Tuesday, February 23, 2010

The Sea Sloth

Thalassocnus is an extinct aquatic or semi-aquatic sloth-like animal from South America. Order Xenartha (or Pilosa depending on who you ask). It is generally thought to be a herbivore, living off of seaweed and sea grass.

I have been reading about Xenartha most of the morning. Fascinating stuff.
Many massive thanks to Cameron McCormick for intoducing me to this topic:
He has various scientific periodicals linked from his blog post I have linked to.

Ironically, this species in generally lumped among the "ground sloths" merely because whatever it is it isn't a tree sloth. And the term sloth is quite misleading. Sloths have a specific lifestyle. I don't think it is exaggeration to say that their best known distinguishing traits are lacked by the "ground sloths." Namely, tree sloths live their entire lives upside down, they move very slowly, and their fur is green-ish (a result of algae living in their moist fur, lending sloths with longer hair more chamouflage...a survival trait). None of these three traits are probably present in the "ground sloths," although I hesitate to make any absolute assertions.

Thalassocnus is almost as much an anteater as a sloth-proper. Of course, as my dad pointed out, anteaters are known for eating ants. And that is almost certainly not what fossil evidence suggests.

However, the "ground sloths" are most definitely Xenartha (grouping of armadillos, anteaters, and sloths), and they are most definitely related fairly closely to the sloths (judging from all available evidence). The "ground sloths" are represented by a few major fossil groupings, with Thalassocnus NOT among the archetypical genus, represented by Megatherium.

I want to remind the reader that although teeth are a very good indicator of what an animal eats, it is hardly foolproof. Please observe the Giant Panda. It has the teeth of a carnivore, and yet lives off of mostly plant matter (bamboo) which really confused Western scientists for while.
Also, it should be mentioned the aquatic habits aren't really something that can be confirmed, either.



  1. I first read about the sloth in Willard Price books, the old fashioned nature adventure writer. Despite the insult I'd be quite pleased if a Deadly Sin was named after me. Pride, Vanity, Sloth, Mitzi (the sin of eating chocolate for dinner on Saturdays.) PS nice galapagos tortoise you have there, is it a descendant of Darwin's friend Harrier?

  2. My friend Moe is an Aldabra tortoise actually, although I wouldn't have known from the photo myself. Around 60 years old and 400 pounds, I'd guess.

  3. http://scienceblogs.com/tetrapodzoology/2007/01/ten_things_you_didnt_know_abou.php

    The "tree anteater" the tamandua is worthy of note in the xenarthan diaspora.