Dawsonoceras Hyatt, 1884

Kröger, Björn, 2013, The cephalopods of the Boda Limestone, Late Ordovician, of Dalarna, Sweden, European Journal of Taxonomy 41, pp. 1-110 : 30

Genus Dawsonoceras Hyatt, 1884

Type species

Orthoceras annulatum Sowerby, 1816 , Wenlock Series, Coalbrookdale, Shropshire, England; by original designation.

Diagnosis

Slender, circular or slightly compressed orthocones with symmetrically curved septa and straight transverse sutures; sutures parallel to the annulations in each groove of the annulations; annulations regularly spaced, with fine transverse ornamentation or growth lines; growth lines in some species festooned. In some species with longitudinal ridges that may form nodes at the ridges of the annulations; siphuncle subcentral in early growth stages, central in late growth stages, narrow, but expanded within the chambers; septal necks short suborthochoanitic to achoanitic. Incipient annulosiphuncular deposits.

Remarks

The diagnosis is adopted from Kröger & Isakar (2006). There the genus was revised and discussed in detail.