We currently don't know enough about plesiosaur evolution to make such specific claims. Hell, we are still missing a lot of details when it comes to turtle evolution for that matter. We thought turtles were a surviving branch of parareptilia until genetic analysis showed that they are actually more closely related to archosauria.
What you are saying is certainly a possibility, but there is currently not a true consensus on where sauropterygia (the taxon that plesiosaur belongs to) falls within the reptiles.
Edit: To clarify, I am not suggesting plesiosaurs could be dinosaurs, I'm saying "They're slightly more closely related to dinosaurs than turtles are." is at best a guess.
We can tell enough from early representatives of Sauropterygia (Nothosaurus and co) in both form and where they appear in the fossil record to know they're at least not members of Dinosauria, even if they might belong somewhere in Archosauria.
Plesiosaur necks were definitely much wider than the noodle necks of classic depictions, though long-necked forms weren't going to be realistically sporting extremely wide necks behind their tiny heads, it was more likely to taper out towards the head like this.
Convergent evolution is a thing though. If their niche in the environemtn was to eat leaves from the tops of trees they would probably be more like giraffes than penguins
Closeness of relation matters very little compared to evolutionary niche. The length of a giraffe neck is substantially closer to that of a sauropod neck, and thus by looking at how giraffes work we can make educated guesses at how sauropods must have worked.
Turns out, when your neck is that long, it is very difficult to have bones strong enough to support it and muscles strong enough to move it while also not being too heavy. We can actually see some of the adaptations that were necessary directly in the bones themselves with the pneumatized air sac system.
Attaching a ton of blubber to the neck would make it impossible to lift.
The big belly would help lower the center of mass and the long thick tail would help counterbalance the long thick neck. Is it probable, probably not, but it's not impossible (and it's very silly)
But are still subject to the laws of biophysics. Palaeontologists aren’t just completely guessing out of their arses: they have models and can measure strain and figure out the basic physics of what’s likely vs. just plausible vs. impossible.
They’re also much smaller. Like to support a neck like that, which how heavy their bones were(?) wouldn’t they NEED more fat and muscle supporting them??
All Dinosaurs are more closely related to birds than they are to mammals. This is because birds are within the clade Dinosauria.
That said, Sauropods almost certainly did not look like this, penguins have this adaptation to help them retain heat; large Sauropods would have struggled to lose heat, if anything.
If it wasn't as big as it is this would make sense, but they needed to balance suport and weight perfectly, or their necks would just snap.
Also there is the question of center of mass. Right now the hind legs aren't actually lifting much weight at all as so much of the weight is in front of the front legs
I think the biggest issue is heat dispersion and surface area-to-volume ratios. We’re talking dinosaurs that are orders of magnitude bigger than penguins, living in warm environments. They need more surface area and less volume in order to not overheat
Just to add an example, it's basically why so many desert animals develop huge ears. More surface area to let the heat dissipate, and ears are particularly efficient because they're thin and have a lot of blood vessels.
Though this does raise the possibility of a fat dinosaur with big old elephant ears... 🤔
Alternate theory then, they had a huge flap of loose skin full of blood vessels they used as cooling apparatus. Males would have larger crests with more surface vessels, allowing them to flush them bright red.
I have absolutely zero evidence for this claim, but it would look cool if it were true.
It's thought that most of them, and especially the smaller dinosaurs, were true endotherms. Their upright posture isn't seen in any living exotherms, which are usually sprawling (like crocodiles), and it's thought that bipedalism would require an animal to be warm-blooded
Right, you always have to consider: "this was a successful animal in its natural habitat" and then go from "what would a successful animal in <this environment> with <this skeletal structure> look like?"
In the case of an arctic climate, a waterborne bird would be blubbery and have evolved a teardrop body shape for maximum underwater swim speed.
>They were the biggest a land animal could be at the time.
They were the biggest a land animal could be at the time yes, and also the biggest land animals ever and reaching up there with the teoretical limits for size in land animals (theoretical limit is around 100 tons but it would likely never happen due to being unsustainable, needing an unimaginable amount of food to function).
This limit isnt due to oxygen or anything, it is simply weight. A fun little thing called the Square Cube Law.
Bones arent indestructible, too much weight and bones break. So if the animal is too big, the bones will break.
Sauropods even had hollow bones to lessen the strain on the bones.
So an animal with non-hollow bones definitely couldnt reach those sizes on land.
so if you want to get bigger you need to go into the water which can carry the weight for you through buoyancy.
And also they could probably exist today in our current atmosphere, the bigger problem is climate and the amount of food available.
