A groundbreaking study led by Dr. Robert Brocklehurst at Harvard University has revealed that the evolution of mammals from their sprawling ancestors to upright walkers was a nonlinear journey, characterized by unexpected evolutionary detours.

To reach these conclusions, the study employed advanced techniques to analyze the humerus of over 60 non-mammalian synapsids and 140 living vertebrates, focusing on bone characteristics crucial for locomotion.

The findings suggest that the transition to fully upright walking occurred much later in mammalian history than previously assumed, challenging established theories regarding the timeline of posture evolution.

A particularly significant result showed that the development of fully upright walking, or parasagittal posture, took place later than earlier hypotheses suggested, which had claimed it was a defining characteristic of early mammals.

The research indicates that mammalian evolution was marked by bursts of innovation, with ancestors experimenting with a variety of postures rather than following a simple path from sprawling to upright.

Interestingly, early synapsids, previously thought to have limb functions akin to modern reptiles, were found to possess unique limb functions, highlighting their distinctiveness as creatures.