MrNahual2099 not impossible, but highly unlikely. Close relatives of Dunkleosteus from Gogo are preserved with excellent soft tissue preservation. There is no evidence of substantial soft-tissue masses over the biting surfaces.
Something amazing about the Dunkleosteus' jaw is that its bite is not only impressively strong, its opening (contrary to crocodilians) is maybe one of the strongest ever. This means that it probably hunted using a combination of extreme sucking, and then a crushing bite. The stuff of nightmares.
I've never heard anyone else address this issue - an answer before the question was asked! This was fascinating and enormously thought-provoking, thanks so much.
Amazing to think that my arms , legs , lungs . and jaw are a gift from a 300m year old fish . Called Brenda Bella Psis . I wish I'd met her . Just to talk about the good old days .
We know that’s not the case because we can use chemical analysis to determine their food source. If there’s no need for a jaw, they probably dont have them
Unlikely. We still have jawless fish today, but not cartilaginous jaws. Jaws need to be strong to be functional. Even in cartilaginous fish, like sharks, the jaws and teeth are the only part that is heavily calcified (ant that's why you can find lots of decorative shark jaws but not complete shark skeletons)
@@juanausensi499 Chondrichthyes have cartilligous jaws, though. Cartilligous doesn't mean soft, cartilage has several morphotypes, including the hyaline cartilage, which is very hard and absolutely hard enough for jaw bones. The only bone chondrichthyes have is on the base of their scales, everything else is secondarily cartilligous.
@@JayManty Thanks for the clarification. I knew shark jaws aren't bone, but they are distinct than the rest of the skeleton. My point still stands, i think it's very unlikely that an animal would have a hardy skeleton and a soft jaw.
This is entirely possible, however the current research shows that the (admittedly paraphyletic but still fairly well understood) clade of agnathan fish-like vertebrates called ostracodermi had a large armor-like structure covering a big chunk of their body made of primitive acellular bone. Since this group did not have jaws, we conclude that neither did their ancestors, and it is unlikely that ostracidermi would develop a non-bony jaw from their extensive bony head structures, only for them to return to a bony jaw again. Is it possible though that there was some small stem group of vertebrates that had some kind of a jaw-lite and went extinct? Yes. But unlikely, though anything can happen in paleobiology.
The dunk model at the Cleveland Museum of Natural History is one of my kids' favorites. Granted, that's partly because there's a cheeseburger in its open mouth, lol
@@cheeseycrouton Yep, in the model hanging from the ceiling, not the fossil. CMNH has about a dozen things like that scattered around throughout the museum's main collections. There's a VW bug in with the beetles downstairs, lol. There are memes of that one floating about.
i recall theories of the armored fish dying out since the boney fish were able to store calcium and use it when it got scarce, along with that they also had kidneys to help regulate water in not-so-salty waters, unlike the armored fish who again had the armor to regulate water. i forget where i read this but if anyone can then i would like to hear your take on it.
I've always heard that they mainly died out because faster, bigger predators could crush their armor without much trouble. Bony fish speccd into speed and flexibility on top of a mineral-storing skeleton
Your videos take me to an entirely different plain of thought. I get lost in this complex but yet simpler world of our past. Never stop uploading dude, I'm here for every one.
I know this is a science channel, but channels like yours are responsible for some of my music. I'm inspired by nature, and you do a great job at describing it.
The Blue Wave I knew what he meant, however not everyone would. Many people would actually take it as fact. That’s like if I tell a toddler that dogs are the first mammals to walk
This is so cool, science is always changing and that’s what I love about it. Yet it can hold a basis of imperial data from simple induction deduction to go off of. This will help me study Oceanography more, and thank you for putting the names all written down.
Narrator: "And were unable to push their mouth together with anymore force than you can push your lips together" Me: *starts smashing my lips on my finger*
@@Vypren, If you fish in bodies of freshwater that are known to have a lot of freshwater non Teleost ray finned fish (Like Gars, Bowfins, Sturgeons, Paddlefish, Bichirs, and Reedfish), Teleost fish that have bony tongues (such as Arapaima or Arowana), or lungfish you will be able to fish so many prehistoric fish that it will be near impossible to catch a fish that isn't a living fossil.
Makes me wonder how different things might have been had we descended from something marginally closer to *Dunkleosteus* (with it's extraordinary shearing jawbone extentions in place of teeth)..? Or if our body plans had been based round *Six Limbs* ( *Hexapodal* ) instead of *Four* ( *Tetrapodal* )..?
