Hematitida

Hematitida Temporal range: Carboniferous PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Coleoidea
(unranked):	Belemnoidea
Order:	†Hematitida Doguzhaeva et al., 2002 [1]
Family and genera
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 ^[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

References

1. Doguzhaeva, Larisa A.; Mapes, Royal H.; Mutvei, Harry (2002). "Shell morphology and ultrastructure of the Early Carboniferous coleoid Hematites Flower & Gordon, 1959 (Hematitida ord. nov.) from Midcontinent (USA)". Abhandlungen der Geologischen Bundesanstalt. 57: 299–320'. ISBN   3-85316-014-X. ISSN   0016-7800.
2. Nishiguchi, Michelle; Mapes, Royal K. (2008), "Cephalopoda", in Ponder, Winston F.; Lindberg, David R. (eds.), Phylogeny and evolution of the Mollusca, Dordrecht, The Netherlands: Springer, pp. 163–199, ISBN   978-0-520-25092-5
3. Bandel, Klaus; Reitner, Joachim; Sturmer, Wilhelm (1983). "Coleoidea from the Devonian Black Slate ("Hunsruck-Schiefer")" (PDF). Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 165 (3). Stuttgart: 397–417.
4. Doguzhaeva, Larisa A.; Mapes, Royal H.; Mutvei, Harry (2003). "The shell and ink sac morphology and ultrastructure of the Late Pennsylvanian cephalopod Donovaniconus and its phylogenetic significance". Berliner Paläobiologische Abhandlungen. 3: 61–78.