A new euchondrocephalan chondrichthyan (Chondrichthyes, Euchondrocephali) from the Middle Mississippian (Viséan) Joppa Member of the Ste. Genevieve Formation at Mammoth Cave National Park, Kentucky, USA and a reassessment of the Lower Mississippian (Tournaisian-Viséan) "Helodus" coxanus Newberry, 1897
Hodnett JM, Toomey R, Sues H, Santucci V, Tolleson K, Tweet J. 2025. A new euchondrocephalan chondrichthyan (Chondrichthyes, Euchondrocephali) from the Middle Mississippian (Viséan) Joppa Member of the Ste. Genevieve Formation at Mammoth Cave National Park, Kentucky, USA and a reassessment of the Lower Mississippian (Tournaisian-Viséan) "Helodus" coxanus Newberry, 1897. Pages 87–93. In Lucas SG, Morgan GS, Hunt AP, Lichtig AJ (ed). Fossil Record 10. New Mexico Museum of Natural History and Science. Albuquerque, New Mexico. New Mexico Museum of Natural History and Science Bulletin. Bulletin 100
A new euchondrocephalan chondrichthyan, Macadens olsoni gen. et sp. nov., is identified from the Middle Mississippian (Viséan) Joppa Member, Ste. Geneveive Formation from Mammoth Cave National Park, Kentucky. Macadens olsoni shares various morphological traits with the enigmatic taxon “Helodus” coxanus Newberry 1897, from the Lower-Middle Mississippian (Tournaisian) Keokuk Limestone of Iowa. These morphological traits of a lower symphyseal on a narrow mesiodistally elongated base with rounded and blunt cusps are not seen in Helodus and we create a new genus name and combination, Rotuladens gen. nov. coxanus Newberry 1897. Macadens and Rotuladens are proposed as members of unnamed clade with a sister-group relationship with Eugeneodontiformes.
- Type
- Book Chapter
- Authors
- Hodnett, John-Paul; Toomey, Rickard; Sues, Hans-Dieter; Santucci, Vincent; Tolleson, Kelli; Tweet, Justin
- Units
- MACA
- Keywords
- paleontology
- Subjects
- Ecological Framework: Geology and Soils | Paleontology | Paleontology