How Sloths Went From the Seas to the Trees

  • Published: 29 November 2018
  • The story of sloths is one of astounding ecological variability, with some foraging in the seas, others living underground, and others still hiding from predators in towering cliffs. So why are their only living relatives in the trees?

    Thanks to Ceri Thomas for allowing us to use few sloth reconstructions! Check out more of Ceri's paleoart at and

    And thanks as always to Franz Anthony and everyone at for their great paleoart.

    Produced in collaboration with PBS Digital Studios:

    Super special thanks to the following Patreon patrons for helping make Eons possible:

    Katie Fichtner, Aldo Espinosa Zúñiga, Anthony Callaghan, Esmeralda Rupp-Spangle, Gregory Donovan, Ehit Dinesh Agarwal, الخليفي سلطان, Gabriel Cortez, Marcus Lejon, Anel Salas, Robert Arévalo, Robert Hill, Kelby Reid, Todd Dittman, Betsy Radley, PS, Colin Sylvester, Philip Slingerland, John Vanek, Jose Garcia, Noah offitzer, Eric Vonk, Tony Wamsley, Henrik Peteri, Jonathan Wright, Jon Monteiro, James Bording, Brad Nicholls, Miles Chaston, Michael McClellan, Jeff Graham, Maria Humphrey, Nathan Paskett, Connor Jensen, Sapjes, Daisuke Goto, Hubert Rady, Yuntao Zhou, Gregory Kintz, Tyson Cleary, Chandler Bass, Maly Lor, Joao Ascensao, Tsee Lee, Sarah Fritts, Ruben Winter, Ron Harvey Jr, Jacob Gerke, Alex Yan

    If you'd like to support the channel, head over to and pledge for some cool rewards!

    Want to follow Eons elsewhere on the internet?
    Facebook -
    Twitter -
    Instagram -

  • Science and Technology Science and Technology

Comments • 1 434

  • Jay420
    Jay420  2 days back

    wha if sloths are related to seals jus how coyotes are related to cats and not dogs🤔

    • Edy Coyote
      Edy Coyote  2 days back

      All fossils were put here by Satan to test people's faith. They weren't real animals

      • Thomas Lucas
        Thomas Lucas  2 days back

        Why didn't it drown when it developed lungs? How did ll the bacteria enzymes in its digestive system know to all evolve at the same time to digest food on land? What caused its muscles and skeleton adapt to much stranger gravity to support much more weight than in water. There are so many things wrong with evolution as explained now its beyond ridiculous. We need a better theory cause evolution doesn't work.

        • Canzandridas Joe
          Canzandridas Joe  3 days back

          I've been laughing for a while and I feel sad that I probably will never be able to use the words "metabolically challenged" in a sentence.

          • Zack Nimkoff
            Zack Nimkoff  3 days back

            "forgive me for this" okay, i will "very slowly" i have changed my mind

            • Thea Daily
              Thea Daily  4 days back

              Who's Steve?

              • CheatsythePimp2
                CheatsythePimp2  1 weeks back

                I’m still sad that we can’t clone ground sloths back from extinction...

                • Peter Kröger
                  Peter Kröger  1 weeks back


                  • Aurum
                    Aurum  2 weeks back

                    whales/sloth= role reversal

                    • who else but zane?
                      who else but zane?  2 weeks back

                      0.25x speed

                      • Legacy of Lore
                        Legacy of Lore  3 weeks back

                        6:22... Anyone else thinking badger moles from Avatar the Last Airbender?!

                        • C C
                          C C  3 weeks back

                          6:37 where the host mimics "furiously digging" 😆

                          • Floppyfish288
                            Floppyfish288  3 weeks back

                            How many species of ground sloth are there???

                            • BroliYTwins
                              BroliYTwins  4 weeks back

                              I relate so much to this animal.

                              • 5pecular
                                5pecular  4 weeks back

                                Survival of the cutest.

                                • Front Desk
                                  Front Desk  4 weeks back

                                  i like his button down shirt. i want one. where do you find it.

                                  • The Friend of Many Squirrels


                                    • Estefanía
                                      Estefanía  4 weeks back

                                      I hate this voice..

                                      • Alice Dixon
                                        Alice Dixon  4 weeks back

                                        Sloths are my favourite animal! I was having a bad day but this video cheered me up. Thank you PBS Eons!

                                        • SeanNotConnery
                                          SeanNotConnery  4 weeks back

                                          Megatherium is an amazing animal to research.

                                          • DomesticOnion
                                            DomesticOnion  4 weeks back

                                            The only way to say Thalasocnus is slowly

                                            • V Guyver
                                              V Guyver  4 weeks back

                                              I got a really interesting one. How much sunlight the earth is getting now compared to the time of the dinosaurs and prior as the earth's rotation has slowed down.

