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 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 lacks a ring. It resembles extant 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.

Archaeomarasmius is an extinct genus of gilled fungus in the Agaricales family Tricholomataceae, containing the single species Archaeomarasmius leggetti. It is known from two fruit bodies recovered from amber, one consisting of a complete cap with a broken stem, the other consisting of a fragment of a cap. The cap has a diameter ranging from 3.2 to 6 mm, while the stem is 0.5 mm (0.02 in) thick. Spores were also recovered from the amber, and are broadly ellipsoid to egg-shaped, measuring roughly 7.3 by 4.7 μm. The species, which resembles the extant genera Marasmius and Marasmiellus, is inferred to have been saprobic on plant litter or other forest debris.