The Cretaceous Period (Kreidezeit) ranges between 145 to 66 million years ago.
The era's oxygen content was about 30 vol% or 1.5 times that of today's level,
while the mean surface temperature was 18°C, or 4°C higher than today,
over period duration. Terrestial fauna during the late Cretaceous included
the Tyrannosaurus Rex, one of the largest land predators of all time, the up to
2 meters-long Velociraptor, the most recognizable Triceratops, the mammal Eomaia, and
the winged Pterosaur. The end of the era came with the impact of probably an asteroid
which is accepted as the main reason for the Cretaceous-Paleogene extinction event.