long. While mature light colored spores are present in many agarics, darker colored mature spores are found in some genera. Palaeoagaracites presents the oldest, and only, evidence of fungal parasitism by other fungi in the fossil record. The fossil displays a complex interrelationship between three different fungal genera. The preserved P. antiquus cap is host to both a mycoparasitic fungus and a hypermycoparasitic fungus. The surface of the Palaeoagaracites specimen hosts the extinct necrotroph fungus Mycetophagites atrebora. The mycelia of Mycetophagites are found across the surface of the P. antiquus pileus, and the hyphae penetrate into the P. antiquus tissues themselves forming necrotic areas. Mycetophagites is in turn host to a hypermycoparasitic necrotrophic fungus species Entropezites patricii. Hyphae of Entropezites are preserved penetrating the Mycetophagites hyphae, forming areas of decomposing tissue. Entropezites also displays a range of growth stages for probable zygospores. The combined distinguishable characters of Palaeoagaracites were not enough for Poinar and Buckley to place the genus further than Agaricales incertae sedis. The overall size, shape of the spores, and structure of the cap hint at a relationship to the genera Mycena, Marasmius and Collybia. References †Palaeoagaracites Agaricales enigmatic taxa †Palaeoagaracites Prehistoric fungi Fossil taxa described in 2007 Natural history of Myanmar Cretaceous fungi Burmese amber Fossils of Myanmar Taxa named by George Poinar Jr.