Newly Discovered Dinosaurs Ate Like Hyenas and Sharks
Posted on March 6, 2008
The fossils of two meat-eating dinosaurs named Eocarcharia and Kryptops have been discovered in the Sahara Desert. The newly discovered dinosaurs appear in a paper this month in the scientific journal Acta Palaeontologica Polonica. The fossils were discovered in 2000 on an expedition led by University of Chicago paleontologist Paul Sereno.
Sereno and co-author paleontologist Stephen Brusatte of the University of Bristol say the new fossils provide a glimpse of an earlier stage in the evolution of the bizarre meat-eaters of Gondwana, the southern landmass. "T-rex has become such a fixture of Cretaceous lore, most people don't realize that no tyrannosaur ever set foot on a southern continent," said Sereno. Instead, particularly distinctive meat-eaters arose, some of which bore no resemblance to the "tyrant king," beyond their appetites for fresh meat.
The two dinosaurs have distinctive faces. Kryptops probably ate mostly from already dead carcasses (like hyenas) and Eocarcharia dinops ate live prey (like sharks).
Short-snouted Kryptops palaios, or "old hidden face," was named for the horny covering that appears to have covered nearly all of its face. "A fast, two-legged hyena gnawing and pulling apart a carcass," remarked even Brusatte, "is how we might best imagine Kryptops' dining habits." Kryptops also had short, armored jaws with small teeth. The scientists say these teeth make Krptops better at eating from a carcass than trying to eat live prey.
Eocarcharia dinops - or "fierce-eyed dawn shark" - was named for its blade-shaped teeth and prominent bony eyebrow. Unlike Kryptops, the scientists say its teeth were designed for disabling live prey and severing body parts. Eocarcharia and kin (called carcharodontosaurids) gave rise to the largest predators on southern continents, matching or exceeding Tyrannosaurus in size. Eocarcharia's brow was swollen into a massive band of bone, giving it a menacing glare.
Both of the newly discovered dinosaurs were about 25-feet long. Project Exploration has more information about the new dinosaurs, their contemporary species and Cretaceous habitat, and the expedition on which the fossils were discovered.