A mid-Cretaceous, 99-million-year-old mushroom has been found in Burma. Like a scene from Jurassic Park, the preserved soft tissue of this organism is helping us re-create something. Not giant, prehistoric megafauna with six inch teeth like you might hope for, but something a bit more valuable to the scientific community. This fungal specimen along with other preserved insects from the time are helping us understand ecological interactions and the true species diversity before Tyrannosaurus rex made it onto Earth’s scene.
Palaeoagaracites antiquus is its name, and is one of five fruiting bodies ever to be found like this. Soft bodied gilled mushrooms are never fossilized, which is why our mycological fossil record is non-existent. There are fossilized strands of hyphae, but nothing we could distinctly describe. Even with the sap of a prehistoric tree preserving the fine details of this fungus, we are not adequately able to place it on the phylogenetic tree. That didn’t stop us from naming it though.
We know it is a part of the class Agaricomycetes and it is these fungi that have wide ranging ecological roles. Decomposing dead organic matter, parasitizing other organisms, and pairing symbiotically with plants, these fungi engineer ecosystems. This single mushroom lets us know that the forest floor nearly 100 million years ago was a thriving, functional place, jam-packed with biological activity. Although this fungus offers profound insight about ancient fungal diversity and the function of the forest floor, other insects preserved in amber and fossilized in rock are providing us with knowledge of the trophic interactions that molded the ecological trajectories of the present day.
Phylogeny between fungi (red) and mycophagous beetles (green). Cai et al. 2017.
Several beetles have also been found in the same area of Burma, excavated from the Early Cretaceous. Some of them have mouthparts specialized in mycophagy; the specialization of fungal feeding. Similar small teeth-like structures are found in species that feed on fungi today . This, along with other morphological similarities assign these species found in Burmese amber to the extant subfamily Oxyporus.
Mycophagous beetles fossilized and preserved in amber.
Together these biological fragments of Earth’s past tell us a more detailed story of the prehistoric forest floor. It was a place just teaming with trophic interactions. Gilled mushrooms where abundant enough to drive the specialization of a living group of beetles. Although we only have proof of one mushroom that existed 99-million-years ago, with the discovery of mycophagous beetles, one can confidently fathom the fungal diversity before T. rex was terrorizing the land.
This edition of Fungi Friday is dedicated to my Mother Linda, a loving high school science teacher who always inspires me. Happy Birthday!