Comments
EntangledPhoton82 t1_issb9ak wrote
Thousands of years ago is easy.
Changes are high that you'll have a lot of their descendants living today.
By observing them, noting the differences between de descendants and the earlier versions and making comparisons to other animals alive today you can make excellent educated guessed.
Further more, you might have other types of evidence such as footprints, human drawings of the animal, descriptions,...
And finally, you might even be able to get DNA samples or find partially preserved remains.
If we're talking about animals that lived millions of years ago then we still use the same principles but we just don't have the same abundance of data.
But we could for example extrapolate that a dinosaur and a Casuarius that share similar legs and pelvic design would have walked in a similar fashion. If we then find fossilized imprints of the dinosaur's feet and compare them with those of a Casuarius (stride length, spacing,...) then we might use that to confirm or correct our assumption.
This is of course a very brief description about how we can formulate rational assumptions by combining multiple pieces of information; both ancient and modern. So, just understand that it's much more complex then a brief explanation can do justice.
IWishIHavent t1_issdkcn wrote
We can create parallels between the bones we find and what we know of living animals today and make quite a few educated assumptions.
Besides that, it's not only bones. We have other tissues, we have traces left in fossilized rocks showing skin texture, footprints, fossilized excrements, fossilized flora, and other hints. It's never a complete picture, but it is a more complex picture than just bones.
Bikewer t1_issmq9p wrote
If we look at the skeletons of contemporary lizards, they’re all rather similar. Likewise fish. Yet both these groups have wildly different externals as to color, textures, etc.
Likely the case with truly ancient organisms. Someone posted a picture of a hippopotamus skull and how it might be “fleshed out” by a researcher who’d never actually seen one of these critters…. Not much resemblance.
But we can certainly get the basic body shape quite closely.
UpbeatForever232 t1_isspbw1 wrote
great answer, thanks
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ReturnToCrab t1_isst5uo wrote
> Likely the case with truly ancient organisms. Someone posted a picture of a hippopotamus skull and how it might be “fleshed out” by a researcher who’d never actually seen one of these critters…. Not much resemblance.
Someone still thinks paleoart works like that?
ChrisARippel t1_issu3w2 wrote
We also have
And fossils and traces of the environment.
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wolfgang784 t1_issvign wrote
Educated guesses based on other info and closest living relatives.
Check out dinosaurs for example - first we thought they had scales, then we thought they had skin and feathers, then we thought it might have been a combo of the two, then we thought some of each existed - the theory evolves over time and we likely won't ever know the 110% true facts of the matter.
There's also multiple examples of skeletons being put together incorrectly or a mix of several creatures (sometimes even from drastically different time periods) being combined and so on. So we aren't even always right that X creature existed at all or was even shaped the same.
Turd-In-Your-Pocket t1_issw0dg wrote
Don’t forget the little holes on bones where blood vessels attached help us know what kind of blood flow the animal needed to oxygenate its organs. Combine that with what we know of the oxygen levels in its environment and you can accurately guess the mass that was supported along with whether it was endothermic or exothermic (warm or cold blooded). We compare these to bones of existing animals, along with brain size and shape of the inside of a skull to come up with stuff like “Allosaurus ate meat and likely had the metabolism of an ostrich and the hunting and eating behaviors of a crocodile”.
the_original_Retro t1_isswqft wrote
TL;DR: That's not all we have. Bones are one evidence point and teach us tons. But there's all sorts of other 'fossils' that are often found with them and add to a far greater story.
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Let's start with bones first.
From the way bones are constructed, we can tell if they have to support heavy weight like an elephant, or let the animal climb a tree like a squirrel, or allow the animal to unhinge its jaw to swallow very large prey like a snake, or show lots of evidence where tendons were firmly anchored to them that indicate an animal with massive strength like modern gorillas. Worn-down and scratched up flat teeth might indicate a grazer that ate a lot of grit.
Then there's the chemical composition in those bones. Certain trace chemicals can teach us about the animal's diet, or about its health. Was it malnourished? Did it live long? And so on.
But there's TONS of other stuff too. Those bones could be found with smaller bones of the creatures that were in the animal's stomach or that passed through into its dung. Its footprints could have been preserved in mud and teach us how long its stride was while walking or running. Certain types of skin and hair are very often preserved too.
So we add it ALL up, and compare it to what we know about modern animals for similarities, and there ya go.
EPalmighty t1_isszogf wrote
Exactly. We can also compare to modern day animals (which is kind of implied in your answer).
hilburn t1_ist12nd wrote
Not to mention how they're found can give clues as to how they lived. Large groups together imply they lived in herds, smaller group with 2 adults and a number of juveniles is likely a family grouping etc
CallMeLargeFather t1_ist2miz wrote
This seems very misleading though, usually a herd wont all die at once and fossilize right?
