11509  In Hibbett and colleagues ' 1997 publication , Protomycena was placed in the subfamily Myceneae , which at the time was considered part of the Tricholomataceae family ; Mycena is currently classified in the Mycenaceae family . The placement was based solely on the visible structures , or macromorphology of the fruit body . Many of the features which are typically used to classify species into fungal families and subfamilies are based on microscopic features not visible or preserved in the amber specimen . Consequently , the assignment to Mycena is provisional ( the authors also note certain similarities with extant members of Marasmius ) , and the describing authors leave open the option of treating the genus placement as incertae sedis ( uncertain placement ) within the Agaricales . Protomycena is distinct from other amber @-@ preserved mushroom taxa such as Coprinites , in the grooved surface of its pileus and its anastomosing gills . 