Hematitida
From Infogalactic: the planetary knowledge core
| Hematitida |
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Hematitida
Doguzhaeva et al., 2002[1]
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Hematitidae
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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 USA.[2] The only family described so far is 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