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hilburn t1_ist3dvy wrote
Not normally, but they can do due to particular events - mudslides, floods, volcanic eruptions etc
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xtaberry t1_ist65s7 wrote
And fossils usually form due to one of those kinds of events. The body needs to be quickly covered with sediment after death to have the best chance to become a fossil.
Noto987 t1_isthvym wrote
How do we know if it has feathers?
Azudekai t1_istim2k wrote
We look for fossils that show them. If leaves can make fossil impressions, so can feathers.
simple_mech t1_istnjnm wrote
The feather and armor thing always throws me off, how would you know that from the bones?
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SexyAxolotl t1_istsqdg wrote
You wouldn't, but feaghers and scales can make imprints on the rock, similar to leaves.
[deleted] t1_istuk7k wrote
Warm blooded or cold blooded is possible to determine. This goes for animals going back 100s of millions of years ago too. We can see when the cold to warm switch occurred in fossils from the Permian which was before the triassic, which was before the jurassic and cretaceous
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HomeworkInevitable99 t1_isu7j1z wrote
Fossilised footprints tell us how animals walked. And combined with bone structure tell us about eight and movement.
Stomach contents tell us about diet
Damaged bones tell us about fighting, falling and even disease.
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hotinhawaii t1_isv01ll wrote
yes, but over time as we have accumulated more fossils, many of those mistakes from the past have been corrected and so we know MUCH more now than ever before. And the accuracy of the conclusions reached by examining the fossils improves over time.
throwawaymysocks t1_isv2cma wrote
An example of how paleontologists look at modern animals is the theory that triceratops form a circle with the herd to ward off predators and protect their young similar to how elephants and muskox do today. We have little evidence to support that triceratops actually did this besides the fact that similar large herbivores with horns/tusks on their head also do this.
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Petal_Chatoyance t1_isv77ec wrote
Forensics. The marks on bones show where muscles attached and how big they were. Grooves and pits show where nerves and blood vessels ran. All animals with skeletons follow the same universal body plan, and how the bones go together is well known. Wear and tear on the bones shows what stresses they were put on when alive - from that we can calculate weight, habits, behaviors and movements.
But there is always more than just bones. Imprints of skin and soft tissues in the rock tell even more, as well as traces of proteins and DNA that survive intact. Add in parts trapped in amber, or preserved in peat or other chemical laden preserves, and even more can be known. In some cases, such as the Wooly Mammoth, entire animals were perfectly preserved in ice - explorers have literally eaten their meat.
For even older creatures - try tens of millions instead of thousands of years, such as dinosaurs - there are now examples of tails, with feathers, preserved in amber. We know exactly what dinosaur feathers looked like thanks to that. We can recover the color pigments of their feathers, skin and eggs (eggs tended to be blue-green, their feathers every color including neon shades like parrots, and skin, various browns and tans).
Add to that footprints which can tell us size, gate, weight, density and more, and we have a wealth of information!
_imNotSusYoureSus t1_isvefk4 wrote
We look at the animals we have today and their bones, find patterns like "if this bone is this size then there is this much meat on it" until we have a network of patterns that pretty well define the only way a fossil could have looked like
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lesham67 t1_isvfcp1 wrote
Archeology is one of the most interesting fields out there. It uses bones, skeletal analysis, bone composition, grinding of teeth can show what types of food were eaten. You can actually tell if animals had sounds and what they might have sounded like. You can get a sense of age and the environment they lived in by examination of the soil around where they are fossilized - above them is earlier and below is later. You can get a sense of the environment by the sediment surrounding. And then it all gets pretty complex. So interesting!
mrockracing t1_isvh0q1 wrote
Why do I feel like one day a metric ton that we thought we "knew" about the past will be radically altered or just downright proven wrong?
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triplefreshpandabear t1_isvlpf6 wrote
Probably because that's already happened a lot, but there are things we get right, science is an ongoing process, it's why scientists are very reluctant to say things definitively and instead say stuff like "research indicates" or "it's likely that" or so on to that extent. I think this makes science more trustworthy, of course media often skips that and says things like "scientists say chocolate causes cancer" or something when in actuality it'd be more like "mice who were exposed to this chemical that can also be found in small amounts in the cacao plant had higher rates of cancer than a control group that wasn't exposed to the chemical" and this sort of misrepresenting makes science seem less credible. It's why media literacy is important. A lot of what we "know" isn't things we know as fact but things that we have indications of and science acknowledges that, unfortunately popular media often ignores that.
StrangeAsYou t1_isvlvod wrote
Of course it will be.
We now know that some dinosaurs had feathers and that's relatively new information.
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Xanderbell0120 t1_isvnuhz wrote
what indicates feathers?
