Stictopora

Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Cryptostomata
Genus: Stictopora Hall, 1847
Cincinnatian Species: Stictopora neglecta

Taxonomic Details

Type Species: Stictopora fenestrata (Hall, 1847)
Synonyms:

  • Dicranopora (Ulrich, 1882)
  • Hemidictya (Coryell, 1921)
  • Rhinidictya (Ulrich, 1882)
  • Sulcopora (d’Orbigny, 1849)

History: (Nickles & Bassler, 1900)

  • 1847 Stictopora Hall, Pal. New York, I, p. 73.
  • 1879 Stictopora (in part) Hall, Twenty-eighth Ann. Rep. New York State Mus., p. 122.
  • 1882 Stictopora (in part) Hall, Eleventh Ann. Rep. Indiana Geol. Nat. Hist., p. 247.
  • 1889 Stictopora (in part) Miller, North American Geol. Pal., p. 323.
  • 1897 Stictopora (in part). Simpson, Fourteenth Ann. Rep. State Geologist New York for the year 1894, p. 605.
  • Not Stictopora Eichwald, Lethaea Rossica, I, p. 390.
  • Not Stictopora Ulrich, Jour. Cincinnati Soc. Nat. Hist., V, 1882, pp. 152, 168 (=Rhinidictya)
  • Not Stictopora Hall and Simpson, Pal. New York, VI, 1887, p. xx (=Cystodictya)
  • Not Stictopora Ulrich, Geol. Surv. Illinois, VIII, 1890, p. 388 (=Rhinidictya)
  • Not Stictopora Grabau, Bull. Buffalo Soc. Nat. Sci., VI, 1899, p. 172 (=Cystodictya)
  • Observation: This name has been applied to a number of unrelated forms. A description and figures of the internal structure of the genotype have never been published. Thin sections of S. elegantula show that the genus is related to both Stictoporella and Taeniodictya. It resembles the former in the long primitive portion of the zooecial tubes, but is distinguished by the well-marked peristomes and absence of mesopores. From the latter it differs in the absence of hemisepta, the presence of peristomes, and the long primitive portion of the zooecial tube.

Species found in the Cincinnatian, USA

  • Stictopora emacerata (Nicholson, 1875)
  • Stictopora fenestrata (Hall, 1847)
  • Stictopora fidelis (Ulrich, 1886)
  • Stictopora fragilis (Billings, 1866)
  • Stictopora internodia (Miller & Dyer, 1878)
  • Stictopora lata (Ulrich, 1882)
  • Stictopora meeki (James, 1878)
  • Stictopora neglecta (Ulrich, 1893)
  • Stictopora parallela (James, 1878)

Stratigraphic Occurrences

Stictopora_strat

Geologic Range
Early Ordovician – Early Silurian

Geographic Occurrences

Map point data provided by iDigBio.

Stratigraphic Description

Sequences (Formations)

  • C6 Sequence (Upper Whitewater, Elkhorn)
  • C5 Sequence (Lower Whitewater, Liberty, Waynesville)
  • C4 Sequence (Arnheim)
  • C2 Sequence (Fairview: Fairmount, Mount Hope)
  • C1 Sequence (Clays Ferry/Kope: McMicken, Southgate, Economy, Fulton)

Identification in Hand Sample:
Stictopora_diagram2

  • Zoarium Morphology:Branching or unbranching, sheet-like to frondose, sometimes anastomosing; narrowly compressed branches
  • Zooecia: Elliptical to subrectangular; arranged in multiple, long, straight rows
  • Mesozooids:
  • Monticules: Common, generally scattered in zoaria.
  • Maculae: Randomly spaced, consist of irregular zooecia maculae more common in species having wide zoarial branches.

Published Description

Steve Holland (2013, UGA strat lab):

  • Branched zooarium, sometimes unbranched, sheetlike to frondose, rarely anastomosing with large openings in zooarium. Elliptical to subrectangular zooids arranged in multiple, long, straight rows.

McFarlan (1900):

  • Genus Rhinidictya (Synonym of Stictopora): Zoarium dendroid, of narrow, compressed, parallel edged branches; continuous with an expanded base
  • Apertures in longitudinal rows

Treatise on Invertebrate Paleontology. Part G (1983):

  • Zoarium branched or unbranched and explanate, rarely cribrate. Mesothecae generally straight, may be locally sinuous in longitudinal section. Median rods subelliptical in cross section. In endozones, autozooecia subrectangular to subrhomboidal in cross section, contiguous, with straight continuous longitudinal walls. In exozones, autozooecia in straight ranges, generally contiguous, with straight to slightly sinuous longitudinal walls, subrectangular in cross section , walls locally may be vesicular in inner exozone. Mural styles common, mostly in autozooecial boundaries or scattered in walls. Living chambers generally elliptical in cross section. Superior hemisepta rare to common, regular, thin, curved proximally, variable in length. Inferior hemisepta in few species; short, thin, generally projecting from mesotheca, scattered in zoaria. Basal diaphragms thin, slightly curved, variable in spacing, absent in some. Monticules common, generally scattered in zoaria. Extrazooecial steroem laminated , may be sparse in zoarial midregion.

Karklins (1969):

  • Definition: Zoarium ramose with relatively straight, ribbon-shaped branches having zooecia in linear ranges demarcated by range boundaries. Zoarial attachments in some species formed by encrusting expansion having few, randomly spaced, irregular zooecia.
  • Zooecia rectangular, with straight to slightly curved walls in endozone, about ovate cavities in exozone in tangential views, form an approximate ogee-shaped curve from mesotheca to zoarial surface in longitudinal view. Zooecia in ranges adjacent to margin at an angle with growth direction of branch, strongly elongate occasionally.
  • Zooecial walls thicken gradually in some species, abruptly in others with change in direction of zooecial growth at base of exozone; walls occasionally elevated laterally and proximally to cavities at surface.
  • Laminae of mesotheca poorly defined, form intermittent junctions with zooecial wall laminae of endozone, merge or continue without apparent break with laminae of zoarial margins. Laminae of zooecia poorly defined, irregularly U-shaped, convex to zoarial surface, inclined to cavities, being somewhat longer in distal than proximal zooecial walls in exozone.
  • Boundary zones, formed by abutting or adjoining laminae of adjacent walls, begin at mesotheca. Range boundaries relatively straight along median between laterally adjacent ranges, continue longitudinally throughout zoarium, probably bifurcate near margins and in areas of branching. Zooecial boundaries form slightly curved zones between longitudinally adjacent zooecia within ranges.
  • Median tubuli of mesotheca well defined, ovate in cross section in transverse view. Mural tubuli poorly to well defined, small, formed by irregular cone shaped flexures of zooecial wall laminae at right angles to zoarial surface, begin within boundaries of ranges, zooecia or apparently rise at random in distal zooecial walls in inner exozone; commonly more abundant in areas of branching, margins of some species.
  • Vesicular tissue, formed in distal zooecial walls at base of exozone in some species, extend for varying distances within exozone. Diaphragms planar, thin, randomly spaced in cavities, abut or merge with wall laminae; few in some species, absent in others. Superior hemisepta thin, hooklike, formed by laminar extensions of proximal zooecial walls at base of exozone; well defined in some species, poorly defined or absent in others; inferior hemisepta rare.
  • Monticules, macules rare, randomly spaced, consist of irregular zooecia. Maculae more common in species having wide zoarial branches.