by Patrick McShea
At first it seems absurd to discuss speed in front of adiorama in which nothing moves. With appropriate prompts, however, this threedimensional snapshot of galloping pronghorn antelopes can generate an astonishing level of mind’s eye animation.
When viewed from dusty Wyoming roadsides, distant pronghorns appear to gallop without sound, even when their pace suddenly changes and their speed doubles for 100-yard stretches.
At the close vantage point offered by the diorama, such antelope maneuvers would undoubtedly produce a sensory mix of blurred furred forms, the staccato clatter of hooves against rock, and the powerful scent of crushed sage.
The species’ blazing speed invites speculation about its evolutionary history. Could pronghorn antelopes be adapted to elude a predator no longer found on western landscapes? A large extinct cat termed an American cheetah is sometimes cited as the missing participant in this natural selection process.
Fossil evidence examined during the past 25 years complicates this narrative. Paleontologists point to expansive ranges for these big cats that include mountainous areas and sea coasts, and the absence, to date, of sites containing both cat and antelope fossils.
With the identity of the pronghorn’s prehistoric predator unsettled, a viewing position in front of the diorama is a place to ponder possibilities.
Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences of working at the museum.
