This website gives an overview of all current information known about fossil fungi. In particular, it is a recompilation of available information about fossil fungi from Argentina. Eventually the website will be expanded and include information for all South America.
Who am I?
I'm a paleobotanist from Argentina currently working for the CONICET as a research investigator and I'm located in Anillaco, La Rioja, northwestern Argentina. My research interests include the paleobiology and paleoecology of fungi through time. My previous research included the paleoenvironmental reconstruction of a Late Oligocene sedimentary sequence using geological and paleobotanical data from deposits in Ethiopia. Currently, I'm studying fossil plants and fungi from Mesozoic and Cenozoic sequences in Patagonia and northwestern Argentina.
Overview of the fossil record of fungi:
Fungi are significant members of modern ecosystems and have an origin that may well extend back to the Precambrian (Heckman et al., 2001). However, although supposed fungi have been described from Precambrian deposits, unequivocal representatives of major fungal groups are no older than the Paleozoic (Taylor et al., 2009). A limited number of world deposits, concentrated in the Northern Hemisphere, have provided the majority of information known about fossil fungi. As a result, the fungal fossil record is incomplete relative to other fossils studied by paleobotanists and known only from a limited number of regions and geological ages (Taylor et al., 2009). One such deposit that has been intensely studied paleomycologically for around a hundred years is the famous Devonian-age Rhynie Chert from Scotland, where the oldest, structurally preserved, representatives of major fungal groups have been found (Taylor et al., 2004, 2009). Possible older records of some of these groups, including endomycorrhizal fungi characterized by Glomus-like chlamydospores from Wisconsin and multi-celled spores attributed to ascomycetes from the Silurian of Sweden were recovered from macerated sediments (Sherwood-Pike & Gray, 1988; Redecker et. al, 2001). Conclusive evidence about fossil basidiomycetes appears later in the geological record, in Carboniferous deposits from France (Krings et al., 2011). Several other fungi, especially those described from chert- and amber-bearing deposits, spanning the Phanerozoic, such as those found in Permian and Triassic silicified peat from Antarctica, have provided significant information about the paleobiology and evolution of this group. Another place displaying a significant diversity of fungi and fungus-like organisms is the newly discovered chert-bearing geothermal deposits from the Jurassic of Patagonia in southern Argentina. Fungi described from these sites include examples of mutualists, biotrophs, necrotrophs and a variety of saprotrophs associated with plants, animals and arthropods (Remy et al., 1994; Taylor and White 1991; Schmidt et al., 2007; Garcia Massini et al., 2012). These records demonstrate that, despite the still heterogeneous fungal fossil record, fungi underwent a rapid radiation since their origin, accompanying the diversification that occurred on land when other organisms started to colonize the Earth since the early Paleozoic.
More recently, a greater number of researchers have been studying fossil fungi from worldwide deposits and today the record appears finer than thirty years ago. However, many gaps remain and a greater effort and number of projects dedicated to the study of fossil fungi are needed before their evolution and roles in the past can be more fully discerned. Most productive depositional paleoenvironments for the study of fossil fungi are those where special features of the preservation mode, such as those that occur during permineralizations and petrifications, allow the recovery of tri-dimensionally preserved specimens. In those cases it is possible to discern anatomically, in addition to morphologically, fungal structures and the different biological inter-phases characterizing the interactions occurred between them and other organisms present in ancient ecosystems. Although these kinds of deposits are uncommon in the geological record, they are known from throughout the Phanerozoic and are continually providing information about fossil fungi. Amber deposits, especially those of Cretaceous and younger ages have also provided significant information about the evolution of fungi. In summary, although fossil fungi have been studied for over a hundred years a lot of information remains to be collected about their presence in paleoecosystems. Their study, therefore, is an ongoing process that is continually providing additional documentation of fossils from different periods and geographic areas filling up holes about their origin, extinction and diversification through time, thus, allowing the fossil record to play an increasingly significant role in the task of deciphering the evolution and biology of extant fungi.
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