Constellaria emaciata

Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Cystoporata
Genus: Constellaria
Species: Constellaria emaciata Hayes & Ulrich, 1903

Stratigraphic Occurrences

C.emaciata_strat

Geographic Occurrences

Map point data provided by iDigBio.

Stratigraphic Distribution

Sequence (Formation)

  • C1 Sequence (Fulton, Cynthiana)

Identification in Hand Sample
C. emaciata_diagnostic

  • Zoarium Morphology: Erect, flattened branches or fronds (frondose)
  • Zoecia: polygonal
  • Mesozooids: More numerous in maculae
  • Monticules: Surface with depressed stellate (star-shaped) maculae
  • Spaces between rays elevated and occupied by rows of close apertures

Diagnosis: Same as C. florida, but dwarfed in growth with sharper and narrower maculae (McFarlan)

Constellaria_emaciata_800px

Constellaria emaciata from Arnheim Formation of Butler County, Ohio (OUIP 1082)

Published Descriptions

McFarlan (1931):

  • This species agrees with C. florida in all internal characters but differs in the dwarfed growth and the more sharply and more narrowly rayed maculae. “The usual growth obtaining in C. florida is of rather broad, flat branches, seldom less than 10 mm. in breadth and 3 or 4 mm. in thickness dividing rather regularly at intervals of several centimeters. C. florida emaciata, however, is dwarfed in growth, the branches being usually rounded and from 3 to 5 mm. in diameter but sometimes reaching a breadth of 6 or 7 mm. Division occurred at short, irregular intervals, and an entire zoarium consisted of a small clump of closely interwoven narrow branches instead of a rather broad expansion as in C. florida” (Ulrich and Bassler, 1904a, p. 38).

Nickles (1905):

  • Zoarium consisting of small fronds, or of rounded or compressed branches, about 3 mm. in thickness and from 4 to 7 mm. in breadth, and from 15 to 30 mm. in height. Division occurred at short, irregular intervals, and an entire zoarium consisted of a small clump of closely interwoven narrow branches. The surface is marked by small, stellate maculæ, usually well elevated, each consisting of from 5 to 8 narrow ridges radiating from a center. Apertures with a narrow, distinctly marked rim. Mesopores very numerous, especially between the stellate maculæ. The zoœcia have diaphragms about 3 tube diameter apart. The mesopores are closely tabulated.
  • Occurrence:—A very common form in the Winchester group. Specimens were collected from Lexington, Winchester, Pleasant Valley, Lair and other points. The Kentucky examples form wider fronds, on the whole than the Tennessee forms, upon which this species or variety is based, but seem to differ in no essential particular. The Tennessee forms are stated to occur at the top of the Bigby limestone at Columbia, Tenn., and in the shaly parts of the Catheys limestone.

Ulrich & Bassler (1904):

  • This subordinate name is proposed for a very abundant fossil of the Bigby limestone of Tennessee. The form agrees in all essential internal features with the Lorraine Constellaria florida, and differs only in growth and in the arrangement and size of the “stars”. The usual growth obtaining in C. florida is of rather broad, flat branches, seldom less than 10 mm. in breadth and 3 or 4 mm. in thickness, dividing rather regularly at intervals of several centimeters. C. florida emaciata, however, is dwarfed in growth, the branches being usually rounded and from 3 to 5 mm. in diameter, but sometimes reaching a breadth of 6 or 7 mm. Division occurred at short, irregular intervals, and an entire zoarium consisted of a small clump of closely interwoven narrow branches, instead of a rather broad expansion as in C. florida. Another difference is in the shape of the stellate maculae which, although of about the same size in both species and variety, are most sharply and narrowly rayed in the variety than in the species.