Kansas Geological Survey, Current Research in Earth Sciences, Bulletin 251, part 1
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Kansas Geological Survey, Current Research in Earth Sciences, Bulletin 251, part 1
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The Cottonwood Limestone Member (Beattie Limestone) in Greenwood County, Kansas, contains in situ remains of the calcareous marine phylloid alga Calcipatera cottonwoodensis described by Torres et al. (1992). The term phylloid was introduced by Pray and Wray (1963) to describe membranous leaflike calcareous algae found in late Paleozoic rocks. Phylloid means "leaflike" or "resembling a leaf" and, according to Pray and Wray (1963, p. 209), has no implication as to the growth habit of the algae. Codiacean genera Eugonophyllum, Calcifolium, and Ivanovia, and the rhodophycean genus Archaeolithophyllum are Pennsylvanian and Permian algae to which the term phylloid is usually applied. Anchicodium also has been included in this group by some workers (Konishi and Wray, 1961; Laporte, 1962; Crowley, 1969), but other workers (Baars and Torres, 1991; Torres and Baars, 1992; and Torres et al., 1992) have clearly demonstrated that Anchicodium is "cylindrical and branching," as originally described by Johnson (1946), and thus not a phylloid alga. Two growth habits have been recognized for Archaeolithophyllum: an encrusting form, A. lamellosum (Wray, 1964; Wahlman, 1988, 2002) and an erect "phylloid" form for A. missouriense (Wahlman 1985, 1988, and 2002). The growth habit of Calcifolium has been inferred, but in situ evidence is undocumented in the literature. Indeed, Calcifolium may be a sponge (Torres, 1995). Torres (1995, 1997) documented the cup-shaped, cyathiform thalli of Ivanovia and Eugonophyllum and noted the morphological similarity of the thalli of these two genera to the fossil taxon Calcipatera and the extant taxon Udotea cyathiformis. Elias (1963) discussed the habitat and mound-building tendencies of Ivanovia in the Pennsylvanian of the Paradox basin. Cross and Klosterman (1981, p. 48) described in situ phylloid algal thalli from the Virgilian of New Mexico with "rare occurrences of preserved internal structures," which were "preserved erect in growth habit" and "suggest a taxonomic similarity to the codiacean genus Eugonophyllum." Based on well-preserved internal structures, Kirkland et al. (1993) confirmed Cross and Klosterman's tentative identification as Eugonophyllum. Wahlman (1988, p. 184-186) recognized two main phylloid algal growth forms that commonly occur next to each other in his Zone IV phylloid algal bafflestone/boundstone in the Permian basin of West Texas and New Mexico. The most common was sinuous to nearly horizontal, prostrate plates that, when identifiable, were Eugonophyllum or Ivanovia. Forms, identifiable as Archaeolithophyllum, were in situ curved to U-shaped plates with an orientation in common with adjacent plates suggesting an ecological response such as phototaxis. Babcock (1977) proposed a similar interpretation for clusters of open conical phylloid algae in the Middle Permian Capitan reef of the Guadalupe Mountains, West Texas.
In situ erect thalli of Calcipatera cottonwoodensis in the Cottonwood limestone in Greenwood County, Kansas, occur at only one known locality (figs. 1 and 2). The Cottonwood Limestone Member (Beattie Limestone, Council Grove Group, Wolfcampian Series, Permian System) is a lithostratigraphic carbonate unit that can be traced from southeastern Nebraska to Greenwood County, Kansas. South of Greenwood County, it is an interbedded limestone and calcareous shale (Laporte, 1962).
Figure 1--Geographic location of in situ Calcipatera occurrence. Sample site is a roadcut on the north side of U.S. Highway 54, 0.5 km east of the county line (SE SE SW sec. 3, T. 26 S., R. 8 E., Greenwood County, Kansas) (from Torres et al., 1992; used with permission of the Journal of Paleontology).
Figure 2--Graphic section at sample site. (a) Bafflestone containing in situ Calcipatera cottonwoodensis. (b) Platy algal packstone containing Calcipatera fragments. (Modified from Torres et al., 1992; used with permission of the Journal of Paleontology).
A unit of stacked in situ Calcipatera approximately 45 cm thick is situated near the upper part of the exposure (fig. 2a). This unit is underlain and overlain by fragmental algal packstones. The lower one is particularly typical of most phylloid algal occurrences (fig. 2b), and it forms the most conspicuous unit of the exposure. As described by Laporte (1962, p. 531), the thin, wavy, plate-like thalli are generally oriented parallel to bedding, and in weathered relief, give the rock an irregular, crenulated texture--a texture often described as a pile of potato-chips or corn-flakes. At this exposure, the algal packstone is referred to as an accumulational occurrence, and the in situ unit is referred to as a constructional occurrence (Samankassou and West, 2002, 2004).
Laporte (1960, locality 42), who previously studied the Cottonwood limestone at this locality, did not report the in situ Calcipatera. Laporte (1962) identified the abundant broken fragments of Calcipatera as Anchicodium, but noted that the platy external shape did not agree with Johnson's (1946) original description of Anchicodium as being cylindrical and branching. Torres et al. (1992) discussed the morphology and taxonomy of the phylloid algae in the Cottonwood limestone.
Torres et al. (1992) reconstructed an in situ Calcipatera life assemblage. Such in situ occurrences probably represent patchy distributions analogous to some present-day algae. Large (up to 60 mm) fragments of Calcipatera compose the algal packstones that may occur between the in situ patches.
The purpose of this paper is to provide some insight into the ecology of Calcipatera, its role in marine benthic communities, and the significance of this occurrence in terms of preservation, gross morphology, structure, and potential mound-building capabilities. A phylloid algal community from the Hueco Limestone (Permian) in West Texas (Toomey, 1976) is compared to the Cottonwood limestone occurrence.
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