Hyenas' Bite Force vs. Dogs': Z. Jack Tseng's 2-Minute Thesis main content.

Hyenas' Bite Force vs. Dogs': Z. Jack Tseng's 2-Minute Thesis

by AMNH on


Last summer, the popular website PhD Comics invited graduate students from around the world to record and submit two-minute descriptions of their theses. Of more than 200 entries submitted, 12 were chosen to be animated. 

One of those featured belongs to Z. Jack Tseng, Ph.D., a Frick Postdoctoral Fellow in the Museum's Division of Paleontology

The video explains his thesis, which explores the evolutionary journey of some "of the most awesome animals on Earth: hyenas." 

As Tseng explains, hyenas are "incredible bone-crushing machines," capable of cracking through the leg bones of large animals.

Spotted hyena
Spotted hyena, photographed in Namibia, Africa
Yathin S Krishnappa

And though hyenas and dogs are both in the order Carnivora, they are not as closely related as you might think. (Hyenas are more closely related to cats.)

Nonetheless, as Tseng learned during his thesis research, hyenas and dogs evolved a parallel set of adaptations that allowed them to ably crush bone, a compelling example of convergent evolution.

Tseng's work here at the Museum builds on the work featured in the video. By examining skulls using computed tomography (CT), building computer models, and reconstructing ancestral skull shapes, Tseng is studying the "biomechanical capability of the predecessors of modern carnivores."

"These analyses," says Tseng, "will help us interpret the lifestyle and ecology of some of the earliest carnivores, and get a good sense of what mammals close to the ancestral condition for living bears, dogs, hyenas, cats were capable of doing with their skull and teeth."

See another PhD Comics Two-minute Thesis, this one on the "secret lives" of stars.