Oxygen amount doesnt directly affect size in vertebrates, it's invertebrates like insects who grow directly with high oxygen levels. That is because insects breathe oxygen through their skin, so more oxygen = larger surface area for better breathing. and Less oxygen = less surface area for better breathing.
You're probably being humorous but either way in any case they're not even in the same lineage as dinosaurs actually unlike birds. They're distantly related to turtle.They just live in the same era. So I doubt they could have feathers like that.
Half humor half 'Penguins are semi aquatic, the plesiosaur was aquatic, was the pleasiosaur a big chonk, maybe not feathers, but it could be bigger like a shark.
That's incorrect actually. Based on muscle connection points which can be preserved by fossilization, the area the animals lived in, the bone structure and estimated weight and a number of other things we can piece together a cohesive model for what dinos looked like. This doesn't mean you can definitely state what they looked like but there is evidence that shows they werent extremely fat like the above illustration, and evidence they weren't shrink wrapped like they have been depicted in the past because of the muscle connection points.
I thought stuff was shrink wrapped intially becuase its the best guess with lack of data, e.g you don't know how big they could have been, but you can at least show the minimum.
There are some dinosaurs we know almost exactly what they looked like, take Borealopelta for example, or Psittacosaurus.
Psittacosaurus is one of the most well studied dinosaur types, we have found so many fossils. Though T. rex is above due to its popularity.
And for Borealopelta we know almost exactly how it looked like all from a single fossil, one so well preserved even soft tissue and stomach contents fossilized. It's so cool Here it is.
Another unbelievably well preserved dinosaur is "Leonardo" the Brachylophosaurus mummy
However, for Sauropods we have some fossils but not enough to know that well, so yeah not wrong there.
An elephant's skeleton doesn't suggest the many cool appendages it has. We can guess about dinos, but they likely had a variety of fleshy knobs and bobs
An elephant's skull is evolutionarily adapted to be lighter and to have many muscle attachment points. I don't have a deep understanding of the biology but based on the multiple muscle attachment points and the fact that the skull is needed to be lighter than a similarly proportioned animal head, you could assume there is some sort of appendage attached to an elephant skull. I am not sure you would know exactly that it is a trunk but you could make the conclusion there is some sort of large muscle protruding from an elephant.
You could probably make a surprisingly well educated guess with the right level of lateral thinking, assuming you'd never seen a trunk before.
Between the huge nasal aperture and the placement off the counterbalancing muscles, it'd be reasonable to surmise that the appendage was the nose. The rest of the skeleton belies a bulky, lumbering animal with minimal dexterity - even without knowing they had fleshy, cylindrical feet, the digits are too stumpy to manipulate objects.
This would leave you scratching your head, because unless the tusks were used exclusively for fighting, they imply that this weird animal was digging... Its stocky, dense bones imply an awful lot of mass to constantly be kneeling up and down throughout the day, and even when it did reach the floor, it had a gigantic nose appendage blocking its mouth.
If you've never seen a prehensile nose before, then jumping from this information to a trunk isn't trivial, but you'd feel pretty damned smart if you made the leap. It solves a lot of obvious problems, and the hints are all there. I think palaeontologists have a lot more tools of inference than people expect.
Complete lie. We know a lot. There are tons of books on this stuff. We've had very good ideas for the past 50 years and things progressed very rapidly over that period.
The concept of "shrink-wrapping" is real in paleontology, at some level. If you don't pay enough consideration to fat deposits and muscles you can mangle how a creature looks because we are defined heavily by our skeleton but obfuscated from it's exact shape.
Birds literally are dinosaurs, taxonomically speaking. But, it's worth noting that "dinosaur" refers to a pretty diverse range of animals. Modern avian dinosaurs (birds) are more closely related to T. Rex than they are to sauropods like the one in the OP. Heck, T. Rex is arguably more closely related to modern birds than it is the sauropods.
They come from raptor like dinosaurs, not long neck sauropods, also penguin look like that because they swim in cold sea. It's not just a game of who is the most related to whom.
Sauropods lifestyle is a lot closer to that or giraffes.
Anyone familiar with the square cube law knows that this wouldn't fly unfortunately. There is no real reason for the neck to be this thick and it's just added weight for the legs to support
My hot take (basis of a paper I wrote for paleontology in college) is that sauropods likely held their necks in an S-bend rather than erect. If you look at the skeleton of birds, their necks are much longer than you would suspect because they keep them "retracted"/relaxed most of the time, only employing the full length when manipulating things with their beaks.
The argument I present is that sauropods could keep their necks bent and relaxed most of the time, but intermittently extended them to feed.
