Dinosaurs Grew Rapidly, Say Florida State University Researchers

"All dinosaurs - primitive and advanced, large or small - grew at rates accelerated beyond those typical of reptiles today," said Erickson, who also teaches gross anatomy in the FSU College of Medicine.

Prior to the 1960s, Erickson said, dinosaurs were thought to be scaled up versions of living reptiles with slow growth rates compared to mammals and birds. In the 1960s and 70s, the conventional wisdom was turned on its head when researchers came to believe that dinosaurs were more like living birds.

"Recently, it has been contended that the presence of growth lines in dinosaur bones - a typically reptilian attribute marking cessations in growth during development - coupled with a highly vascularized matrix like birds and mammals indicated growth rates between reptiles and birds or mammals," he said.

Essentially, Erickson explained, dinosaurs had a unique pattern of growth that linked growth rates with mass. Small dinosaurs tended to grow more slowly than large ones and the largest dinosaurs piled on the pounds like a whale.

"Small chicken-sized dinosaurs grew like marsupial mammals, horse-sized dinosaurs like precocial birds, elephant-sized dinosaurs like eutherian mammals, and gigantic sauropod (long-necked dinosaurs) like whales."

This new information is important, Erickson said, because growth rates are a clue to a dinosaur's life history: its reproductive maturity, diet, and other characteristics.

"We're a long way from Jurassic Park," Erickson said. "Nevertheless, recent research efforts employing new integrative, cross-disciplinary techniques have placed paleontology on the brink of numerous major breakthroughs."