The fossil was discovered in Dominican amber and formally described as a new species in 2000 by George Poinar Jr., Eric Peterson, and Jamie Platt. The holotype specimen (Poinar AF9-17B) is kept at the University of Oregon.[1]
Because of its resemblance to modern-day members of Parmelia, the fossil lichen has been placed provisionally in that genus, although the authors acknowledge that without sacrificing more of the single available specimen for analysis, it is impossible to assert this definitively. Although the authors noted "striking resemblance" to some members of Hypotrachyna, they chose to tentatively group the fossil taxon in Parmelia because of the mostly simple (i.e., unbranched) rhizines, a trait characteristic of that genus.[1] Some later authors have opined, however, that this taxon, and another fossil lichen described concurrently, Parmelia ambra, do not belong to the genus concept of the Parmelia as presently circumscribed, although there is agreement that the Parmeliaceae is the appropriate family.[2][3]
Based on what types of organisms are used for dating, Dominican amber dates from 15–20 million years ago (based on foraminifera fossils), to 30–45 million years (based on coccolith fossils).[1] Because lichens are scarce in the fossil record, specimens like this are often used as calibration points for molecular clock analyses to improve understanding of lichen evolution.[4][5][6]
