Taxonomy of Diplocynodon and Tooth Wear in Caiman latirostris

Martin, Jeremy E. and Martin Gross. 2011. "Taxonomic clarification of Diplocynodon Pomel, 1847 (Crocodilia) from the Miocene of Styria, Austria" Neues Jahrbuch für Geologie und Paläontologie - Abhandlunge, 261:2 DOI: 10.1127/0077-7749/2011/0159

Abstract
A re-examination of the original type series of Prangner (1845) and Hofmann (1887a) of the primitive alligatoroids from the middle Miocene of Styria, led to a reappraisal of the taxonomy of the following species of Diplocynodon: D. steineri and D. styriacus. Of unsettled affinities, Enneodon ungeri was also re-examined. It is here demonstrated that it belongs to the same taxon of the specimens described by Hofmann (1887a). These taxa are in fact junior synonyms of the previously erected Enneodon ungeri. Moreover, comparison with other European alligatoroids reveals that the Austrian specimens described by Prangner (1845) and Hofmann (1887a) belong to the same genus: Diplocynodon Pomel, 1847. According to the rules of the International Commission on Zoological Nomenclature (ICZN), Diplocynodon has priority over Enneodon. Under the principle of priority, it is therefore proposed to rename all the Miocene remains of alligatoroids from Styria as Diplocynodon ungeri Prangner, 1845. Comparison of almost complete skulls from various Miocene contemporaneous localities reveals that there is no reason to erect another taxon for the French specimens of D. "styriacus" described in Ginsburg & Bulot (1997). However, these specimens need to be redefined as D. ungeri as well. D. ungeri was coded and included in a character matrix to cladistically test its affinities with other alligatoroids. A total of six species of Diplocynodon were analysed including: D. ratelii, D. hantoniensis, D. tormis, D. muelleri, D. darwini and D. ungeri. The results are consistent with previous studies and favour a monophyletic diplocynodontid clade. D. ungeri is the first species of the genus to be recognized from distant coeval European deposits, namely the Paris and the Pannonian Basins.

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Ősi, Attila and Paul M. Barrett. 2011. "Dental wear and oral food processing in Caiman latirostris: analogue for fossil crocodylians with crushing teeth" Neues Jahrbuch für Geologie und Paläontologie - Abhandlunge, 261:2 DOI: 10.1127/0077-7749/2011/0161

Abstract
Almost all of the 23 extant species of crocodylians are opportunistic predators that consume their food without extensive intraoral food processing. Posterior bulbous crushing teeth with heavy dental wear in two specimens of Caiman latirostris, however, indicate that oral food processing can be an important factor during feeding. Wear pattern analysis in two specimens of C. latirostris clearly indicates crushing of hard food items that produced large wear surfaces on tooth crowns in the posterior part of the tooth row. This type of wear suggests that the diet was predominantly composed of durable, hard-shelled prey (e.g.molluscs, crustaceans, turtles), a supposition confirmed by recent studies on the stomach contents of several C. latirostris specimens. The absence of similar wear patterns in other ontogenetically mature specimens of C. latirostris, however, indicates that specific, possibly regional differences in food resources might affect the degree and type of dental wear. The dental features we report in C. latirostris can provide an important extant analogue for fossil forms with similar dentitions (e.g. Bernissartia, Unasuchus and globidontan eusuchians).