Changes

However, Pleistocene sediments also contain many large mammals which are now extinct. These include [[giant sloth]]s, [[woolly mammoth]]s, and [[sabre toothed cat]]s.

However, Pleistocene sediments also contain many large mammals which are now extinct. These include [[giant sloth]]s, [[woolly mammoth]]s, and [[sabre toothed cat]]s.

[[Horse]]s and [[camel]]s once galloped across the North American plains and giant birds with 25 foot wingspans stalked prey.

[[Horse]]s and [[camel]]s once galloped across the North American plains and giant birds with 25 foot wingspans stalked prey.

[[Scientist]]s speculate that these extinctions may have been caused by a combination of changing climate, disease, and overhunting by [[human]]s.

[[Scientist]]s state that these extinctions may have been caused by a combination of changing climate, disease, and overhunting by [[human]]s.

== Bibliography ==

== Bibliography ==