| subdivision_ranks = Family and Genera
| subdivision =Hematitidae- Hematites
- Bactritimimus
- Paleoconus
}}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.
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
Classification
The classification for this group comes from Doguzhaeva et al. 2003[6]
Order Hematitida Doguzhaeva, Mapes, & Mutvei, 2002
- Family Hematitidae Gustomesov 1976
- Hematites Flower & Gordon 1959 - type genus
- Bactritimimus Flower & Gordon, 1959
- Paleoconus Flower & Gordon, 1959
References
1. ^1 {{cite journal | last1 = Bandel | first1 = Klaus | last2 = Reitner | first2 = Joachim | last3 = Sturmer | first3 = Wilhelm | year = 1983 | title = Coleoidea from the Devonian Black Slate ("Hunsruck-Schiefer") | journal = Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen | volume = 165 | issue = 3 | pages = 397–417 | place = Stuttgart | url = http://webdoc.sub.gwdg.de/pub/geo/geobiologie/2005/reitner/1983-coleoids.pdf}}
2. ^1 {{cite journal | last1 = Doguzhaeva | first1 = Larisa A. | last2 = Mapes | first2 = Royal H. | last3 = Mutvei | first3 = Harry | year = 2003 | title = The shell and ink sac morphology and ultrastructure of the Late Pennsylvanian cephalopod Donovaniconus and its phylogenetic significance| journal = Berliner Paläobiologische Abhandlungen| volume = 3 | pages = 61–78}}
3. ^1 2 {{Citation | last1 = Nishiguchi | first1 = Michelle | last2 = Mapes | first2 = Royal K. | year = 2008 | contribution = Cephalopoda | title = Phylogeny and evolution of the Mollusca | editors = Ponder, Winston F., & Lindberg, David R. | pages = 163–199 | place = Dordrecht, The Netherlands | publisher = Springer | isbn = 978-0-520-25092-5 }}