Protarea richmondensis

Classification
Phylum: Cnidaria
Class: Anthozoa
Subclass: Tabulata
Order: Heliolitida
Family: Coccoserididae
Genus: Protarea
Species: Protarea richmondensis (Foerste, 1909)

Taxonomic Details

Taxonomic History

  • 1909 Protarea richmondensis Foerste, Bull. Denison Univ., 14, p. 210; p. 308, pl. 7, fig.8.
  • 1924 Protarea richmondensis Foerste, Upper Ordovician faunas in Ontario and Quebec, p. 73, pl. I, fig. 4.

Stratigraphic Occurrences

P.richmondensis_strat

Geographic Occurrences

Map point data provided by iDigBio.

Stratigraphic Description

Sequences (Formations)

  • C6 Sequence (Elkhorn)
  • C5 Sequence (Whitewater, Liberty, Waynesville)

Identification in Hand Sample

  • Always encrusting another species of marine organism
  • Characterized by the presence of 12 distinct septa, scarcely reaching half the distance to the center
  • Corallites (Individual coral polyp skeletons) are all of equal size, 4-5mm
Protarea_richmondensis_800px

Protarea richmondensis from Whitewater formation, not georeferenced (OUIP 1937)

Published Description

Holland (UGA Strat Lab, 2013):

  • Always forms a low, encrusting mat on other shells

McFarlan (1931) :

  • Corallum an encrusting layer about 2 mm. thick. Corallites polygonal, of about equal size, 4 in 5 mm. Septa 12, scarcely reaching half the distance to the center. In some associated specimens, the septa are replaced by papillae giving the appearance of a Protares incrusted by Labechia papillata. P. richmondensis makes its appearance in the Clarksville member of the Waynesville in Ohio and is common in both Liberty and Whitewater. In Kentucky, it is characteristic of the Liberty on both sides of the arch.

Foerste (1909) :

  • The type of this species, here figured, is characterized by the presence of 12 distinct septa. It was found in the Whitewater beds, at Tates hill, east of Dayton, Ohio. This form occurs at the same horizon at numerous localities in Ohio and Indiana. In the Liberty beds, it is common from Ohio and Indiana as far south as central Kentucky. It makes its first appearance in the upper part of the Middle or Clarksville division of the Waynesville bed, in Clinton and Warren counties, Ohio, and occurs also in the Upper or Blanchester division.
  • Typical specimens of Protarea richmondensis are associated with other specimens in which the septa are much less distinct. They appear to be replaced by papillae, those along the margins of the calyces being larger, those at the base being smaller. At times these papillate specimens resemble growths of Protarea richmondensis covered by a thin film of so-called Stromatapora or Labechia papillata. However, if this were the case, the so-called Labechia papillata should be common on other fossils at the same localities, which is not the case. This papillate form of Protarea is illustrated by figures 9A and 9B, on plate V, in volume XIV of this Bulletin, and also on plate X, figs. 2A, and 2B accompanying the present article.
  • The most southern locality at which Protarea richmondensis has been found is at Raywick, in Marion county. On the eastern side of the Cincinnati geanticline, it has been found as far south as directly east of Wyoming, in the southwestern part of Fleming county. At both localities, the horizon was the Liberty bed.

Foerste (1924):

  • Thin papillate stroma with about four shallow, rounded depressions or calyces in a width of 5 mm., papillae along the walls of these depressions tending to radiate inward for a short distance like septa, and in typical forms of this species fairly distinct and about twelve in number. Specimens originate as a thin papillate stroma covering the surface of some shell or other solid support. As this stroma grows thicker, some of the papillae increase in height around central areas of depression, or calyces; these areas of depression approximately of the same diameter and depth, both the depressions and the intervening spaces papillate, the papillae being coarser on the spaces between calyces. Only the thicker specimens show a tendency toward the arrangement of the papillae along septal lines, but even the thickest of these rarely attain 3 mm. No intermediate tubules with transverse dissepiments known in this species, such as those figured by Lambe for Protarea vetusta (Hall).
  • In Ohio, Indiana, and Kentucky, P. richmondensis ranges from the base of the Clarksville to the top of the Whitewater, where the type was secured. This species is known also known from the Richmond in Tennessee, Illinois, Minnesota, and other western localities. The writer has never seen P. vetusta, from the Trenton and Black River of New York and Canada in the form of thin incrustations on other bodies, but it must have grown on something. The latter occurs in much thicker growths, 10 to 20 mm. thick, built up from a succession of lamellar expansions, many of them partly separated by argillaceous material, a feature unknown in the Richmond species. The spaces between the corallites are occupied by a massive substance in which Lambe detected minute tubules crossed by dissepiments. the septa, in cross-sections, are clearly defined. The species was described from the lower Trenton, near its junction with the Black River limestone at Watertown, New York, but excellent specimens occur also in the Trenton at Nepean point (Ottawa) and elsewhere in Ontario.
  • Locality and Horizon: Found on the west side of Gore bay (No. 8535) and at Clay cliffs in the Meaford. Also in the Whitewater member of the Richmond on Drummond Island, and on Bay de Noc peninsula, northern Michigan.