                                              • Tina McLaughlin
                                                Tina McLaughlin  4 weeks back

                                                Ooooooo! Me Too! Dogs turned into deals, whales you did. Manatees are worth a closer look too.

                                                • Jeremy Heartriter2.0
                                                  Jeremy Heartriter2.0  1 months back

                                                  They should've stayed in the sea.

                                                  • Munchy The Wolf :3
                                                    Munchy The Wolf :3  1 months back

                                                    They went from friggin scary to ADORABLE

                                                    • WHY SO SERIOUS
                                                      WHY SO SERIOUS  1 months back

                                                      Your videos are truly amazing I love them!

                                                      • Kairi Suzuki
                                                        Kairi Suzuki  1 months back

                                                        This is actually my favorite episode of PBS Eons because it has completely changed my view of animals.

                                                        I learned that sloths are weird animals that have thrived in rainforests, caves, and even shallow waters by utilizing their versatile forearms and their ability to live on every kind of plants. Essentially “sloths” are NOT restricted to being suspensory.

                                                        • KommanderChopp'ard
                                                          KommanderChopp'ard  1 months back

                                                          Sloths are just done. They’ve been there, done that. They want nothing to do with any of that anymore. They are done.

                                                          • Joel Aguilar
                                                            Joel Aguilar  1 months back

                                                            Does eons have a podcast or something?? I'd love to be able to have it playing in the background while I'm cleaning

                                                            • FeedMeSalt
                                                              FeedMeSalt  1 months back

                                                              they went from those majestic creatures, To something so stupid it will freeze to death if you wet it.

                                                              • Ramauld Ramharack
                                                                Ramauld Ramharack  1 months back

                                                                So this is what pbs kids went OK.

                                                                • Claudia DeBlieck
                                                                  Claudia DeBlieck  1 months back

                                                                  Video on the Thylacinus family?

                                                                  • Spirit悪の
                                                                    Spirit悪の  2 months back

                                                                    THE Time when Pbs Eons was called pbs kids

                                                                    • Aleksandar Vil
                                                                      Aleksandar Vil  2 months back

                                                                      Next do evolution of sea cows

                                                                      • Andy Miron
                                                                        Andy Miron  2 months back

                                                                        So we need to slow down?

                                                                        • Abhijit Desai
                                                                          Abhijit Desai  2 months back

                                                                          The physiology of the sloths family must have helped them to survive extreme catastrophies and move away to safer places all over the world later to mutate to different varieties.

                                                                          • sherlockbonez
                                                                            sherlockbonez  2 months back

                                                                            Theyve been around the world and now just want to chill on a tree

                                                                            • Avocado English : Education for Young Learners

                                                                              Great educational video

                                                                              • OLD BIRD CHOZO
                                                                                OLD BIRD CHOZO  2 months back

                                                                                A 2 ton sloth? Ok i want one! Bring on jurrasic park !!!

                                                                                • Just doing it.
                                                                                  Just doing it.  2 months back

                                                                                  For some reason I thought that there was still a ground sloth in South America.

                                                                                  • slovan01
                                                                                    slovan01  2 months back

                                                                                    How can these slow dudes swim?

                                                                                    • Noah Boucher
                                                                                      Noah Boucher  2 months back

                                                                                      "Hunting by humans," makes me wonder what ground sloth tasted like...

                                                                                      • BluePixie
                                                                                        BluePixie  2 months back

                                                                                        Lmao I thought I was on crashcourse when I saw the narrator, made me check the channel

                                                                                        • Beast Boy
                                                                                          Beast Boy  2 months back

                                                                                          I was wondering, is it possible that low metabolism is an ancestral trait of all mammals? Or is it something that is inherently unique to the xenarthrans?

                                                                                          • Me Too
                                                                                            Me Too  2 months back

                                                                                            Veeeryy ssslowsslyy.

                                                                                            • Cx0e
                                                                                              Cx0e  2 months back

                                                                                              Could have sloths evolved into something like whales if given enough time and if there was no competition from whales themselves

                                                                                              • Blaze
                                                                                                Blaze  2 months back

                                                                                                Is there a 'Evolution of Seals' episode planned? Because that sounds interesting.

                                                                                                • kennb750
                                                                                                  kennb750  2 months back

                                                                                                  First of all, I LOVE your videos! Keep them coming! Secondly, I'd REALLY like to know where/what these highly intelligent, scarily independent, bite sized things we call domestic cats descend from and how they've been so successful at surviving. Wow... That REALLY sounds like I hate cats. Lol! I don't.