Rio de Janiero, Brazil Scientists on Thursday unveiled the reconstructed skeleton of a sheep dog-sized dinosaur they said was an ancestor of the Tyrannosaurus rex.
Alexander Kellner, a professor at Federal University of Rio de Janeiro who led the team that found the Santanaraptor in Brazil, said the discovery was important, both because of how well it was preserved and the clues it provided about the origins of Tyrannosaurus rex.
"The material is perfect, it's as if it was buried yesterday," Kellner said.
Kellner's team uncovered the bones in 1991 during a dig in southern Ceara state, 1,200 miles northeast of Rio de Janeiro, but it was only recently that the team confirmed it as the only specimen of an extinct species belonging to a group that evolved into the Tyrannosaurus rex.
Because the Santanaraptor lived right at the time when the South American continent was separating from Africa, Kellner believes the discovery proves the Tyrannosaurus rex's roots lie in the Southern Hemisphere.
Even though his team only managed to uncover the dinosaur's two legs and parts of the hips and tail, they were able to reconstruct the whole body by looking at dinosaurs with similar bone structures at around the same stage of evolution and extrapolate.
What they eventually pieced together was a carnivore standing around 2 1/2 feet tall, measuring about 6 feet from head to tail and weighing about 65 pounds.
So well preserved were the remains that scientists even found fossilized soft tissue -- such as blood vessels and muscle -- along with the bones. Although scientists had already found fossilized impressions of soft tissue, Kellner said this marked the first time that tissue itself had been discovered.
"This discovery opens up whole new avenues of research that weren't available to us before. We're still trying to figure out what questions we can ask with this material," Kellner said.
Kellner said it was entirely possible that they would one day be able to retrieve DNA from the specimens, which they could use to determine the dinosaurs outward appearance, such as color and musculature.