Hematitida
Extinct order of molluscs
From Wikipedia, the free encyclopedia
Hematitida is a group of coleoid cephalopods known from the early Carboniferous Period. They are the oldest definite coleoids,[2] although there are controversial claims for even older coleoids from the Devonian.[3] Fossil hematitidans have so far been found only in Arkansas and Utah of the United States.[2] The only family described so far is Hematitidae.
| Hematitida Temporal range: | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Superorder: | †Belemnoidea |
| Order: | †Hematitida Doguzhaeva et al., 2002[1] |
| Family and genera | |
|
Hematitidae
| |
Characteristics
Some features shared by hematitidans include
- a short rostrum, made of aragonite and organic material, and bearing ridges
- a short living chamber, only 1.5 to 2 times the length of the last chamber of the phragmocone
- a spherical protoconch
- a narrow, straight phragmocone
- a multi-layered conotheca - the outer wall of the phragmocone
- a narrow, ventral siphuncle[1]
Classification
The classification for this group comes from Doguzhaeva et al. 2003[4]
Order Hematitida Doguzhaeva, Mapes, & Mutvei, 2002
- Family Hematitidae Gustomesov 1976
- Hematites Flower & Gordon 1959 - type genus
- Bactritimimus Flower & Gordon, 1959
- Paleoconus Flower & Gordon, 1959