NAME Sporocarpon cognatum
AGE Carboniferous-Pennsylvanian.   AGE span: 318.1...299 mya
K&J CLASSIFICATION (2000) Ascomycetes, Eurotiales.
FIGURE(S)
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Pl.29fig.4.jpg
FIGURE REFERENCE Davis B, Leisman GA. 1962. Further observations on Sporocarpon and allied genera; Bulletin of the Torrey Botanical Club, v. 89, p. 97-109.
SPECIES, AUTHORITY S. cognatum Davis & Leisman 1962, p. 103.
LOCATION Palmer mine, about 3 miles northeast of Arma, Kansas, USA.
ORIG DESCRIPTION* Spherical structures with a total diameter range of 315-740 µm and a spherical cavity of 290-370 µm. Wall of irregular parenchymatous cells, 10-20 µm in diameter. Thin portions of wall 3-5 cells thick, prolonged outwards into irregular conical rays 6-8 cells deep. Cell walls usually thin (less than 0.5 µm), thickened to slightly more than 1 µm in cells near tips of rays. Peripheral cells often appear eroded. Cavity surrounded by one or two membranes. Membranes non-cellular, covered with dots (ca. 0.5 µm in diameter) in an irregular pattern, and cuticular in appearance. Cavity often empty, but occasionally with irregular, non-cellular structure, 100240 µm in diameter. Many specimens flattened or slightly invaginated.
COMMENTS* A total of 117 specimens were found. The generic name Sporocarpon was given to these specimens because several layers of cells surrounded the central cavity, as opposed to Dubiocarpon, where only one layer is present. This complies with the criteria set up by Hutchinson (1955) who separated the two genera. This species differs from Sporocarpon spinatum in its lack of prolonged spine-like hairs, and from S. cellulosum in that the cells are not arranged in radial rows. Although the cells of both S. cognatum and S. asteroides are arranged in an irregular number of conical rays, the ray cells in S. asteroides are arranged in a more radial pattern and the rays are composed of fewer cells in thickness (fig. 12). Only the outer cell walls of the ray cells are thickened in S. asteroides, whereas the complete cell is thickened in the outer few layers of ray cells in S. cognatum (figs. 10, 14). The specific name refers to the similarity or relationship to S. asteroides.
PUBLICATION REFERENCE Davis B, Leisman GA. 1962. Further observations on Sporocarpon and allied genera; Bulletin of the Torrey Botanical Club, v. 89, p. 97-109.
K&J REMARKS In the protologue the numbering system used in the text is at variance with that used in the plate legends. Thus, it is not clear whether, and if so in which figure, the type specimen was illustrated. Nevertheless, the illustrated specimens are clearly conspecific, and here fig. 13 is used (as epitype) to illustrate the morphology.
TYPE S. cognatum Davis & Leisman 1962, p. 103. Holotype: Slides 2843B(5)-# 21-1 through 21-13 in the paleobotanical collection, Department of Biology, Kansas State Teachers College, Emporia, Kansas. (Fig. 13 here illustrated.)
ALL NAMES (Including synonyms) Sporocarpon cognatum
SERIAL NUMBER 1607
PUBLIC COMMENTS
 *For source, see Publication Reference.