''Donetzoceras'' is a genus belonging to the
goniatitid family
Gonioglyphioceratidae ; extinct
ammonoids which are shelled cephalopods more closely related to squid, octopus and other coleoids than to the superficially similar ''
Nautilus''
''Donetzoceras'' has a relatively small, thick-discoidal shell, the inner whorls evolute, later stages involute. Sculpture consists of nodelike riblets and umbilical plications which disappear at maturity. Growth lines form shallow ventral sinus and ventrolateral salients. The ventral lobe pointed with a median saddle about half as high as entire ventral lobe itself.
''Donetzoceras'' is the earliest genus now included in the Gonioglyphioceratidae. ''Donetzoceras'' is from the middle and upper Upper
Carboniferous
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...
(Pennsylvanian)
References
* Goniat
* Saunders et al. 1999; Evolution of Complexity in Paleozoic Ammonoid Sutures, Supplementary Material; Science Mag
The Paleobiology Databaseaccessed on 10/01/07
Pennsylvanian ammonites
Goniatitida genera
Goniolobocerataceae
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