Around 300 BC, the Olmec people all of a sudden vanished. There are no known reasons why but thoeries range from simply dispersing and interbreeding with other cultures to others as far-out as being abducted by extra-terrestrials. As of today, there are no pure-bred Olmecs and there probably aren't any half-breds neither. In the end, our personal thoery is that the hideous were-jaguar was in actuality an undiscovered specie of big cat, which over the years learned how to easily kill human beings. Then at the end of the period, numerous jaguarian raids upon their cities and villages eventually resulted in a mass decline in population, eventually ending the entire Olmec culture.