Last updated over 4 years ago
Dinosaurs lived during the Mesozoic, and became extinct about 65 My ago.
Within a species there is a great deal of diversity.
Trilobites were abundant during the Paleozoic. There were thousands of species, some tiny, some more than a foot long. Trilobtes became extinct during the Permian extinction event about 240 My ago.
Although it looks like a dinosaur, and is sometimes mistaken for one, this sailed back reptile lived in the Paleozoic, before dinosaurs, and is ancestral to mammals.
Chordates like ourselves are more closely related to echinoderms than to animals like arthropods. Both chordates and echinoderms are deuterostomes.
Some animals are parasitic. Nematodes are the most abundant animals. As many as 4 out of every 5 animals are nematodes.
Beetles are the most diverse order of animals.
In the 18th centuty the French scientist Jean Andre Peysonnel discovered that corals were animals. Earlier naturalists believed they were plants or rocks.
Some animals like birds, insects, and pterosaurs, have evolved the ability for active flight.
Some animals are carnivores.
Some animals are herbivores.
With about a million described species, insects are the most diverse animals in the world.
Animals commonly known as water bears are among the smallest in the world.
Many animals have a brain and nervous system.
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