NAME Helicoönites
AGE    AGE span:  mya
K&J CLASSIFICATION (2000) Fungi Imperfecti, Helicosporae.
FIGURE(S)
FIGURE REFERENCE
SPECIES, AUTHORITY Helicoönites goosii Kalgutkar & Sigler 1995, p. 519, fig. 16.
LOCATION
ORIG DESCRIPTION* ORIGINAL DIAGNOSIS: Conidia simple, tightly coiled or twisted in three planes to form an ovoid, ellipsoidal (doliiform) to cylindrical or beehive- to barrel-shaped spiral; spirals made up of variable numbers of ascending coils or gyres, with each successive gyre usually of smaller diameter; filaments multiseptate, fuscous; cells rectangular.

Monotypic.
COMMENTS* Described and illustrated previously as Helicoön/Helicodendron-type (Kalgutkar & McIntyre, 1991, their figs. 1-3). Although it is easy to identify a helicosporous conidium because of its distinctively twisted structure, the conidia of some species of Helicoön and Helicodendron are so similar in appearance that it becomes impossible to separate them on the basis of their morphology alone. The most significant character separating the two extant genera is the mode of conidial development. In Helicodendron, the conidia are proliferating, forming catenate chains, or tangled masses or clusters, whereas in Helicoön the conidia are produced singly. In both genera, the conidia can be acrogenous or acropleurogenous and doliiform with tightly coiled spirals. In sediments, however, such secondary conidial aggregates are unlikely to be retained on the mycelial tissue or conidiophores during deposition, and are generally preserved in scattered condition. Therefore, tightly coiled conidia of species of Helicodendron are extremely difficult to distinguish from similar conidia of Helicoön (see Kalgutkar & McIntyre, 1991). Helicoönites is created to encompass all fossil helicosporous conidia with a definite ellipsoidal, ovoid or doliiform shape, and that are loosely to tightly coiled or twisted in three planes.

Helicoönites differs from Involutisporonites Clarke 1965, emend. Elsik 1968, Colligerites Jain & Kar 1979, Helicominites Barlinge & Paradkar 1982, and from Helicosporiates and Paleoslimacomyces, by its helically coiled filaments in ellipsoidal to beehive-shaped spirals. Except Helicominites, in these genera the conidia are generally flat and coiled in one plane. In Helicominites the conidia are bent or twisted in different directions.

Goos et al.(1986) mentioned the occurrence of nearly 650-yr-old specimens from an archaeological site near Beetley, Norfolk, England, that appear to be assignable to modern Helicoön richonis (Boud.) Linder (1929). The conidia of this subfossil were slightly larger than those of the extant species, but otherwise appeared similar in shape and color.
PUBLICATION REFERENCE Kalgutkar RM, Sigler L. 1995. Some fossil fungal form-taxa from the Maastrichtian and Palaeogene ages; Mycological Research, v. 99, p. 513-522.
K&J REMARKS
TYPE
ALL NAMES (Including synonyms) Helicoönites;
SERIAL NUMBER 677
PUBLIC COMMENTS
 *For source, see Publication Reference.