Evopharciceras, Korn & Bockwinkel, 2021

Korn, Dieter & Bockwinkel, Jürgen, 2021, The pharciceratid ammonoids from the Roteisenstein Formation of Dillenburg (Cephalopoda, Ammonoidea), European Journal of Taxonomy 771, pp. 1-79 : 36

Genus Evopharciceras gen. nov.

urn:lsid:zoobank.org:act:60AADDAB-845B-44EB-A858-DBB8FD5EA16A

Type species

Evopharciceras formosum gen. et sp. nov.

Diagnosis

Pharciceratinae with evolute juvenile and adult stage, whorl profile moderately to strongly depressed. Adult stage with weakly depressed whorl profile; venter rounded. WER low or moderate. Juvenile stage sometimes finely ribbed, adult stage with weak to strong, single or paired ventrolateral grooves. Suture line with wide external lobe, short E 1 lobe, high median saddle, deep lanceolate E 2 lobe, large, deep lanceolate lateral lobe, two outer and two inner umbilical lobes. Suture line formula (E 2 E 1 E 2) L U 2 U 4: U 3 U 1 I.

Included species

Evopharciceras formosum gen. et sp. nov., Rhenish Mountains; Pharciceras evolvens Bockwinkel, Becker & Ebbighausen, 2009 , Anti-Atlas.

Remarks

The new genus differs from Pharciceras first in the conch geometry with a high umbilicus/ diameter ratio in all stages, which in Pharciceras decreases in the course of ontogeny. Second, the two genera are distinguished in the form of the external lobe: in Pharciceras the median saddle is low and usually does not reach half the height of the external lobe; in Evopharciceras gen. nov., however, the median saddle is very high and reaches more than three-quarters the height of the external lobe.