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| Clavusodens mcginnisi Hodnett, Egli, Toomey, Olson, Tolleson, Boldon, Tweet & Santucci, 2025 Netsepoye hawesi Lund, 1989 Art by Benji Paysnoe. |
Abstract
Obruchevodid petalodonts are rare small chondrichthyans known from nearly complete to partial skeletons from the Upper Mississippian (Serpukhovian) Bear Gulch Limestone of central Montana and isolated teeth from the Upper Mississippian Bangor Limestone of northern Alabama. New records of obruchevodid petalodonts are presented here from the Middle Mississippian (Viséan) Joppa Member of the Ste. Genevieve Formation at Mammoth Cave National Park, Kentucky. Obruchevodids are here represented by multiple teeth of a new taxon, Clavusodens mcginnisi n. gen. n. sp., and a single tooth referred to ?Netsepoye sp. Clavusodens mcginnisi n. gen. n. sp. is characterized by teeth with pointed mesiodistal and lingual margins and more robust chisel-like cusps on the anterolateral and distolateral teeth. The suggestion that obruchevodid petalodonts evolved to inhabit complex reef-like environments and other nearshore habitats with a feeding ecology analogous to extant triggerfish is explored and discussed.
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| Netsepoye hawesi; (1) Reconstruction of the skeleton of Netsepoye hawesi based on holotype CM 46092 from the Heath Formation of Montana; (3) revised reconstruction of the upper and lower dentition of N. hawesi. |
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| Tentative reconstruction of Clavusodens mcginnisi n. gen. n. sp. (modeled after Netsepoye) feeding on phyllocarid crustaceans on the sea floor of a crinoidal forest from the Joppa Member of the Ste. Genevieve Formation, with the ctenacanth Glikmanius careforum swimming overhead. Art by Benji Paysnoe. |
Systematic paleontology
Class Chondrichthyes Huxley, 1880
Subclass Euchondrocephali Lund and Grogan, Reference Lund and Grogan, 1997
Order Petalodontiformes Patterson, 1965
Family Obruchevodidae Lund, Grogan, and Fath, 2014
Genus Clavusodens new genus
Occurrence: Mammoth Cave National Park, Kentucky, Middle Mississippian (upper Viséan) Joppa Member, Ste. Genevieve Formation.
Etymology: Latin, clavus (nail), and dents (tooth); in recognition of the nail-like shape of the distal lateral teeth.
Clavusodens mcginnisi new species
Etymology: In honor of retired National Park Service superintendent and naturalist David McGinnis for his leadership in paleontological resource stewardship during his 39-year career beginning at Mammoth Cave National Park.
John-Paul M. Hodnett, H. Chase Egli, Rickard Toomey, Rickard Olson, Kelli Tolleson, Richard Boldon, Justin S. Tweet and Vincent L. Santucci. 2025. Obruchevodid petalodonts (Chondrichthyes, Petalodontiformes, Obruchevodidae) from the Middle Mississippian (Viséan) Joppa Member of the Ste. Genevieve Formation at Mammoth Cave National Park, Kentucky U.S.A. Journal of Paleontology. First View. DOI: doi.org/10.1017/jpa.2024.40
Fossil Research Identifies New Shark Species at Mammoth Cave National Park
The small shark named Clavusodens mcginnisi, or “McGinnis’ nail tooth,” only measured 3-4 inches in length.
Non-technical Summary: New records of two species of obruchevodid petalodont chondrichthyans are described from the Middle Mississippian Joppa Member of the Ste. Genevieve Formation from Mammoth Cave National Park, Kentucky. The two species are Clavusodens mcginnisi new genus new species, which had more robust crushing-type teeth for its kind, and ?Netsepoye sp., which is based on a partial tooth. These two records represent the oldest known obruchevodid petalodonts, which previously were known from younger Mississippian-age rocks in Montana and Alabama. Obruchevodid petalodonts were among the most specialized cartilaginous fishes during the Mississippian, potentially adapted to live in complex reef and reef-like habitats.
