696


Journal of Paleontology 92(4):681–712


County (Allens Creek Bank, Boy Scout Camp, and Waldrip Site) and Montgomery County (Indian Creek and Crawfordsville upper quarry), Indiana; (2) the Fort Payne Formation (Allen, Clinton, Cumberland, Hardin, Russell, and Wayne counties), Kentucky; Clay, Davidson (Whites Creek Springs), Lawrence (Krivicich et al., 2013 Locality 5 and 6), and Pickett counties, Tennessee; and Dekalb (Krivicich et al., 2013, Locality 1) and Madison (Krivicich et al., 2013, Locality 2) counties, Alabama; and (3) theMuldraughMember of theBorden Formation (Hardin County, Kentucky). In the Fort Payne Formation of south-central Kentucky and


north-central Tennessee, Eretmocrinus magnificus is known from the following facies: crinoidal packstone buildup facies at Cave Springs North, Cave Springs South, Gross Creek, Gross Creek West; wackestone buildup facies at Bugwood, Greasy Creek, Harmon Creek, Lily Creek, Owens Branch, and Pleasant Hill; sheetlike packstone facies at Big Turbidite, Cove Creek, Obey Creek, Seventy-Six Falls, Wolf Creek/Caney Fork Confluence, 61B, 61D, 61DW, 61RS; and authochthonous green shale facies at Blacks Ferry and Celina.


Description.—Calyx widest at arm openings, medium to high cone calyx shape, sides concave from base to arm openings, medium to large size for genus. Calyx width to height ratio 1.66 (range 1.14–1.96), calyx height to tegmen height (to base of anal tube) 1.18 (range 0.88–1.48) (Fig. 7.1, 7.5) (Supplemental Table 5). Proximal calyx (before extreme widening to arm bases) medium to high cone shape. Outline of calyx at level of arm openings circular with slight indentations between rays and half rays. Calyx plate sculpturing variable, but dominant morphology


with flat or modestly convex plates with apparent smooth plate sculpturing, but at high magnification, finely pustulose. Rarely some forms with circular to vertically elongate nodes that are not coalesced into ray ridges or other forms that have a weak to strong ray ridge. Basal rim formed from elongate transverse nodes on basal plates extended horizontally, complete or indented at basal-basal sutures, broadly rounded and narrow to sharp and wide (Fig. 7.1. 7.5), width ~50% of the maximum calyx width. Basal circlet high, ~18–30% (mean=23%) of calyx height, shallow basal concavity for proximal columnal. Basal plates three, equal in size, sculpture as noted above. Radial circlet 10–23% of calyx height (mean=15%); radial plates five, hexagonal, as wide as high; plate sculpturing as noted above. Radial plates 1.9–3.7 times as wide as high (mean=2.7), may be higher marginally than medially. Regular interrays not in contact with tegmen. First interradial large, higher than wide, variously shaped; plating typically 1-2, but the following also occur: 1-1, 1-1-1, 1-2-1; plates above first interradial plate may be equal or unequal in size.


Primanal heptagonal, wider than high; plating P-3-3 or P-4;


not in contact with tegmen. First primibrachials, tetragonal wider than high; approxi-


mately equal in size to second primibrachial; second primibra- chial axillary; additional fixed brachials wider than high; two secundibrachials; last fixed brachials in tertibrachitaxis; free arm facet typically not vertically elongate; surficial plate sculpturing as noted above.


Tegmen medium inverted cone from arm openings to base


of anal tube; tegmen plates with elongate circular spines (Fig. 7.4); one thecal opening on either side of arm openings. Anal tube long; plates spinose, either low circular or low horizontally elongate nodes (Fig. 7.2, 7.3). Free arms commonly 20, range from 18–21. Distal arms


not known from Fort Payne material. Proximal columnal circular with crenularium, lumen


pentalobate.


Materials.—The cotypes of E. magnificus are USNM S 744; and designated herein from these specimens are a lectotype, USNM S 744a, and paralectotypes USNM S 744b–d. Type material of junior synonyms are as follows: Eretmocrinus commendabilis, holotype, FMNH UC 6475; Batocrinus weatherbyi, holotype, FMNH UC 6430. More than 400 complete or incomplete specimens of E.


magnificus were collected from the Fort Payne Formation in the Lake Cumberland area. Representative collections from this study are USNM 639915–USNM 639920, OSU 54490– OSU54499, and CMC IP76362–CMC IP76367.


Measurements.—See Supplemental Table 4.


Remarks.—Eretmocrinus magnificus is the most common Eretmocrinus species in the Fort Payne Formation. It is present in nearly every facies, but it is especially common on crinoid packstone buildups, such as Gross Creek and Cave Springs. As indicated in the description above, E. magnificus is quite


variable morphologically, although distinctive morphs exist. The two most common morphs in the Lake Cumberland area are one with a high calyx, convex and smooth calyx plates, and a somewhat expanded basal rim, and another with a shorter calyx, circular to vertically elongate nodes on ray plates and perhaps interradial plates, and a more expanded basal rim. Lane (1958) regarded B. weatherbyi Miller and Gurley,


E. lyonanus Miller, and B. laterna Miller and Gurley as junior synonyms of E. magnificus. We agree with the placement of E. wetherbyi, but assign E. lyonanus and B. laterna as junior synonyms of E. ramulosus, below. We also place E. commendabilis Miller and Gurley in synonymy with E. magnificus. Eretmocrinus commendabilis is an example of the E. magnificus morph with a high calyx, convex and smooth plates, and a somewhat expanded basal rim. Van Sant (1964) differentiated E. commendabilis from E. magnificus because of the number of arms, plate sculpturing on fixed brachials, and highly nodose tegmen. The arm number of E. commendabilis is 20, and that of E. magnificus is 20–26. Van Sant (1964) noted that E. magnificus has nodes on the fixed brachial plates; however, the most common morph of E. magnificus in the Fort Payne Formation lacks nodes on fixed nodes on fixed brachial plates. Finally, the character of the anal tube is not known on the type specimen of E. commendabilis. Thus, the morphology of E. commendabilis is the same as the common morph of E. magnificus. Eretmocrinus magnificus is distinct among Fort Payne


species of Eretmocrinus because it has a high cone-shaped calyx, width to height ratio 1.66; calyx height to tegmen height ratio 1.18; calyx plate sculpturing variable, most common


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