The Evolution of Hammerhead Sharks

[@wraithwrecker_]

I like how every single hypothesis presented in this video has seemingly near conclusive evidence against it. We really haven't figured why hammerheads have hammerheads at all.

[@richardeast3328]

True

[@PJ3721]

Can I see?

[@2Siders]

It’s to sense crabs under the soil

[@darcieclements4880]

Sure we have, it confers one or more advantage that results in more offspring surviving to produce more offspring. Obviously the diversity shows it had many uses. Looking at convergence, I would guess it is sensory. No need to only look at sharks for convergence. Small changes immediately confer better senses, so the full package would not be needed instantly. Multiple factors likely stacked to produce the final result. Then that extreme form radiated to form less extreme forms after some extinction event

[@jamespierce5355]

It's almost as if evolution is an erroneous theory that can't account for things like the hammerhead shark or bombardier beetle....

[@UATU.]

Trying to imagine their field of vision does a number on my brain.

[@Player-pj9kt]

It's so weird - their eyes are on the side yet they can see front and back

[@henrg]

Imagine if your brain didnt filter out your nose, and if your nose was MASSIVE

[@robwalsh9843]

Then there's the electroreceptors, which confounds things.

[@midgetman4206]

Like us, I'm sure the majority of it is lower quality, specialized in motion detection. You're trying to imagine a high quality picture throughout the whole thing when in reality it'd get less resolution the further out it goes. We don't even have much HD sensing, it's a rather small dot. Our brain is just excellent at filling in the gaps.

[@mattonite6372]

ive always wondered why hammerheads decided to become a tool so glad you made this video

[@doohandarmawan9404]

👍

[@kylemackinnon5696]

Same cant wait for the philips head shark video!

[@jahimuddin2306]

I remember watching an AVNJ video and one of his Twitch viewers called the Winghead Shark a Pickaxehead Shark.

[@gregory_longjohns]

@@kylemackinnon5696😭

[@blondbraid7986]

The hammerheads probably thought that the sawfish needed company.

[@vincentx2850]

Just because an animal is positioned on the basal position in a phylogenetic tree doesn't necessarily mean the it's features is representative of the ancestral condition - they are still evolving after the split and can in fact get really specialized. Smilodon for instance is more basal relative to modern cats, but it by no means reflects the ancestral condition of felines.

[@ryuuguu01]

I was wondering about this when watching.

[@darcieclements4880]

Very much so. We just lost the basal simple hammerhead linages, which is very common. All this means is that bonnet heads are more closely related to most other sharks compared to the most extreme hammerhead sharks that are still alive today. It does not mean that one is more primitive or really properly basal like that's just very out of date thinking. I get that for convenience we still refer to the least related group as basal but we really probably shouldn't be doing that still when we are talking about genetic lineages.

[@LuisAldamiz]

It's strongly suggestive to be around 50% half way to the ancestral condition, the other 50% would be the hierarchical average of the rest, and the great hammerhead is second to diverge, so there goes another 25% in favor of broad winged heads as at least close to the ancestral phenotype.

[@rajarsi6438]

evolution from one species to the next is a joke, aka total nonsense.

[@axelvazquez9385]

I don't think that's what people mean by the "ancestral condition". There are many things to take into account when studying the ancestral condition, and the answer lies in understanding why animals evolved the way they did. Building a hypothesis to understand why animals are the way they are is actually pretty helpful lol.

[@enezjaniw493]

I'd love a video on how closely related all the shark species are.

[@WaterShowsProd]

In case my profile picture doesn't make it obvious, I love this video. Thank you for diving deep with the hammerheads. Absolutely fascinating.

[@sandro5535]

Interesting that the armored fish vanished while cartilage prevailed.

[@Player-pj9kt]

maybe because it's lighter so it let's them swim faster or cartilage is easier to repair then bone

[@sandro5535]

@@Player-pj9kt Yeah figured something like that too. mobility>armor.

[@dr.floridaman4805]

gar sturgeon you so stu[id

[@stanettiels7367]

Cartilage is probably less resource intensive to produce, repair, etc. Exoskeletons also often need to be shed to accommodate growth, making growing a new one resource intensive regarding calorie demands. Cartilage is also lighter, more supple, flexible and overall less prone to breaking/damage. That’s my uneducated guess anyway.

[@tristancoetzee6059]

Your videos always quench my thirst for evolutionary knowledge!

[@rajarsi6438]

evolution from one species to the next is a joke, aka total nonsense.

