During the Cambrian explosion of life (for about 525-510 millions years. Up to this point had not been very successful multicellular life) appeared the first predator to bite, was the Anomalocaris. The biggest predator of the Cambrian seas. Measure up to 1 meter and its name means "strange shrimp."
Possibly it was given this name because when they discovered the fossils were so strange that they thought of three different animals.
It had a segmented body, such as some crustaceans and a current "arms" armed with thorns, compound eyes (with a very developed on their prey, but not entirely confirmed). The mouth was circular and had 32 overlapping layers (four large and 28 small) equipped with small barbs which failed serrated rings around a central opening. With his arms gripping the defenseless Pikaia or trilobites and pounding and crushing.
Like trilobites, the Anomalocaris was an arthropod, bony internal skeleton had not, this was a protection mechanism, a cuticle or exoskeleton made of chitin and proteins such as cuticulina.
Curiosity: A recently described a new species closely related to Cambrian Anomalocaris the Hurdia victoria.
Entelodon has long talked of a huge boar, terrible and effective predator. Well, Daeodon was further developments. It was a little larger, reaching 3.6 meters long and 2 meters high. With a head of more than 1 meter in length that had a strong jaw with a bite (similar in proportion to the actual pigs and wild boars) and large and deadly fangs. The neck was short and thick and had a hump on the back along the spine.
With a strong and robust body reached a speed of 35 km / h, and managed to bring down their prey in the form of ambush and was once a short distance faster than performing a surprise attack their prey and bite and squeeze your strong bite.
He lived during the Miocene, about 24 million years ago in North America.
Among the causes of their extinction is thought to be one of the reasons was the gateway to the continent of Bear-dog or Amphicyon. More agile and fast and safely with a structure similar to the wolf pack that offered a performance at top predator.