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Living fossil facts for kids

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Liphistius.sp.small
More primitive trapdoor spiders, such as this female Liphistius sp., have segmented plates on the dorsal surface of the abdomen and cephalothorax, a character shared with scorpions, making it probable that after the spiders diverged from the scorpions, the earliest unique ancestor of trapdoor species was the first to split off from the lineage that contains all other extant spiders.

Living fossil refers to life forms which have survived with little change for a long time, and which are still around today.

  • Horseshoe crabs are a typical case of living fossil. They have changed little in appearance since the Ordovician period, 450 million years ago.
  • Crocodilians first appeared 220 million years ago, and are close relatives of the dinosaurs. However, modern crocodiles only date back to the Upper Cretaceous of 84 million years ago.
  • Turtles are first known from 215 million years ago, but for some reason they are not often mentioned as living fossils.
  • The Coelacanth is definitely a living fossil. It is the closest link between fish and the first amphibians (408–362 million years ago). The Coelacanth was thought to have been extinct for 80 million years until one was caught alive off the east African coast in 1938. It is therefore also a Lazarus taxon.
  • The Ginkgo tree, Ginkgo biloba, is a good example from the world of plants. It is a gymnosperm. It was thought to be long extinct in the wild, but is now known to grow in at least two small areas in China. The first similar fossils date from the Permian period, 270 million years ago.

Living fossils are not identical to their ancestors, of course. But they lived in the same or similar environments, and their adaptations suggest that their life-style was the same, or very similar.

LingulaanatinaAA
Modern Lingula anatina, very much alive

Examples

Ginkgo Stamm
Ginkgos have not only existed for a long time, but also have a long life span, with some having an age of over 2,500 years. Six specimens survived the atomic bombing of Hiroshima, 1 to 2 kilometers from ground zero. They still live there today.

Some of these are informally known as "living fossils".

Plants

Fungi

  • Neolecta

Animals

  • Vertebrates
    Wild shortbeak echidna
    Echidnas are one of few mammals to lay eggs.
Hoatzins in Ecuador
Hoatzin are born with two visible claws on their wings, but the claws fall out once the birds reach maturity.
Crocodylus acutus jalisco mexico
Crocodilians survived the K–Pg extinction event that killed off the dinosaurs.
Tuatara
Tuataras are reptiles, yet retain more primitive characteristics than lizards and snakes.
Horseshoe Crab
With little change over the last 450 million years, the horseshoe crabs appear as living fossils.
  • Insects
    • Mantophasmatodea (gladiators; a few living species)
    • Meropeidae (3 living species, 4 extinct)
    • Micromalthus debilis (a beetle)
    • Mymarommatid wasps (10 living species in genus Palaeomymar)
    • Nevrorthidae (3 species-poor genera)
    • Nothomyrmecia (known as the dinosaur ant)
    • Notiothauma reedi (a scorpionfly relative)
    • Orussidae (parasitic wood wasps; about 70 living species in 16 genera)
    • Peloridiidae (peloridiid bugs; fewer than 30 living species in 13 genera)
    • Sikhotealinia zhiltzovae (a jurodid beetle)
    • Syntexis libocedrii (Anaxyelidae cedar wood wasp)
  • Crustaceans
    • Glypheoidea (2 living species: Neoglyphea inopinata and Laurentaeglyphea neocaledonica)
    • Stomatopods (mantis shrimp)
    • Triops cancriformis (also known as tadpole shrimp; a notostracan crustacean)
  • Molluscs
  • Other invertebrates

Images for kids

See also

Kids robot.svg In Spanish: Fósil viviente para niños

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Living fossil Facts for Kids. Kiddle Encyclopedia.