How the Chalicothere Split In Two

  • Publicado el 24 abr 2018
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    Two extinct relatives of horses and rhinos are closely related to each other but have strikingly different body plans. How did two of the same kind of animal, living in the same place, end up looking so different?
    Thanks to Ceri Thomas for the very cool Anisodon reconstruction. Check out more of Ceri's paleoart at and
    And thanks as always to Nobumichi Tamura for allowing us to use his wonderful paleoart:
    Finally, thanks to Dmitry Bogdanov, Roman Uchytel, Ryan Somma and Julio Lacerda for their excellent images as well.
    Produced in collaboration with PBS Digital Studios:
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    Prothero, D. R., & Schoch, R. M. (1989). The evolution of perissodactyls (Vol. 15). Oxford University Press, USA.
    Peters, N., & de Vos, J. (2012). First evidence of a chalicothere (Mammalia, Perissodactyla) in The Netherlands. Cainozoic research, 9(2), 141-144.
    Clauss, M., Frey, R., Kiefer, B., Lechner-Doll, M., Loehlein, W., Polster, C., ... & Streich, W. J. (2003). The maximum attainable body size of herbivorous mammals: morphophysiological constraints on foregut, and adaptations of hindgut fermenters. Oecologia, 136(1), 14-27.
    Heaney, L. R. (1991). A synopsis of climatic and vegetational change in Southeast Asia. In Tropical Forests and Climate (pp. 53-61). Springer, Dordrecht.
    Churcher, C. S. (2014). A vacant niche? The curious distributions of African Perissodactyla. Transactions of the Royal Society of South Africa, 69(1), 1-8.
    Werdelin, L., & Sanders, W. J. (2010). Cenozoic mammals of Africa. Univ of California Press.
    Colbert, H. (1935). Distributional and phylogenetic studies on Indian fossil mammals. III. A classification of the Chalicotherioidea. In American Museum Novitates.
    Bai, B., Wang, Y., & Meng, J. (2011). Early Eocene chalicothere Litolophus with hoof-like unguals. Journal of Vertebrate Paleontology, 31(6), 1387-1391.
    Peterson, O. A. (1907). Preliminary notes on some American chalicotheres. The American Naturalist, 41(492), 733-752.
    Munthe, J., & Coombs, M. C. (1979). Miocene dome-skulled chalicotheres (Mammalia, Perissodactyla) from the western United States: a preliminary discussion of a bizarre structure. Journal of Paleontology, 77-91.
    Janis, C. M., Scott, K. M., & Jacobs, L. L. (Eds.). (1998). Evolution of tertiary mammals of North America: Volume 1, terrestrial carnivores, ungulates, and ungulate like mammals (Vol. 1). Cambridge University Press.
    Coombs, M. C., & Rothschild, B. M. (1999). Phalangeal fusion in schizotheriine chalicotheres (Mammalia, Perissodactyla). Journal of Paleontology, 73(4), 682-690.
    Coombs, M. C., Hunt Jr, R. M., Stepleton, E., ALBRIGHT III, L. B., & Fremd, T. J. (2001). Stratigraphy, chronology, biogeography, and taxonomy of early Miocene small chalicotheres in North America. Journal of Vertebrate Paleontology, 21(3), 607-620.
    Coombs, M. C. (1979). Tylocephalonyx, a new genus of North American dome-skulled chalicotheres (Mammalia, Perissodactyla). Bulletin of the AMNH; v. 164, article 1.
    Coombs, M. C. (1975). Sexual dimorphism in chalicotheres (Mammalia, Perissodactyla). Systematic Biology, 24(1), 55-62.
    Semprebon, G. M., Sise, P. J., & Coombs, M. C. (2011). Potential bark and fruit browsing as revealed by stereomicrowear analysis of the peculiar clawed herbivores known as chalicotheres (Perissodactyla, Chalicotherioidea). Journal of Mammalian Evolution, 18(1), 33-55.
    Zapfe, H. 1976. "Die Fauna der miozanen Spaltenfiillung von Neudorf a. d. March (CSSR). Chalicotherium grande (Blv.)." Sitzungsberichte Osterreich Akad. Wissenschaften, Math.-na-turwiss. Klasse (Abt. I) 185: 91-112.
    Zapf 1979. "Chalicotherium grande (Blainv.) aus der miozanen Spaltenfiillung von Neudorf an der March (Devinska Nova Ves), Tschechoslowakei." Neue Denkschriften Naturhist. Mus. Wien 2: 1-282. Zhou, Mingzhun, Yu
    Munthe, J., & Coombs, M. C. (1979). Miocene dome-skulled chalicotheres (Mammalia, Perissodactyla) from the western United States: a preliminary discussion of a bizarre structure. Journal of Paleontology, 77-91.
    Wunderlich, R. E., and W. L. Jungers. "Manual digital pressures during knuckle-walking in chimpanzees (Pan troglodytes)." American journal of physical anthropology 139.3 (2009): 394-403.
  • Ciencia y tecnolog铆aCiencia y tecnolog铆a

