Etymology: Latin, mirus, "wonderful", and after Arce, winged messenger of the titans in Greek mythology, for the evidence suggesting a refined flight apparatus in this species.

Species: eatoni ATTERHOLT, HUTCHISON & O’CONNOR, 2018
Etymology: In honor of Dr. Jeffrey Eaton, for his decades of work contributing to our understanding of the Kaiparowits Formation and the fossils recovered from it.
= Avisaurus nova? HUTCHISON, 1993

Holotype: UCMP 139500

Location: UCMP locality V92097, Grand Staircase-Escalante National Monument, Garfield County, Utah.

Horizon: Kaiparowits Formation.


Age: Late Campanian Stage, uppermost Senonian subepoch, Upper Gulf Epoch, Late Cretaceous.

Material: Several cervical and thoracic vertebrae (including the axis), the pygostyle, almost all phalanges from the left pes and several from the right, a complete humerus, femur, and tarsometatarsus, a partial scapula, coracoid,furcula,and tibiotarsus, as well as fragments of the sternum, radius, ulna, carpometacarpus, and manula phalanges.