this I found interesting. These guys have been extinct for 10 000 years but their burrows live on. they were killed off when humans reached the Americas. The same super conservation minded indian 'elders' who killed off all the fucking horses before they figured they could be ridden....
www.bbc.com
Brazil’s mysterious tunnels made by giant sloths
These tunnels were once believed to hide religious fortunes deep in their chambers, but the real treasure is found in who – or what – created them.