First we had the "Frog from Hell." Now we have the "Snake from Hell." The fossilized remains of a snake have been discovered in Colombia that was absurdly large. The story, in Scientificblogging, notes:
Surrounded by huge trucks extracting coal from Cerrejon, one of the world's largest open-pit mines, researchers discovered fossilized bones of super-sized snakes and their prey, crocodiles and turtles, in the Cerrejon Formation, along with fossilized plant material from the oldest known rainforest in the Americas, which flourished at the site 58-60 million years ago.
Estimated Titanoboa size: 42 feet (13 meters); 1140 kilograms. According to the Guinness Book of World Records, the longest snake ever measured was 10 meters (33 feet) in length. The heaviest snake, a python, weighed 183 kilograms (403 pounds).
The graphic from the Nature article shows the vertebrae of the critter:
Just after the first vertebra in the picture is, for comparison, the vertebebra of a modern 13-foot boa. Look at the size difference!! The snake is being called Titanoboa cerrojonensis. The last paragraph of the recent article in Nature reads:
Discovery of Titanoboa and the additional Cerrejon Formation fossil record indicates that components of modern neotropical riverine vertebrate faunas were assembled at most six to seven million years after the Cretaceous–Palaeogene extinction event.
Evolution moved fast. Here is the Nature citation:
Head JJ, Block JI, Hastings AK, Bourque JR, Cadena EA, Herrera FA, Polly D, Jaramillo CA (2009) Giant boid snake from the Palaeocene neotropics reveals hotter past equatorial temperatures. Nature 457(7230):715-718.