thumbnail

Some silicified strophomenacean brachiopods from the Ordovician of Kentucky, with comments on the genus Pionomena

Professional Paper 1066-L

By:

Links

Abstract

Eight species of silicified strophomenid brachiopods from Ordovician rocks of Kentucky are described in this report. Seven species are strophomenaceans, including six from the Middle Ordovician and one, Leptaena kentuckiana n. sp., from the Upper Ordovician. Pionomena recens Neuman from the Middle Ordovician is referred to the Davidsoniacea. Three of these species also occur in the Middle Ordovician of the northern Mississippi Valley region. Rafinesquina is abundant at many localities throughout the Middle Ordovician section of Kentucky. Other silicified strophomenaceans are rare and have been recovered only from the lower part of the Middle Ordovician section of the area. Oepikinia minnesotensis has a high degree of polymorphism of outline shape, profile, and ornament. Some Middle Ordovician species heretofore placed in Strophomena are reassigned to Tetraphalerella. Furcitella and Holtedahlina are differentiated only by the presence of a prominent fold in adult valves of Holtedaklina because a bifid dorsal medial ridge occurs in species of both genera and because the transmuscle ridges of both genera are similar. The possession by Pionomena recens of a perideltidium, dentifers, dorsal medial node, and impunctate shell indicates relationship of this genus to the Davidsoniacea.

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Some silicified strophomenacean brachiopods from the Ordovician of Kentucky, with comments on the genus Pionomena
Series title:
Professional Paper
Series number:
1066
Chapter:
L
Edition:
-
Year Published:
1982
Language:
ENGLISH
Description:
p. L1-L30