Comentarios • 869

  • Jhon Jerome Satairapan
    Jhon Jerome Satairapan Hace 7 d铆as

    Giraffidae next.

  • Mesozoic Studios
    Mesozoic Studios Hace 11 d铆as

    Pachycephalosaurus horse lol xd馃槀馃槀馃槀馃槀

  • Alejandro Rodolfo Mendez
    Alejandro Rodolfo Mendez Hace 14 d铆as

    you know this video is prove further that the rhynos are the supposed unicorns, horses relative with one corn.

  • Pad Carr
    Pad Carr Hace 15 d铆as

    Eloi and Morloks...

  • LO2L
    LO2L Hace 15 d铆as

    These were beasts of burden in the time travel trilogy "The Saga of the Exiles". Great books set in the Pliocene

  • Allan Richardson
    Allan Richardson Hace 18 d铆as

    Klingon horses maybe? 馃槣

  • Henry Law
    Henry Law Hace 23 d铆as

    Could that dome on the head have been a resonator to amplify their calls?

  • Digicraftmon the Crystal Gem
    Digicraftmon the Crystal Gem Hace 25 d铆as +1 this animal had also been a threat to trilobites and they were the ones who left the infamous 'W' shaped bite.

  • Walrus Latte
    Walrus Latte Hace 25 d铆as

    if the last ancestors were still around one million years ago that means prehistoric humans might have interacted with them 馃槏

  • Emma Dalby
    Emma Dalby Hace 29 d铆as

    So cows killed the unicorns, got it

  • Kansa City Shuffle
    Kansa City Shuffle Hace un mes

    The answer is the daily double

  • Meg Meg
    Meg Meg Hace un mes +1

    I like the horse gorilla

    • Meg Meg
      Meg Meg Hace un mes

      Now I like the horse cat

  • The Jackass Linguist
    The Jackass Linguist Hace un mes

    Does Tylocephalonyx evolve into Tylocephasteelix?

  • Jawbreaker The Hyaenodon

    Imagine if these guys never died out

  • Erin OBrien
    Erin OBrien Hace un mes

    I would like to see something on hummingbird evolution. I know they're specialized, but from where did their brilliant colours, their abilities to fly upside down, backwards, etc, and their other abilities come? What did their ancestors look like? Thanks so much for all of the great videos!!

  • Efrain DT
    Efrain DT Hace un mes

    馃悗wait cousin!馃

  • Pay Pal
    Pay Pal Hace un mes

    I thought it was a video about a mammal doing binary fission.......

  • KR P
    KR P Hace un mes

    They seem to be saying it was sympatric speciation but haven't said why they believe that.
    Animal sympatric speciation is pretty sketchy and ascribing it to long extinct animals is pretty dodgy.

  • Harley Fagan
    Harley Fagan Hace un mes

    5:50 had me dead 馃槀

  • Lute The Mage
    Lute The Mage Hace un mes

    Glyptodons! Megatherium! Giant ducks! Moa! Diprotodon! More videos about them pls. Literally until humans arrived - there were so many cool species. It鈥檚 so sad that we can鈥檛 ever see them again.

  • mrtonyd816
    mrtonyd816 Hace 2 meses

    I didn鈥檛 like him in 鈥渃racked鈥. He鈥檚 not any better here.