@@jamesgabor9284 Indeed. No more bipedal, dextrous, verbose, sociable, apes with hypertrophied brains... What other *Sapience* could develop to fill this niche? (Presuming that intellect & consciousness repeatedly develops - as the evidence suggests. Evolution has no end goal, after all.) We now know that at least 5 other cousin Primates developed both Sentience & Sapience - if profoundly different to *Homo Sapiens* *(Neanderthals, Denisovans* & another, as of yet unnamed branch of *Homo,* then our far more distant relatives, *Chimpanzees* & *Gorillas).* But then there are all the *_Sub-Sapients,_* organisms that are almost - but not quite - Sapient: *Canids, Felids, Ursids, Corvids, Orca, Dolphins* & (going back a ways) *Dromaeosaurs.* (Plus all those I've missed...) We were lucky enough to be land-dwellers, warm-blooded, bipedal, with the capacity to grap things with our hands, the metabolism that could handle such aa tremendously energy-hungry brain & our social structure that's stimulated verbal communication. *_If we could give some, or all, of these characteristics to these Sub-Sapients (through genetic engineering ⊚), what could we create..!?_* [ *_This concept is called "Uplift"_* ] ⊚ As _Scientifically Unethical_ as this would be...
There is a slight inaccuracy with the date of the first appearance of complex multicellular life, the first complex multicellular organisms appeared close to 579,000,000 years ago during the Ediacaran, and later the first mollusks like Kimberella Quadrata would appear close to 558,000,000 years ago, also during the Ediacaran period, 635,000,000 years ago to 541,000,000 years ago.
Scientists never do that because there’s no way to be sure about direct ancestry. They think placoderm species they have fossils for were siblings or cousins of the actual placoderm that developed into bony and cartilaginous fish. For short we can say: “they were ancestors” but in reality the meaning is that “the actual ancestors (probably) were exactly or very similar to this species we have found”. That’s why they use that particular graphic format where the “ancestor” is not on the intersection of the branching.
Very well made :) I agree, the placoderm jaw & the bony fish jaw & the cartilaginous fish jaw are not just convergent evolution! They definitely share common ancestry! But what if the armor on the placoderms was convergent? Like you said, they were incredibly diverse. And they were all under extreme selective pressure from ammonites & sea scorpions & even each other. So then heterostracans, osteostracans & placoderms may not be very close related. And the placoderms certainly have a preservation advantage. Whereas, with cartilaginous fish, sometimes all we have are a few placoid scales & we don't know if it was a shark, shark relative, or something else. So, the placoderms could have inherited their jaws from a cartilaginous ancestor that did not fossilize well.
However!!!!!!!! Let me be fair --- the idea that modern bony fish are placoderms that lost their armor & cartilaginous fish are placoderms that lost their bulky armor & lost the calcium phosphate from their bones, does have the advantage of being most in line with the fossil evidence. It's just many experts think placoderms inheriting their jaws from a cartilaginous ancestor that did not fossilize well is more parsimonious - and that view point is certainly possible given the "poverty of the fossil record" - and the fossil record can be especially limited that far back in time. I am not an expert - I just study this stuff as a hobby & I try to appreciate both viewpoints.
Also, you're absolutely correct, the end Devonian extinction was what did in the armored fish, not just competition from other fish. Part of that may be that all the giant sea scorpions went extinct so the, so they were no longer under so much selective pressure to be armored. And that does lend credibility to the idea that surviving placoderms lost their armor & gave rise to other fish. Whether placoderms passed down their jaw to both bony & cartilaginous fish, or only bony fish descend from placoderms & cartilaginous fish got the jaw from a common ancestor, or whether all 3 got the jaw from a common ancestor - I just don't know. Like I said, I am not an expert, so I just try to appreciate all the options.
Yeah well evolution should of done better so I didn't get trigeminal neuralgia TMJ nerve pinching. I literally had to get my jaw physically and manually relocated by a doctor because my TMJ joint slipped out of place and pinched my trigeminal nerves so badly I was a mess during this chapter of life. Luckily things have improved since that was done but I kind of have trauma that my jaw could get out of place again... It's literally a nightmare. I wouldn't wish it on anyone, not even bony jaw fish ❤️
Belissimo, as always. Bravo; please, continue. Yours is one of the best small channels I've found, where unlike so many others, I've never felt the need here to correct bad Latin pronunciations, or deal with someone's accent being so shite, one can barely tell what they're saying.
@@drjelly9089 modified Rna strands covered by membranes and proteins, that became two different lineages of cells, then one ate the other and they became a bigger cell that ended up bonding together with his siblings
I used to own a big book of dinosaurs and other ancient things. And it went from era to era from the very first thing, and now I can't find it anymore.
Due to convergence evolution, all alien lifeforms will also have a jawbone. The reason is all predators have to eat and without a jaw to grab on to a prey, it will not survive to make offsprings.
One important take away is that prehistoric fish did not have many things: jawbone, pectoral fins, a powerful tail. Thus it is interesting to thing that our modern fish are also missing countless more advantageous parts that won’t evolve to be for several hundred million years as well.
