Become a fan of Slashdot on Facebook

 


Forgot your password?
Close
typodupeerror
×
Science

New "Last Dinosaur" Find Backs Asteroid Extinction 157

Posted by samzenpus from the sky-is-falling dept.
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."
This discussion has been archived. No new comments can be posted.

New "Last Dinosaur" Find Backs Asteroid Extinction More

New "Last Dinosaur" Find Backs Asteroid Extinction

Comments Filter:

  • Nonsense! (Score:5, Funny)

    by Anonymous Coward on Wednesday July 13, 2011 @04:29PM (#36753838)

    They were killed by all of the cavemen for food.

    At least that's what my science teacher told me.

    - A Student from Kansas

    • Re: (Score:2, Funny)

      by ckblackm ( 1137057 )
      Apparently you weren't paying attention. The Flying Spaghetti Monster put the bones out there for people to find, there weren't any dinosaurs as the world is only a few thousand years old!

      • Re: (Score:2, Funny)

        by dkleinsc ( 563838 )

        Aye, matey! Thar be the bones of dragons in the deeps. But which fell by His Noodlyness, and which by me blunderbuss?

    • Re:Nonsense! (Score:5, Funny)

      by CajunArson ( 465943 ) on Wednesday July 13, 2011 @04:41PM (#36754020) Journal

      You religious wingnut! Everyone knows the Dinosaurs went extinct because climate change caused by the the Bush Tax Cuts and Big Oil!

              - A Student from San Francisco

    • They were killed by all of the cavemen for food.

      Mine taught us that they were ridden to death.

    • That's absurd. They died in The Flood, an "extinction event" that lasted 40 days and 40 nights. How else do you think all those dinosaur bones got buried in the sediment?

      • What about the dinosaurs that lived in the water?

        • It rained 1 day of "heavy water" which killed the water dwellers, followed by 39 days of "light water" which drowned everything else. Then, about 99% of the heavy water miraculously disappeared (or changed into light water) leaving us with the current 3600:1 light/heavy ratio.

          • Re:Nonsense! (Score:5, Interesting)

            by alexo ( 9335 ) on Wednesday July 13, 2011 @05:47PM (#36755036) Journal

            It rained 1 day of "heavy water" which killed the water dwellers, followed by 39 days of "light water" which drowned everything else. Then, about 99% of the heavy water miraculously disappeared (or changed into light water) leaving us with the current 3600:1 light/heavy ratio.

            Close, but not quite.

            It actually rained super-heavy water (Tritium Oxide) and not "plain" heavy water (Deuterium Oxide), which killed the water-dwelling dinosaurs via internal beta emission. while being largely ineffective against land-dwelling creatures due to its short biological half-life (7-14 days).

            Also, need for miraculous disappearance since, while Deuterium is stable, Tritium has a half-life of about 4,500 days.

            Science. It works, bitches!

            • Re: (Score:2, Funny)

              by DocHoncho ( 1198543 ) *

              So THAT'S why the instructions for the Ark included two hands of lead shielding!

              • Gopher wood, the mysterious type of lumber specified by YHWH, is remarkably good shield against beta radiation.

            • That was an awesome explanation. Almost awesome enough to make me want to convert.

              • Re: (Score:2)

                by alexo ( 9335 )

                That was an awesome explanation. Almost awesome enough to make me want to convert.

                Note to self: next time add smileys.

                • That was an awesome explanation. Almost awesome enough to make me want to convert.

                  Note to self: next time add smileys.

                  I expect that's what Jesus thought too :-)

              • That was an awesome explanation. Almost awesome enough to make me want to convert.

                Convert to what? A state of perfect Total Humourlessness?

        • Re: (Score:2)

          by JustOK ( 667959 )

          They died when it dried up.

  • What sort of rock was it found in? (Score:1)

    by Anonymous Coward

    What sort of deposit was the horn found in? If there were enough water, isn't it possible that the horn could have been displaced and thus ended up in younger sediments? My university coursebook says that that is oft to occur with dinosaur teeth; could similar happen with a dinosaur's horn?

    • Re: (Score:3)

      by Paltin ( 983254 )
      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.
      • I don't have the full paper, but I got the abstract (which clears up many of the journalistic misrepresentations and errors of the cited re-hash) here [royalsocie...ishing.org] :

        Modern debate regarding the extinction of non-avian dinosaurs was ignited by the publication of the Cretaceous-Tertiary (K-T) asteroid impact theory and has seen 30 years of dispute over the position of the stratigraphically youngest in situ dinosaur. A zone devoid of dinosaur fossils reported from the last 3 m of the Upper Cretaceous, coined the '3 m gap',

        • Re: (Score:2)

          by Paltin ( 983254 )
          They only have one picture of the "fossil" in the paper, and to be honest - it doesn't look like one to me. Preservation looks absolutely terrible. They don't really talk about preservation. It doesn't look like there is more of the animal there (which does, of course, highly support transport). If you can't access the paper, let me know and I'll send it.
          • PM me for an email address. IIRC they were wanting $30-odd for a one-off purchase. Which isn't going to happen. I'm away to Africa in a couple of days, but should settle in by the end of the week and get caught up again.

