Nov 12, 2026 · 2h 27m
Paleontologist explains how science proves dinosaurs were real
#2580 - Kenneth Lacovera
The conversation shows how fossils, geological evidence, and living birds turn dinosaur history from spectacle into testable science.
- 1Fossils gain credibility through independent predictions, exceptional preservation, and reconstructions that clearly separate evidence from inference.
- 2The Chicxulub impact reshaped life on Earth, while burrowing mammals, crocodiles, turtles, lizards, and birds survived its surface-level devastation.
- 3Birds remain living dinosaurs, linking modern behavior and anatomy to the evolutionary history reconstructed from ancient bones.
Don't miss
Lacovara explains why the Chicxulub impact could eliminate non-avian dinosaurs while allowing birds, crocodiles, turtles, lizards, and burrowing mammals to survive.
The brief
Paleontologist Kenneth Lacovara begins with a basic question: why trust dinosaur science? His answer is cumulative and testable, built from predictions, discoveries, and independent verification.
Fossilization is rare, DNA does not survive from the dinosaur era, and skeletons can mislead. Exceptional specimens preserving skin, gut contents, pollen, and parasites show how evidence fills the gaps.
Lacovara’s Dreadnoughtus discovery opens a discussion of gigantism, crocodile evolution, and the limits of reconstructing soft tissue, color, behavior, and missing bones from fossils.
The Chicxulub impact explains the collapse of non-avian dinosaurs, while birds, crocodiles, turtles, lizards, and burrowing mammals endured conditions that devastated surface ecosystems.
The conversation then tests the boundaries of paleontology: cryptids, Neanderthal de-extinction, plate tectonics, fossil hoaxes, dangerous expeditions, and the ethics of reviving extinct animals.
What was said on this episode
73 statements · 31 positive · 16 negative · 3 mixed · 23 neutral
Fossil presence can be predicted from geographic location
“depending on where you live in the world, I can predict whether you will find fossils or not”
Listen at 2:20
Non-avian dinosaur fossils require rocks from roughly 237–66 million years ago
“you have to find rocks that are between about 237 million years old and 66 million years old to find non-avian dinosaurs”
Listen at 2:53
Earth is approximately 4.567 billion years old
“I think it's 4.567 billion years old.”
Listen at 3:50
Any individual organism has an extremely low chance of fossilization
“the chance of any one individual becoming a fossil is almost zero”
Listen at 6:30
Many dinosaur habitats and species likely remain permanently unknown
“there's probably whole environments that were occupied by dinosaur species that we don't know about that we'll probably never know about”
Listen at 7:42
Some fossils preserve original bone and soft tissue
“you can actually have... not only original bone, but original soft tissue preserved in bones as well”
Listen at 11:19
The reported dinosaur blood preservation remains unresolved
“I think maybe the jury's out on that particular one.”
Listen at 12:08
No non-avian dinosaur DNA has been recovered
“We don't have any non-avian dinosaur DNA.”
Listen at 12:42
Dormant chicken genes might potentially be reactivated to express dinosaur-like traits
“you could find those genes and potentially turn them back on again”
Listen at 13:31
Fossilization begins relatively quickly after burial
“the process of fossilization is fairly rapid”
Listen at 14:55
Initial body stabilization during fossilization can occur within months
“Months, years. Months? Yeah. Months.”
Listen at 15:42
Richard Owen named dinosaurs as a group in 1842
“in 1842, a British anatomist named Richard Owens... describes them as a group of crocodile lizards, which they're not. And he gives them the name dinosaur.”
Listen at 19:19
The first discovered tyrannosaur was not Tyrannosaurus rex
“the world's first tyrannosaur discovered was not T. rex”
Listen at 23:57
Hadrosaurs were likely held with their spines parallel to the ground
“we don't think they did that today. We would put the spine parallel with the ground.”
Listen at 24:36
Dinosaur coloration remains unknown and reconstructed speculatively
“The color, we're guessing. That we don't know.”
Listen at 25:41
Tens of thousands of hadrosaur remains have been found
“We have tens of thousands of hadrosaur remains.”
Listen at 27:38
Theropod dinosaurs were probably mostly feathered
“They seem to be mostly feathered.”
Listen at 31:00
Large Jurassic Park-like raptors existed, but were not Velociraptor
“there really were dinosaurs like that that were as big as that. They just weren't velociraptor.”
Listen at 32:34
Feathered Velociraptor-like reconstructions are plausible
“that crazy-looking feathered side, I think that's plausible.”
