Late Jurassic

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Late/Upper Jurassic
161.5 ± 1.0 – ~145.0 Ma
Chronology

The Late Jurassic is the third

million years ago (Ma), which is preserved in Upper Jurassic strata.[2]

In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age.[3] In the past, Malm was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units.

Subdivisions

The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock:[citation needed]

  Tithonian (149.2 ±0.7 – 145.0 ± 0.8 Ma)
  Kimmeridgian (154.8 ±0.8 – 149.2 ±0.7 Ma)
  Oxfordian (161.5 ± 1.0 – 154.8 ±0.8 Ma)

Paleogeography

During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the spawning of the Atlantic Ocean. However, at this time, the Atlantic Ocean was relatively narrow.[citation needed]

Life forms of the epoch

This epoch is well known for many famous types of

crocodylomorphs and the first birds
, appeared in the Jurassic. Listed here are only a few of the many Jurassic animals:

  • Camarasaurus, a large herbivorous sauropod dinosaur from North America
  • Apatosaurus, a large herbivorous sauropod dinosaur from North America
  • Brachiosaurus, a large herbivorous sauropod dinosaur from North America
  • Brontosaurus, a large herbivorous sauropod dinosaur from North America
  • Diplodocus, a large herbivorous sauropod dinosaur from North America
  • Barosaurus, a large herbivorous sauropod dinosaur from North America
  • Europasaurus, a small herbivorous sauropod dinosaur from Europe
  • Brachytrachelopan, a small herbivorous sauropod dinosaur from South America
  • Supersaurus, possibly the largest North American sauropod of them all
  • Dicraeosaurus, a large herbivorous sauropod dinosaur from Africa
  • Giraffatitan, another large sauropod from Africa (usually recognized as a species of Brachiosaurus)
  • Allosaurus, possibly the biggest Jurassic predator, the most common Late Jurassic theropod of North America, also present in Europe
  • Epanterias, one of the largest Jurassic carnivores from North America (possibly just Allosaurus)
  • Saurophaganax, one of the largest Jurassic carnivores from North America (possibly a synonym of Allosaurus)
  • Yangchuanosaurus, a large theropod from Asia
  • Torvosaurus, a large Jurassic carnivore, from North America and Europe
  • Ceratosaurus, a medium-sized Jurassic carnivore from North America, Europe, and possibly Africa
  • Elaphrosaurus, a medium-sized Jurassic carnivore from Africa
  • Ornitholestes, a small theropod from North America
  • Compsognathus, a small theropod from Europe
  • Tuojiangosaurus, a thyreophoran from Asia
  • Stegosaurus, a thyreophoran from North America and Europe
  • Kentrosaurus, a thyreophoran from Africa
  • Gargoyleosaurus, a thyreophoran from North America
  • Dryosaurus, a North American ornithopod
  • Camptosaurus, an ornithopod from North America and possibly Europe
  • Yinlong, an early marginocephalian dinosaur from Asia
  • Chaoyangsaurus, an early marginocephalian dinosaur from Asia
  • Juramaia, a basal mammal from Asia
  • Archaeopteryx, the first known bird, from Europe
  • Rhamphorhynchus a long-tailed pterosaur
    from Europe
  • Pterodactylus, a short-tailed pterosaur from Europe
  • Anurognathus, one of the smallest pterosaurs from Europe
  • ichthyosaur
    from Europe and North America
  • pliosaur
    from Europe
  • Dakosaurus, a medium-sized sea-going crocodylomorph from Europe
  • ammonite
[citation needed]

References

  1. ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy.
  2. ^ Owen 1987.
  3. .