How the world's largest flying animals supported their giant necks? Scientists reveal

A recent study published in the journal Science Direct talks about Azhdarchid pterosaurs, which were the world's largest flying reptiles and remained poorly understood. As per the study, the X-ray computed tomography reveals a complex internal micro-architecture for three-dimensionally preserved, hyper-elongate cervical vertebrae of the Cretaceous azhdarchid pterosaur. The extremely long necks of the species have always been a captivating thing. The study revealed that the incorporation of the neural canal within the body of the vertebra and elongation of the centrum result in a “tube within a tube”, which was supported by helically distributed trabeculae.

Analyzing Azhdarchid pterosaurs

By studying well-preserved vertebrae specimens excavated from Morocco, the scientists concluded that as few as 50 trabeculae increase the buckling load by up to 90 per cent. This further implies that a vertebra without the trabeculae is more prone to elastic instability. The instability is because of the axial loads. 

(Image Credits: ScienceDirect.com)

As per the study, the assessment of pterosaur skeletal anatomy is often limited by a shortage of high-quality specimens which display a3D morphology. This is especially true for the pterosaur neck skeleton. The limited amount of morphological data for Azhdarchidae contributes to the poor understanding of the biomechanics and palaeoecology of these pterosaurs. The three-dimensionally preserved pterosaur bones are rare, and articulated material is even rarer, the mid Cretaceous Kem Kem Group of Morocco is becoming increasingly important as a source of well-preserved, 3D pterosaur bones. This also includes the azhdarchid cervical vertebrae. 

After a XCT scan and 3D manipulation it was concluded that there is a complex internal architecture of the azhdarchid cervical vertebra. A centrally located bony neural tube attached to the centrum wall was also discovered.  The arrangement is somewhat irregular, therefore, the helices are not perfect. This likely reflects changes in the stress regime along a centrum that is not a perfect cylinder.

(Image Credits: Twitter/Fatal3rror)