Alocolytoceratinae is a subfamily of lytoceratids that comprises genera characterized by many deep constrictions in the shell resulting in capricorn-like (goat's horm) ornamention, especially in the middle whorls, but becoming smooth and more involute in the outer whorls. Saddle endings in the suture tend to be phylloid, (leaf-like).
Alcolytocerainae includes ''
Alocolytoceras
''Alocolytoceras'' is a lytoceratid ammonite
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 ...
'', ''
Lobolytoceras
''Lobolytoceras'' is an extinct genus of ammonite in which only the inner whorls have large swollen ribs, later whorls have wrinkled growth lines which coarsen somewhat, near the aperture. The genus is known from the Lower Jurassic Toarcian of Eu ...
'', ''
Pachylytocras'', and ''
Pleurolytoceras'', which are mostly from the
Toarcian. One genus, ''Pachylotoceras'', extends into the
lower Bajocian.
References
;Notes
;Bibliography
*W.J.Arkell, B.Kummel, & C.W.Wright 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L Ammonoidea. R.C.Moore, (ed).
Early Jurassic ammonites
Toarcian first appearances
Middle Jurassic extinctions
Middle Jurassic ammonites
Lytoceratidae
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