11Marsupial lion
There is an extinct, carnivorous cousin of koalas and wombats known as the Marsupial lion.
12Megatherium
An elephant-sized sloth (Megatherium) existed and went extinct only 10,000 years ago. It was one of the largest land mammals, measuring up to 6m (20 foot) and weighing 4 tons.
13Ancient crocodile
There was a now-extinct species of crocodile that could gallop.
14Glyptodon
Ancient humans hunted Glyptodon, an extinct massive armadillo, in order to live within their shells.
15Kauaʻi ʻōʻō
The last Kauaʻi ʻōʻō (now extinct) was male. Its song was recorded in 1987. It was recorded singing a mating call, to a female that would never come. It died in 1987 as well.
16Myotragus bakearicus
A cave goat (Myotragus bakearicus) that went extinct approximately 5,000 years ago is the first known mammal to have become cold-blooded. Their bone growth rate is unlike any other mammal, and more similar to crocodiles in showing slow and adaptive rates to environmental temperature.
17Carolina Parakeet
The Carolina Parakeet, a neotropical parrot that was native to much of the United States up until they were driven extinct by deforestation, hunting, and possibly disease in 1910. They lived in huge flocks of up to 300 birds and were likely poisonous to eat.
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18Rocky Mountain Locust
In 1875, a swarm of locusts (Rocky Mountain Locust) 1800 miles long and 110 miles wide swarmed through the western U.S., causing $200 million in crop damage. At 12.5 trillion insects, it was the largest concentration of animals ever seen. Less than 30 years later the species had vanished and was declared extinct in 1902.
19American Lion
The extinct American Lion that used to range all over the U.S. and into South America and was about 25% larger than today's African Lion.
20Alpine Spaniel
The Alpine Spaniel, a now extinct dog bred by Augustinian Monks for rescuing travelers stuck in the snow of the Great St. Bernard pass. Dogs were sent in pairs so one could alert the monks when they found someone. They are said to be ancestors of modern-day St. Bernards.
