Crocodylus gariepensis

From Wikipedia, the free encyclopedia
Jump to: navigation, search
"Crocodylus" gariepensis
Temporal range: Early Miocene, 17.5Ma
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Crocodylomorpha
Order: Crocodilia
Family: Crocodylidae
Subfamily: Crocodylinae
Species: "Crocodylus" gariepensis
Pickford, 2003

"Crocodylus" gariepensis is an extinct species of crocodile that lived in southern Africa during the Early Miocene[1] about 17.5 million years ago (Ma).[2] Fossils have been found along a bank of the Orange River in Namibia, near its border with South Africa.[1]

When the species was named in 2003, it was hypothesized to be ancestral to the living Nile crocodile, Crocodylus niloticus. During this time the fossil record of C. niloticus was thought to extend back into the Late Miocene, meaning that "C." gariepensis could have been a direct precursor to the species.[3] More recent studies propose that C. niloticus first appeared much more recently, making "C." gariepensis an unlikely ancestor of the Nile crocodile. Moreover, the most recent phylogenetic studies of crocodiles place "C." gariepensis in an evolutionary position outside most other species of Crocodylus, far from the position of C. niloticus.[1] These studies place it in a clade informally called "mecistopins", which includes the living slender-snouted crocodile Mecistops and the extinct genus Euthecodon.[4] Since "C." gariepensis does not fall within the genus Crocodylus defined in its strictest sense (Crocodylus sensu stricto), its name is shown in quotation marks.

Although much of Namibia is currently arid, "C." gariepensis lived during a time when the local climate was humid and subtropical. It likely inhabited gallery forests surrounding the Orange River. Fossils of giant tortoises and a variety of small burrowing mammals have been found in the same deposits.[2]

References[edit]

  1. ^ a b c Brochu, C. A.; Storrs, G. W. (2012). "A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity of Crocodylus in Africa". Journal of Vertebrate Paleontology 32 (3): 587. doi:10.1080/02724634.2012.652324.  edit
  2. ^ a b Senut, B.; Pickford, M.; Ségalen, L. C. (2009). "Neogene desertification of Africa". Comptes Rendus Geoscience 341 (8–9): 591. doi:10.1016/j.crte.2009.03.008.  edit
  3. ^ Delfino, M.; Segid, A.; Yosief, D.; Shoshani, J.; Rook, L.; Libsekal, Y. (2004). "Fossil reptiles from the Pleistocene Homo-bearing locality of Buia (Eritrea, Northern Danakil Depression)". Rivista Italiana di Paleontologia e Stratigrafia 110 (Suppl.): 51–60. 
  4. ^ Conrad, J. L.; Jenkins, K.; Lehmann, T.; Manthi, F. K.; Peppe, D. J.; Nightingale, S.; Cossette, A.; Dunsworth, H. M.; Harcourt-Smith, W. E. H.; McNulty, K. P. (2013). "New specimens of "Crocodylus" pigotti (Crocodylidae) from Rusinga Island, Kenya, and generic reallocation of the species". Journal of Vertebrate Paleontology 33 (3): 629. doi:10.1080/02724634.2013.743404.  edit