Zygospira kentuckiensis

Classification
Phylum: Brachiopoda
Class: Rhynchonellata
Order: Atrypida
Family: Anazygidae
Genus: Zygospira
Species: Zygosprira kentuckiensis (James)

Taxonomic Details

Taxonomic History:

  • 1895 Zygospira kentuckiensis Hall and Clarke, Pal. New York, 8, pt. 2, pl. 54, figs. 11, 15, 16.
  • 1924 Zygospira kentuckiensis Foerste, Upper Ordovician faunas in Ontario and Quebec, pl. 10, fig. 20 a, b, c; pl. 15, figs. 1 a-p; 2 a, b; 4 a, b, c.

Stratigraphic Occurrences

Z.kentuckiensis_strat

Geographic Occurrences

Map point data provided by iDigBio.

Stratigraphic Description

Sequences (Formations)

  • C5 Sequence (Waynesville)

Identification in Hand Sample

  • Plications are subequal in size
  • Pedicle valve is not distinctly limited laterally
  • Median depression of the brachial valve anteriorly is broad and relatively shallow
  • Plications and grooves tend to be more nearly equal in size, especially along the median parts of both valves
  • Distinguished from similar species by a greater number and smaller size of its plications

Zygospira kentuckiensis from the Fairview formation of Cleves, Ohio (OUIP 332)

Published Description

McFarland (1931):

  • A large species attaining a length of 14-15 mm., distinguished from Z. cincinnatiensis by the greater number and smaller size of the plications.

Foerste (1924):

  • Zygospira kentuckiensis appears to be larger and more vigorous than Z. modesta (Plate 10, fig. 21 a, b) with a tendency on the part of both plications and grooves to be more nearly equal in size, especially along median parts of both valves.
  • Four plications occupy flattened median part of pedicle valve, and from flattened part the shell slopes away laterally rather angularly. Median groove, along middle of flattened area, slightly broader than other grooves, but in many difference is almost imperceptible. About eight lateral plications on each side of flattened part. Brachial valve convex posteriorly, but anteriorly there is a broad and shallow median depression. Specimens attain a length of 13 mm. and a width of 15 mm.; but average a length of 11 mm., and width of 12.5 mm.
  • Locality and Horizon. Clay cliffs, Manitoulin island in Meaford (No. 8512), 2 miles southwest of Wekwemikong; in the gully north of the lighthouse of Manitowaning; southwest of McLean hill in the open field 3 miles southwest of Little Current; south of Kagawong; and on the hillside west of Gore bay.

Foerste (1917):

  • Zygospira kentuckiensis…In all of these forms the plications are subequal in size, the median area of the pedicle valve is not distinctly limited laterally, and the median depression of the brachial valve anteriorly is broad and relatively shallow.

Kindle and Williams (1917):

  • Zygospira recurvirostris turgida, var. nov., Figs. 15 A, B, C, evidently is closely related to Zygospira recurvirostris (Hall) and Zygospira kentuckiensis James. In all of these forms the plications are subequal in size, the median area of the pedicel valve is not distinctly limited laterally, and the median depression of the brachial valve anteriorly is broad and relatively shallow.