We can divide animals into two categories, according to whether they have bones or not.
Vertebrates are those animals that have a skeleton or bones in their body. Humans, lions, cows, birds, etc., are examples of vertebrates.
Invertebrates are those animals that do not have any bones in their body. Insects, crabs, octopuses, etc., are invertebrates.
The vertebrates may have a fully formed skeletons like a big animal. Or the skeleton may contain small bones as in a fish.
Vertebrates
Vertebrates are further divided into
Big animals of vertebrates
Very big animals on the earth are all vertebrates.
The Blue Whale is an aquatic mammal 30 metres in length and 180 tons in weight. It is the largest animal. The Blue Whale’s tongue weighs around 2.7 tons. It is equal to the weight of an Asian Elephant. And the blue whales heart weighs about 600 kg!
The largest animal on land is the African Bush Elephant. It can reach up to 6 to 7 metre in length, 3.3 metres in height at the shoulder, and weigh 6 tons or 6000 kg.
The tallest animal is the Giraffe. It stands 5 to 6metres tall and weighs up to 1,600 kg. The giraffe has a long neck, which is 2 m in length.
The smallest vertebrate is a frog that lives in New Guinea. It is called Paedophryne amanuensis, and is only 7.7 mm long!
