for National Geographic News
Pterosaurs, like their dinosaur relatives, didn't wait until they were fully grown to have sex, a new study suggests.
Researchers examined microscopic tree ring-like growth markings in hundreds of bones from a species of the extinct flying reptiles discovered in central Argentina in the 1990s.
The Pterodaustro guiñazui bones came from multiple individuals, including an embryo inside an egg and adults with wingspans between 1 to 8 feet (0.3 to 2.5 meters).
P. guiñazui lived during the mid-Cretaceous, about a hundred million years ago.
"It is quite amazing that even after millions of years, the microscopic structure of the bone is still intact," study author Anusuya Chinsamy-Turan, a paleobiologist at the University of Cape Town in South Africa, said by email.
The team found that the pterosaur attained about 53 percent of its adult body size in just two years.
At that point, the flying reptile was likely sexually mature. Its growth continued slowly for three or four more years.
(Related news: "Dinosaurs Had Sex As Teens, Study Says" [July 20, 2007].)
"Then they stopped growing and maybe they didn't live much longer," said paleontologist and study co-author Luis Chiappe, director of the Dinosaur Institute at the Natural History Museum in Los Angeles, California.
The finding shows that the flying reptiles, like dinosaurs, did not grow throughout their entire lives—as do modern turtles and crocodiles, Chiappe said.
Chiappe, Chinsamy-Turan, and Laura Cordornú from the National University of San Luis in Argentina described the growth patterns of the pterosaur last month in the journal Biology Letters.
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