''Indonautilus'' is an involute nautilid from the Middle and Upper Triassic. (Anisian-Norian), with a small or occluded umbilicus and subrectangular whorl section belonging to the

Liroceratidae 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 broad ...

(Clydonaulilaceae). Flanks are slightly bowed, converging on a flattened venter. Ventro-lateral shoulders are narrowly rounded or angular. Umbilical shoulder are broadly rounded. 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 ...

is subdorsal. ''Indonautilus'' has been found in Egypt, Israel, the Himalayas, and East Indies.

''References''

* Bernhard Kummel, 1964. Nautiloidea -Nautilida; Treatise on Invertebrate Paleontology, Part K. Geological Society of America and University of Kansas Press.
Indonautilus
in the Paleobiology database 4/25/14 Prehistoric nautiloid genera Anisian genus first appearances Ladinian genera Carnian genera Norian genus extinctions {{paleo-nautiloidea-stub