Did Mosasaurs Have Dorsal Fins?

[@spinejackel]

insert marge simpson “i just think they’re neat” meme but she’s holding mosasaur paleo art with dorsal fins

[@daviderizzello9360]

yeah but you can't draw paleoart not based on science, i mean you don't just draw a flying penguin because it isn't a penguin anymore

[@perfectbotgreg5119]

Yeah

[@XWierdThingsHappenX]

@@daviderizzello9360 than I guess Picasso wasn't drawing faces when he was using cubism. Its artist interpretation.

[@spinejackel]

Davide Rizzello thank you for the input, mr. no-fun-allowed, i shall now go and draw flying penguins because the only way you can stop me is if you fight me 1v1

[@daviderizzello9360]

@@spinejackel "the only way to stop me is if you fight me 1v1". and it's me who's mr. no fun, lol. also you can't have a conversation without getting salty and pissed about something that wasn't even remotely meant to offend you but hey, guess you wouldn't listen to mr. no fun, assuming i don't 1v1 you

[@shanerooney7288]

Mosasaurs _didn't_ have a dorsal fin. Spinosaurus Aegyptiacus took them all.

[@tbc1880]

Yes

[@imaredwhale2thenotsoelectr916]

Yes

[@RMSLusitania]

I hate how you capitalized the first letter of the species

[@shanerooney7288]

Okay, I had to look it up. You're right that such grammar isn't common practice. . . *_except_* when the word is derived from a place name... But only for the genus name, not the species name... With a lot of notable exceptions (such as many fruits, eg: Red Delicious). English is a mess. If it makes you feel better, just imagine I'm talking about Mr Spinosaurus Aegypticus.

[@RMSLusitania]

@@shanerooney7288 no its not just English, its binomial nomenclature

[@eljanrimsa5843]

Counter example of fast-moving marine predator without dorsal fin: Sea lion. I guess there is a trade-off between higher end velocity (dorsal fin, stiff spine) and manoeuverability in close quarters (flexible spine, no dorsal fin).

[@bkjeong4302]

What we know of mosasaurs indicates they were headed down the path of open-water pursuit hunting (what with their carangiform swimming style, large tail fluke, often being found in pelagic ecosystems and raised metabolism).

[@ecurewitz]

I was thinking the same thing

[@raulmt4]

Sea lions are more like plesiosaurs, as they both swim wirh their flippers and not their tail. And both lack dorsal fins, so I believe it has more to do with the way they swim

[@ThePotatoSapien]

Sea lions are NOT a good comparison to mosasaurs. They are still partially terrestrial, so they spend a lot of their time on land, and aren’t really converging on the body plan of whales and sharks. If anything, I’d compare seals to nodosaurs, due to them both being still slightly terrestrial and having similar niches. Not saying mosasaurs DID definitely have dorsal fins, just saying that seals/sea lions aren’t a great analogy.

[@ThePotatoSapien]

(Me accidentally replying to this comment twice: wow I’m dumb)

[@gildedbear5355]

Dorsal fins have evolved several different times: whales, sharks, and ichthyosaurs (I leave out bony fishes because the structure is pretty different as pointed out in the video). It's reasonable that /some/ mosasaurs could have had a dorsal fin. Which I suppose is just a summary of the video 8D

[@thedoruk6324]

+GildedBear Convergent Evolution *rules!*

[@isaacslein6432]

While I agree with your reasoning, I feel that mosasaurs would also have a keel like we see in giant sharks and whales

[@NaturesCompendium]

This better not be an April Fool's joke 😉

[@Scarlet_Soul]

Nothing finny about it

[@Kuwagattai]

Hey, i love your channel, your art and narrating is amazing! Subscribed to you, and your second channel (The Naturalist Gamer)

[@ceppoc]

I want at least some of them to have dorsal fins, looks neat!

[@ChaoticPictoris02004]

Finny

[@retard_activated]

@@Scarlet_Soul 🤣🤣🤣

[@delmerputnam1679]

I don’t mind speculation, as long as it is acknowledged by the speculator as such. There are people (not just in paleontology) that will make a speculation that is reasonable and run with it and argue it as fact. These people are have the same problem as those who never allow speculation at all (just on the other ends of the spectrum)

[@TheWhitefisher]

Agreed, and it's not stuffy or negative to require hard scientific evidence in order to believe something or other. I wouldn't want to see speculative paleo art presented as supported by fact--what I look for in paleo art personally is the best portrayal possible with the information at the time. So speculation would be cool but then please let the viewer know what it is.

