The Last Extinction: The Real Science Behind the Death of the Dinosaurs

by Gerta Keller

The story behind Dr. Gerta Keller’s world-shattering scientific discovery that dinosaur extinction was NOT caused by asteroid impact, but rather by volcanic eruptions on the Indian peninsula, a discovery that highlights today’s existential threat of greenhouse gasses and climate change—and one that sparked an all-out war waged by the scientific establishment.

Part scientific detective story, part personal odyssey, The Last Extinction is the definitive account of a radical theory that has reshaped how we understand our planet’s past and, as we face the possibility of a sixth extinction, how we might survive its future.

For decades, the dominant theory held that an asteroid impact caused the dinosaurs’ extinction. But Princeton Geologist Dr. Gerta Keller followed the evidence to the Deccan volcanism, a series of massive volcanic eruptions in India, triggered a long-term climate catastrophe and Earth’s fifth mass extinction. Her findings upended the field and ignited a bitter feud in modern science—what became known as the “Dinosaur Wars.”

Raised in poverty on a Swiss farm and told she could never be a scientist, Keller defied expectations, earning her PhD at Stanford and battling her way into the highest ranks of Geology, eventually becoming a Professor of Paleontology and Geology at Princeton University. Her refusal to back down in the face of ridicule, sabotage, and sexism makes her story as thrilling as her science, which offers urgent insight into today’s climate Sustained planetary upheaval—not a single cataclysmic event—can plunge the planet into an age of death.

Genres: Science, Nonfiction, History, Dinosaurs, Nature

324 pages, Kindle Edition

First published September 9, 2025

Reviews

[Amy · Rating 5 out of 5]

So, I mentioned to my teen that I was reading a book about what really killed the dinosaurs, and she was sure it was an asteroid, a theory that was pretty much debunked before she was even born. But that idea has pervaded because it showed up in so many news stories back when the Chicxulub asteroid was thought to be what killed the dinosaurs. It was a good theory. But over time, scientists looking at various pieces of the puzzle were able to show that the asteroid hit at least 200,000 years before the 5th big extinction event that killed the dinosaurs.

The problem was that the “Impactors” were louder and prouder than those quietly chipping away at the evidence, with one Impactor going as far as to steal core samples and throttle scientific papers that went against his pet theory. People don’t like to be wrong, even scientists. After all, they’ve put lots of money and time into promoting their theories. Interestingly, this is the second book I’ve read recently where scientists taking a multi-disciplinary approach to a scientific idea debunk or question other scientists’ theories, resulting in having their papers throttled from publications in journals like Science by peer reviewers from the opposition. I understand skepticism, but it makes me wonder how many times this happens.

Anyhow, the author details decades and decades of work that she did in conjunction with others from various scientific disciplines that not only to disprove the asteroid theory but also shows what likely really did kill the dinosaurs: a series of volcanic eruptions over many years that made the atmosphere and oceans difficult for many species to survive. The real clincher comes at the end of the book when an “Impactor” does studies related to what everyone had been citing as the smoking gun in the fossil record for the asteroid theory, only to find that that smoking gun is chemically inconsistent with an asteroid. You’d think they would have started with that test rather than waiting decades in the future. But sometimes people want to believe what they want to believe.

This was a slow read in the beginning, but it picked up about midway, and I finished the last half over the course of an afternoon. The ending of the book correlating the current climate crisis with the state of the atmosphere when the dinosaurs died out was kind of startling. Yeah. We’re probably doomed. Happy reading! This book comes out September 9, 2025, but I got an early copy from Netgalley.

[Chris Cox, a librarian · Rating 5 out of 5]

Science is unlike many disciplines in that experts have no choice to go for with the data whether they like it or not. Well, not really.

If you take Keller's position, her position of the fifth mass extinction (the one that knocked off the dinosaurs) was gradual and involved spread out extinction rates. The differing point of view was mass extinction 66 million years ago with an asteroid colliding with the earth. The fascinating battle over these differing ideas make up the main conflict presented in this book.

Let's just say the mass extinction promoters do not allow their point of view go gently into the night.

