Become a fan of Slashdot on Facebook

 


Forgot your password?
Close
typodupeerror
×
Science

Fossil 'Suggests Plesiosaurs Did Not Lay Eggs' 79

Posted by timothy from the fossil-ventriloquism dept.
thebchuckster writes "Scientists say they have found the first evidence that giant sea reptiles — which lived at the same time as dinosaurs — gave birth to live young rather than laying eggs. They say a 78 million-year-old fossil of a pregnant plesiosaur suggests they gave birth to single, large young."
This discussion has been archived. No new comments can be posted.

Fossil 'Suggests Plesiosaurs Did Not Lay Eggs' More

Fossil 'Suggests Plesiosaurs Did Not Lay Eggs'

Comments Filter:

  • Nice (Score:5, Funny)

    by geekoid ( 135745 ) <{moc.oohay} {ta} {dnaltropnidad}> on Friday August 12, 2011 @06:37PM (#37075418) Homepage Journal

    More science, please.

    • But it's in a way upsetting to see so many dinosaur "established facts" I thought I knew turn out to be wrong. They were supposedly crawling out of the water to lay eggs like turtles! This is actually the second shock relating to plesiosaurs, they also were found recently to be warm blooded.

      • Well,

        Where do you think the Platypuses came from - Oh. Wait. Those lay eggs, don't they?

      • Being warm-blooded isn't that much of a surprise- we've known birds descended from warm-blooded dinosaurs for decades.

        • Being warm-blooded isn't that much of a surprise- we've known birds descended from warm-blooded dinosaurs for decades.

          Yes, but plesiosaurs are not dinosaurs so it means yet another branch of reptiles were warm-blodded. There is also evidence that Pterosaurs were warm blooded. Given how far back these branches had a common ascestor, the question becomes: why are crocodiles not?

        • But the evidence that all our favourite childhood dinosaurs were warm blooded is very recent, many in the last two years; sure there were theories in decades past but those were not the mainstream view. Cold, slow, sluggish....now they're hot, fast!

          • But the evidence that all our favourite childhood dinosaurs were warm blooded is very recent, many in the last two years;

            Wow ; that's some latency you've got there. You wrote that post in what? 1979? And it's taken 30-odd years to get through the "tubes" to appear on Slashdot. Impressive connection you've got there.

            (I am a geologist, and like many of my colleagues, I've been paying attention to the "hot or not" debate for all of these decades, since I was a geology student in senior school. And Bob Bakker

      • upsetting science (Score:5, Insightful)

        by macraig ( 621737 ) <mark.a.craig@gmail . c om> on Friday August 12, 2011 @07:10PM (#37075792)

        It's not good science unless it upsets somebody who dislikes having their gospel (or canon, for the more sociologically correct) challenged. Good science always bruises egos.

        I don't personally get it, though. Do the authors of buggy code that gets patched by others also get upset? They should be happy the code finally works.

        Still, why on earth would it ever upset someone who didn't discover/propose/create what's being challenged?

        • In the grand scheme of things, you are correct that the those who espouse the scientific method should be happy that their theories are proven wrong and human knowledge increased. However, we are still fickle humans and hate to see our work that we poured our heart and soul into get trashed in the name of progress. Many people cannot disassociate their ego from their work. I've known many programmers who do not like code reviews for that reason. No matter how much they want to acknowledge that it makes

          • Re: (Score:3)

            by macraig ( 621737 )

            "... get trashed in the name of progress."

            That's probably a pretty common way of visualizing it, but the previous work isn't really getting trashed, is it? Were it not for the original work being publicized, there might not have been a competing idea at all, or at least not as soon. Challenges to canon are often still reliant on the existence of the canon in the first place. That's reason to be proud of scientific challenges to one's work, not upset by them. Maybe for science there should be a corollary to the old cliche, "imitation is the most

            • Re: (Score:2)

              by lawpoop ( 604919 )

              but the previous work isn't really getting trashed, is it?

              That's what it feels like, and that's why people initially have a strong emotional reaction to it. The various levels of the brain are all operating simultaneously -- the 'fight-or-flight' part and the higher-level cognitive part. We continue to have emotional, child-like reactions, but our higher-level cognitive functioning arrests and overrides such reactions.

              • Re: (Score:2)

                by macraig ( 621737 )

                "... our higher-level cognitive functioning arrests and overrides such reactions."

                You should meet my neighbors.

