Most violent two-legged Dinosaurs became peaceable vegan, according to new research, writes Geoffrey Lean.
Scientists at Chicago's Field Museum studied the diet of 90 species of theropods – colloquially called "predatory dinosaurs", which in a lot of cases became the ancestors of modern birds – examining the teeth, fossilised dung (the mind boggles) and stones in the stomach that had been used to grind vegetation.
They establish that even though the therapods' bodies still made them ideal hunter-killers – which is how leading scientists had believed they remained until they became extinct – most species, in fact, turned vegetarian.
"Somewhere on the line to birds," says the familiar researcher, Dr Lindsay Zanno, "predatory dinosaurs went soft." Ultimately, they developed toothless beaks.
Another study, by the University of Texas, augments the image of the peace-loving dinosaur by challenging another conventional view – which they took over the world by driving out other animals. Instead, it seems, they were "humbler, more opportunistic creatures" that took benefit of a mass extinction 200 million years ago. "They didn't invade the neighborhood," says Prof Tim Rowe. "They waited for the inhabitants to leave and then moved in when no one was watching."
Monday, July 25, 2011
Two-legged Dinosaurs were peace-loving veggies
Thursday, July 21, 2011
Skeletons of dinosaurs sell for $2.75m
The skeletons of three large dinosaurs are among a treasure trove of natural history artifacts that have sold at a sole auction in Dallas.
The quality stars of the Heritage Auctions bidding were a "fighting pair" of dinosaur skeletons that sold to a museum for $2.75 million (£1.7m), and an enormous, 19-foot-long triceratops that fetched $657,250 (£400,000) from a private collector.
The sale included more than 200 items, including meteorites, minerals and other fossils.
The fighting dinosaurs - an allosaurus and a stegosaurus - were offered mutually because of their discovery in a Wyoming quarry with the jaw of the allosaurus wrapped around the leg of the stegosaurus, leading to speculation that the two were engaged in a predator-prey battle.
Heritage Auctions declined to reveal which museum picked up the pair, though the organisation did say the museum was outside the United States.
"I'm ecstatic that 'the fighting pair' establishes such a great home," David Herskowitz, director of natural history at Heritage Auctions, said in a statement. "These are important and iconic Jurassic-era specimens, which science did not even know existed together at the same time, and now they will be going to a final end where the public will get to enjoy them and where they will be of maximum benefit to science."
Thursday, July 14, 2011
In Argentina Pint-sized ancestor of Tyrannosaurus rex was discovered
The ancestor of Tyrannosaurus rex, who lived when dinosaurs were the underdogs 230 million years ago, has been discovered by scientists in Argentina.
Eodromaeus was four feet long from nose to tail-tip and weighed just 10 to 15 pounds.
Nonetheless the two-legged dinosaur predated the biggest and most fierce land predators that ever lived, including T. rex.
Fossil bones of two of the creatures were unearthing side-by-side at a desert site known as the Valley of the Moon in northern Argentina.
Researchers pieced together a near-complete skeleton of the new species which they illustrate today in the journal Science.
Study leader Dr Paul Sereno, from the University of Chicago, US, described: "It really is the earliest
look we have at the long line of meat eaters that would eventually culminate in Tyrannosaurus rex near the end of the dinosaur era.”
Monday, July 11, 2011
Dinosaur with Single-clawed
Scientists believe Linhenykus monodactylus, which stood just 2ft tall and weighed about the same as a huge parrot, may have used its dino-digits to dig into insect nests.
The biped creature belongs to the alvarezsauroids, a branch of the ''theropod'' family of carnivorous dinosaurs.
Theropods gave rise to modern birds and included well-known names such as Tyrannosaurus rex and Velociraptor.
But researchers found Linhenykus had one remarkable feature not seen in any of its relatives, a single functional finger on each hand bearing a large claw.
Michael Pittman, from University College London, one of the scientists who illustrate the find today in the journal Proceedings of the National Academy of Sciences, said: ''Non-avian theropods begin with five fingers but evolved to have only three fingers in later forms.
Wednesday, July 6, 2011
Dinosaur the size of a giraffe could fly large distances and even cross continents
Dr Mark Witton, a palaeontologist from the University of Portsmouth and Dr Michael Habib from Chatham University USA, has studied how the giant pterosaur, which was as big as a giraffe, could get off the ground.
They found that the reptiles took off by using the powerful muscles of their legs and arms to push off from the ground, efficiently pole-vaulting over their wings.
Once airborne they could fly large distances and even cross continents, the scientists claim.
According to Dr Witton : ''Most birds take off either by running to pick up speed and jumping into the air before flapping wildly, or if they're small enough, they may merely launch themselves into the air from a standstill.
Previous theories suggested that giant pterosaurs were too large and heavy to perform either of these manoeuvres and therefore they would have remained on the ground.
But when investigative pterosaurs the bird analogy can be stretched too far.
These creatures were not birds they were flying reptiles with a definitely different skeletal structure, wing proportions and muscle mass.
They would have attained flight in a completely different way to birds and would have had a lower angle of take off and initial flight trajectory. The structure of these creatures is unique.