[Annabelle Canestraight · Rating 5 out of 5]

At first I felt like the author was too repetitive about her claim that the Impact theory was unproven (and unprovable) bullshit, but after doing a bit more reading online, I see it a bit more for how it is. Gerta Keller is a passionate and dedicated female scientist who spent her career trying to produce real science in the shadow of men who manipulated the public imagination and data to convince the world that an impact killed the dinosaurs. It takes one brief youtube search of pbs dinosaur documentaries to see that a flaming astroid is featured in almost every thumbnail. As a lifelong recreational dinosaur enthusiast, I had no idea the truth could get this manipulated. This led me to think about Montaigne and also modern politics.

But in summary, I liked this book because it was the true story of a strong female scientist who wrote this book at the end of a long and impactful career, probably in an attempt to set the record straight. If you don't read it, let your takeaway be: an astroid impact most likely didn't kill the dinosaurs!!

Also, inspiring to me, a depiction of a happy marriage between scientists in different fields!!

[Molly McDermott · Rating 4 out of 5]

This was reality TV but academia & dinosaurs. The asteroid did not kill the dinosaurs after all!!!! I wouldn’t recommend this book to anyone who isn’t already very interested in this topic because it goes pretty deep into the scientific history. Dr. Keller has some major beef with other academics which was both hilarious & tiring after a while, but I do think she’s right. More like a 3.5 that I’m rounding up for the sassy audiobook narrator who brought the drama to life

[Zach Schab · Rating 5 out of 5]

As a layperson I can’t really speak to the validity of the scientific arguments in any meaningful way, but the case laid out by Gerta Keller seems sound and her personal story was compelling. Definitely a great read!

[Kelsey Harrington · Rating 3 out of 5]

This was a fascinating topic, and Gerta Keller has an incredibly interesting story. However, this read a bit too much like a scientific paper. I can see it being difficult for general audiences to grasp a lot of what is being discussed. Even I had trouble following, and I’m a huge dinosaur nerd.

I wish that Gerta had worked with a coauthor, someone similar to Edward Dolnick or Timothy Eagan, who can take heavily researched topics and make them more accessible for wider audiences.

[Scott Martin · Rating 4 out of 5]

(Audiobook) Sometimes, the worst type of fights are academic fights. What on the outside seems a rather asinine thing to fight over can be life-and-death struggles, where nothing is off-limits and collateral damage is just part of the game. Thus it is with academic fights, and some of the most brutal fights in academia come from the study of dinosaurs. You had the legendary fossil wars of the late 19th century, and now we have the “Dinosaur Wars” of the late 20th/early 21st century. Enter Keller, a paleontologist who studied the Fifth Great Extinction. To her and others in her camp, the Deccan Volcanos of the late Cretaceous Period and their thousands of years of activity were the primary cause of that great extinction, which claimed the dinosaurs as their most famous victims. However, while they worked that theory, you had others that felt that a massive asteroid that slammed into the Earth 65 million years ago in the Gulf of Mexico was the triggering event that led to the immediate extinction of the dinosaurs. Thus, the stage was set for a massive scientific battle royale. Throw in some major-league heavyweight egos with connections to the Manhattan Project and some good old-fashioned misogyny, and thus, a decades-long battle in the lab and press about who was right about the death of the dinosaurs.

Keller is engaging in her topic and clearly offers her side of the story. While you could say there are some axes to grind and some inherent bitterness at how things played out, you can also understand the consternation from her point of view. Was she right? Well, most of the public discourse still holds that the asteroid was the primary killer, but given the evidence and constant reinforcement of the studies (which of course Keller would show as being on more sound scientific analysis), there is a ground-swell to change the narrative. It will be a long process to change anyone’s mind. Not that she doesn’t take down some big names. If they make the movie of this book, than the heel gets played by Dutch scientist Jan Smit. He became the face of the “Impact Theory”, and did everything in his power to keep that theory as the primary, even to the extent of engaging in some underhanded duplicity to prevent Keller and her compatriots from disproving his theory. Haven’t heard his reaction to this work, but I don’t imagine he would recommend this book to others.

