Evolution: special design of a very long neck (Evolution)

by David Turell , Thursday, April 15, 2021, 19:53 (1107 days ago) @ David Turell

A dinosaur beats giraffes in neck size with very special vertebrae:

https://www.sciencedaily.com/releases/2021/04/210414113508.htm

"Little is known about azhdarchid pterosaurs, gigantic flying reptiles with impressive wingspans of up to 12 meters. Cousins of dinosaurs and the largest animals ever to fly, they first appeared in the fossil record in the Late Triassic about 225 million years ago and disappeared again at the end of the Cretaceous period about 66 million years ago. One of their most notable features for such a large flighted animal was a neck longer than that of a giraffe. Now, researchers report an unexpected discovery in the journal iScience on April 14: their thin neck vertebrae got their strength from an intricate internal structure unlike anything that's been seen before.

"'One of our most important findings is the arrangement of cross-struts within the vertebral centrum," says Dave Martill of the University of Portsmouth, UK. "It is unlike anything seen previously in a vertebra of any animal. The neural tube is placed centrally within the vertebra and is connected to the external wall via a number of thin rod-like trabeculae, radially arranged like the spokes of a bicycle wheel and helically arranged along the length of the vertebra. They even cross over like the spokes of a bicycle wheel. Evolution shaped these creatures into awesome, breathtakingly efficient flyers."

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"His team realized immediately that they needed to bring in engineers to understand how the biomechanics of this unusual neck would have worked. Those analyses suggest that as few as 50 of the spoke-like trabeculae increased the amount of weight their necks could carry without buckling by 90%. Together with the basic tube-within-a-tube structure, it explains how the relatively light-weight animals could capture and carry heavy prey items without breaking their necks.

"'It appears that this structure of extremely thin cervical vertebrae and added helically arranged cross-struts resolved many concerns about the biomechanics of how these creatures were able to support massive heads -- longer than 1.5 meters -- on necks longer than the modern-day giraffe, all whilst retaining the ability of powered flight," Martill says

"While pterosaurs are sometimes thought of as evolutionary dead ends, Martill and colleagues say the new findings reveal them as "fantastically complex and sophisticated." Their bones and skeletons were marvels of biology -- extremely light yet strong and durable."

Comment: In my view very careful exacting design was required before this strange creature could take to the skies. Did not appear by Darwinian stepwise evolution.