Dinosaurs evolved from an earlier group of reptiles, and birds evolved from a group of dinosaurs.
One of the earliest birds, Archaeopteryx, dates back to the Jurassic. It has many features of dinosaurs, and indeed, several fossils of Archaopteryx were initially mistaken for dinosaur fossils. It is fairly clear from the fossil evidence that birds evolved from dinosaurs.
Dinosaurs themselves date back to the middle to late Triassic. You may wish to look up Eoraptor. Dinosaurs appear to have evolved from socket-toothed archosaurs common in the mid Triassic, which were an early reptile.
The skeletal structure of dinosaurs bears many similarities to that of birds. Birds are classified as dinosaurs, while all "non avian" dinosaurs went extinct at the end of the Cretaceous.
Answer:That may depend on the dinosaur. All dinosaurs are likely to have ultimately evolved from reptiles, but the theropods (bipedal carnivorous dinosaurs) may have evolved from ancient birds. Birds have many features in common with theropods which suggests that they had a common ancestor. It is generally believed that this common ancestor was a dinosaur but it may well have been a bird (see related links).Looking back in time through the theropod fossil record, these dinosaurs appear to be more bird-like the further back in time you look. Raptors are known to have had feathers and were fairly bird-like, but Archaeopteryx was much more bird-like and lived much earlier and may have been an ancestor of the raptors. There is also a controversial fossil called Protoavis that was dated even earlier and was more bird-like still, with hollow bones like modern birds.
So birds may have been around throughout the mesozoic era and pre-date the dinosaurs. We have little record of them though because their more fragile, hollow bones reduce the chances of any fossils surviving to the present day.
no there mammal
No, a shoebill is not a mammal. It is a large bird species found in East Africa.
Ostrich is a bird, and it is the largest bird species in the world. They are flightless birds with long legs and necks.
Mammal, Reptile, Fish or Bird are 4 main traits: Mammal -gives birth to live young and breathes via air. Reptile -lays eggs that can't be moved and breathes via air. Fish -majority lays eggs and breathes via gills extracting oxygen from water. Bird -lays eggs that can be moved and breathes via air.
Generally, mammal nervous systems are more complex and larger than reptile nervous systems due to the higher brain-to-body ratio in mammals. This complexity often translates to higher cognitive abilities and behaviors in mammals compared to reptiles.
mammal
It is a bird, neither mammal or reptile.
mammal is elephant, bird is ostrich, amphibian is frog, and reptile is nile crocodile
No. A hen is a bird.
A budgerigar is a bird.
It is a mammal
A badger is a mammal.
A badger is a mammal.
mammal
a sparrow is neither a reptile or a mammal. It is a bird.
neither it is a bird
its a reptile