Genus Parvihebetoceras Kröger, 2007

Type species

Parvihebetoceras wahli Kröger, 2007, from the Porkuni Formation, Hirnantian, Porkuni, Estonia, by monotypy.

Diagnosis

Small longiconic orthocones with slightly depressed or circular cross section; truncated adult shell nearly tubular with few, closely spaced, shallow concave septa possessing straight, directly transverse sutures; conch surface smooth or ornamented with faint growth lines; septum of truncation occurs at a conch diameter of about four to five millimeters; adult cross section diameter approximately seven millimeters; siphuncular diameter approximately one-tenth of conch diameter; siphuncle positioned between centre of conch and conch margin; siphuncular diaphragm present slightly adorally of the septum of truncation; septal necks are asymmetric, more elongated at ventral side, achoanitic and suborthochoanitic in juvenile growth stages, suborthochoanitic in adult growth stages; apex bullet-shaped, slightly cyrtoconic, cicatrix present, with diameter at first septum approximately 1.4 mm; no endosiphuncular deposits are known. (Adopted from Kröger 2007.)