Dan Flores

And if this closest living relative of mammoths offers clues, America's ancient elephants would have been highly intelligent creatures, especially acute in what biologists call situational intelligence. Their trunks were elephant analogues to our opposable thumbs, with as many as 150,000 muscle subunits.

And if this closest living relative of mammoths offers clues, America's ancient elephants would have been highly intelligent creatures, especially acute in what biologists call situational intelligence. Their trunks were elephant analogues to our opposable thumbs, with as many as 150,000 muscle subunits.

And if this closest living relative of mammoths offers clues, America's ancient elephants would have been highly intelligent creatures, especially acute in what biologists call situational intelligence. Their trunks were elephant analogues to our opposable thumbs, with as many as 150,000 muscle subunits.

As ecological keystone creatures whose activities shaped landscapes, mammoths and mastodons foraged in ways that likely transformed American vegetation the way modern elephants do in Africa.

As ecological keystone creatures whose activities shaped landscapes, mammoths and mastodons foraged in ways that likely transformed American vegetation the way modern elephants do in Africa.

As ecological keystone creatures whose activities shaped landscapes, mammoths and mastodons foraged in ways that likely transformed American vegetation the way modern elephants do in Africa.

They travel their huge ranges with an unusually powerful geographic memory as a recent study of a woolly mammoth's lifetime movements through Alaska 17,000 years ago, reconstructed by analyzing strontium isotope ratios that reference geography in its tusks, now indicate.

They travel their huge ranges with an unusually powerful geographic memory as a recent study of a woolly mammoth's lifetime movements through Alaska 17,000 years ago, reconstructed by analyzing strontium isotope ratios that reference geography in its tusks, now indicate.

They travel their huge ranges with an unusually powerful geographic memory as a recent study of a woolly mammoth's lifetime movements through Alaska 17,000 years ago, reconstructed by analyzing strontium isotope ratios that reference geography in its tusks, now indicate.

All elephants are what biologists refer to as K species, meaning they do not come into sexual maturity until they're 15 years old or older. A state brought on by periodic musth, the pachyderm version of sexual heat, From insemination to giving birth probably took two years, a generational turnover slow enough to make population recovery difficult in the face of a new threat.

All elephants are what biologists refer to as K species, meaning they do not come into sexual maturity until they're 15 years old or older. A state brought on by periodic musth, the pachyderm version of sexual heat, From insemination to giving birth probably took two years, a generational turnover slow enough to make population recovery difficult in the face of a new threat.

All elephants are what biologists refer to as K species, meaning they do not come into sexual maturity until they're 15 years old or older. A state brought on by periodic musth, the pachyderm version of sexual heat, From insemination to giving birth probably took two years, a generational turnover slow enough to make population recovery difficult in the face of a new threat.

And by the time humans were entering America, mammoths, mastodons, and other archaic elephant species were already suffering from a background rate of extinctions that had been going on for 75,000 years. But as the Rancho La Brea, Folsom, and Clovis sites show, elephants and big cats and many other remarkable creatures still occupied the ground where we now commute and go to sleep in our suburbs.

And by the time humans were entering America, mammoths, mastodons, and other archaic elephant species were already suffering from a background rate of extinctions that had been going on for 75,000 years. But as the Rancho La Brea, Folsom, and Clovis sites show, elephants and big cats and many other remarkable creatures still occupied the ground where we now commute and go to sleep in our suburbs.

And by the time humans were entering America, mammoths, mastodons, and other archaic elephant species were already suffering from a background rate of extinctions that had been going on for 75,000 years. But as the Rancho La Brea, Folsom, and Clovis sites show, elephants and big cats and many other remarkable creatures still occupied the ground where we now commute and go to sleep in our suburbs.

Only they all disappeared quite suddenly and mysteriously long, long ago. that disappearance is one of the most profound ecological and aesthetic events of continental history.

Only they all disappeared quite suddenly and mysteriously long, long ago. that disappearance is one of the most profound ecological and aesthetic events of continental history.

Only they all disappeared quite suddenly and mysteriously long, long ago. that disappearance is one of the most profound ecological and aesthetic events of continental history.

As Darwin's ally in the breakthrough to understanding natural selection and evolution, Alfred Russell Wallace wrote, "'In fact, we present-day Americans live in a zoological impoverished world from which all the hugest and fiercest and strangest forms have recently disappeared.'" Wallace was using recently in a big history sense.

As Darwin's ally in the breakthrough to understanding natural selection and evolution, Alfred Russell Wallace wrote, "'In fact, we present-day Americans live in a zoological impoverished world from which all the hugest and fiercest and strangest forms have recently disappeared.'" Wallace was using recently in a big history sense.