Caribbean monk seal
The only known native seal to the Caribbean Sea and the Gulf of Mexico, the Caribbean monk seal was officially declared extinct as recently as 2008, though none have been seen since 1952. It is the only species of seal ever recorded to have gone extinct primarily due to human causes.
Their demise was foreshadowed during Columbus’ 1494 voyage, when the tiny seals were first discovered. Described as “sea wolves” by Columbus himself, eight were recorded to have been killed and slaughtered for their meat.