            • Re: (Score:2)

              by Paltin ( 983254 )
              I would PM you if I could. don't even know if slashdot has that functionality. email me, krisrhodes at gmail.
  • ...I assert that dinosaurs did not growl or make any other scary sounds...they mooed.

    • Nonsense. They sang show tunes and were summarily executed by all other animals after one too many renditions of "Oklahoma."

    • ...I assert that dinosaurs did not growl or make any other scary sounds...they mooed.

      "Mooing" isn't actually far off the mark, given videos like this [youtube.com] and this [youtube.com]. One might imagine that this antediluvian bird [wikipedia.org] (pictured: a modern reconstruction of the raptor Deinonychus) might have made similar sounds.

    • Tyrannosaurus apparently has the bone structure of a big chicken. So I'm thinking it made VERY BIG clucking and crowing noises! :P
      "COCK-A-DOODLE-DO, MF!!"

      (old joke - Where does an 800 lb. canary sit? Any place it wants too!)

      • Tyrannosaurus apparently has the bone structure of a big chicken.

        Easy to say now they're not around to shred you into dogfood for disrespecting them.

    • Re: (Score:2)

      by cusco ( 717999 )
      At one time the most feared sound in Europe was not 'Grr' or 'Roar', but 'Moo'. Aggressive, foul tempered, prone to stampede towards danger rather than away from it, a quarter-ton of muscle and horn that traveled in herds that could stomp a hunter into a red smear was not a casual choice of prey.
    • There is evidence to challenge your assertion at http://en.wikipedia.org/wiki/Parasaurolophus#Sounding_function [wikipedia.org] and references cites within,

      (I use the sound as my phone's ring tone.)

  • Good news: the Scientific Method is still alive.

    The bad news: This pretty much disproves my hypothesis of Sauroflatulogenic Climate Change.

    • Why, pshaw! How do you think the atmosphere ignited when the meteors hit?

    • Sauroflatulogenic

      Expialidocious? [wikipedia.org]

      "Caused by the flatulence of sauropods" ... if that isn't real latin, then it's the best faux latin I've seen in a long time. And, if it is latin, bravo for knowing it.

      SauroflatulogenicExpialidocious ... oh, that's just funny.

      • The "-genic" element is Greek, isn't it?

        Which just makes it better faux Latin.

        • The "-genic" element is Greek, isn't it?

          Which just makes it better faux Latin.

          Oh, in order to be good faux Latin, it needs at least some grammar elements of actual Latin.

          Which is why Sauroflatulogenic is so brilliant ... you can actually deduce it's meaning. It could actually be close to valid Latin, but I have no idea.

  • Because that was my favorite totally rad "Last Dinosaur".
  • Creepy concidence hre. I had just finished wathing "National Geographic Explorer: 24 Hours After Asteroid Impact" documentary seconds ago when I loaded slashdot to see this story. I recommend that documentary btw; it really dwarfed all my previous imagination of what might have occured...
    • Ah yes, what are the chances of some random nerd seeing a documentary about something that will turn up as a story on /.
      Given enough nerds, actually close to 100% ...

      (Not to bash on you, but coincidence is often overrated)

    • Re: (Score:2)

      by DrEasy ( 559739 )

      Similar coincidence: yesterday I saw Terrence Mallick's beautiful Tree of Life, which also featured the asteroid impact.

  • Dinosaurs became extinct because they had laser eyes and they killed each other. No one has yet been able to disprove this theory.

    https://www.facebook.com/group.php?gid=19135208295 [facebook.com]

  • No, it doesn't (Score:5, Informative)

    by Wyatt Earp ( 1029 ) on Wednesday July 13, 2011 @04:45PM (#36754076)

    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.

    • Re: (Score:3, Funny)

      by Anonymous Coward

      You're right.

      In fact, the truth is that the dinosaur extinction caused the asteroid impact event. Intelligent dinosaurs had maintained a force shield which protected the Earth, but after they died out (turned out that, unfortunately, the force shield was carcinogenic) and the shield went off-line, Earth was wide-open for a cataclysmic impact.

