(The research was funded in part by a grant from the National Geographic Society. National Geographic News is owned by the National Geographic Society.)
Similar to Dinosaurs
Kristi Curry-Rogers, a paleontologist at Macalester College in St. Paul, Minnesota, studies growth patterns in dinosaurs.
She said the pterosaur growth pattern is similar to what she and other scientists have found in a variety of dinosaurs.
"All of them grow faster than modern reptiles, and none of them grow as fast as modern birds," she said. "That's something that's consistent across analyses."
Modern birds reach their full adult size within about a year but often delay reproduction for several years. Eagles, for example, begin to mate at about age four.
The addition of pterosaurs to this data set pushes the evolution of faster growth rates back along the lineage of animals that split from modern reptiles and gave rise to birds, Curry-Rogers noted.
"We're seeing some really interesting biological changes that I can't imagine didn't contribute to their long success on Earth," she added.
Grow Fast, Die Young?
Their faster growth rates were beneficial because they likely allowed early sexual maturity, Chiappe said.
Other scientists have speculated that such a growth strategy helped dinosaurs pass on their genes before the harsh, and often deadly, realities of older age set in.
(Related: "For Tyrannosaurs, Teen Years Were Murder" [July 13, 2006].)
Since the tree ring-like growth marks end once a pterosaur has reached adult size, Chiappe said he and colleagues are uncertain how long P. guiñazui lived.
However, he noted that only a few individuals in their sample of hundreds of pterosaurs appeared to be more than six or seven years old.
"It's likely that these animals did not live very long," he said.
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
|
SOURCES AND RELATED WEB SITES
|
