An entirely new group of Pennsylvanian fishes, belonging to the class Chondrichthyes, is described and their comparative anatomical and phylogenetic relations are discussed.Seven species belonging to five genera are distinguished and placed within the subclass Holocephali as a separate order, Iniopterygia. The iniopterygians are structural, but not phyletic, intermediates between the chimaeroids (as here denned) and the elasmobranchs. Present analysis permits the notion that the holocephalians and the elasmobranchs are sister groups sharing a common ancestor that never possessed a bony dermal armor but an even spread of lepidomorial denticles over the entire skin and the stomodaeum. Iniopterygians and chimaeroids, in turn, appear to be sister groups having evolved from a common ancestor that combined an autostylic jaw suspension with a generalized shark-like dentition.Iniopterygians are presently known only from carbonaceous, sheety shales of the Pennsylvanian basin complex of central North America. IX Logan Quarry PF6661, cf , LQS level J, articulated skeleton, lacking tail fin (XR: LQ237) PF6660, cf , LQS level J, isolated pectoral clasper hooks XR: LQ228)Hajji Hollow PF6587, cf, partly articulated skeleton, incomplete (XR: HH5) Characterization. -Anterior finrays of pectoral fins in males much enlarged and provided with a single file of about 13 fishhook-shaped denticles, diminishing in size distad. Description. -The largest skeletons (i.e., PF6678 or PF6645) are between 30 and 35 cm. in overall length. U.N.S.M. = University of Nebraska State Museum. "XR=X ray plate.
A Campanian fish assemblage is described from the uppermost Blufftown Formation in western Georgia. Fifteen chondrichthyan and eight osteichthyan taxa are identified, virtually all for the first time from the region. The study area represented a transitional zone between the Atlantic and eastern Gulf of Mexico Coastal Plain Provinces during the Late Cretaceous, and shows faunal relationships with both.
Acid etching of a shell-bed zone has enabled us to reclaim numerous fish remains for the Niobrara Formation (Coniacian) of east-central Saskatchewan, including teeth of the following new taxa: Odontaspis saskatchewanensis sp.nov., Synodontaspis lilliae sp.nov., and Cretomanta canadensis gen. et sp. nov. These are associated with remains of Ptychodus cf. Ptychodus rugosus Dixon, Cretodus sp., Cretoxyrhina mantelli (Agassiz), Squalicorax falcatus (Agassiz), and Rhinobatos sp. This is the most northern occurrence from Canada of a Niobrara-age selachian fauna.
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