An illustration of the Devonian period fish, Dunkleosteus, preying on eurypterids (sea scorpions), which in turn were feeding on the smaller trilobites. Depleting oxygen and rising hydrogen sulfide ...

An illustration of the Devonian-period fish Dunkleosteus at its old presumed length of about 30 feet. A 360 million-year-old sea monster that was once thought to be as big as a bus was actually less ...

The Devonian System of western and central Colorado consists of a lower clastic unit, consisting of the McCracken, Elbert, and Parting Formations and an upper carbonate unit, the Dyer and Ouray ...

The human hand is the product of hundreds of millions of years of evolution, beginning with lobe-finned fish in the Devonian period. Early species like Tiktaalik developed limb-like fins capable of ...