Listrognathosuchus is an extinct genus of alligatoroid crocodilian. Fossils date back to the middle Paleocene epoch. In 1997, the generic name replaced that of Leidyosuchus for the species L. multidentatus (now the type species of Listrognathosuchus).[1] "L." multidentalis was first described by Charles Mook in 1930 on the basis of the holotype AMNH 5179, consisting of a partial vertebral column, mandible, partial left ilium, and left tibia, found from a locality in Torrejon Arroyo, New Mexico (then referred to as the Torrejon beds, and now thought to be part of the Nacimiento Formation).[2]
| Listrognathosuchus Temporal range: Middle Paleocene
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Archosauromorpha |
| Clade: | Archosauriformes |
| Order: | Crocodilia |
| Superfamily: | Alligatoroidea |
| Genus: | †Listrognathosuchus Brochu, 1997 |
| Species | |
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Phylogenetics
editThe fragmentary nature of the material referable to Listrognathosuchus have made it hard to classify within Crocodylia, but it is now thought to be a relatively basal alligatoroid. Listrognathosuchus is closely related to Borealosuchus, a more basal eusuchian that is not an alligatoroid, but rather a close relative of a monophyletic group of which the superfamilies Alligatoroidea and Crocodyloidea comprise. In fact, Borealosuchus was first used as a replacement name for four species of Leidyosuchus, the same genus that Listrognathosuchus multidentatus once belonged to. Prior to the reassessment of Leidyosuchus in 1997, many relationships for the genus within Crocodilia have been considered. It was suggested to be a possible member of Diplocynodontinae[3][4] or a relative of later crocodylids,[5][6][7][8] and even as a member of its own subfamily of broad snouted early eusuchians, Leidysuchinae.[9][10][11] However, with the naming of Listrognathosuchus and Borealosuchus, most species previously assigned to Leidyosuchus are now believed to have had little relation to any of the mentioned crocodilians.
References
edit- ^ Brochu, C. A. (1997). A review of "Leidyosuchus" (Crocodyliformes, Eusuchia) from the Cretaceous through Eocene of North America. Journal of Vertebrate Paleontology 17(4):679–697.
- ^ Mook, C. C. (1930). A new species of crocodilian from the Torrejon Beds. American Museum Novitates 447:1-11.
- ^ Gilmore, C. W. (1910). Leidyosuchus sternbergii, a new species of crocodile from the Cretaceous beds of Wyoming. Proceedings of the United States National Museum 38(1762):485-502.
- ^ Rauhe, M. and Rossmann, T. (1995). News about fossil crocodiles from the middle Eocene of Messel and Geiseltal, Germany. Halllesches Jahrbuch fur Geowissenschaften 17:18-92.
- ^ Kälin, J. A. (1955). "Crocodilia". In: Piveteau, J., ed., Traité de Paléontologie, Vol. 5. Masson, Paris. pp. 695-784.
- ^ Berg, D. E. (1966). Die Krokodile, insbesondere Asiatosuchus und aff. Sebecus?, aus dem Eozän von Messel bei Darmstadt/Hessen. Abhandlungen des Hessischen Landesamtes für Bodenforschung 52:1-105.
- ^ Steel, R. (1973). Handbuch der Paleoherpetologie. Vol. 16: Crocodilia. Fischer-Verlag, Portland, Oregon. 116pp.
- ^ Bartels, W. S. (1980). Early Cenozoic reptiles and birds from the Bighorn Basin, Wyoming. University of Michigan Papers on Paleontology 24:73-80.
- ^ Nopcsa, F. (1928). Palaeontoloical notes on reptiles, VII: On the classification of the Crocodilia. Geologica Hungarica (Series Palaeontologica) 1(1):75-84.
- ^ Nopcsa, F. (1928). The genera of reptiles. Palaeobiologica 1:163-188.
- ^ Simpson, G. G. (1937). An ancient eusuchian crocodile from Patagonia. American Museum Novitates 965:1-20.