The mammals emerged during the Triassic, around 225 million years ago. For 160 million years they were the dung beetles of the reptile world, relying on their small size to stay out of the way of T. Rex. But things changed when earth's collision with a massive asteroid 65 million years ago made life tough for large cold-blooded animals. Diversity of form and function that had been lurking under the saurischian-dominated surface was let loose, and within fifteen million years after the advent of the Age of Mammals the world was populated by a whole new array of exotic and quixotic animals.
On the plains of North America, the rabbit-sized ancestors (the Poëbrotheriinae) of the camel family gradually increased in size in the Eocene, grazing on grasses and forming into herds for protection. By the Middle Oligocene (around 30 million years ago) the family had diversified and spread across the New World and Asia, most of its members of a size and shape similar to modern camels.
The Miocene, Pliocene, and Pleistocene (20m-12tya), the great age of apes, was a time of consolidation and expansion for the camel. Most genii died out in the face of new environmental conditions, but two-- Lama and Camellus-- specialized and thrived. The former moved into the isolated mountains of South America, where it today survives as the llama, alpaca, guanaco, and vicuna. Camellus, on the other hand, was a little more adventurous. Crossing the Bering sea land bridge in the early Pleistocene, it emerged onto the arid steppes of Asia and thrived. As Camellus conquered the Old World, it surely must have encountered the other ascendant genus spreading across the world's plains: Homo.
Source: Wilson RT. 1984. The Camel. Essex: Longman Group.
On the plains of North America, the rabbit-sized ancestors (the Poëbrotheriinae) of the camel family gradually increased in size in the Eocene, grazing on grasses and forming into herds for protection. By the Middle Oligocene (around 30 million years ago) the family had diversified and spread across the New World and Asia, most of its members of a size and shape similar to modern camels.
The Miocene, Pliocene, and Pleistocene (20m-12tya), the great age of apes, was a time of consolidation and expansion for the camel. Most genii died out in the face of new environmental conditions, but two-- Lama and Camellus-- specialized and thrived. The former moved into the isolated mountains of South America, where it today survives as the llama, alpaca, guanaco, and vicuna. Camellus, on the other hand, was a little more adventurous. Crossing the Bering sea land bridge in the early Pleistocene, it emerged onto the arid steppes of Asia and thrived. As Camellus conquered the Old World, it surely must have encountered the other ascendant genus spreading across the world's plains: Homo.
Source: Wilson RT. 1984. The Camel. Essex: Longman Group.
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