Late Mississippian Productoid BrachiopodsInflatia, Keokukia, andAdairia, Ozark Region of Oklahoma and Arkansas

Abstract

Specimens of the Late Mississippian productoid genera Inflatia and Keokukia from northeastern Oklahoma and northwestern Arkansas, collected from the Boone and “Moorefield” Formations, Hindsville Limestone, and Fayetteville Shale, display morphologic similarities and differences that delineate species and determine their biostratigraphic ranges. Generic assignments are based primarily on internal characters. Systematic descriptions include seven species of Inflatia Muir-Wood and Cooper: Productus inflatus McChesney (the type species), P. cherokeensis Drake, P. clydensis Girty (figured herein for the first time and for which a lectotype is designated), four new species of Inflatia (I. cooperi, I. gracilis, I. pusilla, and I.? succincta), and one species of Keokukia (the type species for the genus, K. sulcata Carter). Also proposed and described is a new genus, Adairia, with its type species Productus (Marginifera) adairensis Drake. All these species of Inflatia, Keokukia, and Adairia have biostratigraphically restricted ranges within the Meramecian and Chesterian sequence in the Ozark region.

New productide brachiopods (Productoidea) from the Carboniferous of Ixtaltepec Formation, Oaxaca, Mexico

“…The specimens have all the features mentioned by Gordon et al, (1993, p. 7) for I . inflata , but the specimens of Ixtaltepec present a slightly larger size.…”

“…muralis , and N . dunbari have been reported from Carboniferous strata in Missouri (Hoare, 1961); Ohio (Sturgeon and Hoare, 1968); Nevada (Beus and Lane, 1969); Oklahoma, Arkansas (Girty, 1909; Gordon and Henry, 1990; Gordon et al, 1993); Nebraska, Kansas (Dunbar and Condra, 1932; Spencer, 1967); Wyoming (Gordon, 1975); or Idaho (Butts, 2007) and their presence in Oaxaca confirms the similarity between the fauna of brachiopods from Ixtaltepec with faunas referred to the Midcontinent. Other invertebrate taxa, including mollusks and crinoids from the Ixtaltepec Formation have similar pattern of paleogeographic distribution (Quiroz-Barroso and Perrilliat, 1997, 1998; Quiroz-Barroso et al, 2000; Villanueva-Olea et al, 2011).…”

“…inflata , but the specimens of Ixtaltepec present a slightly larger size. The species occurs in the Upper Mississippian of United States in Montana (Brewster, 1984), Oklahoma, Arkansas (Gordon et al, 1993), and Idaho (Butts, 2007), as well as in Egypt (Kora, 1995) and Australia (Roberts, 1975). The genus Inflatia is described for the Middle Carboniferous from Brazil, Egypt, Australia and North America.…”

“…lovei by an increased convexity to a half of the total length; absence of spines on the lateral flanks; presence of only four spines on the trail and a shallow depression that differentiates the ears. Inflatia inflata (McChesney) of Fayetteville Shale from Serpukhovian of Arkansas (Gordon et al, 1993) differs from I . coodzavuii by larger size; greatest number of spines parallel to the hinge; most spines on the trail; strongly concave dorsal valve and concentric rugae on the trail.…”

“…coodzavuii by larger size; greatest number of spines parallel to the hinge; most spines on the trail; strongly concave dorsal valve and concentric rugae on the trail. Inflatia cherokeensis (Drake, 1897), of Fayetteville Shale from Serpukhovian of Arkansas (Gordon et al, 1993) is different from I . coodzavuii by the subrectangular form, greater number of spines on the visceral disc, most number of spines in a row parallel to the hinge, spines absent on trail, prominent ears, and ventral sulcus that starts 4 mm of the beak.…”