The genus is solely known from the Lower Cretaceous, Upper Albian stage (about 100 Ma), Burmese amber deposits in Myanmar.

[1] Palaeoagaracites is one of only five known agaric fungal species known in the fossil record, the second oldest to be described, and only genus from Burmese amber.

[4] AB-368 was collected from one of the amber mines in the Hukawng Valley area southwest of Maingkhwan, Kachin State, Northern Myanmar.

[1] It was first studied by a pair of researchers led by Dr George Poinar from Oregon State University who worked with Ron Buckley.

[1] The flesh is a bluish-gray color, hairy, and radially furrowed with sixteen grooves visible on the intact section of pileus.

[1] The combined distinguishable characters of Palaeoagaracites were not enough for Poinar and Buckley to place the genus further than Agaricales incertae sedis.

The overall size, shape of the spores, and structure of the cap hint at a relationship to the genera Mycena, Marasmius and Collybia.