Overall, an engaging book to read, and not just for the analysis of why Keller thinks Deccan volcanism was the reason for the loss of the dinosaurs. Quite a lot of high-school type drama. Could have done with a little less of the moralization of the non-paleontology topics, but I will also give Keller some credit for fighting this fight. She was getting railroaded, even if you don’t take her word completely for it. Good call to have a woman read the audiobook for a woman’s memoir.

[Sarah Jensen · Rating 5 out of 5]

Book Review: The Last Extinction: The Real Science Behind the Death of the Dinosaurs by Gerta Keller

A Provocative Reexamination of Dinosaur Extinction
Geologist Gerta Keller’s The Last Extinction challenges one of science’s most entrenched narratives—the asteroid-impact theory of dinosaur extinction—with meticulous research and bold dissent. This book is not just a scientific treatise but a compelling narrative of academic rivalry, paradigm shifts, and the painstaking detective work behind paleontology.

Key Strengths
-Scientific Rigor Meets Narrative Drive: Keller presents complex geological and paleontological evidence in accessible prose, making her case against the Chicxulub impact as the sole extinction driver. Her focus on Deccan volcanism’s role adds nuance to the debate.
-Underdog Perspective: The book reads like an intellectual thriller, detailing Keller’s decades-long battle against mainstream theories and the resistance she faced.
-Timely Relevance: By examining Earth’s past mass extinctions, Keller subtly parallels current anthropogenic climate crises, inviting reflection on planetary resilience.

Potential Considerations
-Dense Sections: Some technical passages may daunt readers without a STEM background, though Keller’s explanations are generally clear.
-Controversial Stance: Those wedded to the asteroid theory might find her arguments provocative, though she marshals evidence persuasively.

Score Breakdown (Out of 5)
-Scientific Depth: ⭐⭐⭐⭐⭐ (5/5) – A masterclass in interdisciplinary research.
-Accessibility: ⭐⭐⭐ (3.5/5) – Brilliant but occasionally jargon-heavy.
-Narrative Appeal: ⭐⭐⭐⭐ (4/5) – Surprisingly gripping for a science book.
-Originality: ⭐⭐⭐⭐⭐ (5/5) – A paradigm-challenging work.
Overall: ⭐⭐⭐⭐ (4.5/5) – Essential for science enthusiasts and critical thinkers.

Ideal Audience
-Science buffs craving fresh perspectives on paleontology.
-Readers of The Sixth Extinction or T. rex and the Crater of Doom.
-Anyone intrigued by scientific controversies and the human stories behind them.

Gratitude
Thank you to NetGalley and Gerta Keller for the advance review copy. The Last Extinction is a testament to the vitality of scientific dissent—a reminder that even the most accepted truths deserve scrutiny.

Final Verdict
Keller’s book is a rare blend of erudition and drama, transforming academic debate into a page-turner. While its niche subject and technical moments may narrow its appeal, it’s a groundbreaking work that reshapes our understanding of Earth’s most famous extinction. Highly recommended for those who relish science that challenges conventions.

Note: This review reflects the ARC edition; minor changes may appear in the final publication.

[Ula Tardigrade · Rating 4 out of 5]

My initial reaction to this book is the best proof of its importance. "What is this woman writing about? EVERYBODY knows it was an asteroid that killed the dinosaurs!" Fortunately, I was curious enough to do some digging — after all, what publisher would approve a strange conspiracy theory? And that's how I learned about "the Nastiest Feud in Science." I was appalled that I had never heard about it before, even though I have read many natural history books.

A quick search revealed that Gerta Keller, the author, is a well-respected geologist and paleontologist with an intriguing biography. She refused to be silenced for decades while pointing out the lack of scientific proof of the impact theory. According to Keller, the theory's popularity was partly achieved thanks to its simplicity and appeal:

„From the moment it was first published in the June 6, 1980, issue of Science magazine, the impact hypothesis captured the public imagination. An asteroid hurtling through space . . . a catastrophic explosion . . . a gigantic dust cloud that plunged Earth into freezing darkness and destroyed the dinosaurs. Who could be immune to such a spectacular story? As Australian journalist Ian Warden later reflected, all it lacked was ‘some sex and the involvement of the Royal Family and the whole world would be paying attention.’”

