Bones contained entirely within the skin of some of the largest dinosaurs on Earth might have stored vital minerals to help the massive creatures survive and bear their young in tough times, a new study has suggested.
According to a team of researchers from the University of Guelph, the study of two sauropod dinosaurs, an adult and a juvenile, from Madagascar, suggested that these long-necked plant-eaters used hollow “skin bones” called osteoderms to store minerals needed to maintain their huge skeletons and to lay large egg clutches.
Sediments around the fossils show that the dinosaurs’ environment was highly seasonal and semi-arid, with periodic droughts causing massive die-offs.
“Our findings suggest that osteoderms provided an internal source of calcium and phosphorus when environmental and physiological conditions were stressful,” Matthew Vickaryous, co-author of the study, said.
Shaped like footballs sliced lengthwise and about the size of a gym bag in the adult, these bones are the largest osteoderms ever identified. The adult specimen’s bone was hollow, likely caused by extensive bone remodelling, said Vickaryous.
Osteoderms were common among armoured dinosaurs. Stegosaurs had bony back plates and tail spikes, and ankylosaurs sported heavily armoured bodies and bony tail clubs.
Today these “skin bones” appear in such animals as alligators and armadillos.
Such bones, which are today found only in animals like alligators and armadillos, were rare among sauropod dinosaurs and have appeared only in titanosaurs. These massive plant-eaters included the largest-ever land animals.
“This is the only group of long-necked sauropods with osteoderms,” he said.
The study has been recently published in Nature Communications.