puc-header

Avian Dinosaur Tail Evolution and Bone Fracture Healing

28 Pages Posted: 27 May 2021 Publication Status: Review Complete

See all articles by Joseph Sheheen

Joseph Sheheen

Clemson University - Department of Biological Sciences

Dana Jones Rashid

Montana State University - Bozeman - Microbiology and Cell Biology Department

Kevin Surya

Montana State University - Molecular Biosciences Program

John R. Horner

Chapman University

Susan C. Chapman

Clemson University - Department of Biological Sciences

More...

Abstract

Bird tails transitioned during the Mesozoic from long to shortened and distally fused. Fusion of the distalmost vertebrae manifests as the bony pygostyle structure, a trait retained in extant avians that contributes to flight aerodynamics. Here, we investigate the mechanism responsible for pygostyle formation. Transcriptomic profiling and histology in extant tail tissue reveal that the immune system is crucial for this important adaptation in avian evolutionary history. Pygostyle formation commences with cell death in the intervertebral discs, within the nucleus pulposus and annulus fibrosus. The nucleus pulposus, previously thought absent in birds, forms differently in fused versus unfused regions of the tail, and its deterioration in the pygostyle is integral to the cascade of events that eventually lead to ankylosis. The complement and coagulation cascades, angiogenesis, neutrophil-like cell function, involvement of both the innate and adaptive immune systems and multiple additional events mirror those observed during bone fracture healing. The key common denominator in both processes that differentiates them from general endochondral ossification is the inflammatory response. These studies indicate that a universal mechanism for bone repair has been co-opted in avian evolution for the formation of a flight-adapted tail structure.

Keywords: bird evolution, nucleus pulposus, complement, inflammation, heterophil, neutrophil, Archaeopteryx, chicken, osteoimmunology

Suggested Citation

Sheheen, Joseph and Rashid, Dana Jones and Surya, Kevin and Horner, John R. and Chapman, Susan C., Avian Dinosaur Tail Evolution and Bone Fracture Healing. Available at SSRN: https://ssrn.com/abstract=3854523 or http://dx.doi.org/10.2139/ssrn.3854523
This version of the paper has not been formally peer reviewed.

Joseph Sheheen

Clemson University - Department of Biological Sciences ( email )

132 Long Hall
Clemson, SC 29634-0314
United States

Dana Jones Rashid (Contact Author)

Montana State University - Bozeman - Microbiology and Cell Biology Department ( email )

Bozeman, MN
United States

Kevin Surya

Montana State University - Molecular Biosciences Program ( email )

Bozeman, MT 59717-2920
United States

John R. Horner

Chapman University

Orange, CA 92866
United States

Susan C. Chapman

Clemson University - Department of Biological Sciences ( email )

132 Long Hall
Clemson, SC 29634-0314
United States

Click here to go to Cell.com

Paper statistics

Downloads
12
Abstract Views
660
PlumX Metrics