Print ISSN: 0031-0247
Online ISSN: 2274-0333
Werneburg et al. New Permian Caseid from France
Field trip guides/EAVP Annual Conference/2023
Embrithopod from Croatia
BLANCO ET AL.—NECK POSTURE OF M. PATACHONICA
Small sauropod tracks, Southern France
Une nouvelle espèce de Steneosaurus (Thalattosuchia, Teleosauridae) dans le Callovien du Poitou (France) et la systématique des Steneosaurus longirostres du Jurassique moyen d'Europe Occidentale.middle Jurassic; nov. sp.; phylogenetic relationships; skulls; Steneosaurus pictaviensis; Systematics; thalattosuchian crocodile
The study of all the available skulls allows us to review the systematic relationships of the longirostrine Steneosaurus from the Middle Jurassic of western Europe. Up to now, Aalenian and Bajocian deposits have not yielded any significant Steneosaurus remain. In the Bathonian, the only valid longirostrine species, S. megistorhynchus, is known in the Britain-Normandy Basin, the Poitou and the Lorraine. In the Callovian, most of the longirostrine Steneosaurus remains can be attributed to the species S. leedsi. Nevertheless, some remains from the Middle Callovian of Poitou (France) show important differences with S. leedsi. A new Steneosaurus species, only known in Poitou, is created and named S. pictaviensis. The specific characters are carried by the skull (preorbital pit well marked, orbit and ptetygoid fossae shapes), by the mandible (symphysis shape) and by the teeth (ornamentation). S. megistorhynchus is probably situated near the stem of the Callovian species but remains from the Bathonian and Lower Callovian are very scarce and it is very difficult to precise the phylogenetic relationships between the longirostrine species of the Middle Jurassic.
Published in Vol. 27, Fasc. 1-2 (1998)
La morphologie dentaire des Thalattosuchia (Crocodylia, Mesosuchia).Dental morphology; Dental types; feeding habits.; Jurassic; Metriorhynchidae; Systematics; Teleosauridae; Thalattosuchia
The tooth morphology of the Thalattosuchia (marine crocodilians from the Jurassic and the Early Cretaceous) is analysed. The Callovian from Poitou and the Kimmeridgian from Quercy have yielded many remains of Metriorhynchus, Steneosaurus and Machimosaurus. These remains allow us to study the variations of tooth morphology during ontogenic growth, tooth replacement and the location of the teeth. We have defined different tooth types for these genera. In Metriorhynchus, the two tooth types defined do not coincide with the two groups recognized in the Callovian (broad-skulled and narrow-skulled metriorhynchids) but reﬂect the prey preferences of these forms. In Steneosaurus and Machimosaurus the ﬁve tooth types deñned are in agreement with the main taxa known from the Bathonian to the Early Cretaceous. This study allows to precise the function and the prey preference of the Thalattosuchia during the Jurassic and the Early Cretaceous.
Published in Vol. 26, Fasc. 1-4 (1997)