Evidence for fungal proliferation following the Cretaceous/Paleogene mass-extinction event, based on chemostratigraphy in the Raton and Powder River basins, western North America

Abstract

The presence of the amino acid α-aminoisobutyric acid (Aib) within Cretaceous/Paleogene (K/Pg) boundary clay in the Raton and Powder River basins in Colorado and Wyoming, respectively, has been described as compelling evidence that extraterrestrial Aib survived the high-energy Chicxulub impact. Based on contemporary experiments and simulations, however, it is highly unlikely that extraterrestrial Aib survived the impact, which had peak impact pressures and temperatures in excess of 600 GPa and 10,000 K, respectively. In other words, the amino acid signature of the carbonaceous chondritic asteroid that impacted Chicxulub was undoubtedly destroyed upon impact during formation of the vapor plume or so-called “fireball.” The only organisms known to produce Aib are the suite (more than 30 genera) of cosmopolitan saprotrophic filamentous fungi that include Trichoderma Pers., which has recently been hypothesized to have thrived during the K/Pg mass-extinction event. Therefore it is proposed that the Aib horizon in the K/Pg boundary clay in the Raton and Powder River basins correlates with the K/Pg boundary fungal spike, which thus far has only been observed in New Zealand (Southern Hemisphere). This proposition is based upon superimposing the Aib horizon on the well-known iridium and fern-spore spikes, as its stratigraphic position precisely matches that predicted by the fungal spike. If correct, this hypothesis alters the conventional perspective on the tempo and mode of terrestrial ecosystem recovery in western North America, as the heavily sampled K/Pg boundary section in the Raton Basin was instrumental in shaping the traditional narrative of the rapid recolonization of a denuded landscape by ferns via wind-blown spores in the immediate wake of regional deforestation caused by the K/Pg impact event. Perhaps more importantly, it could present an alternative to traditional palynological approaches for locating the fungal spike in other terrestrial K/Pg boundary sections and could provide additional support for the generalization that global mass-extinction events are frequently accompanied by fungal spikes.

Comprehensive phylogenetic analyses of Orchidaceae using nuclear genes and evolutionary insights into epiphytism

“…Zhao et al, 2021; Li et al, 2022), suggesting that the ancestor of Orchidaceae had already acquired the capacity for mycoheterotrophic growth. It was hypothesized that after the K‐Pg boundary sunlight was blocked for decades; furthermore, saprotrophs, such as fungi, were dominant, whereas floristic diversity was greatly reduced (Vajda and Bercovici, 2014; Kaiho et al, 2016; Berry, 2020; Carvalho et al, 2021). Hence, these orchids that had mycoheterotrophic capabilities beyond the germination stage were probably much less affected by the low level of available sunlight than photosynthetic plants and benefited from the dominant fungal community that appeared after the K‐Pg event.…”

Ogród mykologiczny, muzeum grzybów czy mykoteka. Jak ogrody botaniczne mogą promować wiedzę o trzecim wielkim królestwie życia

“…Wystarczy spojrzeć na skamieniałości datowane na pogranicze kredy i paleogenu. Coraz liczniejsze badania wskazują na gwałtowny wzrost zawartości zarodników grzybów w osadach pochodzących niemal z każdego kryzysowego okresu geologicznego Ziemi, jak również chemiczne dowody na zwiększony udział grzybów wśród innych organizmów (Berry 2020;Vajda i McLoughlin 2004; Röhrich i współaut. 2014).…”

Mutualistic interactions between ants and fungi: A review

“…For terrestrial environments, the Permian–Triassic extinction event (251.9 Mya) and the Cretaceous–Paleogene mass extinction (≈66 Mya) resulted in massive amounts of dead plant biomass, followed by the proliferation of fungi that then influenced the evolution of all other living terrestrial organisms (Berry, 2020 ; Heitman et al, 2018 ; Rampino & Eshet, 2018 ). Many fungi participate in the degradation of organic matter as saprophytes, whereas other taxa are parasites (e.g., entomopathogenic fungi), predators (e.g., of nematodes), likely commensals (e.g., yeasts from the guts of insects), and mutualists of chlorophyllous plants (e.g., algae in lichens; plants in mycorrhizal symbiosis) and animals (e.g., fungi cultivated for food by certain termites, coleopterans, and ants; Heitman et al, 2018 ; see also Biedermann & Vega, 2020 for mutualisms).…”