Star Trek Just Murdered The Dinosaurs, But What’s The Real Science?
Let’s visit the distant past… of 1980.
The Season 4 premiere of Star Trek: Strange New Worlds opens with a new take on a very old event. After a mishap sends the Enterprise 65 million years into the past, the crew tries to mediate a conflict between two species who call our solar system home. But time travel is a funny thing, and our heroes can’t stop the affair from escalating until one species has been annihilated and a chunk of their planet is hurdling towards the Earth.
Amid all this excitement, the image of that rock slamming into the Yucatan peninsula and causing a very bad day for the dinosaurs encountered by the Enterprise’s ground crew is the episode’s most familiar element. But while the story of how the dinosaurs went extinct is a pop culture staple, the research that unfolded in reality wasn’t without its own drama.
Finally, we have our culprits.
Rocks of all Sizes
“The whole thing started with rocks in central Italy, in an area where lots of submarine sediment accumulated,” Dr. Alessandro Chiarenza, a paleontologist at University College London, tells Inverse. “This rock is rich in microorganisms useful for dating and understanding past environments. In the ‘70s, scientists started converging in the area, because they were noticing weird patterns. Microorganisms were disappearing in the rock column, and were being replaced by other lifeforms. Walter Alvarez was a geologist interested in figuring out why, because these kinds of rocks can be useful for locating resources, like gases and oils.”
The theory known as the Alvarez hypothesis was formally presented in 1980, meaning our understanding of the Cretaceous–Paleogene (K–Pg) extinction only dates back to the year Pac-Man machines started appearing in arcades. Previous mass extinction events, from the Late Ordovician extinction of 445 million years ago to the Triassic–Jurassic extinction 201 million years ago, had terrestrial causes, like climate change brought on by relentless volcanic activity. An asteroid wasn’t on the radar, as the consensus among paleontologists had been that the dinosaurs had simply faded away.
"If you’ve seen the Disney classic Fantasia, the Rite of Spring scene was actually consulted on by paleontologist Barnum Brown, who discovered T. rex,” Chiarenza says. “The concept at the time was that every species throughout natural history at some point just starts slowly declining. Your environment changes too much, you can’t reproduce, and you eventually disappear and offer the planet to a more advanced lineage, which of course happens to be us. This was the story, it's a bit fatalistic.”
Walter and Luis Alvarez viewing a sliver of iridium.
By Alvarez’s time, scientists had begun pointing to India’s Deccan Traps, where volcanoes had once erupted for hundreds of thousands of years. That steady stream of CO2 would have poisoned the atmosphere, aligning with previous extinctions. But scientists studying those Italian rocks kept running into a problem.
“A few rare elements were popping up in the geochemical analysis of these rocks, and were overcomplicating the puzzle,” Chiarenza says. “Walter Alvarez, he happened to be the son of Luis Alvarez, who worked on the Manhattan Project. He was also interested in scientific issues outside of nuclear physics. He’d recently been consulted about figuring out how to look inside the pyramids, things like that.”
Cosmic dust rains steadily over Earth as it travels through space, so the Alvarezs looked for traces of this dust to determine how quickly these rock samples had accumulated. When they did, they found more iridium than they’d expected.
“Iridium is super rare,” Chiarenza says. “So they were trying to think of why this element was so anomalous. Did it take a very long time to accumulate? But then other elements should also be appearing in large proportions. So maybe something happened in space that brought all this weird cosmic dust, and they looked for traces of plutonium, because plutonium paired with rare elements like iridium are signals of a supernova explosion. But they couldn't find plutonium. So the single explanation left was a huge asteroid.”
And endless dramatic stock art was born.
A Dinosaur Debate
The Alvarezs’ first paper argued that the only viable explanation remaining was an asteroid impact emitting dust and gases that blocked out the sun and triggered a photosynthesis crisis, ultimately causing many species to go extinct. Naturally, many scientists quickly decided that this theory… sounded like overdramatic nonsense straight out of an episode of, well, Star Trek.
“A big conflict of trying to support or disprove this hypothesis started,” Chiarenza says. “Most extinctions had always been explained with earthly mechanisms, and paleontologists were very skeptical of this deus ex machina from outer space coming in and destroying everything. It was too flamboyant. Lots of geologists argued that India’s volcanoes probably caused it. Scientists eventually recorded this iridium anomaly in Spain, Denmark, and then far away in places like Haiti. It was global. So where is the bullet? You should have a huge impact crater.”
