[HN Gopher] Tyrannosaur's Stomach Contents Have Been Found
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Tyrannosaur's Stomach Contents Have Been Found
Author : Brajeshwar
Score : 64 points
Date : 2023-12-10 14:33 UTC (8 hours ago)
(HTM) web link (www.scientificamerican.com)
(TXT) w3m dump (www.scientificamerican.com)
| littlethoughts wrote:
| https://1ft.io/proxy?q=https%3A%2F%2Fwww.scientificamerican....
| civilitty wrote:
| _> Oviraptorosaur nests typically contained at least 30 or more
| eggs. With such large broods, "you could imagine, at certain
| times of year, depending upon the species and when their breeding
| season is, this would not be an uncommon prey for predators,"
| Zelenitsky says. That's why she isn't surprised to find remains
| of this species in this Gorgosaurus' stomach, especially because
| she "can't see the adults going after these tiny little chicken-
| sized or turkey-sized dinosaurs."_
|
| I'm curious why they assume the adult tyrannosaurids wouldn't eat
| the oviraptorosaurs because that makes no sense to me. My cats
| will chase down and eat flies and mosquitos so is there some sort
| of size threshold for agility that the tyrannosaurids pass
| through that makes it impractical to hunt small prey? They are
| believed to be warm blooded so it's not like they could really
| ignore easy prey at that size.
| pvg wrote:
| Your cat doesn't feed itself and is artificially selected to
| hunt for fun which skews this comparison a lot more than just
| the physical size.
| thaumasiotes wrote:
| Pumas have been observed to catch mice.
| civilitty wrote:
| Tigers eat grass and small animals like termites just like
| domesticated cats do so I don't think their diet has been
| selected for as much as you think. They more likely became
| popular as pets _because_ of what they eat.
|
| Avoid evolutionary arguments, they're "just so" explanations
| that can be twisted to fit any narrative.
| pvg wrote:
| I didn't say the diets were selected, just that a domestic
| cat can afford to be habitually inefficient in a way most
| wild animals can't and that we have selectively bred cats
| for some of this. Yes, big predators will opportunistically
| eat smaller prey, it doesn't affect the claim that a
| domesticated cat is a poor starting point for the
| comparison you were making.
| thaumasiotes wrote:
| > Tigers eat grass
|
| Tigers, and housecats, don't have the digestive system to
| get sustenance from grass. A cat swallowing grass is kind
| of like a chicken swallowing gravel; it's not food.
|
| If tigers could _eat_ grass as opposed to just swallowing
| it, they would have no reason to hunt anything; they 're
| more than capable of driving away most things that would
| compete for their grass.
| rightbyte wrote:
| It is probably better to have a less losing strategy to hunt
| smaller pray, while searching for bigger? The marginal effort
| to catch a mouse can't be that high while roaming around
| searching for bigger pray?
| s1artibartfast wrote:
| I think you are underestimating the difficulty of catching
| a mouse.
|
| I have hunting dogs and they can spend several hours going
| after a mouse, and their success rate isn't very good.
|
| Plus, large animals are poorly Suited to hunt much smaller
| animals. Speed, momentum, and anatomy are not in your
| favor. Imagine driving a semi truck and trying to run over
| a mouse
| rightbyte wrote:
| Ye maybe you are right. I would not even try to catch a
| mouse by hand myself. And I have no clue how a lion would
| compare to a house cat in hunting a mouse.
|
| But your dogs, do they hunt with their feet? I don't
| think dogs use their claws like cats do, making it really
| hard to get to the mouse? Like, dogs can't do a slap like
| cats and humans can?
| mitthrowaway2 wrote:
| (Cats are only partly domesticated and feral cats certainly
| manage to feed themselves.)
| andrewflnr wrote:
| Yeah but I bet feral cats don't feed themselves on flies
| unless they have no other options. It's not efficient.
| nunez wrote:
| In case your interested in more light reading on this:
| https://www.newyorker.com/tech/annals-of-technology/are-
| cats...
| mitthrowaway2 wrote:
| > Cats have us do everything for them. We clean their
| litter, stroke them, admire them, but, unlike dogs, they
| do not have to constantly please and satisfy our needs.
|
| It seems like cats may have actually domesticated humans.
| adrian_b wrote:
| Perhaps other big carnivorous dinosaurs might have eaten small
| prey when given the opportunity, but for adult tyrannosaurids
| this seems less likely.
|
| The adult tyrannosaurids had arms that were far too short to be
| able to catch small prey with them.
|
| The heads of the adult tyrannosaurids were very big, so they
| must have had a large moment of inertia that would have made
| difficult to rotate the heads fast enough to be able to catch
| small prey on the ground below them.
