Oryctos
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Accès privé :
| volume 6, 2006 |
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Anne S. Schulp, Geert H.I.M. Walenkamp, Paul A.M. Hofman, Yvonne Stuip & Bruce M. Rothschild, Chronic bone infection in the jaw of Mosasaurus hoffmanni (Squamata). Oryctos 6, 41-52.
A massive infection appears to have destroyed a considerable portion of the quadrate and the posterior part of the mandible of a specimen of the mosasaurine squamate Mosasaurus hoffmanni, housed in the Natuurhistorisch Museum Maastricht collections. The extensive nature of the infection and the formation of reparative bone tissue isolating the infection suggests that the mosasaur survived the infection for a prolonged period of time. The cause of the infection remains speculative.
Key words: Cretaceous, infection, Maastrichtian, Mosasaurus, pathology, Squamata.
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Dan Grigorescu & Emese Kazar, A new Middle Miocene odontocete (Mammalia: Cetacea) locality and the Sarmatian Marine Mammal Event in the Central Paratethys. Oryctos 6, 53-68.
A few disarticulated odontocete (Cetacea: Odontoceti) fossils have been found at Comăneşti in western Romania. The locality had hitherto yielded only brackish mollusks and terrestrial micromammals. The entire stratigraphic section was divided by Radulescu & Samson (in Feru et al., 1980) into two local biostratigraphic units: Comăneşti-1 (Sarmatian) and Comăneşti-2 (Pannonian). On the basis of micromammals of the same deposits, these two authors assigned Comăneşti-1 to the MN8 zone of the Mediterranean Neogene. This can be correlated with the upper Volhynian of the Eastern Paratethys, possibly including also the base of the Bessarabian. The fossils are assigned to "Champsodelphis” fuchsii Brandt, 1873, a species already known from six other localities in the Carpathian Basin, specifically from the Vienna Basin of Austria, south Hungary, and western Romania. Several other late Middle Miocene odontocete localities are known from the Carpathian Basin as well. In all cases where zonation was possible, the stratigraphic position of the occurrences is lower Sarmatian, including the upper Ervilia Zone (ca. 12 Ma). This correlation suggests that there was a ‘marine mammal event’ in the Central Paratethys at that chronostratigraphic level, which was the re-appearance of small odontocetes, mysticetes, and phocid seals from the Eastern Paratethys. The Sarmatian ‘Marine Mammal Event’ followed the marine regression of the late Badenian (ca. 13 Ma), which caused the apparent disappearance of marine mammals in this area. Sperm whales and sirenians, all well-documented from the Middle Badenian, failed to invade the Central Paratethys again.
Key words: Miocene, Sarmatian, Central Paratethys, Romania, Odontoceti.
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Eberhard Frey, Marie-Céline Buchy, Wolfgang Stinnesbeck, Arturo Gonzalez Gonzalez & Alfredo di Stefano, Muzquizopteryx coahuilensis n.g., n. sp., a nyctosaurid pterosaur with soft tissue preservation from the Coniacian (Late Cretaceous) of northeast Mexico (Coahuila). Oryctos 6, 19-40.
Here we describe the first near complete and articulated pterosaur from Mexico. It comes from Late Cretaceous (Early Coniacian) laminated limestones of the Austin Group in the vicinity of Muzquiz, Coahuila (NE Mexico). The specimen is named a new genus and species, Muzquizopteryx coahuilensis gen. et sp. nov. is referred to Nyctosauridae and represents the earliest known member of this taxon. With a wingspan of about two metres it represents the smallest known adult nyctosaurid pterosaur. The preservation of mineralised tendons and the in situ preservation of the carpus allow the reconstruction of some distal arm muscles and the discussion of the orientation of the pteroid bone.
Key words: Northeast Mexico, Cretaceous, Coniacian, Pterosauria, Nyctosauridae, taxonomy, constructional morphology.
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Marie-Céline Buchy, Eberhard Frey, Wolfgang Stinnesbeck & José Guadalupe Lopez-Oliva, An annotated catalogue of the Upper Jurassic (Kimmeridgian and Tithonian) marine reptiles in the collections of the UniversidadAutónoma de Nuevo León, Facultad de Ciencias de la Tierra, Linares, Mexico. Oryxtos 6, 1-18.
We present an annotated catalogue of the Late Jurassic marine reptiles held in the collections of the Universidad Autónoma de Nuevo León, Facultad de Ciencias de la Tierra, in Linares, Mexico (UANL-FCT). Most of the specimens are fragmentary because they were collected in the frame of geological surveys. The collections comprise the holotype of the recently described thalattosuchian Geosaurus vignaudi, from the Tithonian (Late Jurassic) of Puebla State. The collections of the UANL-FCT additionally document a new marine reptile assemblage from the Kimmeridgian (Late Jurassic) of north-eastern Mexico, which represents groups hitherto unknown from the Late Jurassic Mexican Gulf. The assemblage comprises thalattosuchians, ichthyosaurs, pliosaurs, and a single elasmosaur vertebra. Most of the diagnostic specimens are endemic to at least the species level, confirming the partial isolation of the Mexican Gulf during the Late Jurassic, as suggested on the basis of invertebrate assemblages. The composition of this new tetrapod assemblage is compared to the Late Jurassic marine tetrapod assemblages of Europe and South America.
Key words: Thalattosuchia, Ichthyosauria, Plesiosauria, Late Jurassic, Mexico, palaeobiogeography
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Olivier Lambert, First record of a platanistid (Cetacea, Odontoceti) in the North Sea Basin: a review of Cyrtodelphis Abel, 1899 from the Miocene of Belgium. Oryctos 6, 69-79.
The systematic status of remains of odontocetes (Mammalia, Cetacea) from the Miocene of the region of Antwerp (north of Belgium, southern margin of the North Sea Basin) previously referred to the long-snouted dolphin species Cyrtodelphis sulcatus (Gervais, 1853) is revised. A number of the specimens, a rostrum, some rostral and mandibular fragments, probably dated from the late Early to Middle Miocene, are identified as belonging to a member of the family Platanistidae (for which the only extant genus is Platanista from rivers of north-eastern Asia), more precisely to the subfamily Pomatodelphininae. This is the first platanistid record from the North Sea Basin. Another fragment of skull is referred to Kentriodontidae incertae sedis. An isolated tympanic bulla belongs to a eurhinodelphinid. The palaeoecology of the pomatodelphinines is briefly discussed, comparing their palaeogeographic range and the morphology of their feeding apparatus to the eurhinodelphinids, other long-snouted dolphins mainly known from the Miocene.
Key words: Cetacea, Odontoceti, Cyrtodelphis, taxonomy, Platanistidae, Miocene, Belgium.
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