Header

UZH-Logo

Maintenance Infos

The late Miocene caimanine fauna (Crocodylia: Alligatoroidea) of the Urumaco Formation, Venezuela


Scheyer, Torsten M; Delfino, Massimo (2016). The late Miocene caimanine fauna (Crocodylia: Alligatoroidea) of the Urumaco Formation, Venezuela. Palaeontologia Electronica:1-57.

Abstract

The late Miocene Urumaco Formation at Urumaco, Falcón state, Venezuela, is remarkably rich in extinct crocodylians, presenting a diversity hotspot in the Neotropics for the group. Herein, we revise the Caimaninae fauna by including novel fossil material as well as the previously described specimens assignable to this clade. In many instances the taxonomic status of species could be confirmed, which is the case in Caiman brevirostris, Globidentosuchus brevirostris, and Purussaurus mirandai, and novel osteological data is presented to corroborate previous anatomical descriptions. In other cases, specimens needed to be reassigned to different taxa; with material previously identified as Caiman lutescens now considered as belonging to either Caiman latirostris or Caiman wannlangstoni, and material of Melanosuchus fisheri reassigned to Caimaninae aff. Melanosuchus fisheri. Furthermore, Mourasuchus nativus is considered to be a junior synonym of Mourasuchus arendsi herein. This suggests that there are only three species of the duck-billed caimanine Mourasuchus present in the Miocene of South America, having colonised the continent from the northwest (Colombia and Peru) during the middle Miocene and moving to the east and southeast (Venezuela, Brazil and Argentina) in the late Miocene. Other specimens, which were previously identified as belonging to the genus Caiman, lack diagnostic features of the modern genus and are instead considered as Caimaninae indet. Besides improving the knowledge of the late Miocene crocodylians of South America, our results confirm the high taxonomic diversity of the fauna and the outstanding level of sympatry previously reported for the Urumaco Formation.

Abstract

The late Miocene Urumaco Formation at Urumaco, Falcón state, Venezuela, is remarkably rich in extinct crocodylians, presenting a diversity hotspot in the Neotropics for the group. Herein, we revise the Caimaninae fauna by including novel fossil material as well as the previously described specimens assignable to this clade. In many instances the taxonomic status of species could be confirmed, which is the case in Caiman brevirostris, Globidentosuchus brevirostris, and Purussaurus mirandai, and novel osteological data is presented to corroborate previous anatomical descriptions. In other cases, specimens needed to be reassigned to different taxa; with material previously identified as Caiman lutescens now considered as belonging to either Caiman latirostris or Caiman wannlangstoni, and material of Melanosuchus fisheri reassigned to Caimaninae aff. Melanosuchus fisheri. Furthermore, Mourasuchus nativus is considered to be a junior synonym of Mourasuchus arendsi herein. This suggests that there are only three species of the duck-billed caimanine Mourasuchus present in the Miocene of South America, having colonised the continent from the northwest (Colombia and Peru) during the middle Miocene and moving to the east and southeast (Venezuela, Brazil and Argentina) in the late Miocene. Other specimens, which were previously identified as belonging to the genus Caiman, lack diagnostic features of the modern genus and are instead considered as Caimaninae indet. Besides improving the knowledge of the late Miocene crocodylians of South America, our results confirm the high taxonomic diversity of the fauna and the outstanding level of sympatry previously reported for the Urumaco Formation.

Statistics

Citations

Downloads

9 downloads since deposited on 30 Dec 2016
9 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Paleontological Institute and Museum
Dewey Decimal Classification:560 Fossils & prehistoric life
Language:English
Date:29 August 2016
Deposited On:30 Dec 2016 07:10
Last Modified:30 Dec 2016 07:10
Publisher:Coquina Press
ISSN:1094-8074

Download

Preview Icon on Download
Preview
Content: Published Version
Filetype: PDF
Size: 115MB