Parvohallopora multitabulata
Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Trepostomatida
Family: Halloporidae
Genus: Parvohallopora
Species: Parvohallopora multitabulata
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Taxonomic History (Nickles & Bassler, 1900; Under Callopora multitabulata)
Taxonomic History (Nickles & Bassler, 1900; Under Callopora multitabulata)
- 1886 Monotrypella multitabulata Ulrich, Fourteenth Ann. Rep. Geol. Nat. Hist. Surv. Minnesota, p. 100.
- 1893 Callopora multitabulata Ulrich, Geol. Minnesota, III, p. 280, pl. xxiii, 11, 12, 16, 17, 24-26, 30, 31.
- 1896 Callopora multitabulata Ulrich, Zittel’s Textb. Pal. (Engl. ed.), fig. 456, C, D, (p. 274).
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Stratigraphic Occurrences
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Sequences (Formations)
Sequences (Formations)
- C1 Sequence (Lower Lexington)
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Identification in Hand Sample
- Zoarium Morphology: Ramose/dendroid (branching); diameter: 7-8 mm.
- Zoecia: Smoothly oval; thin walled, direct (not oblique)
- Mesozooids: Few
- Monticules: Prominent & regularly spaced, sharp & more/less conical
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McFarlan (1931) (in reference to Hallopora multitabulata):
McFarlan (1931) (in reference to Hallopora multitabulata):
- Zoarium of dendroid branches 7-8 mm. in diameter, with strongly elevated more or less conical monticules occupied by zooecia of about normal size. Zooecia thin-walled, direct. Mesopores few. Diaphragms abundant throughout the zooecial tubes, about 1 diameter apart in the (im) and several times as abundant in the (m).
Particularly common in the Jessamine but ranging up through the Woodburn.
Bassler (1911) (in reference to Hallopora multitabulata):
- Several specimens in the collections from the Wassalem beds at Uxnorm are externally and internally so similar to examples of Hallopora multitabulata from the Black River and lowest Trenton rocks of Minnesota that were the two lots mixed they could not be separated. One of the Russian specimens is almost an exact duplicate of the American specimen shown in figure 202 a, while the internal structure shown in the vertical section, figure 202 d; is repeated in the thin sections of the foreign form.
The zoarium of Hallopora multitabulata is of more or less irregularly divided subcylindrical branches with rather strongly elevated monticules. The zooecia at the surface are angular, thin-walled, and in close contact, about eight in 2 mm. The apertures of the zooecia are often closed with ornamental opercula, as shown in figure 202 c. Mesopores are few. The most marked internal feature is the crowded tabulation shown in figure 202 d. In the immature zone, the diaphragms are seldom more than their own diameter apart and frequently more closely spaced. In the mature zone, six or seven diaphragms may frequently be counted in the space of a tube diameter. The few mesopores present are equally crowded.
Occurrence. – Abundant in the Black River and Lower Trenton strata of Minnesota, Iowa, Kentucky, and Tennessee. Less common in the Wassalem beds (D3) at Uxnorm, Esthonia (Cat. No. 57459, U.S.N.M.).
Represented in the British Museum by a specimen and thin section from Uxnorm.
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