Mimoceratidae

The Mimoceratidae is a family of Lower and Middle Devonian ammonoid cephalopods previously included in the Anarcestaceae but now included in the Mimosphinctaceae along with the Mimosphinctidae and Teicherticeratidae.

Mimoceratid shells are discoidal with a large perforated (see trough)  umbilucus and sutures with 3 lobes, a V-shaped ventral and shallow laterals. Whorls are not dorsally impressed (no embracing of the ventral side by subsequent whorls.)

Two subfamilies are involved. First the Mimoceratinae from the Lower and Middle Devonian, which have no prominent sculpture (ornamentation) and whorls that are in contact. Second the prior Mimosphinctinae (now the Mimosphinctidae) from the Lower Devonian characterized by prominent ribs that cross the venter.

Mimoceratid fossils have been found in China, the Czech Republic, Germany,  Morocco, the Russian Federation, Spain, and Tajikistan.

References

A.K. Miller, W.M. Furnish, and O.H. Schindewolf 1957. Paleozoic Ammonoidea, in W.J Arkell et al Cephalopoda -Ammonoidea. Treatise on Invertebrate  Paleontology Part L.

D. Korn 2006. Paleozoic ammonoid classification.

Fossilworks: Mimoceratidae