Extinction takes numerous species each year. The Amazon rainforest, home to the greatest diversity of animal life on land, has seen some truly amazing species. The strange creatures that stalked the Amazon in times past are all gone now. Today the activities of humans in the Amazon threaten countless more species with extinction.

Sixty million years ago, Earth was home to giants. South American rainforests had their share of these huge creatures. Recent excavations in Colombia unearthed the remains of Titanoboa cerrejonesis. This extinct member of the boa constrictor family reached a length of over 40 feet and weighed around 2,500 pounds. According to University of Florida paleontologists, an extinct species of crocodile, Cerrijonisuchus, likely provided the giant snake’s food supply. Researchers from the Smithsonian Tropical Research Institute and the University of Florida are studying the site to get a picture of what the ecology of the area was like millions of years ago.

According to the University of Florida scientists, the animal was a member of the dryosaurid family of crocodilians. Unlike other members of this group, Cerrejonisuchus had a shorter, broader, tweezer-like snout, which enabled it to exploit a greater variety of food sources such as:

• lizards
  
• snakes
  
• possibly mammals

Most dryosaurids evolved long narrow snouts for catching fish like those found in the Amazon of today.

Imagine a guinea pig the size of a bull. Some eight million years ago, such a giant rodent lived in the Amazon rainforest. According to a report by Marcelo R. Sanchez-Villagra, Orangel Aguilera and Ines Horovitz, published in "Science," Phoberomys lived along the banks of the Amazon and Orinoco Rivers and ate the underwater vegetation.

Phoberomys grew to nearly a metric ton in weight, making it the largest extinct member of the rodent family. Phoberomys is a distant relative of the modern chinchilla.