Crocodiles are the closest living relatives of the birds
, sharing a common ancestor that lived around 240 million years ago and also gave rise to the dinosaurs.
Did alligators evolve from birds?
Since alligators descend from a
common ancestor with dinosaurs
, they can provide a useful evolutionary comparison to birds. (Despite their appearance, birds are more closely related to alligators than lizards are.)
Alligators and birds are part of the same larger group,
called archosaurs
, which has existed for 250 million years and which has given rise not only to birds and crocodilians, but also to dinosaurs. … Millions of years ago, archosaurs diverged into several groups, scientists say.
Birds are most closely related to crocodiles
. … And they are most closely related to crocodiles, which also came from archosaurs. This is what most people mean when they say that birds are reptiles, although technically, according to the phylogenetic system, birds, reptiles, and mammals all share a reptile-like ancestor.
What does a bird and a crocodile have in common?
Birds, crocodiles and dinosaurs have much in common – including, it turns out,
their breath
. The hyper-efficient breathing system of birds is shared with alligators, and probably evolved in archosaurs, the common ancestor of crocodilians, birds and dinosaurs.
Are sharks dinosaurs?
Today's sharks are
descended from relatives that swam alongside dinosaurs in prehistoric times
. … It lived just after the dinosaurs, 23 million years ago, and only went extinct 2.6 million years ago.
Are there any dinosaurs alive today?
Other than birds, however,
there is no scientific evidence that any dinosaurs
, such as Tyrannosaurus, Velociraptor, Apatosaurus, Stegosaurus, or Triceratops, are still alive. These, and all other non-avian dinosaurs became extinct at least 65 million years ago at the end of the Cretaceous Period.
Are birds Amniotes?
Amniota, a group of limbed vertebrates that includes all living reptiles (class Reptilia), birds (
class Aves
), mammals (class Mammalia), and their extinct relatives and ancestors.
Birds have scales like many dinosaurs
and some dinosaurs may have had feathers. Scientists have discovered that the tissues used to produce scales in reptiles are similar to those that produce feathers in birds. This suggests that there is a common ancestor between dinosaurs, birds, and reptiles.
The DNA hypothesis suggests that turtles were
a sister group to the archosaurs
(the group that contains the dinosaurs and their relatives, including crocodiles and their ancestors and modern birds and their ancestors). A second hypothesis posits that turtles were more closely related to lizards and tuataras.
What's the biggest alligator in the world?
The current world record alligator was taken by Mandy Stokes, of Thomaston, in August 2014. It measured
15 feet, 9 inches long
and weighed 1,011.5 pounds.
Are birds cold blooded?
Like people and all mammals,
birds are warm-blooded
. Their body temperature remains constant — about 106 degrees, according to the Audubon Society. To maintain their body heat in freezing temperatures, their bodies have developed several mechanisms. … This heat exchange isn't just used by birds.
What is the closest relative to a crocodile?
Turtles
, not birds, have been found to be the closest relatives of crocodiles and alligators, according to an analysis of the largest available collection of reptile genes.
Are sharks older than dinosaurs?
Sharks are among Earth's most ancient creatures. First evolving over 455 million years ago, sharks are
far more ancient than the first dinosaurs
, insects, mammals or even trees.
What killed the Megalodon?
We know that megalodon had become
extinct by
the end of the Pliocene (2.6 million years ago), when the planet entered a phase of global cooling. … It may also have resulted in the megalodon's prey either going extinct or adapting to the cooler waters and moving to where the sharks could not follow.
What was the first animal on earth?
Earth's first animal was
the ocean-drifting comb jelly