      • Re:Nice (Score:4, Insightful)

        by SilverHatHacker ( 1381259 ) on Friday August 12, 2011 @08:23PM (#37076312)
        Perhaps it's a microcosm of the scientific world at large, but most of our dinosaur knowledge is based on "this is the first idea that popped into my head when I saw the thing, so we'll call it true until proven otherwise". The iguanadon, for example, was thought to have horns on its nose until a full skeleton was discovered and it was revealed that they were thumbs. Don't get me wrong, I don't care that we're creating imperfect theories based on limited knowledge which are expanded when more is discovered; that's how science works and how it should work. What I find to be particularly annoying is when these theories are taught as unchallenged fact. There was one species of dinosaur that was "discovered" in the form of a single bone, but sketches of the full animal were showing up in textbooks. If all you have is a single bone, at least put an asterisk beside the picture please! Maybe our knowledge would advance faster if we knew what exactly we knew and what we don't know.

      • Re: (Score:1)

        by Anonymous Coward

        1- Plesiosaurs are NOT dinosaurs.
        2- Most fully aquatic vertebrates descended from land animals are expected to be born in live birth. Eggs from non-amphibian land vertebrates (amniotes) are not suitable for underwater development, so the choices are to maintain land access for reproduction or live-birth. Many species of plesiosaurs seem to have been physiologically incapable of going on land and surviving (much like whales) so live birth was generally assumed... without proof yet. In this case as in the ca

      • ...the fact that they're reptiles; and not dinosaurs. IIRC the original skeleton was thought to be a dinosaur and the name stuck.

      • But it's in a way upsetting to see so many dinosaur "established facts" I thought I knew turn out to be wrong

        That's a feature of science, not a bug!

      • Plesiosaurs are not dinosaurs.

    • More science, please.

      This is where I first read the story... a little bit more science but not much:
      http://www.sciencedaily.com/releases/2011/08/110811142806.htm [sciencedaily.com]

    • Re: (Score:3)

      by Hatta ( 162192 )

      Unfortunately you can't have any more Science unless you are a member of a subscribing institution or pay exorbitant per issue fees.

      • No more Science, but plenty of science available in PLoS ONE or similar...

      • Unfortunately you can't have any more Science unless you are a member of a subscribing institution or pay exorbitant per issue fees.

        Or pay for a personal subscription. Which I think is on special offer at the moment of $99/year. Which is just under $2/issue. Tempting.

    • I agree, but while science is super nice I'm grateful for anything less likely to descend into interminable bickering over politics.

      A thought occurs: we take "News for Nerds" to mean any news that nerds find interesting. Perhaps we should try news that only nerds want to read.

    • Re:Nice (Score:4, Funny)

      by martin-boundary ( 547041 ) on Friday August 12, 2011 @08:39PM (#37076396)
      Dear Mr Science,

      I too am intrigued by these pleasuresaurs, and would like to subscribe to your newsletter.

  • Livebearers (Score:4, Informative)

    by Oswald McWeany ( 2428506 ) on Friday August 12, 2011 @06:55PM (#37075600)
    Shouldn't be too surprising- livebearing shows up in all sorts of families that typically lay eggs- especially aquatic animals. Everyone is familiar with the humble guppy. You buy one for your daughter despite your better judgement- one week later you're overrun with the gaudy ugly fish as the live young start popping out everywhere. Many species of snail give birth to live young. Or "nearly so". Malaysian Trumpet snails and Quilted Melania two "cloning" species can pop out up to 9 live babies at a time. Even sexually reproducing snails can give live birth- species of Tylomelania from Sulawesi lay a single egg at a time that disolves before your eyes (if you're lucky) to reveal a minature snail. That doesn't mean live-bearing fish or mollusks are common- and if this dino gave live-birth, it doesn't mean that it was common with dinosaurs either.

  • Ovoviviparous? (Score:4, Informative)

    by SMoynihan ( 1647997 ) on Friday August 12, 2011 @06:56PM (#37075616)

    Very interesting. I suppose it makes logical sense that sea living creature would find it difficult to safeguard eggs, and with its size these would be very noticeable (and nutritious!). I guess it is similar to whale sharks nowadays, which are ovoviviparous in their reproduction (wikipedia link as below): the "embryos develop inside eggs that are retained within the mother's body until they are ready to hatch. Ovoviviparous animals are similar to viviparous species in that there is internal fertilization and the young are born live, but differ in that there is no placental connection and the unborn young are nourished by egg yolk; the mother's body does provide gas exchange (respiration), but that is largely necessary for oviparous animals as well."

    http://en.wikipedia.org/wiki/Whale_shark [wikipedia.org]
    http://en.wikipedia.org/wiki/Ovoviviparity [wikipedia.org]

    However, the comment about single young is even more interesting - as whale sharks are even bearing very many (live) young. Maybe different again? (no expert here, just curious!)

