No-one knows for definite because we are always discovering more or a species becomes extinct.There could be more than thousands.There are many types of animals on Earth. I am not positive on how many, but there are vertebrates and invertabrates. Invertebrates are animals without a backbone. For an example, snakes or worms. Vertebrates are the opposite. They are animals with a backbone. For an example, dogs, cats and birds. Most of the animals on Earth are vertebrates.
of course! most animals have a backbone.
These numbers are not accurate, as accurate number of animal species on earth has yet to be discovered. Currently it looks like less than 3% of the known species of animals on earth are vertebrates (have back bones). There are around 50 000 species of vertebrates, most of which are fish. Most animals are invertebrates, and most of those are insects.
about 18,492,002 species consists on earth
An earthworm does not have a backbone.
no. humans are vertebrate because they have a backbone, aka spine, of which 95% of living species on Earth do not, eg insects, plants, etc.
All species of monkeys are vertibrates, they have a backbone, invertibrates do not have a backbone.
Snakes have at least 200 vertebrae and in so species more that 400.
A animal or species without a backbone
False
about 18,492,002 species consists on earth
Many people would argue that no one species was on the Earth before another species. These people believe in creationism.