Paleschara

Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Cryptostomata
Genera: Paleschara Hall, 1874

Taxonomic Details

Type Species: Paleschara incrustans (Hall, 1874)History: (Nickles & Bassler, 1900)

  • 1874 Paleschara Hall, Twenty-sixth Ann. Rep. New York State Museum, p. 107.
  • 1882 Paleschara Ulrich, Jour. Cincinati Soc. Nat. Hist., V, p. 157.
  • 1887 Paleschara Hall and Simpson, Pal. New York, VI, p. xviii.
  • 1889 Paleschara Miller, North American Geol. Pal., p. 313.
  • 1899 Paleschara Grabau, Bull. Buffalo Soc. Nat. Sci., VI, p. 170.

Geologic Range
Ordovician – Devonian

Stratigraphic Occurrences

Paleschara_strat

Geographic Occurrences

Stratigraphic Description

Sequences (Formations)

  • C5 Sequence (Waynesville)

Identification in Hand Sample:

  • Has a sheet-like colony form that is incrusting or parasitic
  • Thin, short zooecial tubes that lack diaphragms or other structures
  • Possesses cells that are larger and less irregularly arranged compared to relative species
  • Cells radiate from a number of starting points
  • Corners of cells are slightly thickened

Paleschara sphaerion from the Niagara Group of Waldron Indiana (CMC 13186)

Published Description

Pitrat and Rogers (1978):

  • Bryozoan that produces colonies which encrust the valves of Spinocyrtia clintoni. Paleschara has a sheet-like colony form which may cover as much as half the brachiopod’s shell surface. Paleschara occurs considerably more commonly on the pedicle valve of Spinocyrtia than on the brachial valve. It is clear that these bryozoans merely used this brachiopod as a substrate.

Treatise on Invertebrate Paleontology. Part G (1953):

  • Thin parasitic expansions upon other fossils, especially cephalopod shells. Zooecial tubes thin, very short, without diaphragms or other structures; apertures direct, angular oblong, with groups of larger ones at regular intervals.
  • May belong among cheilostomes

Kemp (1912):

  • Zoarium incrusting or parasitic mostly upon cephalopod shells, covering the entire surface, consisting of a relatively large oblong (mostly irregularly pentagonal or hexagonal) cells ( 9 to 12 in space 10 mm) with thin, low walls. …this species has larger and less irregularly arranged cells than are found in its chronologically nearest relatives. Paleschara occurs in the Helderbergian, Niagaran, Richmondian and rarely in the Eden. With this species, its range is extended downward to early Trenton.
  • This bryozoan forms a network so delicate it is just barely visible with the naked eye. The cells are all longer than wide and form a continuous layer on the shell; they radiate from a number of starting points, being apparently composed of different confluent colonies. The corners of the cells are mostly slightly thickened and in some places elevated into distinct tubercles.

Hall (1887):

  • Zoarium consisting of thin expansions, usually incrusting other bodies. Cells polygonal, in contact, with frequent maculae of larger cells.