Protomycena is an extinct monotypic genus of gilled fungus in the family Mycenaceae , of order Agaricales . At present it contain the single species Protomycena electra , known from a single specimen collected in an amber mine in the Cordillera Septentrional area of the Dominican Republic . The fruit body of the fungus have a convex cap that is 5 mm ( 0 @.@ 2 in ) in diameter , with distantly spaced gills on the underside . The curved stipe is smooth and cylindrical , measuring 0 @.@ 75 mm ( 0 @.@ 030 in ) thick by 10 mm ( 0 @.@ 39 in ) long , and lack a ring . It resemble extant ( currently living ) species of the genus Mycena . Protomycena is one of only five known agaric fungus species known in the fossil record and the second to be described from Dominican amber .