[@irmaosmatos4026]

I find the same for people who can't stand not scientifically accurate reconstructions. Yes it's not perfect, but it doesn't lose its artistic value no matter what. You don't have to give backlash to an artist because of that, unless it was stated as accurate previously.

[@YoungZibzy]

I think comparing them to early whales, like protocetus, is more appropriate than modern whales. From reconstructions I've seen, early whales didn't have dorsal fins at first, and the skeletons look a whole lot like mosasaurs

[@GandalfTheTsaagan]

Basilosaurus in particular

[@carlosandleon]

Mosasaurs couldn't evolve to more aquatic forms like whales do due to the abrupt extinction event

[@RedXlV]

@@GandalfTheTsaagan I thought Basilosaurus did have a dorsal fin, though.

[@bkjeong4302]

Mosasaurs actually became closer to toothed whales than a lot of the early whales like Basilosaurus were, being more torpedo-shaped. Basilosaurus is closer to what we USED TO think mosasaurs were like.

[@carlosandleon]

@@bkjeong4302 early mosasaurs were surely more basilosaurid

[@Kitsaplorax]

I'd like to see a hydrodynamic ergonomic and manuvering model comparison.

[@Riceball01]

I imagine that it's possible to make a computer model that can do that. Even if there's no software out there that's designed specifically for this, there's probably marine engineering software out there that could probably do this if you could import an anatomically correct mosasaur model into it.

[@reubenc0039]

April 1st? man, mosasaur month is over already. hyped for it again next year!!!

[@bartfoster1311]

There is a t. proriger specimen found in Nebraska that has skin impressions but I don't know that is has been prepped fully and if it the skin impression section includes where a dorsal fun would likely be. Looking at living lizards perhaps a small ridge like an iguana could be present. I don't think they had one but that is my opinion.

[@TalesofKaimere]

Another great video! Solid observations. Things to keep in mind as I continue to refine my speculative mosasaur designs for Kaimere. Cheers!

[@kerianhalcyon2769]

Honestly I think that mosasaurs didn't develop dorsal fins...*yet*. Some of the earliest Icthyosaurs were shown to lack a dorsal fin as well. I'd bet that if the group survived past the K-Pg extinction event they could have developed one on their own if it proved to be handy.

[@chheinrich8486]

youtube.com/@TalesofKaimere

[@rugvedrm3844]

Never thought about it. Love this channel, asking questions I didn't even think about.

[@robertstone9988]

Do you think mosasaur's had viperated tongues since snakes and monitor lizards both have viprecated tongues?

[@KyubiChan95]

Good question, I've wondered about that myself for a while now.

[@thedinogeek4207]

Mosasaurs are the perfect mixture of derpy and terrifying.

[@Hotchpotchsoup]

I love your use of very scientific words such as "snootiest booper" and similar.

[@hayliedlr]

Me too

[@JaxDaHax1]

I like the idea of them converging on a dorsal fin, even if the 4 limbs provide enough stability I'm sure it would pose at least some benefits, even if less necessary because of the 4 flippers

[@toPuPplS]

Looking at ichthyosaur evolution and how their ancestors kinda looked like mosasaurs, if e KT incident were to be postponed a few 10M years or so, there's possiblity mosasaurs could end up looking like ichthyosaurs..

[@magpie3908]

or reptillian whales

[@GeorgeTheDinoGuy]

I do wonder if we could track down the original dorsal fin art, or at least the one that started the trend.

[@paleoph6168]

I want to see more Dan Varner paleoart.

[@Kuwagattai]

Yeeeeeeeeeeeey i am early for once! Amazing video EDGE! Keep them coming!

[@joshuacadavid871]

Hello, my fellow Catarrhines who love the Mosasaurs!

[@yuujinner5801]

Hello fellow fish.