[@willh314]

I really wish I’d been able to take a class going into specifics of how different species evolved like this in college when I got my degree in Ecology & Evolutionary Biology. Love this channel

[@JrIcify]

Maybe it's too big of a subject since any individual animal could be a course in itself.

[@xyan3191]

Ive found that college is really just the "let's catch you up to speed on what foundations we know up until this point" haha. You'll get specialized classes usually in graduate studies where youll find a professor willing (and with enough time and energy) to teach a class like this once students completed their basic literacy in (whatever field aka major).

[@rajarsi6438]

evolution from one species to the next is a joke, aka total nonsense.

[@redneckhippiefreak]

I got to know a Hammerhead shark. He liked to hang out just off of the bar where I surfed. Every day, dawn and dusk he would bet here. At first I was a little freaked out at a 8 ft shark circling me but for some reason when I saw is second fin pop up it kinda put me at ease. Most every surfer worth their wax has been brushed by the sandpaper fish but, My first close encounter with him was when he chased a school of blues past me. Even though Hammerheads have been know to be less aggressive. It was seriously unnerving. Fast and fierce. He nearly hit me and I felt the board buck as the currents hit it from underneath when he turned. If it had been a Mako or a Tiger, I think I would be less a limb or dead. Over the next 6 years I watched the space between the fins grow. He would circle us and lurk on the ocean side of the bar for about 2 hours and carry on his rounds. . Over time he slowly got closer and closer to us.. Id say around 4 years in he started seriously getting closer. The few brushes and buzz bys became pauses in the water and belly flashes, almost like a Dolphin. Strange behavior for a Shark of any kind I have ever know.. By the end of our time together, he would literally let guys pet him. Not in the puppy dog way, but more of a 2-3 second pause in the middle of a turning motion before slapping the water with his tail and powering away.. He would slowly roll back up and flash his belly and do it again from the opposing side. Anyone that knows sharks knows that any side to side movement from a Hammerhead could be a sign of them sizing you up and a shark slapping you with their tail is an attempt to injure you, but we never felt that way with the belly flashing display and all. It was never an aggressive slap or a true expression of his power. We interpreted that as a sign of his intent being simple Curiosity. By this time he was not small by any means. I once saw him clear his gills and he was about a foot clear of the water.. I estimated him at 10 ft. That beautiful brown over silver flash against the orange water was beautiful and a stark reminder of what we were swimming with. . Sadly ,one winter day I noticed he had a few deep scrapes on his rear fin and flank, I suspect it got into a fight or possibly a boat strike. Heck, maybe an idiot surfer stabbed it, I have no clue. It wasn't but a few weeks later that he was starting to grey out completely and some one caught him. He was a news worthy catch at 13 foot 6 inches. He was missed on the bar and needless to say, other sharks moved in and it wasn't 6 months later someone nearly lost their foot to a shark on the bar. We were once again at the mercy of the ocean without our friend and guardian.. RIP Rounder. Wrightsville Beach misses you.

[@KarlBunker]

Wow, neat story!

[@celestinemorningstar4851]

Sharks are naturally curious and intelligent animals, so you all were probably fascinating enrichment for him and made his life richer and better similarly to how he made yours.

[@android584]

His tameness got him hunted?

[@magnarcreed3801]

@@android584 Human scum got him killed.

[@redneckhippiefreak]

@@android584 To some degree he was. With his age and known status on the Island, he had been actively fished. Its a small place. (*4 mi x 1000 yds). He never took the bait though. . I suspect after the injury he was weak and took the opportunistic approach and got hooked.

[@awesomearchivist1705]

Hammerheads are my favorite sharks i think they look cool rather than odd. I like alot of animals people find "weird" usually because theyre very specialized to thier environment or niche. For example my favorite land mammal is the giant ant eater and my favorite bird is a tie between the toco toucan and the roseate spoonbill. Not only do i think asthetically they're amazing but also how they adapt physically to the environment i find fascinating.

[@stanettiels7367]

They’ve always enthralled me since seeing one shot in, I think, a James Bond film (Thunderball I think) where there are dozens of them circling.

[@obibraxton2232]

Anytime I see a notification from Moth Light Media I rush as soon as I see it keep the content coming 🙌🏾

[@Aurora666_yt]

I love this channel because I learn a lot. The narration is very concise and it's also calm and soothing.

[@syafiqjabar]

Bonnetheads probably evolved smaller heads since they do not need many hunting advantages, getting most energy from eating sea grass

[@ZwrP]

my mind was blown when you made me realize sharks are older than god damn trees lol.

[@daturtlegod-2387]

Very interesting, I love your videos Moth light media!

