March 23, 2017, Asian Scientist Newsroom  

AsianScientist (Mar. 23, 2017) - Mushrooms and mushroom-eating beetles preserved in a 99-million-year-old piece of amber suggest that gilled mushrooms have been around for much longer than previously thought. These findings have been published in Nature Communications.  

Mushrooms, or Agaricomycetes, are common, conspicuous and morphologically diverse fungi. Most agaricomycete fruiting bodies are ephemeral, so they are extremely rare in fossils. Up to now, all described species of gilled mushrooms, or Agaricales, have been preserved in amber.  

Evidence indicating the origin and early diversification of Agaricomycetes is very limited. Two of the five known forms of Agaricales are from the Mesozoic era: Palaeoagaracites antiquus from a 99-million-year-old piece of Burmese amber, and the slightly younger Archaeomarasmius leggetti from New Jersey amber (about 90 million year old). The remaining three species are from early Miocene Dominican amber, some 20 million years old.  

In the present study, a research team led by Professor Huang Diying from Nanjing Institute of Geology and Palaeontology (NIGPAS) of the Chinese Academy of Sciences report a diversity of gilled mushrooms and mycophagous (mushroom-eating) rove beetles in Burmese amber, the latter belonging to Oxyporinae, modern members of which exhibit an obligate association with soft-textured mushrooms.  

All the mushrooms studied are very well-preserved and can be grouped in four forms. A stalk and a complete intact cap containing distinct gills are visible in most of these mushrooms. The new discovery suggests a long-term evolutionary stasis of body form for at least 99 million years and highlights the palaeodiversity of mushrooms, pushing back the presence of agarics by at least 25 million years.  

More interestingly, the mouthparts of these early Oxyporine rove beetles, including enlarged mandibles and greatly enlarged apical labial palpomeres with dense specialized sensory organs, match those of modern taxa and indicate a mushroom feeding habit.  

The diverse and morphologically specialized Oxyporine beetles appeared by the Early Cretaceous, some 125 million years ago. Their finding displays an ancient ecological community assembling diverse mushrooms and beetles and established on specialized trophic interaction by this early date.  

From: https://www.asianscientist.com/2017/03/in-the-lab/mushroom-evolution-beetle-amber/