Level‐bottom brachiopod communities in the Middle Devonian of New York

Abstract

Depositional environments of the Onondaga Limestone from central to southeastern New York are found to be normal, subtidal marine, due to the absence of characteristic supratidal or intertidal sedimentary features and the presence of a typical, diverse, marine level‐bottom community framework. Post‐mortem transport has not been extensive, as evidenced by low articulation ratios, lack of abraded valves, and complete ontogenetic gradations within species, which precludes large scale winnowing. Sedimentation rates appear to have been greatest in eastern New York where the Onondaga Limestone reaches a thickness almost three times that of the strata in central New York. Shaly beds in the central area represent periods of cessation of carbonate deposition rather than an influx of clastic material. Deposition terminated with the onset of deeper water characterized by a westerly advance of terrigenous sedimentation (the Marceilus Shale of the Hamilton Group). Nine brachiopod communities can be recognized in the Onondaga Limestone. There is a strong correlation between sediment‐substrate and community type, reflecting the sedimentologic control of brachiopod community distribution. Sandy facies, cherty limestones and coral biostromes and bioherms are associated with inner‐neritic deposition in Edgecliff time; argillaceous lime muds and lime sands are characteristic of mid‐neritic deposition in Nedrow to Moorehouse time; and highly argillaceous lime muds are associated with outer‐nerittc deposition in Seneca time.

Diversity, speciation, endemism and extinction in Devonian reef and level-bottom communities, eastern North America

“…Locality 4 (=6, 23654, 23635, Fagerstrom 1961(=6, 23654, 23635, Fagerstrom a, 1971(=6, 23654, 23635, Fagerstrom , 1982 The data in Table 1 clearly indicate the much higher diversity of Bois Blanc brachiopods than of the other taxa. High brachiopod diversity also holds true for the other communities listed (except middle Detroit River) and also agrees with the author's experience elsewhere in rocks of this age in eastern North America (see also Feldman 1980, Fig. 3).…”

Brachiopod community paleoecology, paleobiogeography, and depositional topography of the Devonian Onondaga Limestone and correlative strata in eastern North America

“…These descriptions of Onondaga brachiopod communities from the shelf area of western New York and the deeper basin to the south in Pennsylvania, Maryland, and the Virginias are based on relative abundance data published by Oliver (1954) and Kindle (1912). Feldman (1978Feldman ( , 1980 has described communities, several of which are similar to those herein described, from the shelf and slope areas of the eastern New York outcrop belt; these are considered in the following section. Fig.…”

“…With the exception of the detailed study by Feldman (1978Feldman ( , 1980 of a part of the northeastem margin of the Appalachian Basin, the brachiopod community paleoecology of the Onondaga has not been elucidated and the relationships of the brachiopod communities to the depositional topography of the Eifelian Appalachian Basin have not been described. In this paper I define and describe the brachiopod communities of the western marginal shelf of the Appalachian Basin and the basinal environments to the south and east, correlating these communities with the environments in which the brachiopods lived.…”

Taxonomic revision and paleoecology of Middle Devonian (Eifelian) fishes of the Onondaga, Columbus and Delaware limestones of the eastern United States

“…The highest diversity will, logically, develop in environments where there is a stable marine temperature, good circulation, adequate nutrients and normal salinity. Feldman (1980) maintains that an Atrypa-Coelospira-Nucleospira zone, found in the Moorehouse of eastern New York, was most favorable for brachiopods and represents the peak of Onondaga diversity. In general, abundance, particularly brachiopods, increased with depth, to a point, and single taxa dominated where diversity was low, such as in deeper waters.…”

“…Much of the literature pertaining to the formation centers on the faunal components, particularly corals and brachiopods, both of which are numerous and characteristic of certain units (e.g. Oliver, 1954Oliver, , 1956bFeldman, 1980;Friedman, 1985).…”