This article is from the source 'guardian' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.guardian.co.uk/science/2013/apr/10/dinosaur-embryos-twitched-eggs-modern-birds

The article has changed 3 times. There is an RSS feed of changes available.

Version 0 Version 1
Dinosaur embryos twitched in their eggs like those of modern birds Dinosaur embryos twitched in their eggs like those of modern birds
(35 minutes later)
Dinosaur embryos moved around inside their eggs and grew in much the same way as those of modern animals such as birds, say scientists who have examined more than 200 fossilised bones from 190m-year-old embryos found in China.Dinosaur embryos moved around inside their eggs and grew in much the same way as those of modern animals such as birds, say scientists who have examined more than 200 fossilised bones from 190m-year-old embryos found in China.
The bones came from the genus known as Lufengosaurus, a long-necked dinosaur that could grow up to eight metres long, and were found among fragments of egg shells at a site near the city of Lufeng in Yunnan, south west China. They are the oldest dinosaur embryos ever found and seem to have come from several nests and from eggs at various stages of development.The bones came from the genus known as Lufengosaurus, a long-necked dinosaur that could grow up to eight metres long, and were found among fragments of egg shells at a site near the city of Lufeng in Yunnan, south west China. They are the oldest dinosaur embryos ever found and seem to have come from several nests and from eggs at various stages of development.
"Most of the time you get single glimpses of embryonic life in a dinosaur because they are preserved as a nest and all the eggs are in the same developmental stage," said Robert Reisz, a palaeontologist at the University of Toronto Mississauga, who led the team that analysed the bones. "Here we have a growth series of embryos, which allowed us to track how these animals grew.""Most of the time you get single glimpses of embryonic life in a dinosaur because they are preserved as a nest and all the eggs are in the same developmental stage," said Robert Reisz, a palaeontologist at the University of Toronto Mississauga, who led the team that analysed the bones. "Here we have a growth series of embryos, which allowed us to track how these animals grew."
The team's results are published in the journal Nature. The team's results are published in the journal Nature. Reisz's team focused their analysis on the largest bone, the femur. They found that, inside the eggs, these bones seemed to be growing very quickly, implying that their incubation period might have been relatively short.
The scientists knew they were dealing with embryonic bones because of holes all over their surface, where blood vessels would have entered them. "When we look at embryos of living organisms, [their bones] are completely invaded by blood vessels that penetrate the bone from various locations," said Reisz. "You have all these little pockmarks on the bone when you look at them. That immediately alerted us to the possibility that these are embryos." Inside the bones is a honeycomb structure of "primary spaces". The larger these are, said Reisz, the faster the embryo would have grown. In addition, the scientists found that the bones were shaped inside the eggs, as they grew, as attached muscles pulled on them. "This suggests that dinosaurs, like modern birds, moved around inside their eggs," said Reisz. "It represents the first evidence of such movement in a dinosaur."
Reisz's team focused their analysis on the largest bone, the femur. They found that, inside the eggs, these bones seemed to be growing very quickly, implying that their incubation period might have been relatively short.
Inside the bones is a honeycomb structure of "primary spaces". The larger these are, said Reisz, the faster the embryo would have grown. In the Lufengosaurus embryos, the spaces took up more of the bone than in any other known dinosaur, telling the scientists they would have grown the fastest.
"These animals are related to the giant sauropods [such as Brachiosaurus and Diplodocus] and we know very little about the early developmental stages of sauropods and their early lives as juveniles," said Reisz. "This gives us opportunities to explore the possibilities that this very fast growth rate may have been a factor in their ability to grow so big."
In addition, the scientists found that the bones were shaped inside the eggs, as they grew, as attached muscles pulled on them. "This suggests that dinosaurs, like modern birds, moved around inside their eggs," said Reisz. "It represents the first evidence of such movement in a dinosaur."