  • OfficeShani
    OfficeShani Hace 2 meses

    Giant rhino horse with cat thingies

  • Trigger Happy
    Trigger Happy Hace 2 meses

    Uuuum.... Cattle?

  • upcoast
    upcoast Hace 2 meses

    Fruits on trees.
    The head was to bump the trees.
    That's my guess.
    One still ate leaves the other ate more fruits.

  • thomassaurus
    thomassaurus Hace 2 meses

    What... why do I get nothing when I google shizerotheriinae?

  • rekkovi
    rekkovi Hace 2 meses

    I still don鈥檛 understand how they completely split if they lived in the same area. Wouldn鈥檛 the long necked and long armed ones still have reproduced and created one new species instead of two? Or ddi I misunderstand and they actually didn鈥檛 live in the same territory?

  • doobiesmoke15
    doobiesmoke15 Hace 2 meses

    How will our modern day horses look in 55 Million years?

  • Antoin Rodrego
    Antoin Rodrego Hace 2 meses +1


  • Zei33
    Zei33 Hace 2 meses

    Could they have cross bred?

  • Rafael Rubio
    Rafael Rubio Hace 3 meses +1

    Ilove this channel, so informative and at the same time fun to watch.

  • PattiMichelle Sheaffer
    PattiMichelle Sheaffer Hace 3 meses

    As long as you're discussing extinction of these species, you probably should mention how lifespans of species vary in general; origin -> extinction. It's very common that evolution "fails" (although that's an anthropomorphism) and species go extinct.

  • themarquess
    themarquess Hace 3 meses

    I have to say, I really don't understand evolution and I wish someone explained it to me. If the evolutionary differences between two generations are too miniscule to notice, how can they have an impact on survival and lead to selective breeding? Take a non-venomous snake, that evolves to look exactly like a dangerous snake, so that predators don't attack it. This trait wouldn't have any impact on survival until it's fully evolved. A snake that's sort of on the way to looking like the venomous one, but has all the colours and patterns all wrong, won't have a better chance at survival. So how does such a trait continue evolving in an incremental manner over generations?

  • KTo288
    KTo288 Hace 3 meses

    Any chance of an episode on convergent evolutuon, it would make a good companion to this one.

  • Jora
    Jora Hace 3 meses

    That Chalicotherium explains where CD Projekt got their inspiration for the fiend in The Witcher 3...

  • Harsh Jadav
    Harsh Jadav Hace 3 meses

    Nice but can you tell me how can I interact more with you guys馃憤

  • Xavier Lapis
    Xavier Lapis Hace 3 meses

    When the ark dossiers aren't enough

  • The_Jedi_ Priestess
    The_Jedi_ Priestess Hace 3 meses

    Parallel Evoollutiionnn I love this guy, he covers it ALL 馃槏

  • Hector Valade
    Hector Valade Hace 3 meses

    Could you do sloth evolution? plz///////:)

  • Oswards306 Oswards306
    Oswards306 Oswards306 Hace 3 meses

    I wonder what the chalicotheres would look like if they survive to our modern times.

  • Timothy Beckett
    Timothy Beckett Hace 3 meses

    Where did each type succeed in the world?

  • Timothy Beckett
    Timothy Beckett Hace 3 meses

    Is there genetic evidence to prove the 2 creatures are related?

  • tembofly
    tembofly Hace 3 meses

    They would not likely have speciated (diverged) in each other's presence. There must have been a separation for this to occur.

  • luciferangelica
    luciferangelica Hace 3 meses

    didn't watch it yet. my guess is an axe

  • Avatrass
    Avatrass Hace 3 meses

    How do you like that silver!

  • Organ Farm
    Organ Farm Hace 3 meses

    If they both occupied the same places at the same times there must have been something that stopped them cross-mating or they would never have developed such enormous differences. Perhaps it was something like a chromosome mutation.

  • Kerian Halcyon
    Kerian Halcyon Hace 3 meses

    The only issue I have with this explanation for chalicotheres is that its body structure doesn't appear to fit. The arms are incredibly long, got that...but so is the neck, and the upper part of the body, so why bother wasting energy reaching for limbs to bring closer to your mouth when you can already reach it by just standing? And if it was to break branches off of the trees and pull them to the ground, it's already physically very top-oriented, so having to bend those forelimbs to get at the food would be awkward and difficult. The claws don't appear opposable, so gripping branches must have been a challenge...
    There has got to be another reason why these animals look the way they do, but I think the current accepted explanation is kind of...pardon the pun..."reaching."

