Mammals first appear in the fossil record of the Mesozoic Era.
Mammals appeared in the late Triassic period about 220-230 million years ago.
Mammals were the most important animals to appear during the Cenozoic era. They diversified and evolved into a wide range of species, many of which still exist today. Mammals became dominant on land, adapting to various environments and playing key roles in ecosystems.
Large numbers of fossils begin to appear around 530 million years ago. It is called the Cambrian Explosion, because it occurred in the Cambrian period. The Cambrian period was the first part of the Paleozoic era.
probably mesozoic era
Vertebrates first appeared during the Paleozoic era.
Humans first appeared in the Paleolithic era, around 2.5 million years ago. This era is characterized by the use of stone tools and the development of early human species like Homo habilis and Homo erectus.
the cenozoic era
The Cenozoic Era is the Age of Mammals!
The Cenozoic Era is the Age of Mammals!
The first dinosaurs lived in the beginning of the Mesozoic Era (or the Age of Reptiles). Birds were amazingly discovered to be dinosaurs so dinosaurs were also alive in the Cenozoic (that's our time-the Age of Mammals) to today.
Mammals and dinosaurs emerged in the Mesozoic era. Plants appeared in the Paleozoic era, which came before it.