The Prehistoric Giants Hall of Fame
What were the largest species of all time? Does the Tyrannosaurus rex make the list?
- By Brian Switek
- Smithsonian magazine, April 2012
Titanoboa was one gigantic snake. It lived around 58 to 60 million years ago, a scant several million years after the mass extinction that wiped out the dinosaurs. It could grow 42 feet or more in length and weigh more than a ton, vastly outslithering the previous fossil record holder, a 40-million-year-old, 33-foot-long snake called Gigantophis. But Titanoboa is just one proud inductee in the Prehistoric Giants Hall of Fame. Meet the other record-holders.
Today’s whales are the biggest mammals that have ever lived. On land, however, mammals hit their top size between 37 and 23 million years ago in the form of Paraceratherium. This huge, hoofed mammal belonged to a group of hornless rhinoceros called hyracodonts, and Paraceratherium itself looked something like a rhino impersonating a giraffe. The herbivore stood about 18 feet high at the shoulder and could have reached its head 25 feet off the ground. Not even the most massive of the mammoths grew quite so large.