| Euthecodon Temporal range: Miocene - Pleistocene | |
|---|---|
| |
| Reconstruction of Euthecodon | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Crocodilia |
| Family: | Crocodylidae |
| Subfamily: | Osteolaeminae |
| Genus: | Euthecodon Fourtau, 1920 |
| Type species | |
| Euthecodon nitriae Fourtau, 1920 | |
| Referred species | |
| |
Euthecodon is an extinct genus of long-snouted crocodyline crocodilians. It was common throughout much of Africa during the Neogene, with fossils being especially common in Kenya. It existed from the Early Miocene to the Early Pleistocene.
Description[]
Scale diagram showing the size of E. brumpti (orange)
Euthecodon was large for a crocodilian. One specimen, LT 26306, found from the Turkana Basin, was estimated by skull length to have been around 10.8 m long.[1] It had a narrow rostrum that was unusually elongate with deeply scalloped dorsal margins. The skull table, however, was proportionally small and is almost square in shape. The jaws were lined with isodont, or slender, similarly sized and shaped, teeth. Unlike nearly all other crocodilians, Euthecodon possessed only four premaxillary teeth. Because they are sharp and bicarinate, they are believed to have been an adaptation for a piscivorous feeding habit, or a diet that included fish.
Discovery and species[]
Collected material now known to be from Euthecodon was initially placed in the genus Tomistoma, of which the modern false gharial is a member. These specimens were described from the Pliocene Omo Group in Ethiopia.[2] The genus Euthecodon was first named in 1920 on the basis of material found from Wadi Natrun, Egypt. This material was believed to have belonged to the same species as the specimens from Ethiopia, yet it appeared to be distinct from the genus Tomistoma. As a result, the material from Ethiopia was reassigned to the new genus along with the material from Egypt, with the species being named E. nitriae.[3]
A new species, named E. brumpti, was found from Lothagam, Kenya and can be distinguished from E. nitriae by skull and rostral proportions as well as tooth count.[4][5][6] E. brumpti is one of the most common fossil crocodylians found in the Turkana Basin, along with crocodiles referred to Rimasuchus lloydi. A complete articulated skull and mandible referrable to E. brumpti was found in situ from the Kaiyumung Member of the Nachukui Formation in Lothagam in 1992.[7]
A shorter snouted species named E. arambourgi has been found from early Miocene deposits in Gebel Zelten, Libya.[8][9][10] Classification of specimens from several localities across Africa are indeterminant at the species level, with material being found from the Sahabi Formation in Libya of early Pliocene age,[11]the Victoria Basin strata of Rusinga Island of early Miocene age,[12] early Miocene deposits in Ombo, Kenya,[13] and possibly the Albertine Rift sediments of the Congo of early Miocene age.[14][15]
Phylogeny[]
Euthecodon was originally considered a tomistomine crocodilian. It has even been suggested to be a direct offshoot of Eogavialis.[16][17] However, it is now thought to be a crocodylid, having been allied with Rimasuchus, Osteolaemus, and Voay in the past.