How the Chalicothere Split In Two

  • Publicado el 24 abr 2018
  • Try CuriosityStream today:
    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 tecnologíaCiencia y tecnología

Comentarios • 815

  • doobiesmoke15
    doobiesmoke15 Hace un día

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

  • Antoin Rodrego
    Antoin Rodrego Hace 2 días +1


  • Zei33
    Zei33 Hace 5 días

    Could they have cross bred?

  • Rafael Rubio
    Rafael Rubio Hace 11 días +1

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

  • PattiMichelle Sheaffer
    PattiMichelle Sheaffer Hace 13 días

    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 14 días

    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 15 días

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

  • Jora
    Jora Hace 17 días

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

  • Harsh Jadav
    Harsh Jadav Hace 18 días

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

  • Xavier Lapis
    Xavier Lapis Hace 19 días

    When the ark dossiers aren't enough

  • The_Jedi_ Priestess
    The_Jedi_ Priestess Hace 22 días

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

  • Eyre Death Borne
    Eyre Death Borne Hace 23 días

    Some video ideas which would be awesome and interesting.
    Largest Land mammal ever.
    History of Rhinos.
    History of the big cats.
    Ancient big cats.
    Apex sea reptiles. Mosasaurs, Pliosauroidea, etc.

  • Hector Valade
    Hector Valade Hace 23 días

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

  • Oswards306 Oswards306
    Oswards306 Oswards306 Hace 24 días

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

  • Timothy Beckett
    Timothy Beckett Hace 25 días

    Where did each type succeed in the world?

  • Timothy Beckett
    Timothy Beckett Hace 25 días

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

  • tembofly
    tembofly Hace 28 días

    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 29 días

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

  • Avatrass
    Avatrass Hace un mes

    How do you like that silver!

  • Organ Farm
    Organ Farm Hace un mes

    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 un mes

    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 un mes

    Damn earth killing off gorilla horses

  • Orbit Noah
    Orbit Noah Hace un mes

    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 un mes

    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 un mes

    "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 un mes

    Please cover Andrewsarchus

  • TheLiberalMachine
    TheLiberalMachine Hace un mes

    The more I learn about evolution. The more fantastical it sounds. Hard to believe. Like where did all these "new" animals come from? And why is this being taught in our schools as a fact? This is just a theory!

  • George Andrews
    George Andrews Hace un mes

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

  • Mike Zam
    Mike Zam Hace un mes

    could you cover the relationship of evolution and complexity theory

  • Pup314
    Pup314 Hace un mes

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

  • Brett Himeda
    Brett Himeda Hace un mes

    Are horses and rhinos branched from early Chalicotheres then?

  • smol mean trans wife
    smol mean trans wife Hace un mes

    Perissodactyls are really strange frogs.

  • ricofresh22
    ricofresh22 Hace un mes

    Rhinos walking on their knuckles that’s very intrigue I’d say!!!!!

  • Jon Laughlin
    Jon Laughlin Hace un mes

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

  • Toughen Up, Fluffy
    Toughen Up, Fluffy Hace un mes

    You're spelling it wrong, it's schizotheriinae, like in schizophrenia. It comes from the Gk root, schizo- 'to split, cleave.'

  • 1Caff1
    1Caff1 Hace un mes

    Why do they look like paracertherium?

  • S B
    S B Hace un mes


  • 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 un mes

    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 un mes

    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 un mes

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

  • Andreas Haase
    Andreas Haase Hace un mes

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

  • Arceus Lord of Creation
    Arceus Lord of Creation Hace un mes +1

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

  • Ishbart Gonzalez
    Ishbart Gonzalez Hace un mes

    Another great video!

  • yohopirate
    yohopirate Hace 2 meses

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

  • Marco Coelho
    Marco Coelho Hace 2 meses

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

  • Deloxo
    Deloxo Hace 2 meses

    You didn’t mention how terrifying a chalicotherium is when you anger it! Jk i’m referencing ARK

  • Fatima Huseynli
    Fatima Huseynli Hace 2 meses

    I love this guy 💓

  • Bryce Vlogs
    Bryce Vlogs Hace 2 meses

    They look like horses on steroids.

  • Astrostevo
    Astrostevo Hace 2 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 2 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 2 meses

    The thumbnail is me eating with my 5'2 friend


    Imagine riding a tylocephalonyx

  • Diego Ochoa
    Diego Ochoa Hace 2 meses

    Primate like horse cat?

  • Sergey Gorski
    Sergey Gorski Hace 2 meses

    Calicotheres look like giant ground sloths.

  • Bill Kotsarinis
    Bill Kotsarinis Hace 2 meses +1

    sory shizerotheriinae

  • Bill Kotsarinis
    Bill Kotsarinis Hace 2 meses +1

    is toxodon one of the long neck halicoferian

  • TransHailey
    TransHailey Hace 2 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 2 meses

    I thought it was kal-ih-koe-there

  • TheMadTitan666 Black Order

    This is why I love Ark.

