The great reptiles were the most successful life forms ever to populate this world. For 140 million years they ruled the Earth, filled the sky, swarmed in the seas. At this time the mammals, the ancestors of mankind, were only tiny, shrew-like animals that were preyed upon by the larger, faster, more intelligent saurians.
Then, 65 million years ago, this all changed. A meteor six miles in diameter struck the Earth and caused disastrous atmospheric upheavals. Within a brief span of time over seventy-five percent of all the species then existent were wiped out. The age of the dinosaurs was over; the evolution of the mammals that they had suppressed for 100 million years began.
But what if that meteor had not fallen?
What would our world be like today?
– Introduction to West of Eden by Harry Harrison
“What if?” is a question that has been tackled countless times in the pages of fiction. What if the Nazis won World War II? What if the South won the U.S. Civil War? What if the Roman Empire never fell? This is the genre of alternate history, which explores paths in history not taken. Most alternate history stories depict a different human history, but occasionally authors go even further and imagine a world where nature itself went in a very different direction.
Alternate history is often classified as a subset of science fiction and fantasy, and it is true that many stories in the genre contain fantastic elements. Sometimes the alternate timeline comes about because time travelers have tampered with the past. Other times the alternate timeline is just one of many parallel realities existing in a multiverse of infinite possibilities. Still, most alternate history stories read like mainstream historical fiction, the only difference being the history depicted never happened.
In the genre, the place where a setting’s timeline begins to differ from our own is called a “point of divergence,” or POD. These points usually pivot around a consequential choice made by human actors, such as a military command that leads to a different outcome in a famous battle or the introduction of a technology at an earlier stage in history. Imagining a POD for natural history is tricky because most natural events appear to us to have an inevitability to them. Human history, on the other hand, is often shaped by people exercising their free will, or at least what most of us are raised to believe. As a result of this bias in perspective, it is easier for an author to justify General Robert E. Lee winning the battle of Gettysburg than, say, an alternate Earth where the supercontinent Pangea never broke up.
By far the most popular POD involving natural history is the survival of non-avian dinosaurs into modern times. The plausibility of this scenario is boosted by the fact that the leading theory for why the dinosaurs went extinct — that an asteroid or comet struck the Earth — was an act of nature so random that it’s easy to ask audiences to accept the idea that the giant rock simply missed. The 2015 children’s movie The Good Dinosaur opened with this premise, showing the asteroid harmlessly whizzing by while dinosaurs watched with bored detachment. This change leads to a world of talking dinosaurs living alongside primitive humans.
The filmmakers behind The Good Dinosaur used alternate history to justify the otherwise anachronistic pairing of cavemen and dinosaurs seen in countless other media properties, from The Flintstones to One Million Years B.C. However, they were not the first to utilize the genre in this way. That distinction likely goes to science fiction author Harry Harrison, who in 1984 published West of Eden, the first in a trilogy of novels depicting an Earth where the asteroid never came crashing down. Harrison details his world in great detail in a series of essays that make up the book’s epilogue. In his timeline, Iceland doesn’t exist as the island was formed by the impact. (The book was written was long before the Chicxulub crater in the Yucatan was identified as the impact site.) Dinosaurs are cold-blooded and therefore inhabit the warmer regions of the globe. Warm-blooded mammals inhabit the colder regions, and among them the Tanu, which are essentially Homo sapiens. They share the world with the Yilane, a race of intelligent reptiles descended from mosasaurs, specifically Tylosaurus. The Yilane’s cold-blooded physiology means they are unable to tolerate open flames and therefore have never developed metallurgy, with genetic engineering instead forming the basis of their technology. Harrison put a lot of work into developing the culture, biology and even language of the Yilane. Unfortunately, he didn’t put as much effort in the rest of his world, populating his alternate Earth with dinosaurs and prehistoric mammals known from the fossil record instead of creating new animals to fill the various ecological niches.
