Epidemiologic study of tumors in dinosaurs.

Occasional reports in isolated fragments of dinosaur bones have suggested that tumors might represent a population phenomenon. Previous study of humans has demonstrated that vertebral radiology is a powerful diagnostic tool for population screening. The epidemiology of tumors in dinosaurs was here investigated by fluoroscopically screening dinosaur vertebrae for evidence of tumors. Computerized tomography (CT) and cross-sections were obtained where appropriate. Among more than 10,000 specimens x-rayed, tumors were only found in Cretaceous hadrosaurs (duck-billed dinosaurs). These included hemangiomas and metastatic cancer (previously identified in dinosaurs), desmoplastic fibroma, and osteoblastoma. The epidemiology of tumors in dinosaurs seems to reflect a familial pattern. A genetic propensity or environmental mutagens are suspected.