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 photo credit: goldenrectangle |
According to the Impact Theory, a rock from space smashed into the earth, threw up a huge dust cloud, chilled the atmosphere and sent down acid rain. All the dinosaurs died immediately all over the globe or in a week or so.
So….where are the bodies of the victims?
Probability of Becoming a Fossil: 0% or 100%
0%
If you die on a high plateau or a grassy meadow or on the average forest floor, far from the influence of river floods, your bones will get chewed, cracked, smashed and digested by scavengers. The remnants will get dried up and will flake away to nothing under the sun. Or, if the ground is wet, worms and grubs and fungi will destroy your osseous remnants.
That happens to most dead bodies, most spots, most of the time. Or…
100%
What if you’re lucky enough to die in a depositional basin, where yearly floods bring in layers of sand, silt and mud, and where lake bottoms accumulate blankets of sediment all the time. A place where huge sand bars develop in streams and rivers….
….then the possibility that some of your bones will get buried and fossilized rises to close to 100%.
Dino Extinction Supposedly Hit While Montana Was Getting Sediment
At the time of the Great Dino Die-Off, no sediment was being laid down in most places in the world. But in Montana’s Cretaceous coal fields, there were many swampy lakes and sluggish rivers, locales where mud and sand was being carried in. This depositional activity seems to have continued right through the end of the Cretaceous and beginning of the next Period, the Tertiary (“Age of Mammals”).
In fact, field geologists have a hard time telling where the Cretaceous mud ends and rhe Tertiary mud begins.
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| photo credit: etee |
If the Impact Theory is right, millions of Triceratops carcasses littered the landscape. Tens of millions of duck-bill dino bones also covered the ground. And….there were no big scavengers to crack the bones. The average dino body would last far longer than usual. Some of the impact victims should have had a high probability of being buried in the mud at the Impact Layer, the sand and silt and mud deposited right after the rock from the sky struck.
Total number of dino bones found right at the Impact Layer – 00.00.
That’s one reason why I am an Impact Skeptic. You have to do some special pleading to explain the lack of dino bones at the impact layer. You could argue that soil acid dissolved the bones. Or that for a hundred years there was no new mud, no new sand, no new silt.
Could be.
Still, I like to begin with a geological peshat (first impression): When I scan the actual facts on the ground, there is no evidence whatever of a sudden massive death of dinosaurian multitudes at the Impact Layer.
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| photo credit: Simone Ramella |
Evidence for a Long, Slow Disaster
There are clues that indicate the dino ecosystem was deteriorating long before the impact. The diversity among big, multi-ton dinos went way down about 5 to 10 million years before the end. In the Latest Cretaceous (Lancian Age) in most places in Montana, there are only two common big dinos – either Triceratops or the duckbill Edmontosaurus. It was a dino-monoculture. At 76 million years ago diversity was much higher.
Serial Killer in Deep Time
The biggest reason I’m a skeptic is the victim profile. When the dinos finally went extinct, salamanders, frogs, pond turtles, river gators all survived and thrived. So did most small terrestrial species. That pattern holds for six other mass extinctions – beginning at 285 million ears ago, long before the first dino. And the pattern is obvious in the last extinction at the end of the Ice Age, 11,000 years ago.
Impact Theory Fails to Predict the Correct Victim Profile
Sudden chill and acid rain will wipe out salamander-oids and frog-oids and turtle-oids. And hit big, active animals far less severely.
The wrong animals died.
Read about my dinosaur extinction theory in an early blog post.
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I agree Dr. Bob, I never have beleived the impact theory to be correct. There are so many holes in it (the theory, not the metorite, ha ha), that I’m shocked it’s lasted so long.
I have a couple questions for you, if you have the time that is.
1) I read in your book “The Dinosaur Heresies” that brontosaurs (sauropod dinosaurs) must have given birth to live calves. But I tuned in to “Clash of the Dinosaurs” last night, and they claimed that brontosaur (in this case Sauroposeidon) babies hatched from eggs. I have also read about the discovery of sauropod eggs in Argentina. Which is correct?
2) I have read that some species of Stegosaurus had four tail spikes, while others (like Stegosaurus ungulatus) had eight. Is this correct, or just a myth?
Thanks!!!
Now, that’s not to say that there was no impact, but maybe it finished off the last individuals. I, too, am a skeptic of the Impact Theory, but I’m also a proponent of more than one factor in Extinction. What killed the Dinosaurs also killed off other species from various groups that still thrive today. If you are curious about where I stand, you can read about it in more detail at my blog: http://paleoquestfossilhunter.blogspot.com/2009/10/fossil-fact-11.html
But what about the iridium found in the K-T boundary? Isn’t that evidence for a devastating impact?
Well, yes, there was an impact, but the question is wether or not that metor is what killed the dinosaurs. The evidence points to other, more earthly factors such as disease being the primary culprits.
The problem is that you’re misunderstanding the impact theory for extinction. The hypothesis states that the impact kicked a lot of dust into the atmosphere (backed up by geological findings) which blocked the sun and triggered global cooling. This caused a lot of plants to either die out or not grow nearly as abundantly as they had. This trickled down the food chain and impacted larger animals hardest as they required the most energy input to survive. The smaller animals also had an easier time adapting as they reproduce more quickly and could more easily evolve to suit their new environments.
I grew up on the impact event hypothesis, and I had never thought of it as a “sudden death” scenario. I had always thought that the impact would have clouded the earth for a few months, killing off plants, then the large herbivores, then the large carnivores. Wouldn’t that explain why small scavengers and animals with slow metabolisms (such as crocodiles) could have outlasted the dinosaurs?
Now I’m not married to the idea. I’m just trying to follow the science. I understand that there is compelling evidence that disease and/or environmental factors played a role in the extinction of dinosaurs. I’m just trying to figure out what role (if any) the impact played.
Austin-
I also grew up on the K-T Impact being “gradual,” but the evidence just seems to point to multiple factors. If we were to look at Extinctions today, there is always a number of factors that contribute to the decline, be it invasive species, Human Intervention, disease, Tectonic Shift, Climate Change, or could be, in the case of the Dinosaurs, a decline in variation and Diversity.
Evidence in the Badlands outside of Drumheller, Alberta, Canada, just a few feet below the K-T Boundary (the Irridium layer) seems to show that they were already in decline near the end of the Cretaceous, as there were approximately 12 known species found near that layer, and then there’s that gap where we find nothing. It’s true that Fossils are rare, but, still, why did the others fossilize and the others didn’t? So, here is where the controversey lies. It may be that they went extinct somewhat after that, but we don’t know. I bet, though, that the diversity would have continued to decline until the impact.
My suggestion is to get the “One Factor” thinking out of your head because there has NEVER been more than one factor that contributes to the decline of certain Animal Groups. In other words, it’s Natural Selection at it’s finest.
Lewis-
Thank you for your reply.
What makes you think I am committed to “One Factor?” Like I said in my last post:
“I’m just trying to figure out what role (if any) the impact played.”