The Yilane spend much of the trilogy trying to destroy the Tanu, who the reptiles view as a pest species. A similar theme can be found in the Destroyermen series by Taylor Anderson, which weighed in at a hefty 14 novels at the time I wrote this essay. In the books, the crew of a World War II destroyer is transported to a parallel world where dinosaurs never went extinct. The humans soon find themselves allied with a race of lemur-like creatures being hunted to extinction by the Grik, which appear to be descended from dromaeosaurids such as Velociraptor.
Both Harrison and Anderson are playing on the popular narrative of dinosaurs and mammals locked in an evolutionary struggle for control of the Earth — a trope that has been drilled into our collective consciousness by numerous nonfiction books and documentaries. This narrative is echoed in the 1993 film Super Mario Bros., based on the video game. In the movie, the asteroid that killed the dinosaurs instead blasted them into an alternate dimension where they evolved into humans, or at least something resembling humans. The tyrannical leader of the dinosaurs — Koopa, who is descended from T. rex — wants to invade our world so the dinosaurs can sweep aside the “disgusting” mammals and take their place at the top of the evolutionary ladder. The comic book series Neozoic depicts an alternate Earth where the asteroid struck the moon instead, allowing dinosaurs to survive to the modern day. Humans also have evolved, but they live in walled cities to protect themselves from the predations of the terrible reptiles. In literature, the theme of dinosaurs vs. mammals is central to the premise of the Star Trek novel First Frontier by Diane Carey and Dr. James I. Kirkland. The conflict in the book is driven by a race of dinosaur-like aliens frustrated by their lower-class status in the galaxy. Believing the human-centered Federation is to blame, the aliens travel back in time and prevent the Chicxulub asteroid from striking the Earth, creating an alternate timeline where dinosaurs never went extinct and some evolved human-like intelligence. It is up to the crew of the Enterprise — shielded from the changes in time — to correct the course of history.
Time travel shenanigans are often employed in helping dinosaurs survive past the extinction event that caused their demise. The short stories “Dinosaur on a Bicycle” by Tim Sullivan and “One Giant Step” by John E. Stith both involve sentient dinosaurs traveling back in time to the late Cretaceous period only to encounter other time travelers from alternate futures where the dinosaurs died out. This premise was expanded into a novel in Dinosaur Nexus by Lee Grimes. In the book, a human expedition to the late Cretaceous discovers a group of intelligent dinosaurs from a future where the reptiles continued to thrive and evolve. Both expeditions come to realize that their actions in the past will determine which future comes to be. The short story “A Sound of Thunder” by Ray Bradbury, first published in 1952, toyed with alternate history a little bit by having human time travelers cause changes that affected the politics of their future world. However, in the 2005 film adaptation of the story, the changes cause “time ripples” that gradually replace the movie’s futuristic setting with chunks of a parallel timeline where evolution took a different turn. Among the creatures featured were some badly animated CGI dinosaurs that resemble baboons. Bradbury’s tale also inspired a series of young adult novels that acted as a sort of sequel, starting with Dinosaur World. Throughout the course of the series, the young protagonists travel to various parts of history that have been altered as a result of the events in the original story, encountering intelligent dinosaurs along the way.
The most detailed exploration of a world where dinosaurs survived to the modern day didn’t rely on time travel or even bother to explain how they managed to do so. The New Dinosaurs by paleontologist Dougal Dixon, first published in 1988, wasn’t concerned about how the dinosaurs survived but rather what they would have evolved into had they lived. The book is an illustrated bestiary featuring several speculative creatures based our understanding of the forces that drive evolutionary processes. Creatures in the book include a predatory dinosaur that has evolved to mimic its prey, a land-dwelling ammonite (a sea creature that went extinct along with the dinosaurs), and a flightless pterosaur that has evolved the body shape and lifestyle of a giraffe. Interestingly, Dixon doesn’t include any intelligent, tool-using dinosaurs in his book, avoiding a trope found in nearly every alternate history story involving the reptiles’ continued survival. In an essay in the afterword, the author rejected the idea that human-like intelligence is an inevitable product of evolution:
Earth’s biological systems have successfully survived without intelligence for 3,500 million years. Over the million years, or thereabouts, that is has been in existence, intelligence has only manifested itself as a civilization for about the last 4,000 years. Intelligence has yet to prove itself as a feature that has any evolutionary advantage at all, let alone representing the ultimate goal of evolutionary development.
