Lichenocrinus tuberculatus
Classification
Phylum: Echinodermata
Class: Crinoidea
Holdfast
Genus: Lichenocrinus
Species: Lichenocrinus tuberculatus (Miller)
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Sequences (Formations)
Sequences (Formations)
- C6 Sequence (Elkhorn)
- C5 Sequence (Lower Whitewater)
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Identification in Hand Sample
- Basal body, highly convex, crater comparatively small and shallow to moderately deep. Circular in outline.
- Crater plates, smooth, flat, polygonal, irregular in size and shape. Arranged in two series, the one nearest the column being composed of smaller plates than the other.
- Interior filled with upright lamelliform plates, radiating from a central point.
- Distinguished from L. crateriformis by its tuberculated plates, more abrupt central depression, and greater uniformity in the size of its plates”
Lichenocrinus tuberculatus from the Whitewater Formation of Clarksville, Ohio (OUIP 2078)
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Davis (1998):
Davis (1998):
- Crinoid base. One of many Richmondian species, this form has many rounded, nodose plates. Waynesville through Elkhorn.
Faber(1929):
- Basal body, usually highly convex, crater comparatively small and shallow to moderately deep. Crater plates, smooth, flat, polygonal, irregular in size and shape; they are arranged in two series, the one nearest the column being composed of smaller plates than the other. The pentagonal column, occupying about half the entire crater area, is composed of thin alternating plates, five of which form a columnal. The body plates are numerous, 5-6 in the space of 3 mm. in Miller’s type and 6-7 in the space of 5 mm. In individual specimens they are nearly uniform in size from the crater to the margin and range from quadrangular to octagonal, though generally from pentagonal to hexagonal; five to six plates can be counted along a radius from the crater to the margin. The plates bear low rounded to high conical tubercles, in some cases surrounded by incised lines parallel to the margins of the plates. Miller’s cotype, a free specimen, has two series of rim plates; the arch plate is revealed near the margin where several body plates are removed.
Miller (1874):
- “Body discoidal, circular in outline; lower surface or surface of attachment, flat, or conforming to the surface to which it is attached; upper surface strongly convex or subhemispheric, with a deep circular depression in the central part, around the column; upper surface of body composed of numerous, irregularly arranged, thin, pentagonal or hexagonal plates, nearly uniform in size, smooth on the underside and highly convex or tuberculated on the outer surface. Excluding the plates immediately surrounding the column, within the central depression, which are much smaller than the others, the remainder will number about one hundred. Interior filled with upright lamelliform plates, radiating from a central point, on which the exterior plates appear to repose.
Column pentagonal, length unknown. It is distinguished from L. crateriformis, which species it most resembles, by its tuberculated plates. It differs, too, in its greater convexity, more abrupt central depression, and greater uniformity in the size of its plates”
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