Deerfield, IL (June 2009) - Many of us have broken bones in our bodies at one time or another, and when this happens a healing process begins. The same was true of animals in the past, and has been well documented in all groups of dinosaurs. But how can we study and understand the healing process? A new study published in the Journal of Vertebrate Paleontology uses high-resolution computed tomography (CT) imaging to guide sampling of bone lesions in the vertebrae of a hadrosaur ("duck-billed”" dinosaur for histological and isotopic analysis.
The detailed sampling made possible by CT imaging allowed scientists led by William Straight of Northern Virginia Community College to examine bone mineral deposited in the repair (the callus). This callus preserves a temperature record of the healing process, a record that can be measured with stable isotopic techniques. The results demonstrated that skeletal repair in at least some dinosaurs shows a combination of reptilian and non-reptilian characteristics. Despite hadrosaurs not being among those dinosaurs most closely related to birds, "healing and remodeling rates in our dinosaur bones are similar to those seen in birds," says Straight.
Dinosaurs seem to be covered with these healed injuries, much more so than modern animals of nearly similar size. As Straight muses: "Quick healing may have offset the consequences of being so large, and being surrounded by other giant animals, in a Mesozoic school of hard knocks."
ABOUT THE SOCIETY OF VERTEBRATE PALEONTOLOGY
Founded in 1940 by thirty-four paleontologists, the Society now has more than 2,300 members representing professionals, students, artists, preparators, and others interested in VP. It is organized exclusively for educational and scientific purposes, with the object of advancing the science of vertebrate paleontology.
Journal of Vertebrate Paleontology
The Journal of Vertebrate Paleontology (JVP) is the leading journal of professional vertebrate paleontology and the flagship publication of the Society. It was founded in 1980 by Dr. Jiri Zidek and publishes contributions on all aspects of vertebrate paleontology.
IMAGES (top to bottom)
Image 1: Photo of a hadrosaur neural spine (the part of the vertebra that sticks out and you can feel along your back) with a fracture zone crossing the shaft at the white arrow. [Photo William Straight]
Image 2: Cross-section (greatly enlarged) of callused bone showing a thin fringe of callus (uppermost left) over normal bone. The overlapping circles are osteons, cross-sections of blood vessel-tracks. [Photo William Straight]
Image 3: Cross-section (greatly enlarged) of callus in the process of being repaired (the lattice-like structure dominating the image). The open loops are precursors to the osteons that ultimately turn the repaired area into mature bone tissue. [Photo William Straight]
Image 4: Reconstruction of a "duck-billed" dinosaur, the type of dinosaur on which the study was based. The bones used in the study came from the ridge along the dinosaur's back. [Image Dmitry Bogdanov, 2008]
William H. Straight, PhD
Northern Virginia Community College, Fairfax, VA