Plesiosaur Credit: Nicolle Rager, National Science FoundationThis artist s rendering reveals what an ancient marine reptile called a plesiosaur discovered in Antarctica may have looked like. The plesiosaur described in a forthcoming issue of the Journal of Vertebrate Paleontology, though not the same species, also sported four fins and a long neck. Analyses of shark teeth embedded in the reptile s bones suggest a feeding frenzy of sorts once the reptile died.
Monster WhaleCredit: Brian Choo / Source: Museum VictoriaThis ancient whale, extinct 25 million years, was a vicious hunter, scientists figure. Though likely an ancestor of modern baleen whales, gentle giants of today’s seas this beast had monstrous teeth and huge eyes thought to have been good for hunting.
Aerosteon dinosaurCredit: Todd Marshall c 2008, courtesy of Project Exploration. This flesh rendering of the predator Aerosteon shows its lungs (red) and air sacs (other colors) as they might have been in life about 85 million years ago. This huge carnivorous dinosaur that lived about 85 million years ago had a breathing system much like that of today s birds, a new analysis of fossils reveals, reinforcing the evolutionary link between dinos and modern birds.
Dunkleosteus terrelliCredit: Mark Westneat This prehistoric fish, Dunkleosteus terrelli, was big, mean, and it could bite a shark in two. Scientists say Dunkleosteus terrelli might have been "the first king of the beasts." The prehistoric fish was 33 feet long and weighed up to four tons. The creature lived 400 million years ago. Art by Karen Carr in the Field Museum s Evolving Planet exhibit.
MammothCredit: Stephan Shuster Lab, Penn StateDrawing of a woolly mammoth. These beasts were bigger than mastodons and and curved rather than straight tusks. They died off around 10,000 years ago, and scientists aren t yet sure if climate change was to blame -- as the Ice Age ended -- or if human hunting pressure played the larger role. Some even think a comet did them in.