ABSTRACT
Fragments of fossil fungal remains are commonly seen in macerated residues prepared for palynological studies. These are less frequent in samples from Palaeozoic strata but are better represented in preparations of Lower Mesozoic sediments. A great spurt in fungal diversity is witnessed in the Tertiary Period. Except for some distinctive Tertiary forms, fossil fungal remains can not be generally ascribed to modern taxa, hence, their classification with living fungi is not possible. Fossil fungal remains are, therefore, described as Form Genera under the Artificial System of classification which is based on morphological characters only However, wherever possible their affinities with extant forms are provided.
Innumerable variety of fossil fungal remains are described as spores, filaments, fruiting bodies and mycorrhiza which have been reported from Cretaceous to Tertiary sediments. Ascomycetous fungal remains got well-established during the Cretaceous time and became conspicuously abundant by the Tertiary Period. Enormous varieties of fossil fungal spores are reported from these sediments. Fossil spores are described under “Dispersed Spores” which include detached spores, microscopic sporangia and fragmented mycelia. Based on characters associated with size, symmetry, pores and septa, the spores are 2described under different morphologic groups. Fruiting bodies of epiphyllous fungi are commonly found in Tertiary sediments. These can be compared with extant forms with greater accuracy than the spores. The fruiting bodies or the ascocarps are variously shaped ostiolate or non-ostiolate bodies made up of radiating rows of mycelia giving an appearance of tissues arranged in a radiating fashion. The ascocarps contain asci.
Fossil fungi provide significant information about the past habitats and the hosts. Fossil epiphyllous fungi are more reliable and advantageous for palaeoclimatic interpretations. Occurrence of these fossils reflects moist and humid climate of tropical to subtropical belts. Studies particularly focusing the host fungus relationship are of great significance in attempting the palaeoenvironmental interpretations. This chapter encompasses the aforesaid aspects of fungi from palaeoenvironment.
