MISSISSIPPIAN SYRINGOPORID CORALS, SOUTHERN CANADIAN ROCKY MOUNTAINS

Abstract

ABSTRACT Analysis of 511 syringoporid coral colonies, collected from 64 Mississippian sections totalling about 140,000 stratigraphic ft (42,672 m) in the southern Canadian Rocky Mountains, indicates that three genera, five species and four subspecies are present. Parameters considered important in differentiation are wall thickness and tabular pattern for generic, and corallite diameter and spacing (frequency) for specific and subspecific differentiation. Genera recognized are Syringopora, Pleurosiphonella and Oharaia nov. Species of Syringopora are S. harveyi White from the Banff and Pekisko Formations; S. harveyi subsp. A. nov., S. harveyi subsp. B. nov. and S. harveyi subsp. rudyi Nelson from the Shunda Formation; and S. harveyi subsp. dingmanae Nelson and S. bassoi Nelson from the Mount Head Formation. Syringopora from the underlying Turner Valley Formation belong to the S. harveyi group but are too sparsely distributed for analysis. In Canada these species of Syringopora range from Kinderhookian through Meramecian. They are diagnosed by having thin walls and centrally or subcentrally located infundibular tabulae. They contrast with Pleurosiphonella and Oharaia that have overlapping and higher ranges -- from Meramecian through Chesterian -- and are diagnosed by proportionally thicker walls and exocentric infundibular or vesicular tabulae. Pleurosiphonella has very thick walls and vesicular tabulae; Oharaia has proportionally thinner walls and typically infundibular tabulae. Pleurosiphonella, represented only by P. virginica (Butts), is Meramecian and very low Chesterian, extending through the Mount Head and lower Etherington Formations. Oharaia is represented by O. magnussoni (Nelson) and O. drummondi (Nelson). Oharaia magnussoni is Upper Meramecian and Lower Chesterian; that is, upper Mount Head to lower Etherington. Except for one questionable occurrence in the Mount Head, O. drummondi is known from only one locality in the uppermost Etherington Formation, considered Upper Chesterian. Syringoporid corals show promise in intra- and intercontinental correlation. The three subspecies of the Osagean Shunda S. harveyi appear to be present in the approximately coeval Redwall Formation of Arizona. Pleurosiphonella virginica, a common and characteristic Meramecian species, extends from Virginia to the northern Yukon Territory and may be conspecific with P. crustosa Tchudinova from the Ural Mountains and Armenia of the U.S.S.R. Oharaia drummondi has been identified from Wyoming, appearing in the same stratigraphic position as its Canadian counterpart.