      --Alastair

    • Re:No, it doesn't (Score:5, Insightful)

      by thoromyr ( 673646 ) on Wednesday July 13, 2011 @05:02PM (#36754352)

      what I got from reading the article was that the author had a conclusion that wasn't supported by the evidence. Taking the finding at face value, a solitary find that is significantly closer than expected to the estimated time of impact would tend to support a gradual extinction. If the extinction were sudden, due to the asteroid impact, then a wealth of fossil data would be expected all the way up to the estimated time of impact, with very little (quickly going to none) following it. Instead there is (apparently, and this is information provided and agreed on by the article) a significant gap with -- to date -- a single fossil found in the region.

      As far as I can tell it is another data point of no particular significance. To "disprove" gradual extinction before the impact a number of fossils representing normal population levels and distributions needs to be found.

      • To "disprove" gradual extinction before the impact a number of fossils representing normal population levels and distributions needs to be found.

        Which becomes quite a task when your fossils are 45cm long.

        However this is precisely what they did to establish the location of the K-T boundary at this site. They collected hundreds, if not thousands, of fossils, plotted the mean populations of fossils per centimetre of section examined, and then plotted the changes in those populations.

        Elsewhere in this thread

    • Re: (Score:3)

      by Paltin ( 983254 )
      The thing is - if they were in fact concurrent - then we'd expect that as better data becomes available, the dates converge.

      This is exactly what has happened over time. There's actually new work being done by Zircon workers that continues to close the gap.

      And yes, this IS evidence that supports that dinosaurs went extinct at the boundary. It increases the possibility of that, to the exclusion of others possibilities, by at least a little bit.

    • 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.

  • Wait a fricken' second. (Score:3)

    by blair1q ( 305137 ) on Wednesday July 13, 2011 @04:47PM (#36754106) Journal

    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.

    • Re:Wait a fricken' second. (Score:4, Informative)

      by Paltin ( 983254 ) on Wednesday July 13, 2011 @05:25PM (#36754706)
      That's not how it works.

      Considering the vast amount of time captured in even 13 cm of strata, there are many more generations of dinosaur corpses created and sorted through the taphonomic filter than would be created by a sudden extinction event. The deposition associated with the Hell Creek is one of rivers - which means there's a lot of energy to destroy things, as well as problems transporting from death location into the river to begin with. Simply put, there is no reason to expect that you'd fine a single bone from the last generation of dinosaurs - and even if you did, you'd have a hell of a time proving it.

      Here's an example paper from the modern that looks at this problem : http://www.cornellcollege.edu/geology/greenstein/personal/Reprints/Diadema.pdf [cornellcollege.edu]

      Clear record of mass mortality, like you expect, requires exceptional preservation such as that captured in the Burgess Shale. That isn't the case for the Diadema, or for the Hell Creek formation.

      And yes, of course you can associate things at 13cm. The number of vast changes in flora and fauna at the K/T boundary match up as well as could be expected with the Iridium spike and other impact markers. This is strong evidence that there is an association.

  • huh? (Score:5, Interesting)

    by vlm ( 69642 ) on Wednesday July 13, 2011 @04:50PM (#36754154)

    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.

    • Re: (Score:3)

      by Paltin ( 983254 )
      In geologist terms, 13cm is "right up until". Add in the Signor-Lipps effect and it's statistically indistinguishable.

      http://en.wikipedia.org/wiki/Signor%E2%80%93Lipps_effect
    • Two points to consider:
      1. The K-T boundary position is very well-constrained; the uncertainty regarding its exact age is irrelevant..
      2. Sedimentation rates are estimated to have ranged from 52 to 81 meters per million years. Thus 13 cm represents no more than 2500 years.

      Now, is it possible, based on the available evidence, that the last dinosaur died out 2500 years before the big meteorite impact at the Cretaceous-Tertiary boundary? Certainly. However, is it likely? As a geologist, I'd have say NO!

      • Re: (Score:3)

        by Paltin ( 983254 )
        >Sedimentation rates are estimated to have ranged from 52 to 81 meters per million years. Thus 13 cm represents no more than 2500 years.

        Sedimentation rates are not constant. They tend to come in fits and bursts. I would not draw that conclusion from the evidence.

      • While I realize that as a geologist you may not have much more understanding of the climate and weather considerations involved than I do, but since I know basically nothing about climate, weather, or geology, you might have a better idea of what was going on during the K-T events than I do.

        So this big old rock slams into the Earth and makes enough dust out of itself to create the world-wide iridium enriched sedimentary deposits that are the K-T boundary. And in so doing, creates a very long winter.

        So h

        • ...

          So this big old rock slams into the Earth and makes enough dust out of itself to create the world-wide iridium enriched sedimentary deposits that are the K-T boundary. And in so doing, creates a very long winter.

          So how long does it take for all that dust to actually settle? How much other sediments brought about by the more rapid erosion of the early part of the Long Winter would bury the remains of the megafauna before most of the asteroid dust was deposited?...

