NAME Sporocarpon ornatum
AGE Carboniferous.   AGE span: 359.2...299 mya
K&J CLASSIFICATION (2000) Ascomycetes, Eurotiales.
FIGURE(S)
Image of
Pl.29fig.9.jpg
FIGURE REFERENCE Williamson WC. 1880. On the organization of the fossil plants of the Coal Measures.--Part X. Including an examination of the supposed radiolarians of the Carboniferous rocks; Philosophical Transactions of the Royal Society of London, v. 171, p. 493-539.
SPECIES, AUTHORITY S. ornatum Williamson 1880, p. 510-511, pl. 18, fig. 39.
LOCATION Laggan Bay, Arran, Scotland.
ORIG DESCRIPTION* "Figure 39 is a transverse section of an organism from Halifax for which I am indebted to Mr. Spencer. Being the only specimen I have seen of this type I am unable to determine whether, in its perfect condition, it was a spherical or a cylindrical body. Its central cavity has a mean diameter of about .055. This is surrounded by a ring of dark, carbonaceous, compressed fragments, a, which I have no doubt represent compressed parenchyma, apparently the innermost portions of the layer, b. This is a layer bounded externally by an undulating outline and consists of a very regular form of parenchyma, the cells of which appear as if slightly thickened at their angles. Under a low power these dark angular points are the only portions of the cells that are visible. The outermost of these cells have a mean diameter of .0022, but they become smaller as they approach the inner boundary of the tissue where many of them have less than half that size. The outermost layer of this organism is very peculiar. I have already observed that the periphery of the middle layer is an undulating one. Each of its peripheral projections sustains a cluster of very large thin-walled cells, d, d, most of which are prolonged radially. Each interval between these projecting cell-clusters is occupied by a single row of very strongly-marked, thick-walled cells, c, which appear to be modifications of the inner parenchyma, but whose entire cell walls are thickened to form a protective layer at the depressed points of the surface of the organism. I find no trace whatever of any epidermal or other layer external to the large cells, d, and the obviously protective character of those marked, c, makes it clear that this is not an organism torn from its surroundings, but that we have substantially its true peripheral outline. There are some features of resemblance between the layer, b, and the cells, a, of fig. 38, hence it is not impossible that they may ultimately prove to belong to the same, or at least to allied plants."
COMMENTS*
PUBLICATION REFERENCE Williamson WC. 1880. On the organization of the fossil plants of the Coal Measures.--Part X. Including an examination of the supposed radiolarians of the Carboniferous rocks; Philosophical Transactions of the Royal Society of London, v. 171, p. 493-539.
K&J REMARKS With reference to Sporocarpon ornatum, Hutchinson (1955, p. 433) made the following comments: "Sporocarpon ornatum Williamson cannot be included in any of the above genera [i.e. Dubiocarpon, Mycocarpon or Sporocarpon] on account of its characteristic wall structure and the lack of evidence that it is spherical. It is noted that in his description of the type specimen Williamson stated that he was '... unable to determine whether, in its perfect condition, it is a cylindrical or a spherical body'. It is not clear on what evidence he subsequently changed his opinion and referred to them as 'spherical' bodies, as there is no indication from these specimens of their shape at right angles to the plane of the section and he does not report on the examination of other material. The specimens are not unlike sections of a vascular stem from which the central tissues have been removed, and it is therefore thought advisable to record them as Fossiles Incertae Sedis".
TYPE
ALL NAMES (Including synonyms) Sporocarpon ornatum
SERIAL NUMBER 1614
PUBLIC COMMENTS
 *For source, see Publication Reference.