A key feature contributed to sauropods getting so enormous, new dino foot study reveals - The Conversation

For the first time, we have shown that a soft heel pad was crucial to how sauropod dinosaurs supported their immense weight, according to a new digital reconstruction of their feet.

Sauropods, which weighed up to 50 tonnes and dominated the world’s ecosystems for around 100 million years, appear to have developed soft heel pads early in their evolution, and it was likely a key step that allowed sauropods to become the largest animals to have ever walked the earth!

One of the most notable things about sauropods is the immense size of some species: the feet of sauropod dinosaurs would have shaken the earth as they walked.

Around 230 million years ago, the ancestors of these dinosaurs were small, two-legged animals that would have looked very much like their saurischian cousins, the theropods; most probably wouldn’t have weighed more than an ostrich.

But starting around 210 million years ago, sauropod ancestors increased in size, with an estimated body mass approaching one tonne.

Having spent many years tracking sauropods in the Kimberley, I [Steve Salisbury] have long pondered what their feet might have looked like in life.

It has long been assumed that like other dinosaurs, sauropods walked on their toes, with the ankle joint elevated off the ground.

Armed with knowledge of what the foot skeleton of various sauropods looked like, along with information about their tracks, Andréas Jannel went about trying to figure out how their feet may have worked, as part of his PhD at The University of Queensland.

Andréas generated 3D digital models for the foot skeleton of various sauropods and sauropod precursors.

Put simply, without that pad beneath the heel, bones in the feet of sauropods would have crumpled under their immense weight

By 170 million years ago, the first “true” sauropods were exceeding 10 metric tonnes, and tracks attributed to them show a well-developed heel pad

The stage had been set, and within 10 million to 15 million years, titans weighing more than 30 tonnes were walking the earth, and the diversification of giant sauropods had begun