The early dinosaurs multiplied. Some grew larger, some began to walk on four legs, and others grew into different shapes. Each new feature, a long neck or sharp teeth, or bony plates, if it helped the animal survive, was passed on to later generations. These features became the hallmark of each new kind of dinosaur. Certain groups, like the sauropods, thrived during the Jurassic Period . Later they became scarcer. Others like the ornithopods dominated the third and final period of the Mesozoic Era before all dinosaurs but for birds, became extinct 65 million years ago.
[{"birds": "n/a", "color": "n/a", "months": "n/a", "extinct": "n/a"}]
[{"birds": "n/a", "color": "n/a", "months": "n/a", "extinct": "n/a"}]