  • tty23
    tty23 Hace 2 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 2 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 2 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 2 meses

    do a video like this on cows vs buffalo. pls

  • El topo Brujo
    El topo Brujo Hace 2 meses

    I hear hank i like

  • kyle ford
    kyle ford Hace 2 meses

    i like to know about salt water amphibians

  • Judicial78
    Judicial78 Hace 2 meses

    Domes are for ramming trees to knock fruit down.

  • Jerome Man
    Jerome Man Hace 2 meses

    What are you talking about?! Horses and rinos. Thats the ancient sloth you fools.

  • RichCommander
    RichCommander Hace 2 meses

    Please do a video about the evolution of manatees

  • Kyle Cappo
    Kyle Cappo Hace 2 meses

    How did giant sloths and tree sloths diverge?

  • milxl
    milxl Hace 2 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 2 meses

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

  • Matt Parker
    Matt Parker Hace 3 meses

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

  • Matt Parker
    Matt Parker Hace 3 meses

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

  • Heru Setiawan
    Heru Setiawan Hace 3 meses

    Well talking about splitting.
    Look at dogs.

  • Keys879
    Keys879 Hace 3 meses

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

  • pizza 4breakfast
    pizza 4breakfast Hace 3 meses +1

    Long-armed knuckle-walker, my new favorite insult

  • vin 950
    vin 950 Hace 3 meses +1

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

  • God Of War
    God Of War Hace 3 meses

    Evolution is key to our survival

  • luciables
    luciables Hace 3 meses

    Cooooool!! Can you also do a video on rumens and the mammals that have four stomachs and how that came to be? Is there already one?

  • Comic Book Guy
    Comic Book Guy Hace 3 meses

    So how the heck did ancestor of deer, cattle, hippos, etc evolve four stomachs? How do you go from one stomach to four, in small increments of mutational change which, in themselves, aren't really advantageous?

    • worfoz
      worfoz Hace 3 meses +1

      It's more like the stomach decided into four compartments.
      But now having these ruminants is a huge is advantage because they produce huge amounts of greenhouse gas.
      They should be outlawed.

  • Bmh
    Bmh Hace 3 meses


  • cacadodo666
    cacadodo666 Hace 3 meses

    'How the Chalicothere MIGHT HAVE Split In Two'

  • Decembirth
    Decembirth Hace 3 meses

    Honestly thought this would be about trees.

  • C B
    C B Hace 3 meses

    Hank, I'm confused. Did the Chalicos die out, while horses and rhinos, which existed cotemporaly with Chalicos, carried on in their place? (This seems to be what your closing remarks imply.) Or did the Chalicos evolve into horses (one strain) and rhinos (the other strain)? If the latter, then why use the phrase "they couldn't survive"? They did survive, but only the horsey or rhino-y ones, didn't they? Evolution did "get them out of" their situation (i.e. changing habitat). Am I missing something?

  • GhostlyGhille
    GhostlyGhille Hace 3 meses +1

    This show deserves primetime spotlight, not reality show B's. Not even discovery channel teaches anymore.

  • Shin Nightwood
    Shin Nightwood Hace 3 meses

    Did these two types interbred?

  • 5chr4pn3ll
    5chr4pn3ll Hace 3 meses

    These are really good videos. Great balance of accessibility and information, if only the videos were longer

  • Rebecca Conn
    Rebecca Conn Hace 3 meses

    What about urbanization such that human beings do not know what is edible in their own environment?

  • Marcel Klein
    Marcel Klein Hace 3 meses

    Do an episode about Andrewsarchus, an enormous carnivorous pig that looked like a wolf but was bigger than a bear.

  • Robert Chavez
    Robert Chavez Hace 3 meses

    Humans are specialized in depending on electricity and our technology let's see how long we last

  • Sharof S.
    Sharof S. Hace 3 meses

    So, they should have evolved their intestines instead of developing claws?

  • Ariana Negron
    Ariana Negron Hace 3 meses +1

    i love eons and might consider the things that sponsor it
    but too bad im a poor american college student

  • The Mr. Jones Show
    The Mr. Jones Show Hace 4 meses

    I'm here because I was looking up how to tame a Chalico in Ark

  • Conrado Javier
    Conrado Javier Hace 4 meses

    My Little Ponilla.

  • luke towner
    luke towner Hace 4 meses

    This guy reminds me of Paul Gilbert.

  • Derrick Bonsell
    Derrick Bonsell Hace 4 meses

    People always forget the poor Tapir.

  • HenryManson
    HenryManson Hace 4 meses

    someone had to say it:
    Life finds a way!ídeo.html

  • Bold - Spirit
    Bold - Spirit Hace 4 meses

    that's mean it is possible to find unecorn.

  • Deepmalya Chakraborty
    Deepmalya Chakraborty Hace 4 meses

    Sir the reason they probably got bigger acc to me is because of gymnosperms like sequoia trees which were demandind that kind of height to exploit their leaves.
    When angiosperms came and almost wiped out the giagantic trees the larger dinos were starved to death.
    I think if angiosperms were toxic to dinos as presently vegetarian reptiles are still very very rare.