[@perfectbotgreg5119]

@@yuujinner5801 mosasaurs are not fish

[@yuujinner5801]

99%of all vertebrates are fish. Mosasaurs, as monitors, came from reptiles, which came from amphibians, which came from fish. You cannot outgrow your ancestry. Humans are fish, a bird is a fish, and even mosasaurs are fish.

[@perfectbotgreg5119]

@@yuujinner5801 fish share common ancestors with reptiles 🦎 how ever fish are no longer even distantly related to lizards like mosasaurs also technically you can out grow our ancestry wen most of not all of the Jeans of that Ancestry are completely gone and Mutations completely erase them

[@perfectbotgreg5119]

@@yuujinner5801 99% is inaccurate

[@ครยฬร]

Some questions are too important to go to sleep without knowing huh

[@gojirazillasaurus6341]

Have you guys ever thought when they figure out new things about dinos then the people at the museum are like “aw crap it took us three days to put up that skeleton now we gotta change it??”

[@benfuentes2118]

hahaha this cracked me up

[@hyperactivehyena]

I think this is just the thing- a vast majority of oceangoing animals need that fin for extra stability, but mosasaurs in particular developed a different method of dealing with that problem. Their huge maneuverable flexible fins, super elongated snaky bodies, powerful and very developed tail fluke- I see them as forgoing that 'stability' entirely in favor of being able to maneuver like an eel or sea snake, with rapid undulating body movements and an advanced sense of balance to compensate. And as such it'd make sense that a mosasaur that began developing a different lifestyle- one that required more of that up/down balance seen in other aquatic animals- would also begin developing a dorsal fin. I mean as body structures go I can't imagine a fin is a massive evolutionary leap, just some soft tissues anchored to the spine.

[@bentufte7774]

Love the new intro!

[@KCsFunHouse]

You definitely have some of the best animators!!

[@scottbrower9052]

Love your channel, man.

[@quietstories98]

I love the new intro animation, its so cute

[@WildBillCox13]

I dunno if you're old enough to remember the classical interpretation of mosasaurs having an eel-like crest down the ridge of the spine. Oarfish probably sparked that idea. On a side note, I am amazed that sharks developed frikking laser beam eyes and mosasaurs did not. You'd think the more derived form would include such useful ergopathic weaponry, if only to defend itself against mermaids..

[@lyly_lei_lei]

6:40 “Look out! I think Moto Moto likes you!”

[@Titus-as-the-Roman]

That Mosasaur in Jurassic World should have been a Predator X Pliosaur, it would have been much closer in the size depicted and they think it may have actually hunted in this way.

[@logandelacruz2152]

That animal’s size was also exaggerated. It’s now believed that the pliosaur was in the range of 6 meters. If anything, Mosasaurs hoffmanni was closer in size to the JW mosasaurus at ~13 meters.

[@nadagainagain4987]

I could see them having a bit of a ridge down their back but not a fin. I picture them swimming something like a combo between agiant leopard seal and a croc . Leopard seals are one of the scariest animals today.

[@prototropo]

I'm impressed with the deductive reasoning! I'd love an engineering tutorial on how, exactly, such a teensy, cartilaginous (?) keel-like thingy on humpback and blue whales can serve such a presumably powerful stabilization function. I always wondered that in my rear cranial room of stupid questions, and it's very reassuring to have an intelligent observer haul the secret wonder out of the dark of shame! Perhaps keels generally only need to establish the slightest suggestion of a median plane--aka sagittal or longitudinal plane--that's efficient. But interestingly, in whales it is always posterior to the animal's center of gravity, or maybe that's an artifact of being most ideally situated along its gradient of propulsion, so as to be an assist and not a hindrance to spinal attachments of muscular alignment, and that sweet spot just occurs a bit behind (or below) the waist in tetrapods. The human coccyx might be the anchor of a past or future dorsal fin. I'm pretty sure mine would have or will be a deep, metallic teal, with a streamlined profile possessed of an intriguing, understated curve that turns heads and rivets the attention of men, women, children and dogs wherever hipsters hunger for the aesthetically cool. In many fish, the dorsal fin looks to be smack in the middle, or even anterior to the center, I think (?). They aren't tetrapods, really, but they do possess an unerring aesthetic sense. I welcome corrections from anatomically astute, but kind, scholars.

