NAME Protoascon missouriensis
AGE Middle Pennsylvanian.   AGE span: 311.7...307.2 mya
K&J CLASSIFICATION (2000) Phycomycetes, Saprolegniales?.
FIGURE(S)
Image of
Pl.19fig.16.jpg
FIGURE REFERENCE Batra LR, Segal RH, Baxter RW. 1964. A new Middle Pennsylvanian fossil fungus; American Journal of Botany, v. 51, p. 991-995.
SPECIES, AUTHORITY P. missouriensis Batra, Segal & Baxter 1964, p. 991, fig. 1-11 (holotype: KANU, R.W. Baxter Paleobotanical Collection, coal ball A.C. 38, peel No. 8).
LOCATION Pioneer Mine, Appelton City, Missouri, USA.
ORIG DESCRIPTION* Spore-sac 59-75 µm in diameter (25 measurements), space between the spore-sac and the wall of the fruiting body variable in dimensions; fruiting body globose to subglobose, measuring 66-140 x 60-130 µm (50 measurements); the fruiting body attached to a vesicular, appendiculate base approximately of the same dimensions as the fruiting body; basal appendages 10, rarely 11, symmetrically placed, all arising from the same plane near the truncate end of the base, running parallel to each other and enveloping the fruiting body, appendages of mycelial nature, septate, unbranched, curved, enlarged near the base and gradually tapering towards an obtuse apex.
COMMENTS* As for the genus.
PUBLICATION REFERENCE Batra LR, Segal RH, Baxter RW. 1964. A new Middle Pennsylvanian fossil fungus; American Journal of Botany, v. 51, p. 991-995.
K&J REMARKS Baxter (1975) reexamined all the type material of Protoascon missouriensis and found that a number of features were more comparable to the Phycomycetes than to the Ascomycetes. The terminal cell of the hypha, surrounded by a whorl of septate appendages, was compared in some ways to the oogonia and surrounding antheridia of certain species of Saprolegniales. Baxter also concluded that the very poor preservation of the seed integuments making a surrounding matrix of coal ball vascular plants around the fungus, suggested that "the seed may have been submerged in water of the surrounding swamp and that the fungus was a saprophytic aquatic form comparable to the Saprolegniales." Pirozynski (1976a), however, considered it to be a zygospore of the Absidia [Mucorales] not unlike A. glauca.
TYPE
ALL NAMES (Including synonyms) Protoascon missouriensis
SERIAL NUMBER 1445
PUBLIC COMMENTS
 *For source, see Publication Reference.