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wally-217 t1_iusli1g wrote

Not a paleontologist but Comparative anatomy gives a lot of insight into fossils - e.g. Proportionally long legs (specifically lower legs) correspond to animals adapted for speed or sprinting. Robust bones are indicative of heavy set animals with lots of muscle of fat. Unusually dense bones can be indicative of aquatic animals.

The texture of the bones themselves can reveal even more information - deeper scarring on muscle attachment sites means beefier muscles in that area; rugosities and landmarks on the bones can reveal places where keratin sheathes would anchor to or where blood vessels flow. Quill knobs are seen where feathers anchor on some dinosaurs.

Some fossils are preserved well enough to preserve scales, skin and feathers. A handful of fossils even preserve melanosomes which determines colour. Evolution also leaves lots of remnants of a species' ancestry behind - for example: pliosaur, crocodile and spinosaur teeth are extremely similar but theropod (the group of Dinosaurs spinosaurus belongs to) teeth are flat with serrated edges, so even though spinosaurus teeth are evolved convergently to other fish-eating animals, they have subtle remnants of traits only seen on theropod teeth, in this case being slightly less circular and having faint ridges where the serrated edge used to be. Teeth themselves are hugely informative of diet and environment too to the point that microscopic wear marks can tell you how a herbivore moves its mouth! In mammals, the patterns in teeth is even more unique (compare the pattern on an elephant molar to a cow to a human).

All these things offer different pieces of the puzzle. Phylogenetic bracketing takes all these clues, adaptions and identifying features and models the most likely relationships, this can then reveal where along the chain certain traits pop up (for example, feather-like filaments have been found across a range of distantly related dinosaur and even pterosaurs, indicating that all dinosaurs probably evolved from an animal with some level of proto-feathers). All of this can also be compared with chemical isotope analyses of fossils and the formations they are found in, to build up an even better picture.

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Akitiki t1_iut4j60 wrote

This here! Also simply looking at modern relatives; things like deinosuchus probably looked really similar if not basically identical (outside of being much bigger) to modern crocodilians.

Still some interpretation to be had, sure, but we can apply what current birds look like to smaller raptors (microraptor, velociraptor, etc) given they were getting close to modern avians along with cues from the fossils as mentioned above.

I see a picture floating around sometimes of a swan shrink wrapped with no feathers and using its featherless wing as a stabbing implement and people believe it. And some other animals given similar treatment. No. Just, no. We aren't as off as we were, where we had tons of dinos standing upright...

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atomfullerene t1_iuwhnm8 wrote

> a swan shrink wrapped

This is from the excellent book All Yesterdays, a book of paleoart. The point of those images wasn't to represent issues with well done reconstructions, but instead to reimagine modern animals if we shrink wrapped them the same way that is (and especially was) done with dinosaur reconstructions in the past...trim muscles, no body fat, no feathers or fur of any sort, no fleshy bits. And then monsterize them a bit because they are dinosaurs after all. A Jurassic Park raptor probably isn't much closer to true life appearance than that swan. And there are plenty of older reconstructions that are further off.

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Firm_Brother_7124 OP t1_iuuoy4u wrote

Interesting! How accurate is this estimation?

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wally-217 t1_iuv3689 wrote

It very much depends on the species. For something well studied like a T. rex, we have a very complete picture of it's general shape, how it hunted and even how it grew (Adults were incredibly stocky but sub-adults were built for speed - in a loose sense, a bit like a cheetah that morphs into a giant Hyena as it grows!) but how social it was, the skin texture, colour and feather coverage is still speculative. For animals like sinosauropterx, anchiornis and psittacosaurus we have complete pictures of their colours and patterning. Some species are often fossilised in groups or mass burials, which is a strong indicator they were social or partially social animals.

Something like spinosaurus is a good example of something we don't have a huge amount of fossils for (well, we actually had no remaining fossils until the 2014 specimen) and you can see just how much it changed as new fossils were discovered and studied. Fossils of large sauropods are usually only a handful of bones so so we're a long way off the species level resolution that we can reconstruct smaller dinosaurs with. Which is arguably why most sauropod species are reconstructed very very similarly. Many fossils are only known from teeth, which are probably more likely to see the biggest changes as new discoveries are made. Especially for some fossil mammals. And then you have some things like Dunkleosteus which only has a few known relatives, and limited fossils - so we have a good picture of how the head would look! But not much else. And finally we have animals like the Tully Monster, which we didn't really know if it was related to us, insects or mollusks until recently due to how basal (and then derived in its own way) it is, and how there aren't really any known modern analogues.

