''Holconautilus'' is a genus of nautiloids from the family Tainoceratidae and order

Nautilida The Nautilida constitute a large and diverse order of generally coiled nautiloid cephalopods that began in the mid Paleozoic and continues to the present with a single family, the Nautilidae which includes two genera, ''Nautilus'' and ''Allonauti ...

, named by Mojsisovics, 1902, and known from Upper

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

sediments in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and E Indies (

Timor Timor is an island at the southern end of Maritime Southeast Asia, in the north of the Timor Sea. The island is East Timor–Indonesia border, divided between the sovereign states of East Timor on the eastern part and Indonesia on the western p ...

). Its shell, evolute, discoidal, with simple coarse lateral ribbing; whorl section, subrectagular with a broadly arched venter. ''Holconautilus'' somewhat resembles the Permo-Triassic ''

Pleuronautilus ''Pleuronautilus'' is a nautiloid genus; family Tainoceratidae, order Nautilida. Description The shell is evolute, discoidal; whorl section subquadrade, flanks generally straight but may converge toward the venter. Inner flanks have course ...

'' except its suture has ventral saddles instead of ventral lobes and lateral ribs are continuous. ''

Anoploceras ''Anoploceras'' is a genus of Middle and Upper Triassic nautiloids included in the Tainoceratidae, known from eastern Europe. The shell is evolute with only a slight overlap of previous whorls. Whorl section is subquadrate, like ''Pleuronautilu ...

'', from the same time and place as ''Holconautilus'' is also similar except for having a wider whorl section and a venter that is slightly concave.

References

* Bernhard Kummel, 1964. Nautiloidea-Nautilida. Treatise on Invertebrate Paleontology, Part K. Geological Soc. of America and University of Kansas press. Teichert and Moore (eds) Prehistoric nautiloid genera Nautiloids {{paleo-Nautiloidea-stub