  • Necrodermis
    Necrodermis Hace 3 meses

    Damn earth killing off gorilla horses

  • Noah
    Noah Hace 3 meses

    But if they were evolving in the same place and were technically the same species while the process began, wouldn't they be breeding with one another either negating the extremes or giving them all both long necks and long arms? I'm sorry if I sound ignorant, but there seems to be a giant hole in your explanation of parallel evolution.

  • Cyrus Hale
    Cyrus Hale Hace 3 meses

    So you are saying the hump header one is what turned into the horse and the lanky one turned into the rhinoceros? Okay, now I'm confused.

  • Shaun Earsom
    Shaun Earsom Hace 3 meses

    "There are some things that evolution just can't get you out of" Maybe that's why we developed brains and tools?

  • Andre Prawardana
    Andre Prawardana Hace 3 meses

    Please cover Andrewsarchus

  • George Andrews
    George Andrews Hace 3 meses

    Split in two? I bet they "AXED" for it :o)

  • Mike Zam
    Mike Zam Hace 3 meses

    could you cover the relationship of evolution and complexity theory

  • Pup314
    Pup314 Hace 4 meses

    The larger ones with the claws and knuckle walking remind me of the giant ground sloths.

  • Brett Himeda
    Brett Himeda Hace 4 meses

    Are horses and rhinos branched from early Chalicotheres then?

  • smol mean trans wife
    smol mean trans wife Hace 4 meses

    Perissodactyls are really strange frogs.

  • ricofresh22
    ricofresh22 Hace 4 meses

    Rhinos walking on their knuckles that鈥檚 very intrigue I鈥檇 say!!!!!

  • Jon Laughlin
    Jon Laughlin Hace 4 meses

    I'd say bears and ground sloths put them out of business.

  • 1Caff1
    1Caff1 Hace 4 meses

    Why do they look like paracertherium?

  • S B
    S B Hace 4 meses


  • NexusDarkworldProductions

    I might be bad at remembering names and terms, but it's rare to watch one of these that I know nothing about. Good job.

  • Dennis
    Dennis Hace 4 meses

    I would like to see more about whales and more whales plus those pesky seals. And it would be great to see more about early plant evolution. And/or just what's new in modern evolution science theory, like is punctuated evolution still a thing or something along the lines of how speciation happens and what is speciation precisely. One more idea, it would be very interesting to get your guys thoughts about the idea's proposed in the PBS series "The Botany of Desire" what I found very interesting was how the series basically took the perspective of what was best for the plants and how plants influenced and 'manipulated' or acquiesced the desirers of the environment around them to spread their gene pool.

    MICHAEL GOLD Hace 4 meses

    I wonder what shizerotheres used their claws for. Maybe protection or to mark trees the way tigers do. It's really a shame that the calicotheres died out a mere 1 million years ago. They were such cool animals, especially the long armed ones.

  • Charles Feigin
    Charles Feigin Hace 4 meses

    What you're describing is divergent evolution, not parallel evolution.

  • Mango Loewe
    Mango Loewe Hace 4 meses

    leopards and lions share the same habitat and are different species too ;)

  • Arceus Lord of Creation
    Arceus Lord of Creation Hace 4 meses +1

    Long-necked horses...or short-necked giraffes?

  • Ishbart Gonzalez
    Ishbart Gonzalez Hace 4 meses

    Another great video!

  • yohopirate
    yohopirate Hace 4 meses

    Love the supporting graphics, is there anywhere to see more like the 'Eocene epoch' at 1:37

  • Marco Coelho
    Marco Coelho Hace 4 meses

    Any chance the Chalicothere were extinct due to hunting by our ancestors, like the Siberian Mammoth?

  • Deloxo
    Deloxo Hace 4 meses

    You didn鈥檛 mention how terrifying a chalicotherium is when you anger it! Jk i鈥檓 referencing ARK

  • Fatima Huseynli
    Fatima Huseynli Hace 4 meses

    I love this guy 馃挀

  • Bryce Vlogs
    Bryce Vlogs Hace 4 meses

    They look like horses on steroids.

