When Did Dinosaurs Live

When did dinosaurs live? You may be astonished to find out dinosaurs lived on the Earth for millions of years. You can use this simple timeline to explain the three distinct dinosaur eras to your child.

Triassic Period: 245 to 208 Million Years Ago
The structure of Earth's continents was very different back in the Triassic period. At the beginning of the Triassic period, the land masses we know as continents were all fused together as one large piece of land called Pangea. This giant continent began to break apart during the Triassic period.

Late in this period, some of the little dinosaurs appeared. These dinosaurs were lighter in weight and smaller in size than the giants we often think of as dinosaurs. They lived with crocodiles and other reptiles. This is also when the first mammals came into existence. Unfortunately, there was a mass extinction of many of the animals of the Triassic period, which is what marks the beginning of the Jurassic period.

Triassic Period Dinosaurs

  • Coelophysis
  • Desmatosuchus
  • Eoraptor
  • Ichthyosaur
  • Iguanodon

Jurassic Period: 208 to 146 Million Years Ago
During this period, dinosaurs multiplied and thrived as Pangaea continued to break apart into the separate continents. Jurassic dinosaurs evolved to be quite large, and both herbivores and carnivores existed in great numbers.

Plant life also evolved into deciduous and flowering varieties. Most plant life before the Jurassic period appeared to be evergreen. This time period also experienced an extinction that marked the transition to the Cretaceous period. Most dinosaur species survived the tragedy.

Jurassic Period Dinosaurs

  • Allosaurus
  • Apatosaurus
  • Archaeopteryx
  • Compsognathus
  • Diplodocus
  • Mamenchisaurus
  • Stegosaurus

Cretaceous Period: 146 to 65 Million Years Ago
The continents were still forming and drifting apart from Pangaea during this period. Dinosaurs, birds, mammals and plants covered the Earth, existing in a delicate system of balance. This time period ended with a massive extinction of the dinosaurs. Somehow the reptiles and mammals survived this extinction. One theory for this extinction holds that a massive asteroid collided with the Earth, possibly in the Gulf of Mexico, creating a blanket of dust in the atmosphere that blocked the sun for several months.

Cretaceous Period Dinosaurs

  • Ankylosaurus
  • Giganotosaurus Carolinii
  • Hadrosaurus
  • Megaraptor
  • Orinthomimus
  • Seismosaurus
  • Triceratops
  • Troodon
  • Tyrannosaurus Rex
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