Phylum: Bryozoa
Class: Stenolaemata
Order: Trepostomatida
Family: Monticuliporidae
Genera: Prasopora Nicholson & Etheridge, 1877
Cincinnatian Species: Prasopora falesi, Prasopora simulatrix

Taxonomic Details

Type species: Prasopora grayae (Nicholson & Etheridge, 1877)

Synonyms: Prasoporella Vinassa de Regny, 1915; Prasoporinai Bassler, 1952

Species in Cincinnatian of Ohio, Indiana, Kentucky (

  • Prasopora calycula (James, 1875)
  • Prasopora eccentrica (James, 1882)
  • Prasopora falesi (James, 1884)
  • Prasopora newberryi (Nicholson, 1875)
  • Prasopora nodosa (Ulrich, 1883)
  • Prasopora simulatrix (Ulrich, 1886)

Taxonomic History (Nickles & Bassler, 1900)

  • 1877 Prasopora Nicholson and Etheridge, Jun., Ann. Mag. Nat. Hist., ser. 4, XX, p. 38.
  • 1879 Prasopora Nicholson, Pal. Tabulate Corals, p. 324.
  • 1881 Prasopora Nicholson, Genus Monticulipora, pp. 102, 202.
  • 1882 Prasopora Ulrich, Jour. Cincinnati Soc. Nat. Hist., V. p. 153.
  • 1883 Prasopora Foord, Contr. Micro-Pal. Cambro-Sil., p. 10.
  • 1887 Prasopora Foerste, Bull. Sci. Lab. Denison Univ., II, p. 170.
  • 1889 Prasopora Miller, North American Geol. Pal., p. 201.
  • 1890 Prasopora Ulrich, Geol. Sur. Illinois, VIII, p. 371.
  • 1893 Prasopora Ulrich, Geol. Minnesota, III, p. 244.
  • 1896 Prasopora (in part) Zittel’s Textb. Pal. (Engl. ed.), p. 104.
  • 1896 Prasopora Ulrich, Zittel’s Textb. Pal. (Engl. ed.), p. 273.
  • 1897 Prasopora Simpson, Fourteenth Ann. Rep. State Geologist New York for the year 1894, p. 586.


  • Nickles & Bassler, 1900 (Synopsis of American Bryozoa) places this genus in the family Monticuliporidae, whereas places this genus in the family Mesotrypidae. Museum Victoria ( lists Prasopora under Monticuliporidae as well.) Brett & Baird, 1997 also place Prasopora within Monticulipora. It is possible that it has been moved in recent years, but I have yet to find documentation of this.
  • Holland, UGA Strat Lab: Astrova (1978) considered Aspidopora to be a synonym of Prasopora, but Karklins (1983) retains it as a separate genus
  • Aspidopora has also been synonymised with Prasopora, but this is dubious.

Stratigraphic Occurrences


Geologic Range
Ordovician – Silurian

Geographic Occurrences


Stratigraphic Distribution

Sequences (Formations)

  • C1 Sequence (Clays Ferry/Kope, Lexington/Pt. Pleasant)

Identification in Hand Sample:

  • Zoarium Morphology: Discoidal or hemispherical
  • Zoecia: Prismatic; generally surrounded by angular mesopores; acanthopores present, but not numerous or strong
  • Mesozooids: Small, angular abundant
  • Found adhering to other objects

Species Differentiation

Published Description

Holland (UGA Strat Lab, 2013):

  • Prasopora has a discoid to hemispherical colony shape. Zooecia contain cystiphragms in overlapping series connected by diaphragms. Mesozooids are small, with numerous diaphragms.

McFarlan (1931):

  • Zoarium more or less hemispherical with concentrically wrinkled epitheca. Zooecia thin-walled and generally surrounded by angular mesopores. Acanthopores when present are never numerous or strong. Prasopora differs from Monticulipora in that Monticulipora has a massive structure and granular acanthopores.

Karklins (1984) :

  • Genus PRASOPORA Nicholson and Etheridge, 1877 Type species.— Prasopora grayae Nicholson and Etheridge 1877, p. 392; “Craighead beds, Craighead Quarry, Ayrshire,” Great Britain. Remarks.— Ross (1967a) emended the concept for the genus Prasopora; her diagnosis for the genus is followed herein.

Nickles & Bassler (1900):

  • Prasopora Nicholson and Etheridge, Jun.: Zoarium massy, usually free, with wrinkled epitheca on the under surface; zooecia prismatic or cylindrical, thin-walled, with cystiphragms, and generally surrounded by angular mesopores; acanthopores sometimes present, but rarely numerous or strong; diaphragms crowded in mesopores.

Foord (1883):

  • Free, or loosely adhering to foreign objects, forming hemispherical masses, or thin expansions, with a wrinkled epitheca covering the lower surface. Tube cylindrical or prismatic, and having one or both sides lined with cystoid diaphragms. Interstitial tubes often completely isolating the proper zooecia, and crossed by numerous diaphragms. Spiniform tubuli sometimes nearly absent, in other cases more numerous.

P. falesi

P. simulatrix