  • Astrostevo
    Astrostevo Hace 5 meses

    Why are you pronouncing it "Ka-lick-othere"" when its spelt with a "Ch" like cheese or chives? Shouldn't it be said, "Cha-lick-o-there?" Puzzled.
    Otherwise, fascinating, informative, great clip - thanks.

    • Karma Arachnid
      Karma Arachnid Hace 4 meses

      I believe it's because the roots of the the word chalicothere are Greek. Think about how "ch" is pronounced in other words with Greek origin like chiropractor or archaeologist.

  • Salutations Human!
    Salutations Human! Hace 5 meses

    The thumbnail is me eating with my 5'2 friend

  • 膼脝脩脰R漠艆 艢虐脴艠沤茝脩脝M女艩

    Imagine riding a tylocephalonyx

  • Diego Ochoa
    Diego Ochoa Hace 5 meses

    Primate like horse cat?

  • Sergey Gorski
    Sergey Gorski Hace 5 meses

    Calicotheres look like giant ground sloths.

  • Bill Kotsarinis
    Bill Kotsarinis Hace 5 meses +1

    sory shizerotheriinae

  • Bill Kotsarinis
    Bill Kotsarinis Hace 5 meses +1

    is toxodon one of the long neck halicoferian

  • TransHailey
    TransHailey Hace 5 meses

    So then why do we have giraffes but no animals that just pull the tree down today? I know I'd love to see that

  • Anonymous Mouse
    Anonymous Mouse Hace 5 meses

    I thought it was kal-ih-koe-there

  • El Papi Diablo
    El Papi Diablo Hace 5 meses

    This is why I love Ark.

  • tty23
    tty23 Hace 5 meses

    I feel like this is what's going to happen to republicans and democrats... ones going to develop long necks to look down on others, the others long hands to take hand outs and point fingers.

  • Breeze Cardenas
    Breeze Cardenas Hace 5 meses

    Another video suggestion for PBS : EONS ... How did the Tiger get it's stripes? Or how did the Lion get it's Mane?

  • cherubin7th
    cherubin7th Hace 5 meses +2

    Why didn't both groups not mix before they became two species? I mean I understand if they lived at different places, but at the same place but did not mix? Doesn't make any sense to me.

  • Fantastic Yeast
    Fantastic Yeast Hace 5 meses

    do a video like this on cows vs buffalo. pls

  • El topo Brujo
    El topo Brujo Hace 5 meses

    I hear hank i like

  • kyle ford
    kyle ford Hace 5 meses

    i like to know about salt water amphibians

  • RichCommander
    RichCommander Hace 5 meses

    Please do a video about the evolution of manatees

  • Kyle Cappo
    Kyle Cappo Hace 5 meses

    How did giant sloths and tree sloths diverge?

  • milxl
    milxl Hace 5 meses

    i don't like that "bluring" effect of some of the pictures
    it does not make sens

  • alessandro trimboli pitterman

    love your videos!! would it be possible to cover the evolution of horses ???

  • LightsCamera Ashley
    LightsCamera Ashley Hace 5 meses

    Kinda like what happened with humans right? We come in variety

  • Matt Parker
    Matt Parker Hace 5 meses

    I鈥檇 love to hear more about life right after the major extinction events. What survived and why?

  • Matt Parker
    Matt Parker Hace 5 meses

    Finally some talk about perissodactyls and they just barely mention my favorite extant animals: the tapirs.

  • Heru Setiawan
    Heru Setiawan Hace 5 meses

    Well talking about splitting.
    Look at dogs.

  • Keys879
    Keys879 Hace 5 meses

    All I can think while watching this is: "Damn, Spore could have been so cool..."

  • pizza 4breakfast
    pizza 4breakfast Hace 5 meses +1

    Long-armed knuckle-walker, my new favorite insult

  • vin 950
    vin 950 Hace 6 meses +1

    but why didn't each type reproduce together? Was there an eventual geographical split?

  • God Of War
    God Of War Hace 6 meses

    Evolution is key to our survival