Protomycena is an extinct monotypic genus of gilled fungus in the family Mycenaceae, of order Agaricales. At present it contains 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 has a convex cap that is in diameter, with distantly spaced gills on the underside. The curved stipe is smooth and cylindrical, measuring thick by long, and lacks a ring. It resembles 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. Discovery and classification The genus is known only from the holotype specimen, a single fruit body (mushroom) currently residing in the private collection owned by Ettore Morone of Turin, Italy. The specimen was collected in one of the amber mines in the Cordillera Septentrional area of the island of Hispaniola, in the Dominican Republic. The amber is believed to date from the Miocene Burdigalian stage, about 20 to 16 million years before the present. It was first studied by a group of researchers consisting of David Hibbett and Michael Donoghue from Harvard University, with David Grimaldi of the American Museum of Natural History. Hibbett and colleagues published their 1997 type description in the American Journal of Botany. The generic name Protomycena is noted as "first", and "Mycena", a modern genus that it resembles. The specific epithet electra was coined by the authors from the Latin or Greek word for "amber", in reference to the mode of preservation. When it was reported, Protomycena electra was the third species of fossil agaric fungus to be described. The two species Coprinites dominicana and Aureofungus yaniguaensis are also known from the amber mines of the Dominican Republic, while the fourth species Archaeomarasmius leggeti is from the older, Cretaceous age New Jersey Amber. With the 2007 publication of a fifth extinct agaric species, Palaeoagaracites antiquus, the minimum age for the order Agaricales was pushed back to the Albian (approximately 100 Ma). Description The holotype of Protomycena is a single fruit body without any associated structures, preserved in a piece of clear light yellow polished amber approximately wide. The pileus is in diameter and has a convex shape, sporting a raised central region (an umbo). The pale flesh appears yellowish in the