Ponticeras Matern, 1929

Korn, Dieter & Bockwinkel, Jürgen, 2022, The early gephuroceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea), European Journal of Taxonomy 823, pp. 10-47 : 21

Genus Ponticeras Matern, 1929

Type species

Ammonites aequabilis Beyrich, 1837 (original designation).

Diagnosis

Genus of the subfamily Ponticeratinae with extremely discoidal, subevolute to evolute conch. Often with ventrolateral grooves. Suture line with very wide external lobe, moderately high median saddle, small E 2 lobe, shallow and rounded lateral lobe. Suture line formula (E 2 E 1 E 2) L: I or (E 2 E 1 E 2) L: U I.

Included species

Ammonites aequabilis Beyrich, 1837 , Rhenish Mountains; Ponticeras altaicum Bogoslovsky, 1958 , Altay; Gephyroceras auritum Holzapfel, 1899 , Timan; Goniatites bisulcatus Keyserling, 1844 , Timan; Ponticeras discoidale Glenister, 1958 , Western Australia; Gephyroceras Domanicense Holzapfel, 1899 , Timan; Gephyroceras Kayseri Wedekind, 1918 , Rhenish Mountains; Gephyroceras Keyserlingi Holzapfel, 1899 , Timan; Gephyroceras Lebedeffi Holzapfel, 1899 , Timan; Ponticeras orientale Bogoslovsky, 1958 , Altay; Goniatites complanatus perlatus Hall, 1874 , New York; Gephyroceras regale Holzapfel, 1899 , Timan; Gephyroceras Tschernyschewi Holzapfel, 1899 , Timan; Gephyroceras uralicum Holzapfel, 1899 , Timan; Ponticeras materni sp. nov., Rhenish Mountains, and questionably:

Ponticeras acutilobatum Bogoslovsky, 1958 , Altay; Probeloceras costulatum Petter, 1959 , Ougarta; Manticoceras (Prochorites) prumiense platystoma Clausen, 1969 , Eifel Mountains; Goniatites Prumiensis Steininger, 1853 , Eifel Mountains; Ponticeras regulare Chao, 1956 , Guangxi; Goniatites Wildungensis Waldschmidt, 1885 , Rhenish Mountains.

Remarks

Ponticeras is, next to Pseudoprobeloceras , the stratigraphically oldest genus of the Gephuroceratoidea . The two genera mainly differ in the shape of the external lobe; in Pseudoprobeloceras it is quite narrow with a low median saddle and in Ponticeras it is very broad with a quite high median saddle. The genera of the closely related family Gephuroceratidae differ from Ponticeras in the acute lateral lobe, which is rounded in Ponticeras .