Generally speaking, we have a pretty solid understanding of most fossil groups as a whole, but lesser known species are ones that will be reconstructed as more generic. The general proportions and posture of many groups as a whole will probably not change much, but we will likely see much more variation between individuals as science progresses (although some groups are inherently more diverse than others) - Deinocheirus and spinosaurus are good examples of this.

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mycomment_name t1_ius9xtd wrote

A lot of the paleo artists will learn anatomy of current animals and rebuild and interpret based on muscle structures. For example, birds are a lineage of dinosaurs. There’s also new technology that pops up such as the ability to tell light/dark color patterns on feathers. And the super cool mummified ones too!

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[deleted] t1_iurslo5 wrote

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Ltates t1_iusmgbl wrote

The “modern” image you linked is actually a meme and not a modern interpretation of T. rex. It’s because, post 2010s, there was an overcompensation to thicc and feathery tyrannosaurs after the discovery of larger feathered relatives and people went a bit overboard.

Here is the most modern take on Sue the T. rex and an edmontosaur that is displayed in the field museum and made by blue rhino studio. Highly recommend checking out their paleo art and sculptures, they’re gorgeous and very accurate to the known science.

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nicolasknight t1_iusofgq wrote

You are entirely correct this was just the closest I could find right now on short notice but it carries the point across.

Still, yours is quite a bit closer to what actual scientists think was reality.

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frontal_robotomy t1_ius0y7w wrote

Can you post a different link? Getting a 403 Forbidden error with this one

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crazy1000 t1_ius2n4s wrote

Same, this worked for me https://external-preview.redd.it/1aIib08nONHHJ-HNABoUWlocs_vwrNtJs58e24xoAXE.jpg?auto=webp&s=0a3f619388dd232694481d68f346cc0d65e28224

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echosixwhiskey t1_iux8l4h wrote

Ok but where are the little arms? If it had a beak then wouldn’t that have fossilized too? What happened to the teeth?

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wattnurt t1_iurthvk wrote

>https://external-preview.redd.it/1aIib08nONHHJ-HNABoUWlocs_vwrNtJs58e24xoAXE.jpg?auto=webp&s=0a3f619388dd232694481d68f346cc0d65e28224

I had never seen this, but man that makes so much more sense. Essentially a flightless bird with vestigial wing arms.

Similarly, this is an owl skeleton.

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danby t1_iusfjb0 wrote

There's still a lot of arguments over what kind of musculature and what types of feathers and how sparse they might have been so that actual appearance is still open to a lot of artistic interpretation, but there's increasing evidence that many dinosaurs would have been feathered. And we have fossil evidence of this for about 50 species (I think)

And for T.Rex we know that some close relatives had feathers: https://institutions.newscientist.com/article/mg25133560-800-t-rex-with-feathers-chinas-fossils-are-rewriting-the-dinosaur-story/

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Tiktaalik414 t1_iusp3py wrote

I’m having a hard time believing the scientific validity of that image given that Saitama from One Punch Man is drawn next to it. I don’t doubt that T. Rex had feathers of some sort, but I don’t believe they were as fluffy as this drawing would have you believe. If anything I would guess they probably looked more like a cassowary with a long meaty tail

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oracle427 t1_iusrfnp wrote

Wait what? That is the modern rendering of a trex? That looks nothing like the original ones

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notabillionaire__yet t1_ius0ytj wrote

Is there another link for that image? I'm just getting an error when I click on it

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Evolving_Dore t1_iuu3uk8 wrote

I answered a similar question to this one several years ago and it was well-received. Here's a link to that comment and the subsequent thread.

The only change I want to add is that I am no longer pursuing a Master's in paleontology. I caught the Master's and have since tamed it for my own purposes, for all the good a Master's in paleontology can do for a person.

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Trips-Over-Tail t1_iuuyx61 wrote

I am sorry to hear that you caught master's and I wish you a speeder recovery.

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Puppy-Zwolle t1_iutmnlf wrote

Ever seen the Sphinx cat? Ever seen a Maine Coon? Fossilized you would not be able to tell them apart. Bit of a size difference but that's it.

There now is a big discussion about dinosaurs having had feathers. Would change the look tremendously. But the bones and muscles are pretty much scientifically extrapolated.

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lornezubko t1_iut5ww1 wrote

Before more contemporary techniques were developed scientists DID mess up putting dinosaur bones together, all the time. They would mix and match different species because the bones were found close together and looked like they should be able to fit. Today they are pretty accurate with it through a multitude of tests

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[deleted] t1_iut7zz8 wrote

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lornezubko t1_iut88ce wrote

Exactly, short faces bears were mistaken for giants all of the time. they have a little excerpt on it at my local museum. Seeing the skeleton it's no wonder they thought that, everting except for the two canines makes it look like a human skeleton, just 10 feet tall lolol

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