[@notoriousbigmoai1125]

Survive all five mass extinctions Evolve unique head shape for survival Are literally movie stars (Jaws, The Meg) Sharks are truly gigachad of evolution.

[@widodoakrom3938]

Wrong shark only existed for 400 milions year first mass extinctions happened 470-450 milions years ago

[@corocsat8469]

They also get bullied by dolphin's... sharks are just memes in the wild

[@rajarsi6438]

evolution from one species to the next is a joke, aka total nonsense.

[@wildworldadventureTravel]

⁠@@corocsat8469yeah by a pod of dolphins Try imagine a large bodybuilder who can 2 punch you out of existence vs 10 nerds who have 10x more stamina than you you think that punch would help?? Think again Imagine shark are way older than mammals

[@happysaladd8951]

Xiphancatus and dunkelosteus made sharks look innocent

[@thediscodemon357]

Great video as always, I am so Intrigued by the Hammerheads. I have an idea for another video, you could discuss the unknown world of Appalachia. Cretaceous Laramidia is easily the most famous prehistoric landscape, but the landmass right beyond it is an enigma. The creatures we do know in Appalachia are strange as well. I think it would be a really interesting video.

[@mondraymondo]

hey hey hey my favorite shark!!! finally featured in Moth Light

[@bariumselenided5152]

I have gone almost 25 years never knowing there was more than one species of hammerhead.

[@MatthewTheWanderer]

Hammerheads are so weird and cool that I think they might be my favorite kind of shark!

[@thelaughinghyenas8465]

Thank you. I really enjoyed this and was fascinated by the vision overlap study.

[@nomad3182]

Thank you man! What a way to start the weekend

[@KyriosMirage]

My favorite sharks! Awesome video!

[@WormBurger]

A new MLM video! Glad it's not a scam.

[@lara_xy]

I love all your content, but sharks are one of my favourite animals, so i always love to learn more cool things about them from your amazing channel!

[@EdgarCastillo-c6j]

Hemmerheads are my favorite shark ever since I was little because of their hammerheads

[@normalratrat]

Love your videos, never add them to watch later because i watch them asap. Can you do a video on beaks, like i have no idea how avian dinosaurs went from reptile like mouths to beaks

[@Ben-bg2lp]

Best BG music and volume level ever. Goes perfectly with your buttery voice.

[@icedo1013]

Moth Light Media upload? On Hammerheads?!! Instant thumbs up

[@budmcbudderson4250]

This is my favorite channel on youtube!

[@forever-raine]

"a truly unique structure... in the animal kingdom..." hammerhead worm: am i a joke to you!?

[@Dunkleosteusenjoyer]

Yeah Boi, new Moth Light Media video and it's on Hammerheads. Hell yeah.

[@DeRien8]

And of course, the bonnethead is the only shark known to get nutrition from plants. They'll eat seagrass!

[@SquirrelASMR]

The hammerhead chasing the ray is cute

[@Titus-as-the-Roman]

People will look back in paleontology and be amazed at all the really strange creatures, being an outdoors-man I can verify that we still have some seriously strange creatures skulking about, I routinely catch Bonnet Head Sharks (not on purpose), the smallest member of the Hammerhead family of sharks, up close they are truly strange looking

[@extofer]

fascinating as ever. thanks for putting this out.

[@johnsalisbury3768]

Love the videos as usual, thank you and keep it up!

[@nyyppa7956]

Could... Could we get the sawsharks next? I really want to know how my whole toolbox came to be.

[@mariastevens6406]

I said this before and I'll say it again: please, PLEASE don't change your storytelling style. Your voice and tempo is so soothing and makes it easier to absorb what you're saying. Plus, it may or may not be nice to fall asleep to with your vids on autoplay...

[@cooldudemcswagcooldudemcsw4697]

Looking at the hammerhead for this long makes me appreciate how big they made their heads

[@demos113]

Interesting work. 🙂

[@winstonzuo1230]

So why did the cephalofoil evolve? I don't think this is answered. Is it just a mystery?

[@randompianist8359]

yh still isn’t fully known

[@JaymieSword]

video on my feed: the evolution of... me, who's obsessed with evolution: oh hell yes oh HELL YES oh hell yes

[@transnewt]

hammerheads are so *incredibly* weird. not only are they the *only* sharks to develop such an extended head, they are also the only sharks to have an omnivorous species (bonnet/shovel heads) and the most basal species has the largest hammer. truly, the weirdest cartilaginous fish.

[@johnnijenhuis2296]

Amazing video as always

[@erichtomanek4739]

CephaloFoilCetacean anyone? Imagine if they had evolved as a sister group to the true whales? How different would the series "My Friend Flipper" be? Thank you for a fascinating in-depth study of Hammer Heads. Do left handed Hammer (heads) exist?

