Andy Casagrande

America's Greatest Animals takes us across North America on a revelatory mission: which of the continent's landmark creatures deserve to make the list?

Two teams of experts go to extraordinary lengths to take shark science into the wild as they investigate two of the most iconic shark superpowers - speed and bite force. In California the race is on as Andy Casagrande attempts to ...

Dr. Tristan Guttridge believes hammerhead sharks can reach monster sizes by hunting other sharks -- but the only way to prove it is to get tissue samples from some of the largest sharks on the planet.