The latest study found the creature walked on all fours. However, pareiasaurs usually boasted limbs that extended from the side of the body, then curved downwards at the elbow.
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But in Bunostegos, Turner said, “The elements and features within the forelimb bones won’t allow a sprawling posture”.
“Aspects of the anatomy of the shoulder and the forelimb indicate that the humerus could not have jutted out in a “sprawling” posture”, said Dr. Linda Tsuji of the Royal Ontario Museum, study co-author and a member of the team that found the Bunostegos in Niger.
Furthermore, National Museums of Scotland vertebrate paleontologist Dr. Nick Fraser comments, “Here’s this big, cow-sized animal in this very arid region”. Credit: Marc Boulay/ Wired ” A lot of the animals that lived around the time had a similar upright or semi-upright hind limb posture, but what’s interesting and special about Bunostegos is the forelimb. The answers lie in the pre-reptiles’ shoulder joint, humerus, elbow and ulna.
It might be that Bunostegos akokanensis was quite a sight, what with its oversized body and its bony armor, but it’s not its looks that paleontologists are quite fascinated with.
The bones in four areas: 1) the shoulder 2) the humerus 3) the elbow joint 4) the radius and ulna.
Bunostegos stood in another way than all the remaining, with the legs exclusively beneath the physique, she stated.
“Sprawling” posture describes the way lizards’ legs come out of their bodies – horizontally in the upper part of the limb, and vertically from the joint down to the ground.
But Turner stated she wouldn’t be stunned if different animals of the time are ultimately additionally discovered to have similarities to this posture, which advanced independently in reptiles and mammals a number of occasions over the eras.
In addition, the Bunostegos had a more limited elbow joint compared to sprawling pareiasaurs, which tend to have greater mobility at the elbow.
Instead, it would only swing in a back and forth direction, like a human knee does.
Bunostegos is a 260-million-year-old pre-reptile that roamed the supercontinent Pangea munching on plants.
‘Bunostegos was an isolated pareiasaur, ‘ explained Turner.
According to the release, the Bunostegos’s posture suggests that it was an outlier.
For the lengthy journeys between meals, Turner stated, the upright posture may need been crucial for survival.
“Bunostegos is much further back on the evolutionary tree than anything else that exhibits this posture”, Turner told redOrbit.
“Posture, from sprawling to upright, is not black or white, but instead is a gradient of forms”, Turner said.
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And the more we learn about this animal, the more we learn about evolution from almost the beginning of all legged creatures overall. “The anatomy of Bunostegos is unexpected, illuminating and tells us we still have much to learn”.
