We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is the Great American Interchange?

Michael Anissimov
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The Great American Interchange may sound like some sort of freeway, but it's actually a paleozoogeographic event that occurred in the Americas about 3 million years ago, during the Pliocene epoch. The Great American Interchange was caused when volcanic activity created the Isthmus of Panama, linking together North and South America, which had been separated for 200 million years, since the breakup of the supercontinent Pangaea. Numerous mammals, part of lineages which had been separated for eons, were exchanged between the continents, which thereafter became part of the same general biogeographical region, the Americas.

The mammalian fauna of North America prior to the Great American Interchange were in general boreoeutherian, a clade composed of sister taxa Laurasiatheria and Euarchontoglires, which encompasses the New World primates, lagomorphs (pikas, rabbits, hares), rodents (rats and mice), moles, shrews, gophers, ancient horses, deer, the now-extinct American Camel, skunks, bears, saber-tooth cats, wolves, foxes, cougars, American Lion, and others. The South American fauna was more unique to just that continent, including marsupials (with some carnivorous variants), xenarthrans (armadillos, anteaters and sloths, including giant ground sloths), porcupines, Vampire Bats, the Dire Wolf, "Terror Birds," numerous native ungulates (hoofed animals) including the peculiar Macrauchenia, which is described as a humpless camel, low in stature with a short trunk.

In general, if the Great American Interchange is seen as a sort of evolutionary competition, North America won. The North American fauna, living in a somewhat harsher, colder, and more climate-diverse continent, had adaptations better suited to competition than the South American fauna, much of which was heavily adapted to rainforest and made it no further than Central America. An exception are the notorious Terror Birds, which made it as far as Texas and Florida, presumably consuming millions of small mammals along the way with their huge, razor-sharp beaks. Yet this success was short-lived, as the Terror Birds went extinct within a million years of making the journey.

Some examples of animals that successfully made exploited the Great American Interchange and survive to this day include the armadillo, found most often in Texas, the Virginia Opossum, the only marsupial found north of the Rio Grande, porcupines, the Vampire Bat, found in Mexico, the cougar, and the King Vulture, which can be found throughout Central America.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Michael Anissimov
By Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology, astronomy, chemistry, and futurism to his articles. An avid blogger, Michael is deeply passionate about stem cell research, regenerative medicine, and life extension therapies. His professional experience includes work with the Methuselah Foundation, Singularity Institute for Artificial Intelligence, and Lifeboat Foundation, further showcasing his commitment to scientific advancement.
Discussion Comments
By hangugeo112 — On Jan 24, 2011


It is also possible that numerous of these species discovered the isthmus at different times. They had plenty of time to multiply and discover new territory, and I doubt they all suddenly rushed toward the isthmus at the same time.

By Proxy414 — On Jan 22, 2011

The Panama canal is drawn across a small space over which hundreds of species are said to have crossed in this great interchange. It is likely that fossils found in this area during the digging confirmed evidence of the new predatory opportunities which presented themselves after the conjoining of the two continents. Species from all over two large continents converged on a small isthmus over time.

By Tufenkian925 — On Jan 19, 2011

Sometimes I wonder how animals got to places which would be inaccessible due to water. Pangaea is a good explanation, but still it is incomplete. Certain species were obviously brought by humans as we spread across the world on boats. These species affected the diets and customs of tribes around the world, as well as the theriomorphic gods they worshiped.

By Leonidas226 — On Jan 18, 2011

Throughout evolutionary history, numerous animals have had geographical splits in their evolution and have subsequently been reunited as different species. This is also the case with the cichlids of Lake Malawi in Africa. Over time, the lake became three lakes, allowing for separate evolution of different main species. When the water level rose again after thousands of years, the fish were reintroduced as separate forms. This is why there is such beautiful diversity in African cichlids, and many prefer them as pet fish.

Michael Anissimov
Michael Anissimov
Michael Anissimov is a dedicated All The Science contributor and brings his expertise in paleontology, physics, biology...
Learn more
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.