[@alioman6896]

Mosa with a dorsal fin is cursed and blessed at the same time

[@Yeely-cw5gi]

One such Mosasaur, the Megapterygius Wakayamaensis, had a dorsal fin on it's vertebrae which provides stability while swimming.

[@jmashups6804]

8:30 Oh my god, that's the Denver Museum. I'd recognize those brick walls and whale skeleton anywhere. That just hit me with a wave of nostolgia.

[@MathisBrothers2275]

When I was young I read a book that depicted a mosasaurus going on land to lay eggs even though going on land is outdated but the laying of eggs may have been ahead of its time.

[@thegloriousspamton5210]

It would make sense for a mosasaur to have a keel or dorsal fin although the possibility of finding such a specimen is scarce to none. I have a feeling that their will be a specimen turning up in fossil records or being discovered in the near future

[@petersmythe6462]

pelagic animals with no dorsal fin: 1. almost every variety of pelagic squid, octupus, or cuttlefish. Even with *jetpowered* speed and, in tropical areas, potentially higher metabolic rates than comparably sized mammals. Humboldt squid are capable of extremely fast movement and propulsion in water and can engage in jet- powered aerodynamic flight above water below a certain size. Above this size, they are still volant but in a purely ballistic manner, as their stall speed would be faster than they can probably go. Even so, there is evidence that their migration must take place at least partially above water and be 2-3 times more efficient than underwater travel at comparable speeds. Low metabolic rate deep sea predatory squid such as the giant also do not have a dorsal fin. 2. Turtles: Whether their shell is hard or soft, turtles don't have this sort of structure. that being said they don't engage in this type of swimming. 3. seals and sea lions. Large active predators that engage in exotic twisting motions but have no dorsal fin. 4. Penguins and other birds. No dorsal fin for a semiaquatic animal feeding entirely on marine food sources.

[@azrielmoha6877]

All of animals that you listed doesn't use its tail for propulsion through the water though. Here's a comparison as animals that do use its tail to move underwatwr and do have dorsal fins 1. Bony fishes 2. Sharks 3. Cetaceans (dolphins, whales) 4. Sirenians (dugong, manatee) 5. Sea snakes (not a forked fin but still they have flattened wide fin like tail) 6.Phylliroe, a type of sea slug with some fish like features including a forked dorsal fins. So yeah, it's not unreasonable that mosasaurus have dorsal fins when these animals posses them Edit: just switched dorsal fin with caudal fin. This is what happen if you go through the comment without watching the video first. Sorry about that

[@alexandermelchers1497]

Very informative! Learned a lot about mosasaurs I didn't know before!

[@paleoph6168]

Good question, how about plesiosaurs and pliosaurs? 🤔

[@grebnedu1219]

Pliosaurs are underrated

[@paleoph6168]

@@grebnedu1219 I agree

[@elliotminto4730]

that’s quite a thought actually. my initial guess would be that due to their close relation and similar locomotion to sea turtles that they wouldn’t, but who knows? after all loggerheads have raised carapace ridges along their dorsal ridges and the plesiosaur family were around for a long time so plenty of time for different forms to appear

[@PelagicDragon]

I want an E.D.G.E out of context video

[@Gandenkris]

Your videos truly bring to life how damn smart paleontologists are!

[@UnderseaDee]

I guess the interesting part here would be if any basal mosasaurs had fins that could've carried over into later branches in any form, or if these potential instances were just random happenings

[@BigBossMan538]

I wonder if a filter-feeding mosasaur existed or could’ve existed in an alternate universe where the KPG mass extinction never happened

[@FredstarOfBritain]

The question is: Do mosasaurs communicate like porpoises and whales?

[@wolfafterdark]

I imagine they moved like otters (or less so sealions), but swam more in the vertical plane.

[@thedoruk6324]

6:45 - What an *Absolute* Unit! Look @ that *CHONK!*

[@qibli7679]

"the imfamous dorsal fin that gives us naked apes the heebie-jeebies"

[@mariajoffy1086]

Now what we need is a mosaure that has spikes on its back and a shark fin and clawed flippers and 2 big fang like teeth

[@majorcheirus77]

When will you do an episode on Iguanodon???!!! I love iggys so much

[@botmoderator3405]

I see them get destroyed in ark by inaccurate raptors

[@bretthess6376]

As a separate dorsal structure, large or small, probably not. Well, maybe not. As an extended dorsal ridge, very likely. Many lizards do.