    • Browsing further, the Science article seems to address this and indicates that they were fully viviparous (like us, I guess). Just reading the abstract now, unfortunately - though interested if anyone can chime in on the science?

      • Placental sharks (Score:4, Interesting)

        by zooblethorpe ( 686757 ) on Friday August 12, 2011 @08:29PM (#37076332)

        If memory serves, I recall hearing that sharks run the gamut from plain oviparous through to placental warm-blooded viviparous.

        Ah, yep, here's Google [google.com] to the rescue.

        Sometimes I run across news about discoveries where the commentators are all surprised, but in ways that make me think we need to get over ourselves :) as the utmost pinnacle of evolution or some such nonsense and just realise that we are no more than a combination of various biological strategies that had already been "invented" in numerous other branches of life. We're just a happy accident of much larger processes.

        Cheers,

        • Re: (Score:2)

          by rts008 ( 812749 )

          I find your comment very interesting, and frankly, a relief of sorts.
          I was starting to feel like I was alone with this POV.
          That made me question it, and still could find no 'chink in the armor', which caused me to question others about it.
          That was a circuitous path that led back to no 'chink in the armor'.

          I wonder if dolphins pity us for being 'landlubbers'?

    • Re: (Score:3)

      by dryeo ( 100693 )

      However, the comment about single young is even more interesting - as whale sharks are even bearing very many (live) young. Maybe different again? (no expert here, just curious!)

      I'm no expert either. Generally the smaller the litter, the less the mortality rate. In this case it possibly would point to the parent[s] looking after the young unlike sharks where the young are left to fend for themselves.

  • The real point (Score:1)

    by Anonymous Coward

    The line keeps getting blurred between dinosaurs, reptiles, birds and mammals. It's hard to justify a warm blooded reptile since cold bloodedness is a large part of being a reptile. Live birth is nothing new. A number of snake species give birth live. A lot of ancient animals that are called reptiles probably weren't. Pterosaurs are still called flying reptiles inspite of the fact that every condition that gave them the title of reptile has been disproven. It's mostly dogma that keeps them reptiles. Ancien

  • Plausible speculation (Score:3)

    by LongearedBat ( 1665481 ) on Saturday August 13, 2011 @12:04AM (#37077128)

    By making comparisons with modern animals, such as whales, which give birth to larger, single young and then go on to care for them, Dr O'Keefe and his colleague, Luis Chiappe from the museum, attempt to infer something about plesiosaur behaviour.

    ... plesiosaurs, the authors suggest, might have been doting parents.

    But Dr Smith was less convinced. He said that it was "certainly quite possible... but is very speculative".

    Of course it's speculative, but it's still plausible. I would expect any animal who gives birth to one young at a time to spend time with its offspring until the offspring is strong enough to survive on its own.

    The more we learn, the more it seems to me that different epochs of life on Earth were in many ways much more familiar than we used to believe. If only we could see into the past...

    A little off topic...

    When you get right down to it, behaviour doesn't fossilise

    True, mostly. But sometimes we get very lucky... Velociraptor vs. Protoceratops [bhigr.com]. This gave some insight to how velociraptors used their big claws. (For gripping and stabbing, not slashing.)

    • Re: (Score:2)

      by pbhj ( 607776 )

      > But sometimes we get very lucky... Velociraptor vs. Protoceratops [bhigr.com]. //

      That looks incredibly fake to me. I just can't imagine the conditions in which these animals would die in mid fight like that and remain perfectly preserved. From the fossil it appears both animals died at exactly the same time and were preserved without being fed on by scavengers big enough to carry off a single bone.

  • Seriously, Slashdot. This article has been up for quite a while and not a single high-rated comment mentions Nessy! I'm disappointed.

    Here's hoping it's the fault of my comment threshold being mucked with.

    • "Nessie is a toy submarine with a head made out of plastic wood. Ogopogo is a plesiosaur. A f***ing plesiosaur!"

  • I have guppies in my aquarium, they give birth to live babies (they don't lay eggs). And theoretically dinosaurs are more evolved/advanced than mere fish, so it shouldn't be a surprise at all that some of them are livebearers.

Slashdot Top Deals

Don't tell me how hard you work. Tell me how much you get done. -- James J. Ling

Close