The genus is solely known from the early Miocene, Burdigalian stage, Dominican amber deposits on the island of Hispaniola.[1][3]Coprinites is one of only four known agarics fungus species known in the fossil record and the first of three to be described from Dominican amber.[2][4]
The holotype of Coprinites is a lone fruiting body without any associated structures and a partly disarticulated stipe preserved in a piece of clear yellow amber approximately 9–6 millimetres (0.35–0.24 in) and weight 0.5 grams (0.018 oz).[1] The pileus is 3.5 millimetres (0.14 in) in diameter and has a convex shape sporting a small central depression. The brownish-pink flesh is thin with a scaly-pectinate surface. The margin is striated and slightly flared. Coprinites sports fifteen nondeccurent lamellae, or gills, which reach the outer pileus and thirteen lamellulae, short gills which do not reach the edge, of varying lengths.[4] The pileus is centered on the stipe, which is 4 millimetres (0.16 in) in diameter and incomplete, with part of the stipe base preserved in the amber next to the pileus.[1] The light brown basidiospores, present on the hymenium associated with the fruiting body, are smooth and ellipsoidal to oblong. Each basidiospore is approximately 6 to 7 μm long and appear to possess a germ pore.[1]
Coprinites was originally placed in the family Coprinaceae based on the visible structures, or macromorphology of the fruiting body and the microscopic features preserved in the amber specimen. The combination of characters present did not match any modern genus of the mushroom order Agaricales leading Poinar and Singer to erect the genus Coprinites.[1] The lack of autodeliquescence along with the mushrooms morphology lead David Hibbett, Michael Donoghue and David Grimaldi to question the placement of Coprinites.[2] They noted the characters of the genus are similar to those of genus Leucocoprinus mushrooms. They suggested that Coprinites could be treated as either a member of Coprinaceae or Agaricaceae, to which Leucocoprinus belongs. With a number of molecular studies a large portion of the genera formerly placed in Coprinaceae, including Coprinus, have been moved into Agaricaceae. Thus supporting the suggestion of Hibbet, Donoghue, and Grimaldi.[6]
^Poinar, G.O.; Buckley, R. (2007). "Evidence of mycoparasitism and hypermycoparasitism in Early Cretaceous amber". Mycological Research. 111 (4): 503–506. doi:10.1016/j.mycres.2007.02.004. PMID17512712.
^Redhead SA, Vilgalys R, Moncalvo J-M, Johnson J, Hopple JS Jr (2001). "Coprinus Pers. and the disposition of Coprinus species sensu lato". Taxon. 50 (1): 203–41. doi:10.2307/1224525. JSTOR1224525.