7 replies to this topic

[Auspex]

LINK

[Bullsnake]

Really interesting stuff! That's quite a gap between this discovery and what was previously thought.
With it having such unique characteristics, namely the teeth, I would think it more likely to be a branch that never completed migration south, rather than an ancestor, which came later.
Just a thought.

[Auspex]

The fossil is Miocene (20 MYO); when did the land bridge between the continents form? Maybe I'm showing my ignorance, but was the Isthmus terra firma then, or is this a case of bloat-and-float?

[Bullsnake]

To clarify my post, I'm suggesting that it was a species that evolved to adapt to that environment, failed, and for whatever reason no mammals traversed the isthmus for another 17million years; that being the gap I was referring to.
Bloat and float seems plausible, though. But maybe it was like Kansas...it's water,it's land,it's water,it's land...
And don't think you can out-ignorance me, Mr. Auspex

[siteseer]

Two genera of ground sloth arrived in North America about 9 million years ago and one genus of peccary appeared in South America about the same time. Sloths are surprisingly good swimmers even today and peccaries are a hardy lot in any case. The isthmus formed slowly and may have existed as a series of small islands during the Miocene and much of the Pliocene. Individual animals of many groups may have "island-hopped" as storm survivors rafting on floating vegetation though few arrived in sufficient number to maintain viable populations. Connecting the dots might have been easier during intervals of lower sea level as well, as you suggested.

The land bridge was not completed until about 2.7 million years ago, a time marked by the appearance of various North American land mammals in South America and a lesser invasion from the south to the north.

I should add that the isthmus formation has been previously explained as a piece of southern Mexico breaking off sometime in the Late Cretaceous-Cenozoic, then sliding into its current position.

Yes, I think that camel species (a descendant of castaways) might have survived on a "Panama island" by the skin of its teeth long enough to adapt by decreasing in size and broadening its diet (explaining the odd teeth).

To clarify my post, I'm suggesting that it was a species that evolved to adapt to that environment, failed, and for whatever reason no mammals traversed the isthmus for another 17million years; that being the gap I was referring to.

Bloat and float seems plausible, though. But maybe it was like Kansas...it's water,it's land,it's water,it's land...
And don't think you can out-ignorance me, Mr. Auspex

[Auspex]

>MORE<
Wherein we learn that the site was the southernmost land in Central America at the time; no bridge needed.

[AgrilusHunter]

>MORE<
Wherein we learn that the site was the southernmost land in Central America at the time; no bridge needed.

"crocodile-like camels"

Now there's an odd image. Any one else think this would make a great Farside cartoon.

[pleecan]

NEAT ARTICLE! I like the part of camel being the size of a dog....