''Karagandoceras'' is an

ammonoid Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

genus belonging to the goniatid family

Karagandoceratidae The Karagondoceratidae is a small family of tornoceratin Goniatitida from the Lower Carboniferous (early Mississippian) which typifies the Karagandoceratoidea Karagandoceratoidea is an Early Carboniferous (Mississippian) superfamily within th ...

that lived during the early Mississippian (lower

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

). ''Karagandoceras'' has an involute, lenticular shell, with an acute ventral margin. The ventral lobe of the suture is wide with subparallel to divergent sides, divided by a median saddle with a relatively wide median lobe. Karagandoceratids, which include ''Karagandoceras'' and '' Mesonoceras'' are a rare offshoot of the Prionorceratinae that differ from their parent group by possession of an acute ventral margin and an increasingly trifid ventral lobe.

References

Paleobiology database-''Karagandoceras''
8/22/10

8/22/10 * ''Masonoceras'', a new Karaganoceratid Ammonoid from the Lower Mississippian (Lower Osagean) of Kentucky, by David M Work and Walter L Manger. Jour Paleo May 2002; v.76; no. 3; pp 574–577 Goniatitida genera Karagandocerataceae Mississippian ammonites {{Goniatitida-stub