Juan Leandro García Massini
Department of Geological Sciences, Southern Methodist University, PO Box 750395 Dallas TX 75275-0395 U.S.A.
Several stages of the life cycle of an endoparasitic fungus of the Chytridiomycota, here assigned to the extant genus Synchtrium, are described as the new species permicus from silicified plant remains from the Late Permian (~250 Ma) of Antarctica. The thallus of Synchtrium permicus is holocarpic and monocentric and consists of thick-walled resting sporangia, thin-walled sporangia, and zoospores in different stages of development. A life cycle is hypothesized from the range of developmental stages. The life cycle begins when zoospores encyst on the host cell surface, subsequently giving rise to thin-walled sporangia with motile spores. Some zoospores (haploid) function as isogamous gametes that may fuse to produce resting sporangia (diploid). Roots, leaves, and stems of plants are among the tissues infected. Host response to infection includes hypertrophy. Morphological and developmental patterns suggest similarities with the Synchytriaceae (Chytridiales), particularly with Synchytrium. Previous records of chytridiomycetes are known from the Devonian Rhynie Chert and from the Carboniferous and the Eocene of the northern hemisphere; this report is the first on chytridiomycetes from the Permian.
KEY WORDS: Endoparasitic fungi, fossil fungi, chytridiomycetes, Synchytrium
Article source: Palaeontological Association December 2007.