hers fill that 70 million-year gap, as well as provide a portrait of tyrannosaur lineage in North America. Moros links the earliest, smaller tyrannosaurs to Tyrannosaurus rex.
”With a lethal combination of bone-crunching bite forces, stereoscopic vision, rapid growth rates, and colossal size, tyrant dinosa
urs reigned uncontested for 15 million years leading up to the end-Cretaceous extinction — but it wasn’
t always that way,” said Lindsay Zanno, lead study author and paleontologist at North Carolina State Un
iversity, in a statement. “When and how quickly tyrannosaurs went from wallflower to prom king has been vexing pal
eontologists for a long time. The only way to attack this problem was to get out there and find more data on these rare animals.”
Zanno and her team spent a decade searching for fossils from the Late Cretaceous period. Th
ey recovered teeth and a hind limb consisting of a femur, a tibia and parts of a foot belonging to Mo
ros in the same area where Zanno found the fossil of a giant carnivorous carcharodontosaur.
But Moros stood between 3 and 4 feet tall. The dinosaur they found was 7 years old when it died, a nearly full-grown adult
that would have weighed around 172 pounds. The elongated leg and foot bones indicated that it would be a great runner.
Giant dinosaur footprints found and saved from floods in Queensland
”Moros was lightweight and exceptionally fast,” Zanno said. “
These adaptations, together with advanced sensory capabilities, are the mark of a formida
ble predator. It could easily have run down prey, while avoiding confrontation with the top predators of the day.”