What IS a Horn? - Animals That Don't Really Have Horns
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- Опубликовано: 1 июл 2024
- Some animals have AMAZING horns. Other animals have things that LOOK like horns, but are not. Let's explore the diversity of animals and find out which ones have horns, and which ones do not. Please subscribe to continue learning what makes life AWESOME: BioBush.tv/subscribe
True horns have a very specific defintion. The American Heritage Science Dictionary defines a horn as, "Either of the bony growths projecting from the upper part of the head of certain hoofed mammals, such as cattle, sheep, and goats. The horns of these animals are never shed, and they consist of bone covered by keratin."
That seems very oddly specific compared to the way we use horn in normal language, which is "something that looks like a horn".
By going through a series of animals that break the "rules" in different ways, we will learn how that definition was made, and gain a new appreciation for the diversity of life.
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Copyright
Photo "Pavón o Guan Cornudo" by Roberto González, via Flickr (www.flickr.com/photos/6910903.... Used under Creative Commons cc-by 2.0.
Photo "Rhinoceros Hornbill nipping a peanut" by Thomas Quine, via Flickr (www.flickr.com/photos/quinet/.... Used under Creative Commons cc-by 2.0.
Photo "Rhinoceros Hornbill" by Steve Wilson, via Flickr (www.flickr.com/photos/pokerbr.... Used under Creative Commons cc-by 2.0.
Video "コンゴウフグ Longhorn cowfish Lactoria cornuta" by Sasuke Tsujita ( • コンゴウフグ Longhorn cowfis... ). Used under Creative Commons cc-by 3.0.
Video "Horned Screamers Loud" by Chingana ( • Horned Screamers Loud ). Used under Creative Commons cc-by 3.0.
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If the horned owl’s “horns” were considered real horns, I’d have a bunch of horns after I wake up everyday. What an odd topic
Oh, yeah. Hair is keratin too. And horns are actually derived from hair in some way I don't understand. So you probably have more claim to having horns than the Great Horned Owl does. This topic took me by surprise too. I thought it was a relatively simple concept, but it just kept getting more complex. Thanks for watching!
I like how you brought casques into this discussion of horns, really interesting. Also love you talked about scientific vs common language, like the gull vs seagull debate.
Hi JJ! Casques are definitely horns in every way that matters to an animal. They are not derived from hair, and they are not on hoofed mammals. But it is a good demonstration of how hard it is to classify living things; even a simple question gets complicated by exceptions and edge cases. I'm not a fan of telling people that they are wrong because they have not learned specialized vocabulary yet. If enough meaning is conveyed for the context, then language has succeeded.
PS - The "true bugs are Hemipterans" is one that I rebel against, because it kills sentences. Instead of "blackbirds eat snails, worms, insects, and other invertebrates" I say "blackbirds eat bugs".
Very informative. Tq
You're welcome, Virupaksha! This reminded me that there is still so much out there to learn. I appreciate you watching again this week!
Never really thought about it. Interesting.
Hi James! Animals are so good at breaking our categories, and maybe that's the biggest lesson here. I'm glad you found it interesting. There are a few more general biology ones coming up. Thanks for watching!
Nice video!
Thank you, Wallace! Living things resist our efforts to classify them. They just do whatever works. :) I'm glad you liked this video. Thanks for watching!
Pronghorns are a weird of in between only branched horn that is shed. a thing of their own. Very unique!!!
I was playing monster hunter and fought nergigante, a monster covered in horns. Starting thinking: "by the way what the hell are horns??" found your video. Good content.
That is such a good story, Tezra. And now we both know the answer, which is that Nergigante is a dragon, so no horns, but it obviously has tons of horns. It's awesome that you're willing to look up that kind of information! Thanks for watching!
Eliminating the “hoofed mammals” criterion, you would still have a pretty good definition of a horn.
I would like the definition to change that way! There's no reason to say a Cassowary doesn't have a horn. Or change it from "some hoofed mammals" to "derived from hair" or an actual physical trait, if it needs to stay an exclusive club. Thanks for your help in error correction while making this!
What stops horned lizards from having horns?
@@marcopohl4875 They aren't hoofed mammals, which is what Vernon is pointing out, that it's unnecessarily restrictive.
@@marcopohl4875 They’re not ungulates (hoofed mammals). That’s my point; if the “hoofed mammal” part were removed, you could include hornbills, cassowaries, and yes, horned lizards, in the list of animals that have horns. To my, there’s really nothing wrong with saying that horned lizards and hornbills have horns, but that rhinos and pronghorns don’t.
