Aquatic ground sloth (was Re: Leedsichthys)

[Pieter.Depuydt@rug.ac.be]

Christian wrote:
> P.S.-On the topic of confusion between land and sea animals, wasn't there word
> of some sort of aquatic giant sloth a few years back? Someone just mentioned
> it to me one day and I never heard of it again. Thalassocnus, wasn't it? Was
> this some sort of grievous error or joke made by the edentate workers, or
> what?

Seems pretty serious. 

Thalassocnus natans was descibed in 1995 on the basis of abundant and 
well preserved remains from marine Pliocene sediments of Peru (Pisco 
Formation, Early Pliocene). T. natans was a medium sized (skull 20cm) 
ground sloth, most closely related to Nothrotherium and 
Nothrotheriops.  Aquatic, at least semi-aquatic habits, are suggested 
by the taphonomy of the fossils: very abundant and complete skeletons 
occur in a typical marine assemblage, together with fish, crocodiles, 
birds (penguins) and dolphins: this assemblage was probably deposited 
in a beach environment, while the coast itself was a desert. 
The anatomy of the animal is consistent with aquatic habits, with 
the ground sloth bauplan showing some adaptations in the hind limb 
and tail. It's diet may have consisted of sea grasses. See: C. de 
Muizon and H.G McDonald 1995: An aquatic sloth from the Pliocene of 
Peru. Nature 375, p 224-227. 

Evolution moves in mysterious ways.

Pieter Depuydt