A big misconception of mine was set straight last week, when I read a book by Stanley Hedeen called Big Bone Lick: The Cradle of American Paleontology. Spanish conquistadors did not bring the first equines to the Americas; they brought the first domestic equines.

Full-sized horses known as equus complicatus (not the small dog-sized eohippus many of us learned about in high school biology) evolved in North America and crossed into Siberia via the Bering Straits land bridge, during the Pleistocene or “ice” age that roughly spanned the period from 1.8 million to10,000 years ago.

As horses and camels, which also evolved in North America, were moving west across the Bering bridge, human beings were moving east into the New World. While humans proliferated, horses and camels eventually disappeared from their original birthplace. Although horses would be reintroduced by the Spanish, camels never regained their foothold in the Western Hemisphere.

Big Bone Lick recounts the rich history of a site that offered the first evidence of extinction of several mammal species, including, the American mastodon and the Columbian mammoth. The source of the title of the book is a salt lick in northern Kentucky, where giant fossilized skeletons lay undisturbed for thousands of years, until French explorers stumbled upon them in 1739.

Native Americans had known about the spot and incorporated it into Shawnee legend, but it was news from the French expedition that eventually attracted the interest of such early American luminaries as George Washington, Benjamin Franklin, and Thomas Jefferson. Many scientific and philosophical assumptions of the day were cast into doubt by the discovery of the big bones and eventually gave rise to the study of fossils for biological and historic purposes.

Camel bones were not among the discoveries at Big Bone Lick. I coincidentally learned about their evolution in North America while reading, at the same time as Big Bone Lick, William J. Bernstein’s A Splendid Exchange: How Trade Shaped the World, also published this year. It is a sweeping history of world trade from Mesopotamia in 3000 BC to present day globalization, including the eras when camels packed incense from the Indian Ocean to the Mediterranean and silk from China to the western fringes of Asia.

It is a fascinating read, but one that I had to finally relegate to my stacks of “For a later date” Right now I am halfway through a just published history by Daniel Mark Epstein: The Lincolns: Portrait of a Marriage. It is almost impossible to put down and is on top of a stack on my nightstand.