Species: Peronopora vera (Ulrich, 1888)
Taxonomic History (Nickles & Bassler, 1900)
- 1888 Peronopora vera Ulrich, American Geologist, II, p. 40.
Map point data provided by iDigBio.
- C2 Sequence (Fairview: Fairmount, Mount Hope)
- C1 Sequence (Clays Ferry/Kope: McMicken, Southgate, Economy/Fulton)
Identification in Hand Sample
- Zoarium Morphology: Bifoliate but more frondose (fan-shaped); 2-6 mm thick, 10 or more cm high; undulating and branching
- Zoecia: Circular; often thick-walled (ring-like in cross-section); 7-8 in 2mm; acanthopores small and numerous
- Mesozooids: Numerous, occupying the wide interspaces (spaces between zooids)
- Monticules: Low, inconspicuous (surface smooth)
- Maculae: Conspicuous; larger apertures; often with a central cluster of mesopores
Peronopora vera from the Fairview Formation of Cleaves, Ohio (OUIP 341)
- Description.— Zoaria explanate, bifoliate, flattened, with explanate lateral expansions at right angles to vertical growth direction, occasionally convoluted, having conspecific overgrowth; parts of zoaria encrusting locally. Mesothecae thin, locally discontinuous, bifurcating occasionally, with exceedingly thin median layers without median rods. Mesothecae constitute imperforate basal layers of encrusting portions of zoaria. In endozones, autozooecia contiguous, occurring
alternately in longitudinal ranges, subrectangular in cross-section with straight to slightly sinuous transverse and lateral walls. One to four basal diaphragms in most autozooecia. Cystiphragms few to common, two or more in most autozooecia, arising locally from mesotheca, decreasing in size distally. In exozones, autozooecia in indistinct rhombic pattern, generally subcircular in cross section, partly contiguous, separated by mesozooecia. Autozooecial walls relatively thick, locally irregularly variable in thickness, relatively thin in encrusting portions of zoaria and in conspecific overgrowth, commonly inflected by styles. Autozooecial boundaries narrowly to broadly serrated locally. Styles common, generally with thin cores, thickened sheaths, irregularly variable in thickness in some zoaria, generally occurring along autozooecial boundaries, locally offset, inflecting autozooecial walls, locally extending into zooecial chambers. Basal diaphragms common, planar to slightly curved, occurring at slightly oblique or right angles to chamber axis, generally scattered in autozooecia, locally evenly spaced, lacking in outer exozones of some autozooecia. Cystiphragms abundant, locally variable in size and shape, occurring in longitudinal, locally superimposed series, extending approximately two-thirds of circumference of autozooecia along distal autozooecial walls, occasionally along entire autozooecium.
- Autozooecial lining thin, discontinuous, occurring locally in some autozooecia. Autozooecial chambers subcircular to subelliptical, locally irregularly variable in cross section, containing occasional poorly defined, elongated brown bodies.
- Mesozooecia abundant, subcircular to subpolygonal in cross section, variable in size, locally coalescing, occasionally partly separating or surrounding some autozooecia. Mesozooecial diaphragms closely and evenly spaced, planar to slightly curved, concave distally, locally thickened, occasionally overlapping among coalescing mesozooecia.
- Maculae common, indistinct, occurring regularly throughout exozones, consisting of polymorphs slightly larger and less regularly shaped than autozooecia and of mesozooecia variable in size and locally filled with zooecial skeletal deposits, occasionally having relatively large styles, in various combinations.
Caster, Dalve & Pope (1961):
- This genus differs from all other by having zooecia on both sides of fan separated by thin wall which may be seen best in thin sections.
- Frond 2-6 mm thick and 10 or more cm high. More or less undulating and branching. Apertures circular, 7-8 in 2mm. Mesopores numerous, occupying the relatively wide interspaces. Acanthopores small, numerous. Maculae conspicuous, of larger apertures, often with a central cluster of mesopores.