[@fanaticbuster8856]

Most likely yes. It's a necessary requirement for any large sized marine vertebrates to move in the surface (e.g. sharks, cetaceans).

[@marcoasturias8520]

I wonder if there are any fluid dynamic studies done with mosasaurs bodies. I think that may help!

[@3characterhandlerequired]

I think it is a question of locomotion type. Penguins don't have dorsal fin, however they use their "wings" to fly thru the water not the tail for movement. If mosasaur uses mainly its fins to move around and tail just for steering it might not need the dorsal fin. If they use the tail for motion like fish then they need dorsal fin for stability.

[@N.Sniper]

Same with sea turtles, which are fully aquatic sea reptiles.They use their flippers for propulsion. Sea crocodiles use their tails primarily to swim and are great swimmers, they have no dorsal fins. But they are not fully aquatic animals.

[@ichthysking863]

4:00 If there's no remains of soft-tissue where the dorsal fin should be, then why does that go against the dorsal fin idea? To me, this seems like a case of 'absence of evidence is evidence of absence'

[@EDGEscience]

Soft tissue was preserved for the rest of the body, why would it be missing for the dorsal fin? The tail, pectoral, and pelvic fins all had soft tissue remains of cartilage and skin that used to be there. It would be highly unlikely, though not impossible, for only the dorsal fin not to make it through fossilization.

[@ichthysking863]

@@EDGEscience If we'd expect the dorsal fin to be preserved if it existed, then we should expect that the finless back would be preserved if it didn't. And none of the given examples show this

[@YoPiedsNus]

I have been thinking about the question the last couple of years. I also wonder if the mosasaurs needed dorsal fins, shouldn't the same be said about the metriorhyncids.

[@mathmeetsmusic]

8:22 sounds like a problem for machine learning.

[@GeorgeTheDinoGuy]

This is your hundredth video 🎉👊

[@tobiaschaparro2372]

I def thought that was a basilosaur in the thumbnail

[@Scrinwaipwr]

I expect they had little baby dorsal fins, especially the ones with only little baby back flippers.

[@johnhanover2229]

Wouldn’t plesiosaurs have one as well since they had equal sized flippers?

[@Spectrulus]

Has anyone researched if Theropods also had dorsal fins for stability?

[@hero-scout9397]

Get with it bro they have dorsal hands

[@kylethedestroyer1117]

NO THEY HAD DORSAL DING DONGS

[@Scarlet_Soul]

Nothing finny about this on April 1st

[@mbvoelker8448]

Interesting analysis.

[@diymike4707]

Biologically speaking there’s a lot of animals throughout history that have had unneeded body parts

[@arcticdino1650]

I think some could possibly have a fin, but definitely not all. (Autocorrect really hates the word fin, everytime I type it changes to fun)

[@paleoph6168]

11:39 The animation reel reminds me of a similar one in a video showcasing a Cretoxyrhina for National Geographic's "Sea Monsters". m.kzbin.info/www/bejne/iqiWZoiqlNicmtk

[@leonardogurney5488]

So what's next, a Mosasaur that has wings like a flying fish 🐟

[@fredbijl3709]

So I have a question, did mosasaurs have split tongues? Because they evolved from monitor lizards right so it would make sense. Or is there a disadvantage to having one when living as a marine creature?

[@diptube6563]

Apparently sea snakes have lost most of their olfactory senses and leaned hard into their vomeronasal senses - we can't say for sure, but since it's entirely aquatic - if it did have a forked tongue - it likely used the taste of the water to help find prey.

[@drsharkboy6568]

Perhaps the mosasaurs made up for not having a dorsal fin by swallowing gastroliths to balance themselves. That’s what plesiosaurs did, and what many aquatic animals without dorsal fins like axolotls do.

[@rileyernst9086]

Do plesiosaurs have dorsal fins? I suspect both groups are in a similar basket.

[@rileymanders2167]

good job

[@leechild4655]

also did it have a forked tongue like a snake or monitor lizard.

