Some cool extinct animals images:
Saber-Toothed Cat Skull
Image by Travis S.
This is the lateral view of a saber-toothed cat skull without the muscle display. The sagittal crest down the back of the top of the skull can be seen. This extension of the skull is to add more surface area for larger jaw muscles.
Also note the incomplete orbit of the cat's skull. This is a common feature in carnivores such as the big cats and www.flickr.com/photos/baggis/2558237108/, a prosimian related to lemurs, were the first of its kind to have a complete orbit. This was probably to protect the orbit of the brachiating animals.
"World's best carnivore?"
Image by xopherlance
"While the marsupial lion Thylacoleo carnifex [thy-la-co-LEE-oh CAR-ni-fex] may not have been the fastest or smartest, it has been described as the most specialized meat-eating mammal of all time because of its enormous meat-slicing teeth!"
-- marsupial lion exhibit at the Australian Museum. The species died out by about 30,000 years ago; which means it could have coexisted with early humans on the continent for 10,000-20,000 years. Pound for pound, it had the strongest bite of any mammal in history.
See where this picture was taken. [?]
Image by Fool-On-The-Hill
Camels evolved in North America, but went extinct about 10,000 years ago like many other native animals. This one was a tiny, fast one. see en.wikipedia.org/wiki/Stenomylus