CHONDRICHTHYAN TAXA ACROSS THE CARBONIFEROUS-PERMIAN BOUNDARY (COUNCIL GROVE GROUP: RED EAGLE FORMATION) OF KANSAS

The Tuttle Creek Lake Spillway near Manhattan, Kansas, exposes outcrops of the Red Eagle Formation that provide a detailed record of the Carboniferous-Permian boundary in North America. The Red Eagle is composed of the Carboniferous-Age Glenrock Limestone at the base, followed by the Permian-Age Bennett Shale, and capped by the Howe Limestone. Since marine vertebrate fossils have been recovered from both the Glenrock and Bennett members, this locality offers a rare opportunity to observe marine vertebrate faunal change across the Carboniferous-Permian boundary. From comparisons of separate formations across large stretches of geography and time, it is known that symmoriiform genera such as Denaea and Stethacanthus represent a significant portion of small to mid-sized predators in the early Permian. Large-bodied ctenacanthiform sharks such as Glikmanius emerged in the Carboniferous and persisted through the Permian as well. Finally, Cooleyella and other neoselachian fauna traverse not only the Carboniferous-Permian boundary, but the Neoselachii endure to become the dominant elasmobranch clade up through the present day. At the Tuttle Creek locality, fossil remains of Denaea sp., Stethacanthus sp., Glikmanius myachkovensis, and Cooleyella sp. provide direct, observable evidence of these deduced biostratigraphic trends that propagated across the Carboniferous-Permian boundary and beyond.