Yes and no: It depends on how you classify animals. There are two main classification systems – the Linnaean system which groups organisms by characteristics and the phylogenetics system, which ...

We learned at school that there are five different classes of animals. These are mammals, birds, fish, reptiles and amphibians. However, this knowledge, long enshrined in textbooks, does not seem to ...

Anyone who has watched a rooster stalking around a farmyard might agree that there is something very dinosaur-like about birds. That may come as no surprise, given that birds are dinosaurs. But in ...

In the race to adapt to a rapidly changing climate, warm-blooded animals might have the edge. New research suggests that over millions of years of planetary history, birds and mammals have ...

Some 247 million years ago, a bizarre, six-inch-long reptile crept down a branch, its prehensile tail and feet clutching the bark like a monkey, and its narrow, birdlike face scanning its surroundings ...

Aug. 13 (UPI) --The tears shed by birds and reptiles are surprisingly similar to human tears, according to a new study. However, researchers also identified key differences. The study, published ...