Hammatoceratoidea
Hammatoceratoidea Temporal range: early Jurassic–Middle Jurassic | |
---|---|
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Subclass: | †Ammonoidea |
Order: | †Ammonitida |
Suborder: | †Ammonitina |
Superfamily: | †Hammatoceratoidea Schindewolf 1964 |
Families | |
|
Hammatoceratoidea, formerly Hammatocerataceae is a superfamily of middle Jurassic ammonites (order Ammonitida), erected by Schindewolf (1964) that combines the families Graphoceratidae, Hammatoceratidae, and Soninniidae.[1] The three families were previously included in the Hildocerataceae,[2] and subsequent classifications.[3] In more recent classifications Hammotocerataceae are referred to as Hammatoceratoidia.
Shells of hammatoceratoids are variably evolute or involute, ribbed at least in the early growth stage; cross section typically compressed (higher than wide); venter commonly with a median keel.
Hammatoceratoidea is derived from the family Phymatoceratidae of the Hildoceratoidea, beginning with the Hammatoceratidae near the end of the Early Jurassic.
References
- ↑ Paleobiology Database Hammatoceratoidea entry
- ↑ Arkell, W.J.; Kummel, B.; Wright, C.W. (1957). Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Lawrence, Kansas: Geological Society of America and University of Kansas Press.
- ↑ D.T. Donovan et al 1981. Classification of Jurassic Ammonitina. The Ammonoidea. Systematics Association special volume 18.