Coelodus is an extinct genus of marine and possibly freshwater
pycnodont fish.[1] It contains only one definitive species, C. saturnus Heckel, 1854 (=C. rosthorni Heckel, 1854, C. suillus Heckel, 1854), from the Late
Cretaceous (
Turonian to
Santonian) of
Slovenia.[2] Other species from the
Late Jurassic to the
Eocene have also been attributed to this genus based on isolated dental elements, but their assignment to Coelodus is uncertain, and this genus likely represents a non-
monophyleticwastebasket taxon. A potential diagnostic trait is a prearticular tooth row with three regular highly elongated teeth.[2][3][4][5][6]
Taxonomy
Life restoration of C. saturnus
In addition to C. saturnus, the following are all dubiously classified into this genus:[7][8]
C. anomalus Choffat & Priem 1904 -
Barremian of Portugal
C. plethodon Arambourg & Joleaud 1943 - Cenomanian/Turonian of
Niger, Maastrichtian of
Algeria
C. portucalensis Jonet 1981 - Cenomanian of Portugal
C. priemi Leriche 1903 - Late Jurassic of France
C. ribeiroi Sauvage 1898 - Turonian of Portugal
C. rostratus Gorjanović-Kramberger 1895 - Cenomanian of Slovenia
C. soleri Rullán 1948 - Albian/Cenomanian of
Catalonia, Spain
C. stantoni Williston 1900 - Albian of Kansas, USA (Kiowa Shale)
C. subsimilis (Cornuel 1880) Priem 1912 - Late Jurassic of France
C. syriacus Hussakof 1916 - Late Cretaceous of
Lebanon
C. vetteri Gorjanović-Kramberger 1895 - Cenomanian-Turonian of Slovenia
C. zambiensis Dartevelle & Casier 1949 - Turonian of the Democratic Republic of the Congo (Kongo Central)
A number of former species in this genus based on complete fossil specimens, such as C. costae Heckel, 1856 (=C. achillis (Costa 1853), C. discus Heckel 1856, C. grandis (Costa 1855), C. pyrrhurus Heckel, 1854) C. subdiscus Wenz, 1989, C. rosadoi Silva Santos, 1963 and C. toncoensis Benedetto & Sanchez ,1972 have since been reclassified into the genera Ocloedus and Costapycnodus, and many of these dentition-only taxa may belong there instead.[2][5] Others, such as the former C. muensteri, are now placed in Anomoeodus.
Indeterminate remains are known from the
Csehbánya Formation of
Hungary and the
Kem Kem Beds of
Morocco.[9][10] Notably, these formations, in addition to other formations that Coelodus remains are known from worldwide, are freshwater deposits, suggesting at a potentially
amphidromous lifestyle for Coelodus given its occurrence in marine environments as well.[10] It is possible that freshwater and brackish environments served as
refugia for Coelodus, allowing for it to survive the
Cretaceous-Paleogene extinction event.[11]