Skeletal parts, including jaws and teeth, of the giant jaguar was discovered on the Platte river, of Nebraska, in 1827, by Ferdinand Vandeveer Hayden. He sent it to Joesph Leidy, at the academy of natural sciences in Philidelphia. Who was working on identifying some of the recent pleistocene megafauna discoveries.
Beginning around the 1840s, more findings came forward, from Flordia, Maryland to Tennessee.
Even Oregon, California (La Brae), and southwestern Mexico had remains of the giant jaguar.
More pieces became available to scientists, and in the early 1920s, they were able to differentiate and classify the different subspecies, sizes and genetics further.