However, there was another reason: the pressure exerted by the author of the theory, a Nobel Prize-winning physicist. The author is very harsh in her criticism:

„From Luis Alvarez, I observed my first lesson in media manipulation. He orchestrated a two-front war—one controlling media and public opinion and the other eliminating or destroying any scientists who questioned or opposed his hypothesis”.

I don’t have the expertise to judge whether Professor Keller is right. Her arguments sound convincing, but she may be biased because she is on a side of this conflict. Nevertheless, I believe the general public should be more aware of this discussion — after all, that's what science is all about.

I encourage anyone with the slightest interest in paleontology, geology, or natural history to read this book.

Thanks to the publisher, Diversion Books, and NetGalley for an advanced copy of this book.

[Edward Canade · Rating 5 out of 5]

For years I unthinkingly accepted as fact that a meteor that impacted the Yucatan Peninsula 66 million years ago was the sole cause of the demise of the dinosaurs. This book was eye opening. I always thought that the scientific community had long since given up back stabbing and blind allegiance to a click. Yes, I knew there was fierce resistance by the church and other groups to ideas such as the configuration of the planets and stars and there were those that long opposed the germ theory for instance. But I thought those days of blind allegiance and bigoted loyalties was a thing of past.

So Gerta Keller's explanations awakened me to the entrenched ideas that refused to consider others' ideas that showed that the dinosaurs survived that impact. The asteroid impact which actually pre-dated the KPB, and the 5th mass extinction by 200,000 years, did so without significant long term effect. Her research revealed that dinosaurs were already in decline and that it was climate change brought on by an extended period of volcanism, mainly from the Deccan Traps of India that were the precipitating cause of the fifth and last mass extinction. In fact the last great extinction like the four previous major extensions was brought on by climate change. Volcanism caused temperatures to rise and the oceans and river and lakes became toxic to life, acidified, from released CO2, nitrates and sulfates. iridium spewed out of these massive volcanic eruptions.

Finally, Gerta Keller warns that we may be on the verge of causing the 6th mass extinction event by our reckless emission that are on course to irreparably change the climate to a condition incompatible with complex life forms.

The lesson here is to remain open minded and not encrusted with any one point of view, I like her book and her presentation. It's the best explanation I have heard SO FAR.

[kylie · Rating 3 out of 5]

I now realize I haven't given a ton of thought to the 5th extinction / the fall of the dinosaurs. I do remember that the general consensus we were taught growing up (zillenial) was that a big-ass asteroid (meteorite?) hit the earth and the dinos fell over dead, which sounds wild now that I think about it. Because like how could one impact kill that species around the entire globe??? Maybe it was implied that it set off a chain reaction of craziness. I don't remember. Point is, turns out that's actually not what happened or how it works.

Overall, the drama was high in this read. I think I would have appreciated more receipts, and less "he said/she said." I'm also incredibly saddened (though not entirely surprised) to learn how unscientific so many of these scientists were. I love science bc it's about constant learning and correcting. Science and fact do not care how ardently you believe in it. And yet... these guys, these impactor fanatics were unwilling to review actual evidence and willing to literally steal samples. WILD.

Also, I noticed that while Keller was fighting the patriarchy in a male dominated field, she had her own biases that appeared from time to time. For example, it stood out to me that she recalled traveling and being driven by a woman professor. Her gender wasn't actually relevant to the story, but it was pointed out nonetheless. This is small, but stood out as Keller was constantly commenting on the power trips the male scientists around her were on.

**I received my copy from Netgalley.

[Kathy · Rating 5 out of 5]

Have you heard of the dinosaur wars?

