Post date: Apr 11, 2012 10:34:26 PM
Argentine scientists discover dinosaur bones and eggs in Patagonia which they believe shows a link between dinosaurs and modern-day birds.
BUENOS AIRES, ARGENTINA (APRIL 11, 2012) (REUTERS) - Argentine scientists announced on Wednesday (April 11) that they had discovered the bones and dinosaur eggs of a new 70-million year old dinosaur that resembled flightless birds.
The palaeontologists said they expect the eggs to provide them with more information about this new species, the Bonapartenykus ultimus dinosaur that was a member of the small, long-legged, fast-moving Alvarezsaurid dinosaur family.
The researchers believe the eggs were likely fertilized and contained highly-developed embryos. Some of the eggs were likely inside the mother dinosaur when she died and other eggs were near her.
Although the link to modern-day birds has been disputed in the past, palaeontologist Fernando Novas said the current batch of bones bares resemblance to the skeleton of the Nandu, a flightless rhea native to Patagonia.
"Part of the skeleton of the Alvarezsaurid is similar, superficially, to the Nandu [South American flightless bird] and the same as size as the Nandu. What is interesting about this discovery by Jaime Powell was not just that the bones allowed us to recognise the lineage of the dinosaur, but the eggs were also found very close by and allow us to determine the method of reproduction used by these creatures that lived in Argentina around 80 million years ago," said Novas.
The work was led by Novas and fellow Argentine researchers, Federico Agnolin and Jaime Powell.
The dinosaur's species was first discovered by Powell and later named Bonapartenykus ultimus, after Dr. Joseph Bonaparte who discovered the first Alvarezsaurid in the early 1990s.
Novas said the latest research allows palaeontologists to trace a line from this dinosaur to the 'living dinosaurs' of today: birds.
"Over time, their arms started to get longer. Their legs were specially adapted to run more agilely and to move at high speeds. The arms originally served to trap their pray, but they ended up being transformed into wings because the skin of these dinosaurs their scales also turned into feathers. These long arms became covered in feathers and so we have a continuation in the story of this lineage. The fall of the meteorite extinguished many dinosaurs, but a group of carnivorous dinosaurs with extended arms and feathered bodies that we call birds survived until today. So we have a story that goes from 230 million years ago until now. Current birds - like pigeons, hummingbirds, condors or eagles - are living dinosaurs."
The eggs are now being analysed with powerful microscopes although some showed traces of fungus damage.
The dinosaur is believed to have been about 8.5-feet (2.6 meters) long, lived in Gondwana, the most southernmost of the two supercontinents at the time. Today, that land is part of Rio Negro province in Argentina.