Classification allows us to group animals together depending on their similarities and differences. Animals are divided into two main groups: Animals with a backbone are called vertebrates.

Among them were the chordates, to which vertebrates (animals with ... most successful and enduring of all prehistoric animals. More than 17,000 species are known to have survived until the mega ...

Queensland Museum scientists have described a 400-million-year-old fossil, which is possibly the smallest vertebrate fossil animal known ... connection to a similar species from northern Scotland ...