Ammonitina HYATT, 1889

Sassaroli, Stefano & Venturi, Federico, 2012, Early Toarcian (post-OAE) Hildoceratinae (Ammonitina) fauna from the Marchean Apennines (Italy), Revue de Paléobiologie 31 (1), pp. 85-114 : 93-95

Suborder Ammonitina HYATT, 1889 Superfamily Hildocerataceae HYATT, 1867 Family Hildoceratidae HYATT, 1867

Subfamily Hildoceratinae HYATT, 1867

Diagnosis: From evolute to moderately involute planulates, more or less compressed shell. The whorl section varies from elliptical to sub-trapezoidal or from sub-rectangular to sub-quadrate. The keeled venter varies from elliptical to ogival, from tabulate to bisulcate or else to tricarinate-bisulcate. The ornament varies also showing ribs from fine to coarse; they can be single, bifurcating, rarely trifurcating and sometimes bundled with sinuous, sigmo-falcoid or strongly angled falcate and rarely almost rectiradiate appearance. The ammonitic suture is simple.

Discussion: This subfamily includes to the presentday the following genera: Hildaites BUCKMAN, 1921 ; Orthildaites BUCKMAN, 1923 ; Cingolites SASSAROLI & VENTURI, 2010 ; Hildoceras HYATT, 1867 ; Urkutites GÉCZY, 1967. All these genera occur in the Apennines outcrops (SASSAROLI & VENTURI, 2010).

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