Some cool extinct animals images:
Laurilland's Ground Sloth
Image by akseabird
Eremotherium laurillardi stood 20 feet tall and weighed several tons. It is one of many species of giant ground sloths, at least four of which were found on the North American Continent.
Apparently many species of sloths survived well passed the end of the last ice age (about 10kya) well beyond many other ice age animals. It is even possible that some species survived on Cuba and Hispanola as late as the mid 16th century
Natural History Museum
Image by InSapphoWeTrust
Fossils of ichthyosaurs, fish-shaped reptiles that lived during the dinosaur era.
Ichthyosaurs are my favorite extinct animals. Gracefully shaped like dolphins, they pretty much were dolphins of their day - except that while dolphins are mammals, these creatures were reptiles. They breathed air, and gave birth to live young. Ichthyosaurs lived worldwide, though the largest known colony was in the vicinity of Oxford; Britain was a warm, shallow sea at the time, and Oxford's clay layers, dating back to the dinosaur era, nicely preserved large numbers of ichthyosaurs.
Another known ichthyosaur population existed in the US state of Nevada, near the ghost town of Berlin. Plate tectonics caused the Nevada seafloor to eventually rise to an elevation of 7,000 feet today; Berlin is home to the largest ichthyosaur fossils ever found, and I had visited it in late 2000.
All marine reptiles went extinct at the end of the dinosaur era, with the sole exception of the turtle family.