Atactoporella newportensis

Classification
Phylum: Bryozoa
Class: Stenolaemata
Order: Trepostomatida
Family: Mesotrypidae
Genus Atactoporella
Species: Atactoporella newportensis (Ulrich, 1883)

Taxonomic Details

Also called: Monticulipora newportensisTaxonomic History (Nickles & Bassler, 1900)

  • 1883 Atactopora newportensis Ulrich, Jour. Cincinnati Soc. Nat. Hist., VI, p. 250, pl. xii, 4-4b.
  • 1888 Atactopora newportensis James and James, Jour. Cincinnati Soc. Nat. Hist., X, p. 183.
  • 1889 Atactopora newportensis Miller, North American Geol. Pal., fig. 456 (p. 294).
  • 1894 Monticulipora newportensis J.F. James, Jour. Cincinnati Soc. Nat. Hist., XVI, p. 206.

Stratigraphic Occurrences

A.newportensis_strat

Geographic Occurrences

		
Map point data provided by iDigBio.

Stratigraphic Description

Sequences (Formations)

  • C1 Sequence (Clays Ferry/Kope: Economy/Fulton)

Identification in Hand Sample

  • Zoarium Morphology: Robust, encrusting, or lobate/subramose
  • Zoecia: Subcircular or ovate apertures; regularly arranged in intersecting series; numerous very small acanthopores
  • Mesozooids: Numerous, but difficult to see externally
  • Monticules: Elevated (at intervals of ~0.12inch), prominent, rounded, often elongated
  • Maculae: Cells larger than average

Atactoporella newportensis from McMillan Formation of Boone County, Kentucky (CMCIP 27917)

Published Description

Holland (UGA Strat Lab, 2013)

  • Atactoporella is typically encrusting, but can also be ramose to massive. Zooecia are thin-walled and bear diaphragms and cystiphragms, which often form overlapping series. Mesozooids are large and numerous, almost isolating zooids and bearing numerous diaphragms. Styles very numerous, causing zooecial openings to be petaloid.

Karklins (1984)

  • Zoaria subdendroid, having relatively thick primary branches, thinner secondary lateral branches, occasionally encrusting, and, commonly, conspecific overgrowth consisting of one or more layers; branches arising from encrusting portions relatively small. In endozones, autozooecia contiguous, curving gently outward, generally five- to six-sided in cross section; walls slightly irregularly sinuous and crenulated locally. Basal diaphragms sparse, locally more common in late endozones; cystiphragms sparse, generally absent. Zones of rejuvenation of autozooecia sparse; few
    basal diaphragms and occasional exceedingly small styles. Endozones of overgrowths narrow, poorly differentiated.
  • In exozones, autozooecia forming an angle between 70° and 90° with zoarial surface, subcircular to subelliptical in cross section, contiguous or partly contiguous, separated by mesozooecia, without preferred orientation. Autozooecial walls slightly sinuous and locally variable in thickness in early exozones, generally of uniform thickness in late exozones. Autozooecial boundaries narrowly serrated, commonly poorly defined in late exozones. Styles abundant to common, with small, well-defined cores and thin sheaths, generally arising in autozooecial boundaries and commonly inflecting autozooecial chambers or projecting locally into chambers. Styles locally absent in parts of zoaria. Basal diaphragms common, straight to slightly curved, at right angles to chamber axis, generally scattered in autozooecia; cystoidal iaphragms common, scattered in zoaria. Cystiphragms common, scattered, occurring in overlapping series or singly, generally extending less than half the circumference of autozooecia along distal walls, lacking in some autozooecia. Terminal diaphragms scattered in zoaria. Autozooecial chambers subcircular to slightly petaloid in cross section, commonly inflected by styles. Mesozooecia abundant in inner exozones, irregularly variable of shape in cross section, locally coalescing and almost completely separating autozooecia, commonly terminated by zooecial skeletal deposits in outer exozones. Mesozooecial diaphragms closely and evenly spaced, generally about 0.04 mm thick; slightly convex distally, occasionally continuous between mesozooecia, locally overlapping. Maculae common, subconical or irregularly shaped, consisting of mesozooecia and larger polymorphs in varying combinations; regularly distributed in some zoaria.

Ulrich (1883):

  • Zoarium robust, growing upon foreign objects, lobate, or throwing off subramose shoots. At intervals of about .12 of an inch, measuring from center to center, the surface is elevated into more or less prominent, rounded, and often elongated monticules, the summits and slopes of which are occupied by cells a little larger than the average. Cells rather regularly arranged in intersecting series, from eleven to thirteen of the ordinary size in the space of .1 jnch, with subcircular or ovate apertures, having an average diameter of 1/100-th of an inch. On finely preserved examples the apertures are surrounded by a slightly elevated rim or peristome, which is often a little inflected at the points occupied by the numerous, though very small, spiniform tubuli. Interstitial cells numerous, but as usual with species of this genus, they are not readily detected externally.
  • … Externally they (A. typicallis and A. newportensis) differ in their surficial markins, the zooarium of A. typicalis being prevalently entirely smooth, while that of A. newportensis is generally strongly tuburculated, besides being of more robust growth. The cell apertures are never so pelatoid as in the type species”