A new petalodont chondrichthyan from the bear gulch limestone of montana, USA, with reassessment of Netsepoye hawesi and comments on the morphology of holomorphic petalodonts

  title={A new petalodont chondrichthyan from the bear gulch limestone of montana, USA, with reassessment of Netsepoye hawesi and comments on the morphology of holomorphic petalodonts},
  author={Eileen D. Grogan and Richard Lund and Mojtaba Fath},
  journal={Paleontological Journal},
A new holomorphic petalodont from the Bear Gulch Limestone, Obruchevodus griffithi, is described and features of the related Netsepoye hawesi are reinterpreted. Comparison of these taxa with the holomorphic petalodonts Janassa bituminosa, Belantsea montana, and Siksika ottae provide insight into petalodont anatomical form and variation. All holomorphic material supports holostyly and nested, subcranial branchial arches. Teeth occur in families with linguo-labial replacement but alignment of… 

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New petalodonts (Chondrichthyes) from the Upper Mississippian Bear Gulch Limestone (Namurian E2b) of Montana

The dental morphology and histology of the clade containing Tanaodus, Harpacodus, and Lisgodus support a hypothesis of sister group relationships with the Petalodontiformes as restricted.

On a dentition of Polyrhizodus (Chondrichthyes, Petalodontiformes) from the Namurian bear gulch limestone of Montana

Abstract A partial dentition of Polyrhizodus is described from the Namurian A Bear Gulch Limestone Member, Heath Formation, Big Snowy Group of central Montana. The dentition is interpreted as

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Relationships of the Chimaeriformes and the basal radiation of the Chondrichthyes

  • R. LundE. Grogan
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    Reviews in Fish Biology and Fisheries
  • 2004
Morphological examination of fossil chondrichthyans indicates that the plesiomorphous state of the gnathostome suspensorium is autodiastylic and that complex labial cartilages are primitive and likely to have been critical to the mechanical architecture of the first jaws.

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Five new specimens ofCtenoptychius korniWeigelt 1930 found in the years between 1984 and 1994 have extended the knowledge of the petalodonts. A new description is given because the original specimen

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