Alternate history stories about dinosaurian survival don’t always result in the animals dominating the world. The 1990s science fiction show Sliders involved a group of characters who traveled between parallel worlds, meeting dinosaurs a couple times over the course of the series. Perhaps the reptiles’ most notable appearance was in the second season episode “In Dino Veritas,” in which dinosaurs are endangered species on an otherwise human-dominated Earth. Dinosaurs also live alongside humans in literature. In The Fallen Cloud Saga by Kurt R. A. Giambastiani, starting with The Year the Cloud Fell, cowboys fight dinosaur-riding Cheyenne Indians in the American Old West. (The cover art from the second novel in the series, The Spirit of Thunder, provided the title image for this essay.) The novel Dinosaur Summer by Greg Bear is set in a 1940s much like our own but with one major difference: Dinosaurs still live in a lost world in the middle of South America. However, unlike most lost worlds found in fiction, these dinosaurs are not prehistoric survivors but rather the evolved descendants of animals we know from the fossil record. Some of the creatures found in the book resemble real-life dinosaurs, but others, particularly the T. rex-sized Stratoraptor, are based on the author’s own speculations.
Because of their popularity, dinosaurs dominate alternate history stories concerning the natural world, but there are a few examples not involving the reptiles. The Sky People by S.M. Stirling admittedly isn’t one of them, but it is different in that its dinosaurs are found on a Venus that was terraformed and turned into a game preserve by aliens in the distant past. The roleplaying game Space: 1889 also features a Venus inhabited by dinosaurs, as well as a Mercury inhabited by even more primitive creatures, although both cases are the result of natural processes. Moving away from dinosaurs, the novel Darwinia by Robert Charles Wilson is set in an alternate early 20th century in which Europe has been replaced by a seemingly alien forest. We later learn this forest is actually a slice of a timeline where life on Earth was slower to transition from water to land. Closer in time, the prolific alternate history author Harry Turtledove has dabbled with changes that had major ramifications for the geology and biology of the world. The Atlantis series, starting with Opening Atlantis, posits that the eastern seaboard of U.S. broke away from North America some 85 million years ago and is an island continent in historic times. The author’s novella “Down in the Bottomlands” is set in a world where the Mediterranean Basin never opened to the Atlantic Ocean, instead becoming a vast desert. Then there’s A Different Flesh, a collection of short stories about the European colonization of a North America inhabited by an early species of hominid rather than Native Americans, resulting in the survival of Ice Age megafauna such as mammoths. (Turtledove also is the author of “Bonehunters,” a novelette about a fossil-hunting expedition in a world where dinosaurs never went extinct. The story had yet to be published at the time this essay was written.)
All the examples cited in the above paragraph proposed radical changes but were still predicated on the survival of humans in their alternate timelines. What about worlds where modern-day humans never existed? Such is the premise of Wildside by Steven Gould, in which a group of teens discover a doorway to a parallel Earth filled with mammoths, sabertooth cats and other Ice Age megafauna because humans never evolved there. The Crack in Space by Philip K. Dick also involves people from our world discovering a parallel Earth empty of humans, although in this case because our ancestor Homo erectus became the dominant hominid species. Canadian science fiction author Robert Sawyer explored a similar theme in his trilogy The Neanderthal Parallax, starting with Hominids, which posits a world where Neanderthals rather than Homo sapiens survived into modern times.
There are certainly many more examples of alternate histories about the natural world found in fiction and comics, but you should have a good overview of the topic by now. To summarize, stories about dinosaurs surviving their mass extinction dominate this literary niche, but that doesn’t mean examples of other points of divergence can’t be found. Also, future writers looking for original ideas shouldn’t despair because there are still a lot of “what ifs” in Earth history left to tackle: What if the Permian mass extinction never happened? What if the continents took on a different shape than what we know? What if most big animals had six limbs instead of four, or if grass — a rarity until recent geologic times — never evolved? These stories have yet to be written, or maybe they have, in an alternate timeline…