While the debate could get unusually intense, this isn’t a knock on those who doubted the Alvarezs, only an acknowledgment that scientific progress is rarely straightforward. But in a story that’s fairly dramatic in its own right, geophysicists Antonio Camargo-Zanoguera and Glen Penfield discovered the Chicxulub crater while working for Mexican oil giant Pemex. While a link between the crater and the K–Pg extinction was in newspapers as early as 1981, everything from Pemex corporate policy to simple miscommunication kept samples from being seriously analyzed until 1990.
Scientists study a rock sample from the Chicxulub crater.
“Geologists flocked in to analyze the rocks and recognized that this is a 66 million-year-old crater,” Chiarenza says. “Eventually, paleontologists also started seeing patterns in the fossil record; there was this disappearance of like 75% of global biodiversity. Even groups that survived, like crocodiles, mammals, and birds, were severely affected. Dinosaurs got annihilated. And so everything was screaming yes, it was an asteroid.”
Skepticism began fading in the early ‘90s, around the same time that Jurassic Park took a stranglehold of pop culture and introduced many young audience members to the subject.
“The great Sam Neill, there’s that scene where that kid talks to him and says he read that a big rock fell on Mexico; he's fundamentally right,” Chiarenza says. “Neill’s character offers an alternative, that the dinosaurs just turned into birds. These are not antagonistic views; that’s a misconception. Evolution’s not a continuous chain of events; it’s more like a branching highway.”
But it wasn’t until 2010 that a paper co-written by 41 varied experts argued that the debate was over and an asteroid was officially to blame.
"There was a shift in opinion when the proof became so global and evident in many disciplines, from astrophysics to paleontology to geochemistry,” Chiarenza says. “Geophysicists cored the asteroid impact crater in Mexico and could find traces of how much the destruction affected the planet.”
Satellite imagery of where the asteroid landed.
But like any other long-running conflict, the dinosaur battles have their holdouts. Professor Gerta Keller, who Chiarenza describes as “Walter Alvarez’s academic arch-enemy,” recently published a book arguing that the Deccan volcanoes were solely responsible for the extinction.
Keller’s quest to, as the New York Times put it in 2003, “rattle the foundations” of geoscience is a long-standing one. By 2018, The Atlantic was calling it “the nastiest feud in science,” and if you flip through her book, you can almost hear the knives being sharpened. Millions of years after the dinosaurs went extinct, they have produced decidedly human drama.
Keller’s theories are now considered fringe, but she continues to get press because, in an ironic echo of Walter Alvarez’s story, we can’t resist the image of the lone scientist rebelling against the established order. Even amateurs and outsiders have weighed in; some Goodreads reviews of Keller’s book are remarkably invested in arguing that a shadowy conspiracy lurks behind the infamous asteroid.
“There's personal things going on with old scientists from the time,” Chiarenza says. “I don't have strong opinions about this, if it was volcanoes, I'm happy with volcanoes. But as a paleontologist I would certainly say that an asteroid was likely the primary driver of the extinction.”
The Future of the Past
Ironically, Chiarenza notes, the Deccan Traps may have actually played a helpful role during the extinction. “We think that maybe the asteroid impact might have been way more severe, and that life wouldn't have survived, if the Deccan provinces hadn't erupted,” he says. “Their heating of the planet might have helped buffer the cooldown brought in by the dust of the asteroid impact. It might have helped the recovery of the fauna, there are some faint layers in Colorado where animals and plants recover in a way that seems to match a rise in temperature of one to two degrees. There may be a story there.”
That remains a theory for now, as while it’s unlikely that any evidence of ancient alien warfare will ever be uncovered, there’s still much more to learn about the extinction. The belief that dinosaurs were already in decline when the asteroid arrived — an echo of the Fantasia story — was debunked last year. Just last week, a paper analyzing remnants of the asteroid impact downplayed the assumption that the rock had choked the atmosphere with its own sulfur. That helps narrow down the asteroid’s origins and, in the words of one researcher, shows that “Being impacted by such a rare, distant projectile really underscores how unlucky the dinosaurs were.”
Dinosaurs on display in Ulaanbaatar.
Chiarenza notes that while the fossil record is rich in places like the Great Plains and Mongolia, we’re still looking for evidence elsewhere. “We’re using new dating techniques to look at sites where people haven't looked for fossils in the past, like Africa,” he says. “It would be great to figure out what was happening in other parts of the planet and understand the story from a multi-continental view.”
That the extinction of the dinosaurs happened a “mere” 66 million years ago, rather than hundreds of millions of years ago, makes it relatively well-documented. But Chiarenza is confident that, as research technology continues to improve, our understanding will too.
"We have new sites to look for more fossils, we have more open borders so we can travel around, and we also have more advanced tools, from medical imaging to geochemical fingerprinting, that make paleontology such a diverse and multi-disciplinary science. With new methodologies and devices being developed, we're probably going to know way more in 10 years than we know now.”
