Hematitidae 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.
Some features shared by hematitidans include The classification for this group comes from Doguzhaeva et al. 2003[4] Order Hematitida Doguzhaeva, Mapes, & Mutvei, 2002