Belongs within: Orthoceratia. The Lower to Middle Ordovician Baltoceratidae were a family of relatively large orthoconic early cephalopods. Characters (from Furnish & Glenister 1964): Smooth, longiconic orthocones with moderately large marginal siphuncle, orthochoanitic septal necks and thin homogenous connecting rings. Baltoceratidae [Cochlioceratidae]K93 |–Murrayoceras Foerste 1926FG64 | `–*M. murrayi (Billings 1857) [=Orthoceras murrayi]FG64 |–Ogygoceras Ulrich, Foerste… Continue reading Baltoceratidae
Tag: Cephalopoda
Troedssonellidae
Belongs within: Orthoceratia. The Troedssonellidae were a Lower to Middle Ordovician family of orthocerid cephalopods that formed endocones in the apical part of their siphuncles. Characters (from Sweet 1964): Siphuncle suborthochoanitic; continual endosiphuncular lining of parietal deposits prolonged adapically to form endocones. Troedssonellidae [Buttsoceratidae, Troedssonellina]S64 |–Tajaroceras wardae Hook & Flower 1976K93 |–Moridunoceras Evans 2005KE19 |–Oxfordoceras… Continue reading Troedssonellidae