell and Petter are in fact the authors of both the generic and the specific names. Later in the same paper, Howell and Petter (1985) rejected the name Hyperhyaena and classified the species leakeyi in Allohyaena (Dinocrocuta). The purpose of this paper is to provide more information about the fossil and to discuss its relationships to other percrocutids. It is concluded that it belongs to the genus Percrocuta Kretzoi, 1938, being morphologically similar to the type species Percrocuta carnifex (Pilgrim, 1913) from the Siwaliks of Pakistan.     

A new mosasauroid (Squamata) from the Late Cretaceous (Turonian) of Morocco

Tethysaurus nopcsai gen. et sp. nov. is described on the basis of both cranial and postcranial material from the Late Cretaceous (Early Turonian) of the Goulmima region, southern Morocco. This new mosasauroid is mainly characterized by a parietal table ending posteriorly in two pointed pegs; jugal with a large ascending ramus; splenial with a large and notched dorsomedial process; surangular exposed medially ventral to the coronoid; large paracotylar and parazygosphenal foramina on vertebrae. A phylogenetic analysis shows that Tethysaurus is the sister-group of Mosasauridae. It fills the gap between the aigialosaurids (mainly Cenomanian) and the mosasaurids (known from the Middle-Late Turonian to the Latest Maastrichtian). To cite this article: N. Bardet et al., C. R. Palevol 2 (2003).     

The ‘Giant of Ksour’, a Middle Jurassic sauropod dinosaur from Algeria

Continental strata of Early and Middle Jurassic age are seldom-exposed, and little is known of the history of sauropod dinosaurs prior to the neosauropod radiation of the end of the Middle Jurassic. Here, we report, in the Middle Jurassic of the Occidental Saharan Atlas (Algerian High Atlas), the discovery of a skeleton, including cranial material, of a new cetiosaurid sauropod. Chebsaurus algeriensis n. g., n. sp. represents the most complete Algerian sauropod available to date, only few remains were found before. To cite this article: F. Mahammed et al., C. R. Palevol 4 (2005).     

A new species of Anthracotheriidae, Merycopotamus medioximus nov. sp. from the Late Miocene of the Potwar Plateau, Pakistan

New anthracotheriid remains, discovered by the H-GSP in well-dated localities from the Potwar plateau in the North of Pakistan, between 10.4 and 8.6 Ma, are described and attributed to Merycopotamus medioximus nov. sp. This new species displays an intermediate morphology between the older M. pusillus and the more recent M. dissimilis. These results permit to emend the Merycopotamus diagnosis. To cite this article: F. Lihoreau et al., C. R. Palevol 3 (2004).

Résumé

Une nouvelle espèce d'Anthracotheriidae, Merycopotamus medioximus nov. sp. du Miocène récent du plateau du Potwar, Pakistan. Des restes d'Anthracotheriidae, découverts par le H-GSP dans des localités bien datées du plateau du Potwar, au Nord du Pakistan, entre 10,4 et 8,6 Ma, sont décrits et attribués à Merycopotamus medioximus nov. sp. Cette nouvelle espèce possède une morphologie intermédiaire entre M. pusillus, espèce plus ancienne, et M. dissimilis, plus récente. Ces résultats permettent en outre d'émender la diagnose du genre Merycopotamus. Pour citer cet article : F. Lihoreau et al., C. R. Palevol 3 (2004).     

First record of a fossil bird from the Early Cretaceous of Thailand

We present the first known occurrence of a Mesozoic fossil bird from Thailand. The new specimen is the distal end of a left humerus, from the Early Cretaceous Sao Khua Formation in the Northeast of the country, and testifies to the presence of a medium-sized avian in these non-marine strata. This is also the first Mesozoic bird known from the whole of Southeast Asia. To cite this article: E. Buffetaut et al., C. R. Palevol 4 (2005).     

A new Early Miocene genus of the family Sciaenidae (Teleostei, Perciformes) from the eastern Paratethys

A new genus of sciaenid fish Caucasisciaena is erected to accommodate the Early Miocene eastern Paratethys species Perca ignota Smirnov, 1936, which, subsequently, was variously attributed to the modern genera, either Larimus or Otolithoides. The materials examined include 32 specimens from four Caucasian and Crimean localities of Sakaraulian age (Lower Burdigalian). The new genus is based on a unique combination of features, including: parasphenoid with a dorsal rounded bony flange; basisphenoid present; premaxilla with short ascending process forming obtuse angle with alveolar process and ascending/alveolar process ratio about 0.17; anterior premaxillary teeth enlarged; posttemporal with few robust spines along its posterior margin; presence of 25 vertebrae; presence of three tiny supraneurals; dorsal fin with 11 spines plus 22–24 soft rays; anal fin with two spines and 7–8 soft rays; second anal-fin spine long and massive; pectoral fin elongate; scales ctenoid on body and cycloid on head (except for one or two rows of ctenoid scales on the cheek). Paleoecological considerations suggest that Caucasisciaena probably was a predatory fish that inhabited the coastal waters of the eastern sector of the Paratethyan basin.     