Listen at 33:20
Later Jurassic Park films became less scientifically accurate than current science
“the movies become less and less accurate over time because they stick with like the 1993 models, whereas science has progressed since”
Listen at 35:24
Dreadnoughtus weighed approximately 65 tons
“it's a 65 ton organism”
Listen at 36:47
Dreadnoughtus is the most massive dinosaur with a confidently calculated weight
“it's the most massive dinosaur for which we can confidently calculate a weight”
Listen at 37:32
Dreadnoughtus was still growing rapidly when it died
“it was growing rapidly at the time of its death at 65 tons”
Listen at 41:34
Crocodiles continue growing as they age
“crocodiles have what we would call indeterminate growth, right? They just get bigger as they get older.”
Listen at 42:21
Cretaceous Sarcosuchus reached approximately 35 feet in length
“in the Cretaceous, there were definitely crocodiles that big. There's one from North Africa called Sarcosuchus Imperator that was like. 35 feet long.”
Listen at 45:35
The largest animal ever, the blue whale, is alive today
“The biggest animal to ever live is alive right now”
Listen at 47:03
End-Triassic volcanism caused CO2 rise, rapid climate change, and mass extinction
“This causes a lot of CO2 to hit the atmosphere, and we get rapid climate change, and we get the fourth mass extinction at the time.”
Listen at 50:59
End-Triassic volcanic CO2 caused warming
“In this case, it was warming because of the CO2.”
Listen at 51:39
Dinosaurs inhabited every continent, including Antarctica
“they're on every continent, including Antarctica”
Listen at 52:13
The Chicxulub asteroid was possibly up to 18 kilometers wide
“an asteroid hits the planet, right? It's maybe up to 18 kilometers across”
Listen at 53:15
The Chicxulub impact rapidly heated Earth’s surface to oven-like temperatures
“within an hour after the impact, temperatures got up somewhere between toaster oven and pizza oven”
Listen at 54:30
Non-avian dinosaurs became functionally extinct on impact day
“I think they're functionally extinct the day of the impact”
Listen at 55:49
Farmers in Sicily regularly find fossil megalodon teeth
“every spring, farmers find megalodon teeth in their fields”
Listen at 59:00
New oceanic crust forms at mid-ocean ridges
“new crust is being created at the mid-ocean ridges”
Listen at 1:17:43
Earth’s magnetic field periodically reverses polarity
“the magnetosphere of the Earth periodically flips”
Listen at 1:17:49
Magnetic reversals occur on average about every 800,000 years
“It happens, if I'm right, on average about 800,000 years.”
Listen at 1:18:53
A magnetic reversal may reduce magnetospheric radiation protection
“I think we lose our protection from the magnetosphere. The gamma rays.”
Listen at 1:19:13
Earth’s magnetosphere is generated by differential rotation of its iron cores
“we have a magnetosphere because we have a... solid iron nickel core surrounded by a liquid iron outer core and they rotate at different speeds”
Listen at 1:21:20
A magnetic reversal might increase cancer and mutation rates
“we would probably have an increased rate of cancer. We would maybe also have an increased rate of mutation.”
Listen at 1:25:17
Magnetic reversal could disrupt navigation in magnetoreceptive marine animals
“Some creatures in the sea use the magnetosphere for navigation, so that would really mess them up.”
Listen at 1:26:27
A cryptid species requires a viable breeding population
“there has to be a breeding population of them to exist”
Listen at 1:34:32
Undiscovered species still exist in remote regions
“there are definitely things out there to be discovered”
Listen at 1:37:03
Homo floresiensis is now generally accepted as a distinct species
“And now I think it's convention that that was a species that existed.”
Listen at 1:40:15
Humans should not recreate Neanderthals
“we should not do that.”
Listen at 1:43:01
Recreating Neanderthals would be extremely harmful or misguided
“that would be a supremely bad idea.”
Listen at 1:43:12
Colossal is doing excellent de-extinction research
“I think Colossal's doing amazing work.”
Listen at 1:43:55
Several Colossal target species recently went extinct largely because of humans
“these are creatures that recently went extinct largely at our hand”
Listen at 1:45:21
Species extinct during human history may still have a place in today’s ecosystem
“during the time of humans, that's still basically this world and they have a place in this world.”