[@petersmythe6462]

white top and black bottom on a marine animal? Mosasaurs are scary but they're not so scary they need aposematic colors.

[@SnubbyDaArtist]

*Mosasaur with Flippers.*

[@russelldecastro7968]

They also have arms and legs! 🤨

[@thomasfarmer1730]

Aqua dynamics??

[@robertjackson1813]

There are several dolphins long-beaked and short that don't have dorsal fins

[@aboomination897]

i asked this exact question on twitter the other day :D the paleoartist did not asnwer tho ^^

[@clausheinrichschmidt]

How di They get air Then? A forked tongue is used to teist Air on land, not in the sea

[@EDGEscience]

A forked tongue can be used to pick up scent particles from water.

[@dynamosaurusimperious6341]

Well at lest for a April Fool's video this was a really good April Fool's video. Alsp once again great artwork,commentary,and animation( buy Kuzim & Tyler )

[@Trianglewitch.]

Some probably did, and some probably didn't

[@garrettlich7140]

He needs a discord so bad

[@iamandyFEARME]

the tail structure does the same thing, the dorsal fin would only assist in that, it makes sense that whales have a small one because their smaller ancestors benefited from it more, it's vestigial

[@EDGEscience]

It's not vestigial if it has a use.

[@iamandyFEARME]

@@EDGEscience then receding in size for whales as their front fins grew in size, they required it less over time and it has reduced in size

[@KalleVonEi]

They look better without one

[@DChatc]

I think I actually gravitate toward the idea of a row of dorsal ridges. That seems about what one would expect for an aquatic monitor lizard like Mosasaur. Very smooth, very short bumpy ridges would make the most sense here.

[@safron2442]

4:03 "it has yet to be preserved".....Where are you hiding living mosasaurs to be preserved in the future?

[@ww6609]

Seems like the more we know of prehistoric animals the more they look like creatures today. Yeah, a dorsal fin would make sense. Sharks and whales have them and the fluke is different with both so biology tends to repeat. Would not be surprised.

[@carafurry7862]

I mean seels and penguins don't have doral fins... Also sea leperds don't have one...

[@Frogboyaidan]

Mabye

[@alfreddino2071]

I don't know if it is fact or fiction. I only know today is April's Fool. 🤔🤔🤔

[@yaeldragwyla8170]

Mosasaurs were descended from lizards. So are snakes. Snakes, including sea snakes, don't have dorsal fins. Is this the answer to the question?

[@azrielmoha6877]

They do have a semi dorsal fins though, albeit a wide and flattened one, not a fork shaped

[@yesman6559]

Yes

[@onandonitgoes5957]

Fact or finction?

[@fanaticbuster8856]

Fact

[@AquaticFlapper125]

April 1st

[@Avabees]

I have a comment on the argument at the end of your video (which was great btw) ... Ive seen other internet people run with that speculation of features that cant be ruled out, who also dont bend when more accurate science comes out. And many of them make fun of the people who go without those features (Talking about fluffy Trex and the study that found it more likely the skin would be elephantine)

[@arcticdino1650]

While people shouldn't make fun of others for making non feathered t rex, t rex isn't the best example to go with. The debate about it being feathered or not is still going. Also, I could find nothing on elephant skin on trexs, I could find articles saying it definitely had *some* scales, but no elephant like skin.

[@jaxrammus9165]

you call people arrogant and that there needs to be definitive counter evidence to dismiss dorsal fins and yet the burden of proof is always to prove the change, not to prove the absence of change. you must prove the fin, not they to prove its absence.

[@Bayoll]

What about ridges like on sperm whale and narwhal?

[@danielegyed840]

Narwhals and Belugas have very reduced dorsal fins due to the frigid environment they inhabit. These whales often swim very close to the underside of the pack ice or floes, so a prominent structure on the back would be easily harmed in that process. The dorsal ridge (instead of a fin) is also believed to be an adaptation for reducing heat-loss thanks to a smaller surface area. I am not sure about sperm whales though. Maybe it also serves the heat balance (since these animals dive very deep to hunt) or it helps to create a body shape that is more efficiently suited for energy-saving descents into the dephts of the ocean and back to the surface? I don't know.