New Study Unravels Complex Evolution of Mammal Upright Posture

Harvard researchers reveal that the transition from sprawled to upright posture in mammals was nonlinear and occurred later than previously thought.

The evolution of mammal posture from sprawled to upright was a complex, nonlinear process that occurred much later than previously believed.
Harvard researchers used advanced biomechanical modeling and fossil data to study this evolutionary transition in synapsids, the ancestors of mammals.
The study found that some extinct species exhibited flexibility in limb posture, similar to modern alligators, before evolving a fully upright stance.
Findings suggest that key traits associated with upright posture evolved close to the common ancestor of therians, rather than in a straightforward manner.
The research provides new insights into unresolved fossil record issues and highlights the role of mass extinction events in shaping evolutionary paths.