Listen at 1:47:18
Capturing a newly discovered human-relative species would constitute kidnapping
“i think it would be yeah”
Listen at 1:47:40
Zoos make major contributions to conservation
“zoos do so much great conservation work”
Listen at 1:50:04
San Diego Zoo substantially contributed to California condor recovery
“I think the San Diego Zoo is largely responsible for the emerging recovery of the California condor.”
Listen at 1:50:12
California condors numbered about 22 individuals around 1970
“they were down to 22 individuals, I think, in around 1970”
Listen at 1:50:19
California condor population has risen to approximately 550
“there's only about 550 of them alive right now, but they're up from 22”
Listen at 1:50:37
Large sauropod dinosaurs had air-filled, pneumatized skeletons
“these big dinosaurs. Do have pneumatized skeletons”
Listen at 1:54:20
Dinosaurs had bird-style lungs with efficient one-way airflow
“they have what we call bird-style lungs, which kind of should be called dinosaur-style lungs”
Listen at 1:55:21
Birds perform well in low-oxygen environments
“birds are really good in what we call hypoxic conditions, right? Low oxygen.”
Listen at 1:56:09
Birds evolved weight-saving adaptations including hollow bones and tooth loss.
“birds have a lot of, yeah. But they have all kinds of weight-saving adaptations. Hollow bones, they've lost their teeth, right? Teeth are heavy. So birds just have beaks.”
Listen at 1:56:52
Hoatzin chicks are born with claws and use them to climb.
“the Hotson? It's a bird when it's born, it has claws, like, you know, harking back to its non-avian dinosaur days, and they climb around.”
Listen at 1:57:28
Pastured, grass-fed chicken eggs are preferable to store-bought eggs.
“Once you have pastured, grass-fed chicken eggs, you can't go back to the store-bought ones.”
Listen at 2:01:05
Every person who has walked on the Moon carried an Explorers Club flag.
“Every human that's ever walked on the moon has had an Explorer's Club flag with them.”
Listen at 2:02:31
The Explorers Club funds young explorers and conservation projects.
“a lot of what the Explorers Club does now is to fund young explorers, to fund conservation projects.”
Listen at 2:04:57
The Explorers Club can help stranded members and organize rescue missions.
“if you're stuck somewhere in the world, you contact the club and there's a good chance that there's somebody that can help you or even put a rescue mission together.”
Listen at 2:05:21
Cope and Marsh’s Bone Wars involved genuine fossils and intense rivalry.
“So those are real fossils, but they had this horrendous competition with each other.”
Listen at 2:07:03
Museums should preserve original large fossils and display reproductions.
“best practice now really is to keep the stuff in the collections and to mount the recreations.”
Listen at 2:12:13
Replicated bones should be displayed in a different color from originals.
“the best practice, if you're going to mount the real bones, is to make the replicated pieces a different color”
Listen at 2:13:09
Paleontologists use phylogenetic bracketing to infer missing dinosaur anatomy.
“We use what we call phylogenetic bracketing”
Listen at 2:13:32
Dreadnoughtus’s neck and skull reconstruction remain uncertain.
“there is, you know, some uncertainty with the neck and the skull of Dretnautus.”
Listen at 2:14:33
Productive dinosaur searches require appropriately aged, exposed sedimentary rocks.
“You have to find rocks of the right age, depending on what you're interested in, right? Those rocks have to be sedimentary rocks. And then today you need exposure.”
Listen at 2:15:03
Meeting geological and geographic conditions makes fossil discovery likely and novelty possible.
“you get those. Three things, the first three things, and you will find fossils. You get the fourth thing, and there's a good chance that what you find is new to science.”
Listen at 2:15:59
Antarctica likely contains thousands of undiscovered dinosaurs and new species beneath its ice.
“It's got to be thousands and thousands of dinosaurs and new species under that ice cap, and we have no idea what's down there.”
Listen at 2:18:07
Edelman Fossil Park’s extinction layer contains over 100,000 fossils from over 100 extinct species.
“we have collected over 100,000 fossils representing over 100 extinct species right in that layer”
Listen at 2:24:39
Edelman Fossil Park offers an exceptional record of the dinosaur extinction transition.
“it's the best window we have in the planet in that pivotal calamitous moment that wipes out the dinosaurs and really makes the modern world as we know it.”
Listen at 2:25:43
Visitors to Edelman Fossil Park can find and take home 66-million-year-old fossils.
“every kid, every grown-up that goes in there who tries a little bit and who's not afraid to get their hands there, and I hope you do it with us someday, finds a 66-million-year-old fossil with their own hands that they get to take home.”
Listen at 2:26:10
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