|
| Perhaps the best chance for an adult tyrannosaurid to catch
| small prey would have been to stomp on it (like many prey
| birds, e.g. the secretary birds, do today). Only then it could
| have easily taken the dead body in the mouth.
|
| This stomping behavior would be a more plausible means for
| tyrannosaurs to catch humans in a movie, instead of their
| typical depictions when they catch easily the humans only
| because those are frozen by fear instead of taking evasive
| actions. (The tyrannosaurs could certainly move their feet many
| times faster than their heavy heads located at the end of long
| necks.)
| HarHarVeryFunny wrote:
| Presumably adults normally went after prey large enough to
| satisfy their appetite, but push come to shove would have eaten
| smaller prey too, just as a modern lion prefers a decent meal
| like a zebra but will still eat anything from a rodent on up if
| it's hungry or an easy chance presents itself.
|
| The "can't see adults going after these" seems a sloppy throw-
| away comment, not based on any evidence, and ignoring common
| sense!
| ravi-delia wrote:
| Large carnivores are kind of the pricey boondoggles of
| evolution. They work, they are successful, but they're
| balanced on a knifes edge. Every step a large carnivore takes
| consumes vastly more energy than it would cost a smaller
| animal. It is all too possible for such a creature to expend
| more energy pursuing small prey than it would get back. That
| is why lions don't hunt small game- they'll scavenge small
| game by driving off smaller carnivores from their kills, and
| they certainly won't turn down eggs if they find any, but
| they will not pursue prey beneath a certain size. Imagine
| trying to catch a rat with your hands- exhausting work, and
| the rat isn't much food
| mannykannot wrote:
| I suspect there are two issues here put together in a possibly
| misleading way: 1) it is not surprising that the juvenile
| Gorgosaurus would have fed on the smaller animals, for fairly
| obvious reasons that have nothing to do with what the adults
| would have fed on; 2) the small animals would not be an
| adequate diet for adults.
|
| If this is the case, then it seems odd for the latter to be
| used as a justification for the former, but when people are
| talking extemporaneously, it is not uncommon for them to jump
| from one topic to another without completing the former.
|
| As an example of how larger predators often ignore small prey,
| consider how some hummingbird species seek out nesting sites
| close to those of hawks:
|
| https://www.audubon.org/news/why-hawk-hummingbirds-best-frie...
| nashashmi wrote:
| What are the two front legs for?
|
| If the ratios in the popular diagrams of a T-rex are correct,
| they cannot make a T-Rex eat anything. And if the creature walks
| the way they are drawn, they effectively cannot be used to hunt
| and grab things either.
|
| It must be a crawler, instead of a creature that stands up and
| walks upright. The head on the T-Rex is too heavy and large in
| proportion to the body for it to be walking upright for too long.
| It must be weighed down. The front two legs are for lifting the
| body in the center off the ground. And the back/bottom legs make
| it good walking forward rapidly.
|
| Unpopular opinion: It is an oversized iguana-like reptile. A
| heavy head, with small front legs and oversized large back legs.
| kadoban wrote:
| The front apendages are far too small for that to make any
| sense. Just compare iguana front legs with T-rex arms,
| proportional to their body size. And that's ignoring square-
| cube law scaling difficulties that would make it even worse.
| Those things would snap like twigs trying to hold up that body.
| HarHarVeryFunny wrote:
| Evolution - T.Rex with it's upright stance evolved out of
| earlier animals that walked on four legs. The small size of the
| arms of most (but not all) species in this family of animals
| tells you that the arms were not normally used.
|
| Some snakes (also having evolved from animals with legs) still
| have vestigial legs - all but disappeared since they too serve
| no purpose.
| projektfu wrote:
| There has got to be some comparison to ostriches, giant moas
| and Phorusracids, where the pectoral appendages are absent or
| vestigial. They're all theropods as well.
| zabzonk wrote:
| iguanas have quite large front legs (but smaller) compared with
| their back ones - a bit like humans and many other animals
| valval wrote:
| Same thing your appendix is for.
| lgkk wrote:
| Interesting.
|
| I hope we can clone and make dinosaurs and other extinct
| creatures again.
|
| It would be fascinating to visit a park where we could see these
| creatures in as natural of a habitat as we can provide them
| today.
| jmnicolas wrote:
| Didn't you see the movie?;)
| ddol wrote:
| It was quite spectacular. I hear they spared no expense.
| dieselgate wrote:
| To each their own, I just wish my iphone 5 would still hold a
| decent battery charge
| zabzonk wrote:
| surprised there are no remains of a fur bikini...
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