The first known creature to have walked on all its four limbs was a horrible cow-like animal that lived more than 250 million years ago. Scientists named it Bunostegos akokanensis and the knobby-looking ‘pre-reptile’ cannot be compared to any other creature that lived in the super continent Pangea.
Having the dimensions of an average cow, this plant-eater animal had bulbous tumor-like excrescences popping up from its head and a bony shield on its muscular back. Its bones were first found in the dry scenery of Sahara in the northern Niger in 2013.
A new research of its skeleton suggests that it raised its whole body from the ground to walk just like the way in which many animals do it today. All the discovered pareiasaurs who lived on the super continent of Pangea during the Permian era more than 250 million years ago were known as “sprawlers”. It means that their legs only jut out from the sides of their body, continue out and slant down, just like some modern reptiles.
A lot of the creatures that roamed around that time had an identical upright and semi-upright back position, but what is exciting and special about the Bunostegos akokanensis is its forelimb and that its framework is sprawling-precluding and going below its whole body – and cannot be compared to any animal that lived during that time.
The parts and features inside its forelimb bone fragments will not allow an expansive position and that is a unique trait. Instead, the scientists think this ugly animal was walking like a cow, having about the same dimensions. In particular, a few findings lead to the conclusion that Bunostegos was standing in a different way than the other prehistoric animals, with its feet entirely below the body.
Going from the shoulder, or glenoid fossa, the alignment of the bones is reaching down in a way that the bone running from its shoulder to the elbow, called the humerus, were straight under its body in a vertical position. This would limit the humerus from protruding to the sides, too, since Bunostegos akokanensis’ humerus does not turn like the one of the sprawlers.
In sprawlers, these bone moves are what allowed the humerus to extend to the side and under the neck, but then it went downwards from the shoulder. The humerus of the animal cannot twist, indicating that if its elbows and shoulders were positioned under its body, the feet could actually touch the ground.
Image source: Nature World Report