A thoroughly fascinating look at the dinosaur wars from the eyes of an insider. The author, Gerta Keller, is the scientist targeted in a smear campaign. Her work disputes the theory that asteroid impacts caused the dinosaurs' mass extinction. The book is a stunning indictment of groupthink, where everyone jumps on a bandwagon and ignores conflicting information. There was a financial incentive to support the asteroid theory. It had grabbed the public's attention and raised fears of future asteroid impacts. NASA saw it as a way to continue its funding. Even major scientific publications had asteroid impactors to sit on their review panels. Thereby blocking any papers that proposed a different theory. Dr. Keller, a Professor of Paleontology and Geology at Princeton, does a great job in describing, in layman's terms, the science behind her theory. There were only a couple of places that got somewhat technical. This is a very accessible read for non-scientists.

This book made my blood boil when I read about the misogyny towards her and her work. The whole account was enthralling. I hope that her theory becomes more well-known to the public.

Thanks to Diversion Books and NetGalley for access to a digital review copy.

[Sarah Overvaag · Rating 5 out of 5]

This book is exactly the reason I think more people should read nonfiction. The first time I heard about the Chixulub meteor impact, I was blown away by its size; surely such a large impact really could cause worldwide devastation. Except that I didn’t know there was little to no scientific evidence for the theory. I didn’t know that the iridium in the KP extinction layer could have been terrestrial, in fact, I only knew what the press told me. The press wasn’t reporting on alternative theories, even the ones with verifiable evidence. Gerta Keller was one of many scientists with alternative theories, but they were ignored, publicly maligned, and professionally assassinated for speaking out. Keller faced a second level of scientific scorn for being a woman from some of the “impactors”. Thankfully, Keller and her associates never gave up. Keller has written a book that is accessible to every day dinosaur enthusiasts, people who are open to seeing new viewpoints and to people who see the dinosaur extinction event as an allegory for our own time. I’m a life-long dinosaur nerd, and I am so glad books like this exist to open my eyes and bring new knowledge to my mind.

[Michael Doane · Rating 5 out of 5]

The Last Extinction is a gripping blend of scientific detective story, intellectual rebellion, and personal resilience. Gerta Keller presents a compelling and meticulously argued case that overturns the long dominant asteroid impact theory of dinosaur extinction, instead tracing Earth’s fifth mass extinction to prolonged volcanic activity in India’s Deccan Traps and the resulting climate catastrophe.

What makes this book extraordinary is not only the science, but the story behind it. Keller takes readers inside the fierce resistance she faced from the scientific establishment, revealing how evidence based research can be sidelined by power, prestige, and entrenched narratives. At the same time, the book draws an urgent parallel between ancient volcanic greenhouse emissions and today’s human driven climate crisis. Clear, courageous, and deeply unsettling, The Last Extinction reshapes our understanding of planetary change and offers a sobering lesson about sustained environmental disruption and how easily it can happen again.

[Brad · Rating 3 out of 5]

Well, this book could be subtitled "And boy, do I have scores to settle!" It is as much about Keller's battle to be taken seriously as a - gasp - woman scientist and her long struggle to prove with irrefutable evidence that the mass extinction of 66 million years ago was caused by volcanic eruptions, not the impact from an asteroid, as it is about the science involved. The way she was treated by leading male scientists in her field, if her story is at all accurate, was nothing less than shameful. In her telling, they were wedded to the "impact" theory of extinction and nothing - no evidence - could convince them that her conclusions were much closer to the real truth.
It's kinda a weird book, repetitious in a lot of ways, and I will readily admit that much of the science Keller describes here was way over my head. If you're not really interested in the topic, I'm not sure this book is for you.

[Andrea Wenger · Rating 5 out of 5]

Professor Gerta Keller’s groundbreaking research challenged the dominant impact theory for the dinosaurs’ extinction, revealing the role of Deccan volcanism. This memoir details her decades-long battle against entrenched scientific opposition and her eventual vindication.

I went into this book skeptical and ended up persuaded by the evidence. The memoir is fascinating and easy to read. I was expecting this book to focus less on politics and more on science—I’m interested in learning more about the Deccan Traps theory. I hope scientists will do a better job in the future in working together to determine how the impactor event and the Deccan Traps eruptions might each have contributed to the K-Pg extinction.

