The Biggest Known Animals

The era of truly giant animals may have passed, with some of the planet's largest species having become extinct thousands, if not millions, of years ago. Giants still exist today though, with all classes of animals having their largest members. Some of these animals may be dwarfs compared to what has walked on this planet, but they are still colossal by modern standards.

  1. Largest Living Mammal

    • The mammalian class has the largest animal to have ever lived on this planet. The blue whale grows to between 82 to 105 feet in length and weighs up to 200 tons. It is a colossal aquatic animal that reaches this size on a diet of tons of tiny shrimp-like organisms called krill. It is found in all the world's oceans, but is classified as endangered due to excessive hunting.

    Largest Living Birds

    • The largest living species of bird on the planet is Africa's ostrich. It is a flightless bird that grows to between 7 to 9 feet in height and weighs up to 350 lbs. The bird has long legs, which make it a fast runner capable of speeds of up to 43 miles per hour. It also holds the record for the largest eye of any land animal, measuring around 2 inches across.

    Largest Living Reptile

    • The world's largest living reptile is a throwback to the giant, now extinct, reptilian dinosaurs. The saltwater crocodile is the largest reptile on the planet by mass; some snakes grow longer, but are not as heavy. It grows to around 20 feet in length on average and weighs up to 2,200 lbs. It lives in southeast Asia and Australia within fresh and saltwater habitats and has a reputation as a man-eater.

    The Largest Living Fish

    • Fish are a large and varied class of animal with species of numerous sizes and shapes. The largest fish in the world is the whale shark. It grows to between 18 and 32 feet in length on average and weighs up to 20 tons. Despite its huge size, it feeds on enormous quantities of tiny plankton, floating vegetation and small fish. It lives in the tropical ocean regions around the globe.

    Largest Living Arthropod

    • Arthropods are the class of animals that include insects, spiders, scorpions, crabs and lobsters. The largest member of this class is the giant Japanese spider crab. It grows to around 12 feet across and weighs up to 40 lbs. Most of its size is because of its long legs. It is also one of the longest-living arthropods, surviving up to 100 years of age.