Crocodiles are not dinosaurs, but both crocodiles and dinosaurs came from the crown group Archosaurs. Archosaurs were reptiles that included birds, crocodiles, pterosaurs, and dinosaurs. Modern-day birds are descendants of feathered dinosaurs, evolving over the last 65 million years.
Reptiles, such as crocodiles and lizards, have legs that sprawl out to the side. Their thigh bones are almost parallel to the ground. They walk and run with a side-to-side motion. Dinosaurs, on the other hand, stand with their legs positioned directly under their bodies.
Crocodilians (including alligators) are also not directly descended from dinosaurs. Alligators and dinosaurs are both archosaurs, therefore alligators (and other crocodilians, such as crocodiles and caimans) are the closest living (non-avian) relatives of dinosaurs.
In fact, birds are commonly thought to be the only animals around today that are direct descendants of dinosaurs. So next time you visit a farm, take a moment to think about it. All those squawking chickens are actually the closest living relatives of the most incredible predator the world has ever known!
Crocodilians are reptiles, the first of which appeared around 320 million years ago. Reptiles arose directly from the amphibians, a diverse group of animals at that time.
Crocodilians are the most closely related group. They evolved before dinosaurs and experts put crocodiles in the larger family group, archosaurs. Strictly speaking, birds are the only direct descendants of the giant, extinct dinosaurs, and crocodiles and alligators are close relatives.
For approximately 120 million years—from the Carboniferous to the middle Triassic periods—terrestrial life was dominated by the pelycosaurs, archosaurs, and therapsids (the so-called "mammal-like reptiles") that preceded the dinosaurs.
The closest living relatives of Tyrannosaurus rex are birds such as chickens and ostriches, according to research published today in Science (and promptly reported in the New York Times). Paleontologists used material discovered in a chance find in 2003 to pin down the link.
In an evolutionary sense, birds are a living group of dinosaurs because they descended from the common ancestor of all dinosaurs. Other than birds, however, there is no scientific evidence that any dinosaurs, such as Tyrannosaurus, Velociraptor, Apatosaurus, Stegosaurus, or Triceratops, are still alive.
Most dinosaurs went extinct. Only birds remained. Over the next 66 million years, birds evolved in many ways, which enabled them to survive in lots of different habitats. Today there are at least 11,000 bird species.
Australia is home to two species of crocodiles, the Estuarine Crocodile and the Freshwater Crocodile. Both belong to the reptile family Crocodylidae (the 'true crocodiles'), members of the sub-class Archosauria.
A new species of crocodile that lived about 95 million years old was discovered in Australia, and researchers discovered it ate a dinosaur as its final meal.
No! After the dinosaurs died out, nearly 65 million years passed before people appeared on Earth. However, small mammals (including shrew-sized primates) were alive at the time of the dinosaurs.
Scientists credit Triops cancriformis as the oldest animal species. Other species may not be quite so old, but the natural histories of the species are similar.
There are two main reasons. First, crocodiles can live for a very long time without food. Second, they lived in places that were the least affected when the asteroid hit Earth.
It may seem hard to find two animals more different than a hummingbird and an crocodile But as strange as it may be, birds and crocodilians (the group containing alligators, crocodiles and gharials) are each other's closest relatives.
There are later descriptions of creatures in the Bible that could be referring to dinosaurs. One example is the behemoth of Job 40:15-19. Even in fairly modern history there are reports of creatures which seem to fit the description of dinosaurs.
It is therefore entirely possible for prehistoric genetic material to survive for up to one million years. But the big dinosaurs departed this life some 66 million years ago. So the prospect of finding enough viable DNA material in what remains of them today is therefore vanishingly remote.
Ok, first thing: Please tell us that dragons could be real.
"Unfortunately, no, we do not have evidence of dragons on this planet. We do have evidence of very cool extinct animals that were kind of similar to dragons, but no fire-breathing six-legged vertebrates, I'm afraid."
Sixty-six million years ago, dinosaurs had the ultimate bad day. With a devastating asteroid impact, a reign that had lasted 180 million years was abruptly ended. Prof Paul Barrett, a dinosaur researcher at the Museum, explains what is thought to have happened the day the dinosaurs died.
Fossil studies have long suggested modern birds were descended from T. rex, based in similarities in their skeletons. Now, bits of protein obtained from connective tissues in a T. rex fossil shows a relationship to birds including chickens and ostriches, according to a report in Friday's edition of the journal Science.
rex parents cared for their young before or after they hatched. No T. rex eggs or nests have ever been found, but fossils of other Tyrannosaur relatives suggest that they laid elongated eggs, roughly 20 or more at a time.
Mammals: After the extinction, mammals came to dominate the land. An early relative of all primates, including humans, survived the extinction. Snakes: Although a number of snake species died out around 65 million years ago, snakes as a group survived.
At its beginning, Earth was unrecognizable from its modern form. At first, it was extremely hot, to the point that the planet likely consisted almost entirely of molten magma. Over the course of a few hundred million years, the planet began to cool and oceans of liquid water formed.
The first year of the world was between 4 and 4.5 billion years ago. The earth, as a planet, formed sometime during the Hadean Eon.