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New "Last Dinosaur" Find Backs Asteroid Extinction
An anonymous reader writes "A new fossil discovery has suggested that dinosaurs were alive right up until the asteroid impact, and did not go extinct gradually due to climate change or changes in sea level, as previous theories have proposed."
They were killed by all of the cavemen for food.
At least that's what my science teacher told me.
- A Student from Kansas
The margin of error on when the last dinosaurs were existent and the margin of error on when the K-T boundary was deposited are both hundreds of thousands of years.
In some places there are at least 300,000 years of sediment between the fossil evidence of the Cretaceous–Tertiary extinction event and the K-T boundary.
K-T boundary has is dated to (65.5 ± 0.3) Ma, the Cretaceous–Tertiary extinction event is dated to 65.5 Ma, so the impact could have been the day the last dinosaurs were alive, it could have been 300,000 years before, 11 years after, or 213,417 years after.
They couldn't find any dinosaur bones within 3 meters of the boundary, then they found one 13 cm below the boundary, and they still claim the asteroid extincted them?
I want to see a bunch of bones lying on the boundary. Contemporaneous with the event. Show that the effect [extinction of dinosaurs] comes after the cause [asteroid that created the K-T boundary]. Until you can do that, you can't even associate the asteroid with the extinction. Even at 13 cm, they're not at all well-correlated.
We collected rock samples above and below the horn to determine the exact placement of the K/T boundary, and were surprised to see that the horn was no more than 13 cm below it.
A new fossil discovery has suggested that dinosaurs were alive right up until the asteroid impact
Speaking as a guy living in a county where the only non-service blue collar jobs left are at the local rock quarry, and having a geologist as a roommate two decades ago, I speak with profound scientific authority that those two quotes only go together if you define "right up until" as being about one zillion years. I suspect most readers define "right up until" on a somewhat shorter scale, like the time difference between the local news and american-idle, not zillions of years. (waves rolled up newspaper) Naughty journalist! Naughty!
"right up until" 13 cm of rock.
I am completely unaware of any political or cultural reason for the authors to be blind to this problem. I have no dog in the fight that I'm aware of. Just saying 13 cm of rock is not "right up until"
It MIGHT be that the real story is on a "bones per cm" basis this raises the curve implying the rate does not "tail off" (get it? dinosaur tail?) until the boundary, but that's not how the journalists are reporting it, as if the tip of the fossil was touching the boundary or chemical analysis of the fossil shows the dinosaur died during the boundary event.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
The thing that I always wondered about with the asteroid impact theory is that we have several species of large reptiles that survived the extinction event. While I'm no scientist, I'm wondering if there might not have been some form of communicable disease that was stressing the dinosaur population beforehand that accounts for the gradual diminishing of fossils in the record and the asteroid impact might have been a coup de grace. I find it hard to imagine that sea turtles and crocadillians would survive while various marine reptiles did not -- moasaurs, plesiosaurs, icthyosaurs, etc. I suppose there will be no easy answers.
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It sounds like some people are really jumping to conclusions here. While finding a fossil from the time of the asteroid impact does indicate all dinosaurs hadn't died out before then, it doesn't mean they weren't gradually dying out due to environmental changes.
Someone dying when a rock fell on his head isn't proof he wasn't wasting away from a terminal disease.
When someone says, "Any fool can see
Hell Creek formation = fluvial (river) deposits.
Reworking is always a possibility.
This specific fossil is claimed to have been found in an overbank deposit, which means that it was out on the flood plain, which if true means it is unlikely to have been reworked. But I'd want to see it for myself.
Alligators are not dinosaurs, they're Crurotarsi, which are well known to deeply hate dinosaurs for playing dirty tricks on 'em back in the Triassic-Jurassic transition. So for your own sake, don't even mention dinosaurs to your pet alligator, and especially don't start an argument about it! Only thing the alligator is going to like about the argument is taste of your ripped-off limbs!
K-T boundary has is dated to (65.5 ± 0.3) Ma, the Cretaceousâ"Tertiary extinction event is dated to 65.5 Ma, so the impact could have been the day the last dinosaurs were alive, it could have been 300,000 years before, 11 years after, or 213,417 years after.
You are assuming both calculations are independent, but they may not be. The asteroid collision threw up a lot of chemicals which characterize well the asteroid collision, among them an abundance of iridium.
You don't need to calculate the date exactly, if a fossil is in this iridium rich layer you can assume it died on the asteroid impact, that is both events happened on the same date even if you don't know exactly which date it was.