A great 'horn' for thought video! I've erroneously been thinking antlers are technically horns all this time!
Hi Koaw! I had a vague idea going into researching this that there was a difference, but I thought the boundaries would be clear and informative. Instead, living things make a mockery of our attempts to put things in neat categories. That IS part of the appeal of living things though, that there is always an exception or surprise waiting! Thanks for watching again this week!
Pecorans are selenodont even-toed hoofed mammals that constitute the infraorder Pecora, all pecorans possess cranial weaponry, a feature not seen in any other mammal, pecorans first appeared during the Eocene, there are four extant families of pecorans within three superfamilies, the superfamilies are Giraffoidea, Cervoidea, and Bovoidea, the latter two are monotypic as they both contain a single extant family being Cervidae (Deer) and Bovidae (Bovids) respectively, whereas Giraffoidea, which is the most basal superfamily of pecorans has two extant families being Antilocapridae (Pronghorn and Fossil Relatives) and Giraffidae (Giraffes and Okapi), pecorans share a more recent common ancestor with the tylopods (infraorder Tylopoda) during the Eocene, the split between the infraorders Pecora and Tylopoda is more derived than the other two main lineages of the suborder Selenodontia, which are Tragulina and Ceratodonta, Tragulina contains a single extant superfamily being Traguloidea, which has a single extant family being Tragulidae (Chevrotains), whereas Ceratodonta contains two extant families being Hydropotidae (Water Deer and Fossil Relatives) and Moschidae (Musk Deer and Fossil Relatives), both under the superfamily Moschoidea, which is the sole extant taxon of the Ceratodonta infraorder.
Hi Indy! Wow, that's a lot of information. I'm glad there are taxonomists doing this type of work to help classify the complexity of Life. Thank you for sharing your knowledge!
Yay for convoluted journey! Haha that’s my life summed up!
Hi KittyKissedBiscuits! Topics that require a convoluted explanation are some of the most fun topics. So maybe a convoluted life journey is the most fun life! Thanks for watching again this week!
Great vid
Thank you, McCoy! There are so many amazing things to learn about animals. Thank you for watching!
Hello BioBush, i've stumbled on this video due to my own research regarding Triceratops. So i was wondering wether or not such prehistoric animals can also classify into having horns? since triceratops specifically, along with other ceratopsians fit the criteria of having a permanent, bony core sorrounded by a keratin sheath. However they aren't mammals, nor hoofed.
Hi Dtomis! I'm glad you found this video helpful. By the current definition, they would have horns in the English definition sense, but not the biological sense. But Rhino horns are also called horns even though they don't match that definition. I kind of wish Triceratops existed today, because we would probably have a better definition of horns. If you ask me, I say call them horns because absolutely everyone will know what you're talking about. Thank you for watching!
the dictionary definition provided excludes the ceratopsians, the horned dinosaurs. this is what we call a taxonomy fail
Hi Dave! That was one of my questions. Did Ceratopsians have keratin covers on their horns? The bony core is obvious on Triceratops, but I could not find a definite answer about the covering. If yes, then excluding an animal covered in horns is not a very good definition. Thanks for watching!
@@BioBush from what I can tell they almost certainly had keratin sheaths covering their horns, just based on the texture of the bones, as well as that most reptiles have keratin coverings on things like that. also thanks for posting
@@BioBush on the cassowary/hornbill question, I think part of why it feels strange to call them horns is their low density. perhaps being dense should be part of the definition too
That is so cool! So yes, the horn definition should definitely change to drop hoofed mammals, because Triceratops should have horns! Maybe add horn density to exclude casques? I still feel like any hard line we try to draw (eg. dense/not dense), living things will still exist on a spectrum and be more complicated than our classification schemes. Thanks for sharing your knowledge, Dave!
Just because you guys are clasifying something as not horn it dosen't mean it isn't
"teeth aren't bones" what? xD
Yeah, I was surprised as well. They both have calcium phosphate to make them hard, but bones are mostly living tissue that can regrow, and teeth are mostly inorganic minerals that cannot regrow. They are different enough that teeth are not classified as bones, which further supports this video's thesis that "living things are complicated to classify". Thanks for watching, Naybla!
@@BioBush thank you for explaining! :)
@@BioBush You are forgetting that some teeth CAN regrow. Sharks, crocodilians, rodents, etc.
Nice vid my guy👍
Thanks for the kind words, Sid! There are so many interesting things out there, and living things resist classification. We're never going to run out of things to learn!
Thanks for watching!