''Mucrodactylites'', which is sometimes considered to be a synonym of '' Collina'',M. K. Howarth 2013. Treatise on Invertebrate Paleontology, Part L, Revised, Volume 3B, Chapter 4: Psiloceratoidea, Eoderoceratoidea, Hildoceratoidea. is genus of

ammonite Ammonoids are extinct, (typically) coiled-shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living octopuses, squid, and cuttlefish (which comprise the clade Coleoidea) than they are to nautiluses (family N ...

that lived during middle to late

Toarcian The Toarcian is, in the International Commission on Stratigraphy, ICS' geologic timescale, an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic. It spans the time between 184.2 Megaannum, Ma (million ...

stage (Bifrons Subzone to lower Variabilis ammonite Zone) of

early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic� ...

. Their fossils were found in Europe, northern Africa and South America. Species belonging to this genus were probably microconchs of ''

Catacoeloceras ''Catacoeloceras'' is a genus of ammonite that lived during Middle Toarcian stage of early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the ear ...

''. As macroconch of ''M. mucronatus'' is considered to be ''Catacoeloceras raquinianum''.

Description

Ammonites belonging to this genus have small, evolute and compressed shells with suboval to subquadrate whorl section. Primary ribs are strong, simple and bifurcating. Secondary ribs are projected.Kovács, Z. (2014). Toarcian Dactylioceratidae (Ammonitina) from the Gerecse Mts (Hungary). Hantkeniana, 9, 45-77.

References

Ammonitida Toarcian life Early Jurassic ammonites of Europe Ammonites of Africa Ammonites of South America Ammonite genera {{Ammonite-stub