🦕 The Past
Dinosaurs & Ancient Eras
Starting off with the Mesozoic Era and everything in between. This era is divided into three periods: the Triassic, Jurassic, and Cretaceous. The Mesozoic Era began 252.2 million years ago.
The oldest period is the Triassic Period, going from 252 to 201 million years ago. All continents during this period were part of one land mass called Pangaea, meaning the differences between many plants and animals were minor. The climate during this time was relatively hot and dry, the land was mostly covered in deserts, and unlike today, there were no polar ice caps. At the end of this period there was a large extinction event, and the causes are still widely debated.
Moving onto the Jurassic Period, which was 201–145 million years ago. (I do not really have much information for this period — even though it is the most widely known!)
So, skipping ahead to the Cretaceous Period — the most recent of the three. This geological period ran from the end of the Jurassic Period to about 66 million years ago.
The Mesozoic Era is actually one of three eras that make up the Phanerozoic times. The name "Phanerozoic" came from a Greek term for "middle life".
As if we haven't moved on enough, there's still one more thing to talk about: placental mammals, otherwise referred to as infraclass Eutheria. These are any members of the mammal group characterized by the presence of a placenta — a vascular organ that develops during gestation, which facilitates the exchange of nutrients and waste between the blood of a mother and the blood of a fetus. Placentals include all living mammals except marsupials and monotremes.
Certain types of scientists called palaeontologists study fossils from back then to see what life was like. These fossils come from all types of dinosaurs, which is how they identify certain dinosaurs through their skeletal system and fossil remains.
