Liroceratidae is an extinct family of
nautilids, shelled marine
molluscs, belonging to the
Clydonautiloidea, consisting of generally smooth, involute, nautiliconic forms with a small umbilicus. The whorl section is usually depressed and broadly rounded, the suture only slightly sinuous, and the
siphuncle
The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and ...
usually more or less central.
The Liroceratidae range from the Mississippian well into the Triassic and may even extend down into the upper Devonian.
The Liroceratidae are probably derived from the
Rutoceratidae
Rutoceratidae is a family of prototypical nautilids, derived probably from either Brevicoceratidae or Acleistoceratidae of the order Oncocerida early in the Devonian. Rutoceratidae comprise a family within the oncocerid superfamily Tainoceratac ...
and form the root stock of the Clydonautiloidea. They also provide the basis for the name for Shimankiy's Lirocerina, a suborder mostly equivalent to the Clydonautilaceae. The Liroceratidae gave rise to the
Ephippioceratidae
Ephippioceratidae is a family of clydonatilacean nautilids with shells as in the Liroceratidae but with sutures that have deep ventral and dorsal saddles. This group, which contains two genera, ''Ephippioceras'' and ''Megaglossoceras'', has ...
early in the Mississippian, which extend well into the Permian, and to the
Clydonautilidae,
Gonionautilidae
Gonionautilidae is a family in the nautilid superfamily Clydonautiliaceae that contains only the genus ''Gonionautilus'', known from the Upper Triassic (Norian) of Europe and North America. (Alps, state of Nevada)
''Gonionautilus'' has a smooth, ...
, and
Siberionautilidae
Siberionautilidae is a family in the nautilid superfamily Clydonautiloidea that contains only the genus ''Siberionautilus'', which comes from the Upper Triassic ( Carnian) of Siberia, Russia.
The family, and genus, are characterized by an invol ...
in the Triassic.
References
*Bernhard Kummel, 1964. Nautiloidea -Nautilida; Treatise on Invertebrate Paleontology, Part K. Geol Soc of America and Univ of Kansas press, R.C. Moore (ed) -- Liroceratidae K444 -K447.
*J. Tuck, R Mapes, & S. Arnoff, 1978. New Coiled Nautiloids from the Wewok Formation (Pennsylvanian) of Oklahoma. Jour Paleo V.52, N.1, pp67–72. Jan. 1978
{{Taxonbar, from=Q16984680
Nautiloids