Parvohallopora ramosa

Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Trepostomatida
Family: Halloporidae
Genus: Parvohallopora
Species: Parvohallopora ramosa (d’Orbigny, 1850)

Taxonomic Details

Has been referred to as:

  • Hallopora rugosa (Milne-Edwards & Haime, 1851)
  • Hallopora nodulosa (Nicholson, 1974)
  • Hallopora andrewsi (Nicholson, 1974)

UGA Strat Lab: Originally named as Monticulipora ramosa. Also called Callopora ramosa, Hallopora ramosa. Includes Hallopora rugosa (Milne-Edwards and Haime, 1851), Hallopora nodulosa (Nicholson, 1874), Hallopora andrewsi (Nicholson, 1874), and Hallopora dalei (Milne-Edwards and Haime, 1851)

Taxonomic History (Nickles & Bassler, 1900; Under Callopora ramosa)

  • 1850 Monticulipora ramosa D’Ori=bigny, Prodr. de Pal., I, p. 25.
  • 1851 Chaetetes ramosus Milne-Edwards and Haime, Pol. Foss. Terr. Pal., p. 266, pl. xix, 2, 2a.
  • 1854 Monticulipora ramosa Milne-Edwards and Haime, British Foss. Corals, p. 265.
  • 1860 Monticulipora ramosa Milne-Edwards and Haime, Hist. Nat. des Corall., III, p. 277 .
  • 1876 Chaetetes ramosus Nicholson, Ann. Mag. Nat. Hist., ser. 4, XVIII, p. 88..
  • 1879 Monticulipora (Heterotrypa) ramosa Nicholson, Pal. Tab. Corals, p. 296, pl. xiii, 2, 2a.
  • 1881 Chaetetes ramosus Quenstedt, Roehren- und Sternkorallen, p. 77, pl. cxlvi, 13-18.
  • 1881 Monticulipora (Heterotrypa) ramosa Nicholson, Genus Monticulipora, p. 110, fig 18, pl. ii, 2, 2a.
  • 1882 Callopora ramosa Ulrich, Jour. Cincinnati Soc. Nat. Hist., V, p. 252.
  • 1888 Monticulipora ramosa James and James, Jour. Cincinnati Soc. Nat. Hist., X, p. 181.
  • 1890 Callopora ramosa Ulrich, Jour. Surv. Illinois, VIII, fig. 5b (p. 315).
  • 1894 Monticulipora ramosa J.F. James, Jour. Cincinnati Soc. Nat. Hist., XVI, p. 204.
  • 1896 Monticulipora (Heterotrypa) ramosa Zittel, Textb. Pal. (Engl. ed.), fig 185 (p. 103), fig. 186 B (p. 103).
  • 1874 Chaetetes dalei (Not of Milne-Edwards & Haime) Nicholson, Quar. Jour. Geol. Soc. London, XXX, p. 501, pl. xxix, 1, 1a.
  • 1875 Chaetetes dalei (Not of Milne-Edwards & Haime) Nicholson, Pal. Ohio, II, p. 192, pl. xxi, 1, 1a.
  • 1883 Monticulipora dalei (Van Cleve) Hall, Twelfth Ann. Rep. Indiana Geol. Nat. Hist., p. 249, pl. xi, 2.

Stratigraphic Occurrences

P.ramosa_strat

Geographic Occurrences

Map point data provided by iDigBio.

Stratigraphic Description

Sequences (Formations)

  • C5 Sequence (Whitewater, Waynesville)
  • C4 Sequence (Arnheim)
  • C3 Sequence (Mt. Auburn, Corryville)
  • C2 Sequence (Bellevue, Fairview: Fairmount, Mt. Hope)
  • C1 Sequence (Clays Ferry/Kope: McMicken, Southgate, Economy/Fulton; Lexington/Pt. Pleasant)

Identification in Hand Sample
Parvohallopora

  • Zoarium Morphology: Ramose (branching); 3-8 mm in diameter
  • Zoecia: Smoothly oval; may be lined; uniform in shape and well separated
  • Mesozooids: Numerous, small, angular; in some cases, completely isolating zooecia
  • Monticules: Prominent & regularly spaced, sharp & conical to continues sharp ridges; several mm apart; characterized by more numerous mesopores
Parvohallopora_ramosa_800px

Parvohallopora ramosa from McMillan formation of Hamilton County, Ohio (OUIP 1297)

Published Description

Singh (1979)

  • Zoaria ramose, only conspecific incrustations. Branches circular to subcircular in cross-section; bifurcating at 60-75 degrees, at intervals of 1-4 cm. Zoarial surface completely covered by monticules. Monticules show gradation between isolated, regularly spaced conical protuberances that are rounded or blunt at their tips, to transversely oriented ridges, partly or completely encircling zoarial branches.
  • Wall commonly attains maximum thickness in early exozone; irregular thickenings in exozone common.
  • Zooecia in endozone parallel-sided, proximally gradually expanding conical, attaining maximum width within a distance of less than 1.5 mm; walls even, except near zooecial bend, may be slightly wavy; polygonal outline in cross-section; smaller zooecia representing proximal portions.
  • Zooecia in exozone usually initiated only slightly proximal to zooecial bend; zooecial openings circular to subcircular in cross-section.
  • Diaphragms common in endozone, closely-spaced in exozone (resultant living chamber short), usually absent in zooecial bend zone; planar, rarely slightly inclined or curved.
  • Mesopores initiated from almost mid-endozone to early exozone; most terminate in mid-exozone; circular to subcircular in cross-section; slightly elongated mesopores have rounded outline; one to several mesopores between adjacent zooecia which, due to shape and distribution, do not give appearance of space-fillers.
  • Walls composed of diaphragm-zooecial lining units; zooecial lining approximately equal in thickness to diaphragms, distally becoming slightly thicker because lining from proximal units may continue distally for some distance before merging with ZCL. Laminae U- to V-shaped; proximal zone of laminae darker in color. Abutting of proximal zones of lamina, seen in longitudinal and transverse orientation, resulting in formation of almost continuous irregular black line or narrow zone with occasional breaks where laminae from zooecial lining interfinger.
  • Monticules variably composed: wall thickening with irregular wall lamina most common; clusters of mesopores and slightly larger (size in cross-section same as zooecia in intermonticular areas) zooecia less common.