CLADID CRINOIDS FROM THE EARLY MISSISSIPPIAN CUYAHOGA FORMATION OF OHIO

A new study of cladid crinoids from the Cuyahoga Formation at Richfield and Lodi, Ohio, including those studied by Edgar Roeser in an unpublished thesis (M.S., U. Cincinnati, 1986), shows a total of 15 species. These include two cyathocrinids: Cyathocrinites cf. iowensis (Owen & Shumard, 1850) and C. cf. lamellosus (White, 1862); three primitive dendrocrinids: Cradeocrinus warreni Laudon et al., 1952, Goniocrinus angulatus Laudon et al., 1952, and Atelestocrinus sp.; and 10 advanced dendrocrinids: Abrotocrinus sp., Acylocrinus lyriope (Hall, 1863), Ascetocrinus subcarinatus (Hall, 1864), Cosmetocrinus crineus (Hall, 1863), Histocrinus aegina (Hall, 1863), Linocrinus merope (Hall, 1864), Linocrinus paternus (Hall, 1863), Pachylocrinus subtortuosus (Hall, 1863), Paracosmetocrinus richfieldensis (Worthen, 1882), and Tropiocrinus simplex (Hall, 1858).

The Cuyahoga Fm. in northern Ohio is Kinderhookian in age (reviewed in Matchen & Kammer, 2006, Sed. Geol., 191:89). The cladids are consistent with this age, although this fauna documents earliest new occurrences of Atelestocrinus, Acylocrinus, Ascetocrinus, Cosmetocrinus, and Tropiocrinus. The two cyathocrinids range elsewhere from the late Kinderhookian Banff and Lodgepole fms. to the early Osagean Burlington Ls. The primitive dendrocrinids C. warreni and G. angulatus also occur in the Banff Fm. For the advanced dendrocrinids, eight species are endemic, but T. simplex also occurs in the Burlington Ls. Several of the endemic species appear closely related to congeners in both the late Kinderhookian Gilmore City and Lodgepole fms., and the early Osagean Burlington Ls., although they are not definitive for either age.

Similarities between the Cuyahoga Fm. primitive cladids in eastern North America with those of the Gilmore City, Lodgepole, and Banff fms. supports an open connection of the epicontinental sea across the Transcontinental Arch during the late Kinderhookian. The advanced cladids were in the vanguard of an extensive evolutionary radiation within this group during the Early Mississippian resulting in their affinities with younger Osagean faunas. The taphonomy (obrution deposits) of the cladids is very similar to the late Osagean Crawfordsville, IN, fauna also found in a siliciclastic shelf/marine deltaic facies.