[@pedrogabrielduarte4544]

You're back dude don't dissapear ever again

[@sirmeowthelibrarycat]

🤔 I hope ‘dissapear’ disappears fro your comment . . . !

[@bernhardvonbraun3826]

I have a question, could you make a video on how endoskeletons evolved, or how vertabrates sperated from invertebrates in general?

[@bkjeong4302]

It should be noted that the connection between binocular vision and predatory behaviour is nowhere near as concrete as often assumed once you move outside of Mammalia (and even within mammals I can think of exceptions). Falcons for example have poor binocular vision compared to most predatory mammals, or even hawks and eagles, and this also applies to things like crocodilians.

[@andrewfleenor7459]

The discussion about the eyes made me think: not every change needs to be specifically helpful, it just needs to not be bad enough to out outweigh the benefits that it's carried along with. So if something about the wide head is really useful, the particular mutation that creates that shape carries the eyes with it, and the shark doesn't need its eyes that much, then those eyes get pulled sideways. Or vice versa, if wide binocular vision is super useful, then that might drag other neutral-ish changes with it. With the super wide form being more basal, it does look like something *really weird* happened to select the hammerhead shape, some very specific circumstance that only lasted for a short time, and selective pressure has been pushing them towards "normal" shark shape ever since.

[@LOL-zu1zr]

Sexual selection is arbitrary, as long as there isn’t too high of a fitness drop

[@x1mpressed]

0:43 Sharks, or shark like holocephalin fishes have evolved hammer head like traits before, such as the case with the Devonian Maghriboselache mohamezanei

[@jhonniboii5884]

Eye width on character creation to the max

[@markdombrovan8849]

NEW MOTHLIGHT VIDEO, WOOOOOOO

[@ruperterskin2117]

Right on. Thanks for sharing.

[@dessertstorm7476]

8:50 when he says "neoteny which you can learn about here" is somethign supposed to pop up? Didn't youtube remove this feature years ago? I never get that stuff anymore

[@SHRUGGiExyz]

A shark's basic locomotion reminds me of a pigeon's but sideways: their depth perception is easily increased by the parallax effect of their head movements while in motion, which could definitely make up for the lack of overlap in their binocular vision

[@bobbressi5414]

It is an odd creature in that the rest of its body is in every other way shark like. It seems akin to discovering a new primate with massive horns on its head.

[@acct5910]

interesting topic, would not have guessed the winghead was the most ancestral.

[@nicolasbaker9601]

I've always wondered, thanks

[@stax6092]

Coolest Sharks.

[@SonGoku31213]

Hammerheads are ma favourite kinda sharks! Thanks for uploading and explaining:) I think it's interesting how they got their nostrils further apart and search the ocean's floor like a good boy~ lol. They pretty cool fellas!🦈🔨

[@HermannCortez]

Similar to using a larger coil when metal detecting, The greater the width of the hammer the deeper the shark can sense for prey buried beneath the seabed.

[@althechicken9597]

Let's go! I'm designing a species with a hammer head adaptation

[@maozilla9149]

nice video

[@Nothingness00000-o]

Sharks are my fav predatory fish of the oceans. Hammerheads are amongst my fav sharks.

[@akechijubeimitsuhide]

They look so cool!

[@ehrenloudermilk1053]

They evolved alongside the nailfish.

[@andreibaciu7518]

hammerheads imply the existence of a species they prey upon, the nailfish

[@Dr.Ian-Plect]

...which eats wood

[@PharaohFluidity]

8:43 Looks like it uses its head shape to get under the stinger of the stingray

[@Exist64]

08:35 so what was the original purpose of the structure?

[@riverortiz2505]

Wake up babe, new moth light media just dropped

[@italomorais9424]

Could you make a video about the evolution of eyes? I always found it fascinating.