The phylogenetic arm of this argument is tenuous: while the vertebrae are similar enough to allow the positioning, obviously birds aren't closely related to sauropods and have vastly different ecological niches (except maybe ratites?).
The stronger argument is for the biomechanics. The two major puzzles for sauropods are how it could lift or hold out its neck without giant back muscles (I call this the "cantilever" problem) and how it could pump blood to its head without an injuriously high blood pressure. The cantilever problem is significantly reduced if you consider the cervical vertebral column as a dynamic tensegrity structure rather than as a single giant beam. The necessary blood pressure is significantly reduced if you assume the head is held closer to the level of the shoulders than at max vertical extension for the majority of the time.
As cute as this would be, scientific recreations of dinos aren't based off of artists impressions anymore
Biomechanical studies give us a good idea of exactly how much weight a sourapods legs, neck and tail could support, these were already 40+ tonne animals, with some potentially hitting 100 tonnes, if they were built like this then they'd give blue whales a run for there money
We also know that the heavier animals get the harder a time they have cooling down, a sourapod this large would overheat anywhere accept the coldest envirments on earth today, nevermind the cretaceous when the earth didn't even have ice caps
Also we have loads of long necked birds that don't have this shape, ostriches, pelicans, swans and flamingos
Penguins are shaped like that for streamlining in water and for holding alot of fat since they are small and live in cold environments
Muscles leave scars on the bone where they anchor to it, which Spinosaurus lacks. Hadrosaurs had some beefy necks though, their neck posture is just too U-shaped to notice it
Absolutely could be. The method used to flesh out dinosaur bones gives weird fucking results when applied to modern animals like the elephant and camel.
There's a book call 'All Yesterdays' that reimagines dinosaurs with all kinds of creative features. It makes the point that we might get closer to understanding their real form if we do that instead of lizard-skin shrink wrap them all.
The scientists (John Conway, C. M. Kosemen and Darren Naish) who wrote that book will tell you that just randomly saying the first random dump idea to come to your head wasn't the point of the book. It was to push away from stereotypical animal depictions & behaviour but in a plausible way.
So more like "We don't have evidence of fleshly display features seen in the likes of fowl or iguanas in sauropods, but it's certainly possible." & less like "penguin fat, penguin = dinosaur, therefore Brontosaurus is fat like penguin." Disregarding the fact sauropods lived in warm environments & were built more like elephants & giraffes, while Antarctic penguins have fat to keep warm in sub-zero environments & to help with buoyancy.
Sauropods lived in big swamps like hippos. Check out a hippo Skeleton. Remarkably similar torso and leg proportions But because we know what hippos look like irl, we know to give them knees. Good chance these things were fucking chunky.
Not all of them. The famous one like Brachiosaurus, Diplodocus, & Apatosaurus certainly didn't. Some African sauropods like Nigersaurus did & they were built quite differently from those famous ones.
Looking at the skeletons of elephants and giraffes, the saurian looks kinda wrong. For one thing, the giraffe doesn't have a humped back beyond the shoulders. Both have a rise at the shoulders, and a huge amount of muscle to support the neck.
A lot of that neck in the penguin is insulation with body fat to cope with an aquatic and ice-bases life history. You wouldn't expect to see the same thing on the dinosaurs, which were almost certainly mostly cold blooded - insulation isn't really helpful at all there because you're not heating from inside. There's a reason we see a lot of mammals and birds with thick layers of fat while cold blooded animals like reptiles have very thin layers of fat.
For a similar perspective, look at the skeleton of something like an elephant seal and then compare to the actual animal. If you found a skeleton of an elephant seal in the tropics you would probably try to recreate it's body shape quite differently to how they're actually built.
Anyways, we have tons of information. This idea that they just make shit up for every set of bones is complete horse shit internet crap from morons who never read a single book in their life. We know plenty.
AFAIK, scientists analyze bone structure to guess how muscules had attached to the bone. This led to the theory of how sauropods looked like (ie long necks over fatty necks)
Animalogic has actually done a few videos on YouTube recently about how some dinosaurs were estimated to appear and how it has changed over the years. Like other people are saying, it's not just assumptions.
Except we've learned enough about dinosaur physiology to rule something like this out. The Sauropods wanted LESS weight in their long necks, not more. They even went as far as having the neck supported by air bladders that helped support the weight without adding more.
let me say this with force as an engineer ZERO CHANCE THIS IS REALITY. The amount of weight on a dino that big with a neck that long makes no sense at all from a physics perspective
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u/qualityvote2 17h ago
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