StrangeAsYou t1_isvqb46 wrote
I'm assuming they used previously unstudied fossil markers plus new examination of DNA as it relates to currently alive animals.
Advances in technology change everything.
Cars, dinosaurs, energy production, what's really alive in dirt. Everything!
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Juicecalculator t1_isvx1wf wrote
I don’t know anything about dinosaur fossils, but I can speak as a food scientist who specializes in matching competitors products there is so much information specialists can glean from seemingly irrelevant or useless data. If I have an ingredient statement and a nutrition facts panel for a sauce or other food product I can create a formula that is 95% of the way there without even looking at a control sample. Like others have pointed out fossils can provide nerve innervation points, blood vessel connections, diet, and overall size of a dinosaur by comparing to other fossils and their understanding of material science. Paleontologists are talented scientists!
jeveret t1_isvybia wrote
Because that’s exactly what good science does, its constantly trying to disprove/improve our current understanding. We are refining our understanding of the cosmos at an exponential rate, but we will never have all the answers, but that is not a reason to stop asking questions and looking for answers.
MaybeImTheNanny t1_isvyrx7 wrote
They found feather impressions first and then extrapolated. We find new things and form new theories. This particular theory is like 25 years old so not so new.
MaybeImTheNanny t1_isvyyvl wrote
Armor can fossilize depending on what body material it is. Feathers leave impressions both fossilized feather impressions and skin impressions with pimpling.
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Pholidotes t1_isw1vv6 wrote
In exceptional conditions, the feathers themselves can be fossilized! China's Liaoning province is one place where this happened - it had very fine-grained sediments capable of preserving exquisite detail in fossils. For example, we know that this small theropod dinosaur (Sinosauropteryx) had a layer of fuzz similar to down feathers. And Microraptor, a smaller cousin of Velociraptor, had full-on wing feathers, plus long leg feathers and a small feathery fan on its tail.
When feathers aren't preserved in a fossil, other evidence may tip off paleontologists to the likely presence of feathers. Quill knobs, bumps on arm bones where feathers attach, have been found in several dinosaurs (including Velociraptor itself). In addition, if a certain dinosaur has no direct evidence one way or the other, but has close relatives with confirmed feathers, it can be reasonably assumed it had them too. This is akin to how extinct cats are depicted with fur because all their modern cousins have it.
StrangeAsYou t1_isw1yd3 wrote
25 years out of 100 thousand is pretty new.
We don't think they are mythical creatures anymore either. Dragons, griffins, hydras, unicorns.
All dinosaurs.
The real cause of the dinosaurs demise was only confirmed in 1988. There were competiting theories prior to that.
Our modern understanding is all pretty new.
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ThisVicariousLife t1_isw41rm wrote
I read an article just recently that said that scientists are starting to rethink the cataclysmic meteor theory and leaning more toward massive volcanic eruption to the scale of Mt. Vesuvius. Nat Geo Article Link
StrangeAsYou t1_isw6pxk wrote
Oohh! So exciting. Thank you for that.
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Decent-Connection944 t1_iswjjsm wrote
Science is an ever evolving thing. Some answers change upon new information so what we thought was once correct is now given something different upon the presented information. So just think that it’s not wrong but there is a possibility that the theory could change and what we once thought something was is just an alternate form.
Kluverbucyy t1_iswsoz1 wrote
Yeah hadn’t seen this mentioned elsewhere yet, the distance apart and the depth can tell approximate speed, running style and weight amongst other things.
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Ok-Championship-2036 t1_it785sp wrote
What you're discussing is called Skeletal Pathology. That means looking at the marks leftover to try and find clues. It's part of forensic archaeology. Here's an overview by Durham University. https://www.youtube.com/watch?v=wbqpzILKENI
Testing/isotopes: This is a video showing how bones can be tested for minerals and isotopes, which is good for determining diet or location. It also goes into dental analysis a bit. https://www.youtube.com/watch?v=J-gC7UXUoYk&list=PLVBHL30tV1pdlB6yNVKzTGsnVlC-k7Uu1
Real life example: https://www.youtube.com/watch?v=2bWNF_eNwvI&list=PLgquNEQ4NAWmku99VbZ9l2At0FTk98Vlu&index=64&t=6s This is a very funny/interesting youtube documentary about how Christopher Columbus had and spread syphilis. Its mostly about syphilis, which interestingly, can lead to a lot of very distinctive bone damage in early middle-age remains. We see it mostly on priests and rich guys, who survived long enough to get damage. Ironic, ha.
varialectio t1_issb015 wrote
Bone size indicates the weight it had to support. Attachment points show what sort of musculature it had. Size and length of limbs and the angles they make with the torso indicate how it could move and how fast. Jaw and teeth give clues about diet. Then there are things like chest size and lung capacity, whether it has feathers, defensive armour which indicate a prey animal, and so on.