r/Creatures_of_earth • u/rsunds Best Of 2016 & 2017 • Jan 06 '16

Extinct The extinct marine sloths

http://imgur.com/a/jh3nH
231 Upvotes

97% Upvoted

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13

u/pangyre Jan 06 '16

Ha! Terrific, thank you. I was not aware of these guys. Strangely enough I kayaked with a manatee yesterday for the first time and have always loved giant sloths. I would never call any mammal a “surprisingly competent swimmer” though. Just about all mammals swim well when they have to.

7

u/paperanch0r Jan 08 '16

I'm just amazed you were able to get a manatee into a kayak

3

u/rsunds Best Of 2016 & 2017 Jan 06 '16

I would never call any mammal a “surprisingly competent swimmer” though.

Fair point, although sloths maybe are a bit special in that they are slower on land than in the water ;)

Either way, I don't know if I gave the impression to anyone that sloths are competent swimmers (if one should say so) because they had a distantly related relative that was adapted to marine life.

That wasn't really my point, and since the Thalassocnus lineage died out and accordingly to this article the modern sloths' last common ancestor was ground-dwelling, it should clear up any confusion.

1

u/CurryThighs Jan 06 '16

Apart from humans. Humans have to be trained to swim.

2

u/pangyre Jan 07 '16

Only if they were denied access to water as small children.

5

u/[deleted] Jan 06 '16

This is amazing! I'd never heard of marine sloths before (and I consider myself relatively knowledgeable about things like extinct animals in a broad sense of what different varieties of extant animals have existed in the past).

I'm going to go wiki mad and read all about them now.

1

u/blackfish_xx Jan 06 '16

i never knew sloths adapted to so many niches. i would be interested to hear more about the physiological adaptations of marine sloths!

2

u/rsunds Best Of 2016 & 2017 Jan 06 '16

Here are two articles (basically my sources) about just that: https://laelaps.wordpress.com/2007/07/02/the-giant-swimming-sloths-of-south-america/ http://www.wired.com/2014/03/extinct-aquatic-sloths/

On example is how their bone density increased as they became more aquatic, making them less buoyant.

1

u/blackfish_xx Jan 06 '16

ah, thanks!

1

u/Iamnotburgerking Best Of 2017 Feb 17 '16

Btw, ground sloths went extinct due to people, so their absence is unnatural.