Biology:"Crocodylus" gariepensis

Short description: Extinct species of reptile

"Crocodylus" gariepensis Temporal range: Early Miocene, 17.5 Ma PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Crocodilia
Superfamily:	Crocodyloidea
Family:	Crocodylidae
Subfamily:	Osteolaeminae
Genus:	Incertae sedis
Species:	†"C." gariepensis
Binomial name
†"Crocodylus" gariepensis Pickford, 2003

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

Classification and Phylogeny

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. 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 other living species of Crocodylus, far from the position of C. niloticus. Indeed, the species appears to be an osteolaemine more closely related to dwarf crocodiles (Osteolaemus) and possibly slender-snouted crocodiles (Mecistops), as shown in the cladogram below:

Crocodylidae	Osteolaeminae   Rimasuchus lloydi†       Voay robustus†       Osteolaemus osborni Osborn’s dwarf crocodile     Osteolaemus tetraspis Dwarf crocodile           "Crocodylus" gariepensis†         Brochuchus parvidens†     Brochuchus pigotti†         Euthecodon arambourgi†     Euthecodon brumpti†           Crocodylinae   Mecistops cataphractus West African slender-snouted crocodile         Crocodylus thorbjarnarsoni†     Crocodylus anthropophagus†         Crocodylus niloticus Nile crocodile       Crocodylus checchiai†     Crocodylus moreletii Morelet's crocodile     Crocodylus intermedius Orinoco crocodile     Crocodylus acutus American crocodile     Crocodylus rhombifer Cuban crocodile       Crocodylus palaeindicus†       Crocodylus palustris Mugger crocodile         Crocodylus ossifragus†     Crocodylus siamensis Siamese crocodile         Crocodylus mindorensis Philippine crocodile     Crocodylus johnstoni Freshwater crocodile     Crocodylus porosus Saltwater crocodile       Crocodylus raninus Borneo crocodile     Crocodylus novaeguineae New Guinea crocodile

Paleoecology

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.

References

Wikidata ☰ Q13618369 entry