The Evolutionary Story of Reptiles and Mammals
Reptiles and mammals are two distinct groups of vertebrates that evolved from a certain common ancestor. However, which one came first? To answer this question, let’s look at the evolutionary story of reptiles and mammals.
How Reptiles Evolved
Reptiles first evolved in the Carboniferous period, some 300 million years ago. They were the first four-legged animals to move onto land and diverged from amphibians over time. A defining characteristic of reptiles is the amniote egg, which is a waterproof egg that contains nutrients necessary for the early developmental stages of these animals.
Mammals Evolve in the Age of Dinosaurs
Mammals evolved from reptiles during the Mesozoic era, around 200 million years ago. This was during the Age of the Dinosaurs, and mammalian growth was inhibited by their large and powerful reptilian counterparts. Mammals were the first animals to incubate their young in their bodies in order to protect them from the harsh environment.
Based on the current scientific evidence, it is safe to say that reptiles evolved before mammals. The amniote egg is a defining feature of reptiles, and it is not found in mammals. Furthermore, mammals evolved during the age of the dinosaurs and were unable to flourish until the dinosaurs went extinct.
- Reptiles evolved in the Carboniferous period, some 300 million years ago.
- Mammals evolved in the Mesozoic era, around 200 million years ago during the Age of the Dinosaurs.
- Based on the current scientific evidence, it is safe to say that reptiles evolved before mammals.