Constantine's free-tailed bat is characterized by its relatively great size and long, rather evenly rectangular skull. Total average length measurements from the occipital condyle to the anterior of the alveolus based on 19 specimens is from 16.5 to 17.4 mm.[3]
Bones of this species found in Slaughter Canyon Cave have been dated to a minimum of 209 ± 9 ka.[4]
^Lundberg, J. and McFarlane, D.A.. 2006. A minimum age for canyon incision and for the extinct Molossid bat, Tadarida constantinei, from Carlsbad Caverns National Park, New Mexico.. Journal of Cave and Karst Studies 68(3): 155-177