          Bear in mind that an event of this magnitude creates a number of major disruptive effects that manifest themselves for different lengths of time. The rogues gallery includes massive amounts of nitric oxides from the heat of impact causing a worldwide super-acid rain, release of massive amounts of CO2 from the carbonate impact strata, in addition to the dust. So we get an instant super-winter awash with super-acid rain acidifiying waters around the world, replaced a few years later with a millenia long heat

        • It would seem that some gap between the last dinosaur fossils and the iridium layer should be expected, but would this be only millimeters, or is 300 centimerters actually a reaonable expectation?

          Given that the asteroid debris would only be a small fraction of the excavated impact crater, and it would not be evenly distributed, even so you can get some back-of-the-envelope estimates.

          The crater is ~200km in diameter, and in the order of 10km deep. That's [calculates] around 300,000 km^3 of debris. Distribut

    • I posted the abstract of the paper up-thread.

      That may correct your misapprehensions as to what the actual claims made are, rather than what has been filtered through journalists.

  • extinctions (Score:5, Interesting)

    by jollyreaper ( 513215 ) on Wednesday July 13, 2011 @04:52PM (#36754184)

    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.

    • Re: (Score:3)

      by Paltin ( 983254 )
      This is one of the bigger problems with the impact hypothesis. Also, amphibians were largely unaffected, and they tend to be very sensitive to environmental problems. Impact having an important contribution to the extinction is still the leading hypothesis, even if there are some things that aren't understood.

      • This is one of the bigger problems with the impact hypothesis. Also, amphibians were largely unaffected, and they tend to be very sensitive to environmental problems...

        Since the alternative hypotheses claim that non-impact environmental problems caused the gradual extinction of the non-flying dinosaurs I don't see how the survival of the amphibian lineages is a distinctive problem for the impact hypothesis.

    • how dare you deny the impact theory. Just because there's valid questions to it doesn't mean it's not true and we should blindly believe everything that is said about it. Raise taxes and fund steps that may or may not do any good.

    • "...some form of communicable disease that was stressing the dinosaur population..."

      Try rewriting that as "...some form of communicable disease that was stressing the mammal population..." - it doesn't really make sense, does it? Dinosaur diversity back then was similar to mammal diversity now* - one disease isn't going to account for all, or even a large fraction, of them.

      However, the dinosaurs may well have been stressed by evolving mammal and bird competitors - some think that this was the primary reason

    • 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.

      Actually you mean "lineages", taxonomic groups that survived. Note that the dinosaurs were in no way reptiles - any more than birds are (quite literally, they are the descendants of flying dinosaurs). The dinosaurs had quite different metabolisms and behavioral patterns, which are postulated to have created unique vulnerabilities to the impact stresses.

      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.

      Theories of this type have been floated. One problem with this approach is that when talking about "the dinosaurs" we are talking about a large group of dive

  • Jumping to conclusions (Score:3)

    by Translation Error ( 1176675 ) on Wednesday July 13, 2011 @04:57PM (#36754256)
    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.
    • They must have got the mat.

    • Re: (Score:2)

      by Paltin ( 983254 )
      Gradual extinction is still a possibility, but that's been covered by other studies and there is little to no evidence that specifically supports it.

      What this paper does way in on is the claims that the extinction happened a long time (3m of rock worth of time) before the impact. If this is an unreworked bone, those claims are dead.

    • Just like a loose correlation between atmospheric carbon and temperature rise doesn't mean SUVs are killing the earth.

  • I have a living alligator here that would like to argue with that "last dinosaur" designation.

    • Re:Not dead yet! (Score:4, Funny)

      by Urkki ( 668283 ) on Wednesday July 13, 2011 @05:52PM (#36755106)

      Alligators are not dinosaurs, they're Crurotarsi [wikipedia.org], 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!

    • You could make a better case for a dinosaur being an alligator than vice versa. Your post would work a lot better if you cited your pet parakeet.

  • One would think that the upheavals of the extinction event would have created some mass graveyards that could be found at the layer itself. I realize that in the grand scheme of things, the one wiped out generation is a statistical blip relative to the millions of generations that came and went through the normal lives and deaths, but given the scale of the disruption to normal ecology, it would be nice to find boneyards right on the KT boundary event itself.
  • Like any catastrophic event, a chain of events leads up to a final point of failure. The straw that broke the camel's back, as it were (at most). Almost never does one factor result in the collapse of an entire system.

  • I've heard and read many times, since years and years ago already, that dinosaurs went instinct due to an asteroid impact.

    And now a news article is saying dinosaurs went instinct due to an asteroid impact?

Slashdot Top Deals

We are each entitled to our own opinion, but no one is entitled to his own facts. -- Patrick Moynihan

Close