''Tylodicoceras'' is a genus of the
Koninckioceratidae
Koninckioceratidae is a family of nautilid genera, typically with more or less evolute shells with depressed whorl sections, that are combined as a family within the Tainocerataceae. As perceived, the Koninckioceratidae contains 11 genera and ...
(Cephalopoda,
Nautiloid) from the
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
thru
Mississippian of North America with a large, slightly
involute
In mathematics, an involute (also known as an evolvent) is a particular type of curve that is dependent on another shape or curve. An involute of a curve is the locus of a point on a piece of taut string as the string is either unwrapped from or ...
,
discoidal
In embryology, cleavage is the division of cells in the early development of the embryo, following fertilization. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size ...
shell that is rounded laterally and concave ventrally. Their sides bear a single row with large rounded nodes.
References
* Bernhard Kummerl. 1964, Nautiloidea-Nautilida. Treatise on Invertebrate Paleontology Part K. Geological Society of America and University of Kansas Press.
Prehistoric nautiloid genera
{{paleo-nautiloidea-stub