Thanks, NetGalley, for the ARC I received. This is my honest and voluntary review.

[Pam · Rating 4 out of 5]

I, like so many other people. have believe that an asteroid caused the extinction of the dinosaurs. Gerta Keller, in a fascinating book, disputes that widely-held theory -- and it must be called a theory -- with extensive research and her very plausible explanation (especially in these days, where climate change is a given, despite certain politicians' rebuttals) that the more likely explanation was climate change leading after volcanic activity. The most interesting aspect of Keller's book is the pushback she received from colleagues regarding her research. Very interesting book and highly recommended. Thanks to NetGalley, the author and Diversion Books for the eARC. aAll opinions are my own.

[Reader Ray · Rating 4 out of 5]

The Last Extinction: The Real Science Behind the Death of the Dinosaurs
Gerta Keller
Date of Publication: September 9, 2025

ARC courtesy of Diversion Books and NetGalley

The Last Extinction is an absorbing, thought-provoking book, part scientific paper presenting compelling evidence of an alternative cause of the Earth’s fifth extinction event, massive volcanic eruptions in the Deccan Traps of west-central India, and in part, an inspiring memoir of her academic plight amidst resistance to her theory and as a female scientist in the male-dominated fields of paleontology and geology.

[Janine · Rating 5 out of 5]

I am scientifically challenged but I’ve always loved dinosaur stories and movies (Jurassic Park especially), so when I came across this book, I thought - oh, goody, a dinosaur story! Indeed dinosaurs comprise the “plot line” of this nonfiction book, but only as to what made them extinct. And that’s a doozy of a good story.

Like many people, I bought the meteor theory of dinosaur extinction - wasn’t it scientists who proved this? Well, as the book’s subtitle indicates, “The Real Science behind the Death of the Dinosaurs” - the science that gave us the meteor theory was faulty and flawed. It was perhaps ego or dominance over a woman who dared to question the science of men that created the Dinosaur Wars detailed in this splendid book.

What I liked about this book was that while it’s filled with a lot of scientific detail, it’s written so laypeople like me can understand. It also is written by a fiercely determined woman with principles for truth and accuracy in reporting scientific results - I came to greatly admire Gerta Keller. As often the sole woman, she endured insults and mockery from her peers and never gave up. Besides focusing on the science, the book also includes Gerta’s story which also gives insight to her character and why truth matters. And finally it’s a great mystery story.

Suffice it to say, I know the real reason for the extinction- you must read the book to find out - and it will be worth it. I enjoyed the read. Great book.

[Normandy · Rating 1 out of 5]

I was aware of the asteroid and volcano debate, but oblivious to the animosity of one side versus the other. In chapters 1 and 2, I was sympathetic towards Keller and the attacks against her. But in Chapter 3, she was even worse against Louis Alvarez, and she was such a whiner. It was such a disappointment to know that informational science was taking a back seat to personal vendettas. I dumped it after reading 15%.

[Debbie · Rating 4 out of 5]

Very interesting account of a female scientist’s career and engagement with the scientific community when you have an alternative theory. How did the dinosaurs become extinct? Really enjoyed the science, and the scientific arguments. A lot of bullying behaviour in play. Thank you to the author. Thank you to # NetGalley and the publisher for an ARC.

[Michelle · Rating 4 out of 5]

This was fascinating. It is part memoir and part science. The most surprising thing was the infighting between the academics. I did not expect scientists to be so petty to each other and block other people's work because it disagreed with their own.

[Tfalcone · Rating 4 out of 5]

Interesting critique of the meteor KPg extinction of dinosaurs with the theory that the Deccan volcanic traps caused this. Not easy being a female scientist.

[Elisa Dorothy · Rating 5 out of 5]

Hi! I sell books and I love reading them. You can contact me on Instagram. Thanks!

[Fixie Nice · Rating 5 out of 5]

Was not expecting this book to be a page turner, however Greta’s persistence in following the facts in the face of those who are stubborn about their theories is quite remarkable.