D. jaekeliStensiö, 1922 - Frasnian of Germany (Bergisch Gladbach Formation)[1]
Indeterminate remains are known from the Frasnian of Iran.[1] Specimens from South Africa that were formerly assigned to this genus have since been described in their own genus, Serenichthys. Another alleged specimen from the Frasnian-aged Gogo Formation of Australia[3] was also later described in its own genus, Ngamugawi.[4] The species D. davisiMoy-Thomas, 1937, from the Mississippian of Ireland, which was formerly thought to be the only post-Devonian species, is now thought to represent a subadult Rhabdoderma, indicating that Diplocercides likely went extinct by the End-Devonian extinction.[2][5]
Description
Fossils of the species D. kayseri are known to have three-dimensionally preserved cranial endocasts, making it one of the only known coelacanths aside from the extant Latimeria where the shape of the brain is known. These endocasts have been destroyed by serial grinding, but still survive as wax mounts.[3][4] In 2010, three-dimensional specimens of tentative Diplocercides were described from the Gogo Formation of Western Australia, with these also containing preserved endocasts; these were later described in their own genus, Ngamugawi.[3][4][6]
LONG, J.A. & TRINAJSTIC, K. 2010. The Late Devonian Gogo Formation Lagerstatte –Exceptional preservation and Diversity in early Vertebrates. Annual Review of Earth and Planetary Sciences 38: 665-680