[@Radio__W]

Hey I have a question about human evolution, especially in regards to our eye placement. This is about what you described, the tendency of predators to have their eyes placed in the front to have better depth perception and prey having them more on the side, to more easily detect a predator. My mother likes to argue that this shows that humans are predators by nature's, since our eyes are very much placed in the front. This does make sense, but I am not too sure that is being a predator caused us to have narrow eyes. I would argue that early (perhaps even pre-) humans (those who had not learned yet to walk bipedal) lived similar to nowaday primates, foraging plant and fruits, and occasionally hunting, but hunting was not their main source of food. This makes them more prey than predator, which is why the eyes should be more on the sides. However, if you a living in a forest and navigate and especially climb and jump through trees, you need very good depth perception for example for hand eye coordination and to judge how you are going to jump. I believe that this, our movement and habitat is the main reason we have our eyes at the front. Of course, once we became more advanced with tools and such made it really easy for us to hunt bigger animals and we became more and more the predators we are today. The difference is, that our eyes were not caused by our behavior, but our eyes made it more easy to adapt this new behaviour. (--> Exaptation). So it's less the question whether we are predators or not, but whether the placement of the eyes can be used as a valid argument in this case. Surely they help, but they have remained the same throughout our change of behavior

[@ucunfoozdme]

All primates have forward-facing eyes because, as you hypothesized, depth perception is extremely important if you're jumping/swimging around forest canopies. Only one modern primate, the tarsier, is carnivorous (as in, most of its nutrition comes from meat, mainly insects and small lizards).

[@DaChimpster]

Love this fella

[@Wnick1996]

Hammerheads are quite fascinating

[@joeshmoe8345]

Thanks

[@Robert399]

8:26 Again, not necessarily. The first animal we classify as a hammerhead may have already had a large cephalofoil but at some point they still evolved from animals without cephalofoils which must have grown bigger over time. Even if the electroreceptors are clustered in the middle, they could've benefited from improved vision.

[@kit-catkaileigh]

I wonder if the hammerhead is an example of a lineage of evolution that may eventually dissapear. It is something that is slowly evolving twards a smaller bonnet shaped head shark.

[@rajarsi6438]

evolution from one species to the next is a joke, aka total nonsense.

[@gallermaez]

Curieusement une mouche a évolué de la mème façon en ce qui concerne l'écartement des yeux : les diopsidae .

[@CG-xb1kh]

Would wider-spaced eyes have been better protection against being blinded by ray barbs?

[@joshuabowen316]

Hammerheads were normal sharks till they smoked that gas station weed.

[@takenname8053]

It would be awesome if we find a Hammerheard fossil

[@OstblockLatina]

2:55 - the numbers on this picture don't ad up - the actual length of the head of the presented specimen is closer to one third of its total body length. And one meter is more than half of 1.9 meter.

[@maxrobinson1504]

Please can you do pufferfish at some point

[@Fredysaurus]

Wake up babe, new moth light media video has dropped And it's about _sharks_

[@hope1575]

You didn't mention that the bonnethead is the only known HERBIVOROUS SHARK. At least, that's what I remember learning about it. I'm gonna have to double check that now

[@ran.glacialis]

What is particular to this shark is that next to it's main food source, crustacean, the bonnethead also eats large quantities of seaweed, which makes it the only known omnivorous shark.

[@Sun-God2]

Please, Could you make a video about what is a Basal Species? A video explaining more about Phylogeny

[@MartinMMeiss-mj6li]

Interesting video. Here's a phrase that caught my attention "...more likely to survive the fossilization process..." Hmmm.

[@themecoptera9258]

Diopsid flies have weird heads as well.

[@deanperkins2091]

Wouldn't more space between the eyes lead to improved depth perception? The closer the eyes are together, the difference between the images decreases, making it harder to determent depth?

[@panyeman2966]

The angle of placement influences depth perception just as much as spacing. The pigeons used as an example have small spacing but outwardly angled eyes. Hence poor depth perception. I posit that the hammerheads eyes angled slightly more inward as the shape evolved, thereby improving depth perception even as spacing increased.

[@Player-pj9kt]

depth perception works because the brain can measure the differences between the two images seen by each eyes. A greater seperation would mean these difference are more pronounced so I would assume it would easier for the shark's brain to perceive depth

[@oddballskull1941]

Was waiting for him to say "as it turns out, it's not even a true shark"

[@drakesmith471]

Lorenzo: “We’re the hammerheads!”🥳🎉

[@axelhenriksson6281]

very interesting video thinks my friend and me

[@williampulfer-melville8536]

Please do a video on the evolution of Hedghogs

[@macdonelldouglas]

Great hammered is just a beautiful gorgeous shark long dorsal fin very rarely reaching 20 feet usually around 15 feet .

[@muscovyducks]

cool vid

[@justdavedoindavestuff3479]

Hammerhead shark "I'm smelling in stereo"😅

[@d.lawrencemiller5755]

3:36 What good would lift do a shark? Don't they have a swim bladder to regulate buoyancy?

[@ni-dirus]

I think it's pretty clear that their eyes need to be far apart so their friends can't make a v shape with their hand's forefinger and middle finger and poke their eyes. It's a lot harder to do that if your eyes are farther apart than your friend's shoulder width