NAME Ordovicimyces gallowayi
AGE Ordovician.   AGE span: 488.3...443.7 mya
K&J CLASSIFICATION (2000) Oomycetes, Saprolegniales.
FIGURE(S)
Image of
Pl.34fig.8.jpg
FIGURE REFERENCE Elias MK. 1966. Living and fossil algae and fungi, formerly known as structural parts of marine bryozoans; The Palaeobotanist, v. 14 (1965), p. 5-18.
SPECIES, AUTHORITY O. gallowayi Elias 1966, p. 13, pl. 2, Fig. 58.
LOCATION Thin sections of the Ordovician bryozoan Nicholsonella cornula. [No further location given in original paper.]
ORIG DESCRIPTION* Unbranching hypha-like filaments, mostly slightly tapering distally; some (fig. 46) resembling "phialids" of Aspergillus and Bombardia (Gäumann & Wynd, 1952, fig. 106, 184, 185); very few with slight medial bulge (fig. 47, left, fig. 53); some with slight to substantial, usually lopsided basal bulge (figs. 49-51); terminated by smooth, subspherical to elliptical zoosporangium; it is differentiated by a slight, abrupt expansion (fig. 46), and is occasionally accompanied by slight constriction (figs. 50-53); few hyphae have a shape of an inverted funnel (fig. 52). Hyphae have a few transverse septa or none; septa are simple or complex, greatly varying in structure and location.

Complex septa are extremely variable; some consist of two to three layers (figs. 54, 55), and may have a very narrow or moderately wide central hole (fig. 55), similar to the septa originating by growth of an "annular bar" so characteristic for Cladophora (Fritsch, 1929, p. 234, figs 69-D, E, I).

Zoosporangia vary greatly in size, shape and orientation. A typical blunt or somewhat acuminate columella is developed in many zoosporangia (fig. 46, 51, 54), usually directly above the upper end of the strand. Columella remains intact after the discharge of zoospores (aplanospores), and apparently seals effectively the emptied hypha; whereas zoosporangial walls apparently disintegrate after discharge of the spores (fig. 47, 60).

Apparently encysted zoospores (aplanospores) develop from cytoplasm in functional hyphae, in some cases apparently only within their zoosporangia. Aplanospores are subspherical, about 1 µm in diameter, with no recognizable flagella. Length of mature hyphae above substratum 15 to 30 µm, the average closer to the higher figure; diameter from 3-4 µm in the middle part, and from 6-20 µm at base of hyphae. Thickness of wall 0.5 to 1.5 µm, rarely locally to 2 µm.

Hyphae very rarely bifurcate (fig. 61) and trifurcate (fig. 62). Zoosporangia occasionally display incipient proliferation (fig. 65); and normally developed secondary hyphae develop inside the abnormally swollen, translucent primary hyphae, somewhat like the "secondary sporangia" in Pythium. [For details, refer to original paper].
COMMENTS*
PUBLICATION REFERENCE Elias MK. 1966. Living and fossil algae and fungi, formerly known as structural parts of marine bryozoans; The Palaeobotanist, v. 14 (1965), p. 5-18.
K&J REMARKS
TYPE O. gallowayi Elias 1966, p. 13, pl. 2, Fig. 58 (lectotype, here selected from inked sketches).
ALL NAMES (Including synonyms) Ordovicimyces gallowayi
SERIAL NUMBER 1166
PUBLIC COMMENTS
 *For source, see Publication Reference.