Sentences with phrase «dinosaur ancestors of birds»

THE DESCENT OF BIRDS Dinosaur ancestors of birds shrank steadily for more than 50 million years.

Not exact matches

It belongs to a group called the oviraptorosaurs — funny - looking feathered dinosaurs with sharp beaks which were ancestors of birds.

«What was impressive was the consistency of the size change along the dinosaur - to - bird transition, with every descendant smaller than its ancestor,» says Lee.

Since then, more four - winged dinosaurs have been found, but doubt remained about whether they were direct ancestors of modern birds, or just an unusual group of dinobirds that later died out.

Like all modern paleontologists, Therrien was acquainted with the spectacular feathered - dinosaur fossils of the Liaoning beds in China, where the idea that dinosaurs are the ancestors of birds got its biggest boost, thanks to the preservation of feathers — both the thread - like ones known as «dinofuzz» and the more familiar shafted kind — in the silky mud of an ancient lake bottom.

Remarkably, the embryonic development of birds provides a parallel of this evolutionary history: The toe starts out like their dinosaur ancestors, but then its base (the metatarsal) becomes twisted, making it opposable.

To define just what changed in the face of bird ancestors, Bhullar examined scores of skulls of dinosaur fossils, birds, and alligators and other reptiles, taking hundreds of pictures at different angles.

For the past two decades, scientists using cladistics have claimed that dromaeosaurs were nonavian ancestors of birds, representing the best examples of how ground - dwelling dinosaurs supposedly evolved into birds.

«The evolution of birds from their dinosaur ancestors was a landmark in the history of life,» says Wang.

The study, published in the journal Current Biology, shows that the familiar anatomical features of birds — such as feathers, wings and wishbones — all first evolved piecemeal in their dinosaur ancestors over tens of millions of years.

To Norell, it's important to read these as feathers all over the body because the major thrust of his work as a scientist is to show that dinosaurs are direct ancestors of modern birds.

Here's what we know about the evolution of flight: By about 150 million years ago, the forests were filled with flying — or perhaps just gliding — dinosaurs like Archaeopteryx, possibly similar to the ancestor of modern birds.

Bhullar's group is trying to reverse bird evolution, tweaking the genes of chickens to make them revert to their dinosaur ancestors.

But all those feathered dinosaurs were theropods, flesh - eating dinosaurs that include the direct ancestors of birds.

In a new study, researchers claim that parasitic lice can tell us much about the course of bird and mammal evolution, including whether the ancestors of these animals made it through a mass extinction that wiped out most of the dinosaurs.

A study into the brooding behaviour of birds has revealed their dinosaur ancestors shared the load when it came to incubation of eggs.

Certainly, but paleontologists disagree — sometimes quite heatedly — on exactly when and where the link exists: in the form of a common ancestor or in an evolutionary shift from dinosaur to bird or bird to dinosaur.

By reorganizing the dinosaur tree, paleontologists have also added further evidence that birds are indeed dino descendants: previously, the theropods we view as birds» ancestors were not considered relatives of the bird - limbed group, but with the new evidence — and reorganization — they're all on the same part of the family tree.

Our data on the evolutionary conservation of digit development are in support of the views of many developmental biologists that the identity of the digits in the wing of birds can not be homologous to the identity of digits in the forelimbs of their hypothesized dinosaur ancestors, unless the identity of digits in theropods is erroneous.

The dinosaur Archaeopteryx is widely regarded as one of the earliest ancestors of modern birds, but the question of whether or not it could actively fly has been debated for decades.