A pair of arms may have been elongated, which when combined with the long gladius and terminal fins, indicates that the morphology of the earliest vampyropods superficially resembled extant squids. As early as the Mississippian, vampyropods were evidently characterized by the loss of the chambered phragmocone and primordial rostrum-traits retained in belemnoids and many extant decabrachians. This strongly challenges the common hypothesis that vampyropods descended from a Triassic phragmoteuthid belemnoid. Using a Bayesian tip-dated phylogeny of fossil neocoleoid cephalopods, we demonstrate that Syllipsimopodi is the earliest-diverging known vampyropod. Syllipsimopodi is the oldest definitive vampyropod and crown coleoid, pushing back the fossil record of this group by ~81.9 million years, corroborating molecular clock estimates. The specimen possesses a gladius and ten robust arms bearing biserial rows of suckers it is the only known vampyropod to retain the ancestral ten-arm condition. nov., from the Carboniferous (Mississippian) Bear Gulch Lagerstätte of Montana, USA. We describe an exceptionally well-preserved vampyropod, Syllipsimopodi bideni gen.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |