NAME Sporocarpon
AGE    AGE span:  mya
K&J CLASSIFICATION (2000) Ascomycetes, Eurotiales.
FIGURE(S)
FIGURE REFERENCE
SPECIES, AUTHORITY Sporocarpon Williamson 1878, p. 346-347.
LOCATION
ORIG DESCRIPTION* ORIGINAL DIAGNOSIS: (Williamson 1878 gave the following description of the material represented in his figs. 75, 75A, 75B, 75C, 75D and 76): "These objects appear to be conceptacles of some kind that have been formed in the midst of parenchymatous tissue, but from which they have shown a remarkable tendency to become detached with a somewhat definite yet irregular contour. [...Some specimens; see fig. 75B] not only exhibit this defined contour, but further show a tendency in the peripheral cells to arrange themselves in fan-shaped or radiating columns at three points. ... I propose grouping these and some allied objects in a provisional genus Sporocarpon."

Williamson 1880 (Part X; ibid., v. 171, p. 507-511) described further finds of conceptacles and introduced three more species, after which he concluded with the remark that "One common feature characterises the whole of the objects that I have included in the provisional genus Sporocarpon, viz.: they exhibit no trace of having possessed any peduncular appendage wherewith to be attached to their parent plants."

EMENDED DIAGNOSIS (Hutchinson 1955, p. 428): Spherical bodies containing a spherical cavity and showing no sign of vascular tissue. The tissue surrounding the cavity consists of parenchymatous cells. It has no definite external boundary, but exhibits an irregular surface of broken cells. The structures show no other sign of attachment to a parent plant.
COMMENTS*
PUBLICATION REFERENCE Williamson WC. 1878. On the organization of fossil plants of the Coal Measures. Part IX; Philosophical Transactions of the Royal Society of London, v. 169, p. 319-364.

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.

Hutchinson SA. 1955. A review of the Genus Sporocarpon Williamson; Annals of Botany, v. 19, p. 425-435.
K&J REMARKS The word "provisional" used by Williamson to qualify his new genus Sporocarpon is not to be taken in the meaning attached to the word by the present ICBN (as signalling a preliminary name, which hence is not validly published); rather it indicates Williamson's opinion that more was to be learned about the functional morphology and biological affinity of these forms. Williamson did not designate a type species, but his species S. cellulosum was described in association with the generic diagnosis (both of them in a rather rambling narrative).

McLean (1912) mentioned the various inappropriate biological affinities attached to Sporocarpon and some similar forms, then adopted the view that they may belong to a separate extinct group of Protozoa, and assigned them all to the family Traquairidae (which he defined). About Sporocarpon, he stated that "the species which is usually taken as the type is ... Sporocarpon elegans" (although he gave no source for this typification). Finally, he redescribed the species proposed by Williamson (1878, 1880), and then suggested that it might be apt to separate S. asteroides, S. cellulosum and S. pachyderma in a provisional genus Perichoderma, which, however, he did not define. Ten years later, McLean (1922 p. 71-90) further described and integrated the several species of Sporocarpon, in which he now included the genus Oidospora. He explicitly designated S. compactum as type species ("as it is the least specialized"; l.c., p. 79), thus rejecting his earlier notion that S. elegans should be taken as the type, and formulated the following [emended] generic diagonosis: "Spherical or spheroidal organisms of minute but very variable size (0.03-0.35 mm); without attachments and surrounded by a stereomatic envelope composed of vesicles that may be radially or tangentially developed. These vesicles contained protoplasm and possessed the power of extension and development during the life of the organism. Reproduction as in the group as a whole." McLean then subdivided the genus into five sections (one of them Perichoderma), that were not individually defined. The section Eusporocarpon includes "S. oidospora," the illegitimate new name given by McLean to Oidospora anomala Williamson 1878, the only species assigned to that genus [the correct new name for this combination is Sporocarpon anomalum (Williamson) comb. nov.]. Hutchinson (1955) emended the generic diagnosis (l.c., p. 428) and gave S. cellulosum as type; however, this choice was preceded by that made by McLean.

Hutchinson restudied the old preparations of Williamson, provided new and emended descriptions and measurements of all species, and proposed two new genera: Dubiocarpon and Mycocarpon. Unfortunately, he was not aware of McLean's work on these forms, and unwittingly included Sporocarpon compactum, which then was already the type of the genus Sporocarpon, in his genus Dubiocarpon. According to Art. 52.1-2 of the ICBN, this makes the name Dubiocarpon nomenclaturally superfluous and illegitimate, as the older name Sporocarpon should have been used for this taxon.

Andrews 1970 (USGS Bulletin 1300) indicated Sporocarpon cellulosum as possible type, but in his Index he did not differentiate between designated type species and first described species (which he would list if no type had been indicated); anyway, this matter had been settled by McLean's choice in 1922. Jansonius & Hills 1976 (Genera File of Fossil Spores) cited Andrews, as they didn't have the full literature available. McLean's choice of type must be followed.

The genus was also discussed by Baxter (1960) and Davis & Leisman (1962). Rothwell (1972) found similar structures in the Pennsylvanian of Illinois. He identified them as fungal sclerotia and described them under the new genus Palaeosclerotium.

More recently, Stubblefield et al. (1983) discussed this problematic taxon and morphologically similar ones, and concluded that the genus represented a heterogeneous assemblage of fungal forms, assigned to several taxa including Sporocarpon, Dubiocarpon and Mycocarpon, that have affiliation to extant Eurotiales (in which similar morphologies are found).
TYPE TYPE: Sporocarpon compactum Williamson 1878, p. 346-347; designated by McLean, 1922, p. 79. Holotype: Slide 1514, Williamson Collection, British Museum of Natural History. [Hutchinson, 1955.]
ALL NAMES (Including synonyms) Dubiocarpon Hutchinson 1955.
Oidospora Williamson 1878. ; Sporocarpon;
SERIAL NUMBER 1603
PUBLIC COMMENTS
 *For source, see Publication Reference.