Hyaenictitherium minimum, a new ictithere (Mammalia, Carnivora, Hyaenidae) from the Late Miocene of Toros-Menalla, Chad

A new species of Hyaenidae, Hyaenictitherium minimum, is described in the carnivore fauna of the Late Miocene layers of Toros-Menalla (Chad). Its size is similar to that of a jackal and it had probably a similar ecological niche. It is found in several fossil-bearing localities of this area. The genus Hyaenictitherium is known from the early Late Miocene in Eurasia from China to Spain; the Chadian material is, perhaps with some specimens from Sahabi and Lothagam, the earliest occurrence of the genus in Africa. It results certainly from Eurasian migration, which will have to be taken into account for the analysis of the bulk of the fauna. To cite this article: L. de Bonis et al., C. R. Palevol 4 (2005).     

Palaeoneuroanatomy of Brachiosaurus

An overview of the palaeoneuroanatomy (brain and spinal cord) of the sauropod dinosaur Brachiosaurus is given. Although having a flexed brain configuration, Brachiosaurus presents on the whole a rather moderately derived neuroanatomical pattern. As other sauropods, Brachiosaurus shows an enlargement of the spinal cord in the sacral area. New Encephalization Quotients are calculated and found to be about 0.62 or 0.79 (depending on the body volume taken into consideration) when Hurlburt's formula is used. This suggests that Brachiosaurus, although it may not have been as a low encephalized taxon (by reptilian standards) as previously believed, did have an undersized relative brain volume.     

The oldest holocephalan (Chondrichthyes) from the Middle Devonian of the Boulonnais (Pas-de-Calais, France)

The Couderousse Member of the Blacourt Formation in the Banc-Noir quarry, Ferques inlier, Boulonnais (Pas-de-Calais, France) has yielded a tooth plate whose morphology is similar to that of Synthetodus, which is considered a holocephalan. Its histology is made of an outer enameloid-like tissue, and an inner trabecular dentine. Its occlusal surface shows a bean-shaped bulge. This tooth plate was prepared from a limestone that is dated from the Middle–Upper varcus Conodont Zone, that is lower upper Givetian. This limestone has also yielded a Pokorninella bricae–Rothpletzella–Tentaculites assemblage, which is indicative of an environment of the inner to middle marine platform boundary. This specimen appears to be the oldest confirmed holocephalan (‘bradyodont’) tooth plate for which the name Melanodus loonesi nov. gen. et sp. is erected.     

Revision of the Early Miocene Hyracoidea (Mammalia) of East Africa

Three genera of hyracoids were recorded from the Early Miocene of East Africa by Whitworth [18], but there has been considerable divergence of opinion about their status. Despite differences in cranial and dental morphology from Megalohyrax and Bunohyrax, Whitworth [18] classified two species in these genera that are recorded from much earlier deposits (Early Oligocene) in the Fayum, Egypt. One of his genera (Meroehyrax) was new. His classification has been the subject of debate, with some researchers [6,13] doubting the hyracoid status of one of his species (Bunohyrax sp), and changing the generic status of another (Megalohyrax championi). Meyer [6] recorded a fourth genus (Prohyrax) from Kenya, linking it to material from Namibia described by Stromer [16,17]. New samples of two hyracoid species collected by the Uganda Palaeontology Expedition throw light on their systematic position and taxonomy. It is concluded that there are three hyracoid genera (Afrohyrax, Brachyhyrax and Meroehyrax) in the Early Miocene deposits of East Africa, the first two of which are new. A fourth genus (Prohyrax) occurs in southern Africa, but is not reliably known from East Africa. To cite this article: M. Pickford et al., C. R. Palevol 3 (2004).

Résumé

Révision des Hyracoidea (Mammalia) du Miocène inférieur de l'Afrique de l’Est. Trois espèces d’Hyracoidea ont été signalées dans le Miocène inférieur d’Afrique orientale par Whitworth [18]. Malgré des différences importantes de la morphologie cranio-dentaire, deux des espèces kenyanes étaient classées dans Megalohyrax et Bunohyrax, genres connus dans les dépôts beaucoup plus anciens du Fayoum en Égypte. Le troisième genre décrit par Whitworth (Meroehyrax) était nouveau. La classification proposée [18] a été débattue ; certains auteurs [6,13] ont remis en cause le statut d’Hyracoïde d’une de ses espèces et ont modifié le statut générique d’une autre. Meyer [6] a signalé un quatrième genre (Prohyrax) au Kenya, sur la base des ressemblances avec le genre namibien décrit par Stromer [16,17]. De nouveaux spécimens récoltés par l’Uganda Palaeontology Expedition permettent d’éclaircir la position systématique et la taxonomie de deux des espèces. Nous concluons qu’il n’existe que trois genres d’Hyracoïdes dans les dépôts du Miocène inférieur d’Afrique orientale (Afrohyrax, Brachyhyrax et Meroehyrax), dont les deux premiers sont nouveaux. Par ailleurs, un quatrième genre (Prohyrax) est connu d’Afrique australe. Pour citer cet article : M. Pickford et al., C. R. Palevol 3 (2004).