Fur, Mammary glands... Off the top of my head. Look at a phylogenic tree with MEIs for more info.
birds are a whole class in themselves. birds reptiles mammals amphibians fish
Birds are aves, a special branch of the reptiles. Only birds belong to the aves.
penguins are not reptiles but they are not mammals either, they are birds.
Birds are... birds. I think there are 4 categories. Mammals, Amphibians, Reptiles, Birds.
Birds are aves, a special branch of the reptiles. Only birds belong to the aves.They are definitely not mammals.
Birds are in a category by themselves. Specifically, the categories are Mammal, Fish, Reptile, Amphibian, and Bird.
Because it has evolutionary features of both non-avian reptiles and birds.
Squid are in their own special group.
No. Dinosaurs are officially classified as reptiles. Their closest living relatives are birds.
No, birds aren't mammals.They are aves, a special branch of the reptiles. Only birds belong to the aves.
The best fossil evidence supporting the division between reptiles and birds would be transitional fossils showing a clear evolutionary pathway between the two groups. Fossils with features characteristic of both reptiles and birds, such as Archaeopteryx, provide strong support for the evolutionary link between these classes.
Mammals are distantly related to birds. Oddly, if you look at an evolutionary tree, birds are actually more closely related to reptiles than they are to mammals.