Recent Cenozoic croc stuff:
The Eocene-Oligocene transition was a period of high faunal and floral turnover, often correlated with climatic deterioration. Crocodyliforms are climate sensitive, and they have been often used for reconstruction of paleoclimates. The description of crocodylian material from the Bartonian of Aaiun-Tarfaya Basin (Morocco) allows the recognition of at least two longirostrine crocodylians, including a gavialoid. This identification is important, because the migration of gavialoids to South America probably occurred during the late Eocene. Close relationships between late Eocene-early Oligocene Eogavialis africanum from Egypt, Argochampsa krebsi from the Paleocene of Morocco, and the South American gavialoid clade suggests that Morocco could have had a particular place in the gavialoid dispersal route to South America. The resemblance between Moroccan material described herein and E. africanum is thus important in this context. Analysis of the distribution of longirostrine crocodylians in the Peri-Tethys area through the Eocene-Oligocene shows a strong difference in the evolution of the distribution between longirostrine crocodylians and Diplocynodon. Whereas the freshwater Diplocynodon has a continuous distribution in western Europe, the mainly marine longirostrine crocodylians have a northern maximal expansion that moves southward during the middle Eocene, being restricted to North Africa during late Eoceneâearly Oligocene. European freshwater Asiatosuchus-like taxa also disappear during the late Eocene. Climatic deterioration, helped by sea level oscillations, may have strongly impacted the diversity and latitudinal distribution of the crocodylians, but we highlight a possible differential tolerance in range of climatic conditions between crocodylians. This could help to refine the use of crocodylians as paleoclimatic proxies.
Crocs' climate clock: Ancient distribution of Crocs could reveal more about past climates
The early Miocene deposits of Bohemia (Czech Republic) contain numerous fragmentary crocodylian remains. Despite this abundance, a detailed taxonomical assignment of these remains was impossible due to the absence of diagnostic cranial elements. Here, we report two partially preserved skulls together with some osteoderms and a partially preserved vertebra from the TuÅimice site (MN3, Most Basin, Northwest Bohemia). Though the specimens were from Bohemia, the exact placement of this site was lost during the last century. Our results confirm that the coal from the reported specimens is consistent with the TuÅimice site. Based on the detailed cranial description of the new material, the crocodylian remains from the above-mentioned locality can be referred to the extinct alligatoroid Diplocynodon ratelii with confidence. Our data extend the known spatial distribution of this taxon to Central Europe.