- Clydonautilidae
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Clydonautilidae
Temporal range: M -U TriassicScientific classification Kingdom: Animalia Phylum: Mollusca Class: Cephalopoda Subclass: Nautiloidea Order: Nautilida Superfamily: Clydonautilaceae Family: Clydonautilidae
Hyatt, 1900The Clydonautilidae are Middle and Upper Triassic nautiloid cephalopods, which are derivatives of the clydonautlicean family Liroceratidae, that have generally smooth, involute, globular to compressed shells, characterized by a suture with prominent lobes and saddles. The family is known to contain five genera', These are:
- Clydonautilus
- Callaionautilus
- Cosmonautilus
- Proclydonautilus
- Styrionautilus
Of these only Styrionautilus is known from the Middle Triassic. The other four are so far restricted to the Upper Triassic.
The five genera in the Clydonautilidae form a sequence of increasing sutural complexity, beginning with Styrionautilus and ending with Clydonautilus. Styrionautilis, which has the simplest suture of the five, has a broad ventral saddle with a flat bottom and a gently curved lateral lobe. Clydonauatilus at the opposite extreme has a secondary ventral saddle within the ventral lobe modifying the primary ventral saddle and a deep, asymmetric lateral lobe. Callaionautilus, Cosmonautilus, and Proclydonautulus fall in between.
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)
Categories:- Nautiloids
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