Prehistoric Safari :The Pleistocene South America2

(Please see the larger image. The smaller version appears to be much paler in tones on the display page. I don't know why this happens...)

The Prehistoric Safari : The Pleistocene southern South America(~Patagonia)
 
Right after the seismic biogeographical event known as the Great American Interchange, South America which had previously been 'the closed continent' quickly became one of most megafauna abundant continents in the world at the time of the Pleistocene.

The rich and charismatic fauna was composed of both immigrants from the north(and the old world) and the continent's own endemic species such as ones you're now witnessing here.

From front to back:

(small to mid size terror bird species of either Phorusrhacinae, Patagornithinae or Mesembriornithinae)

 
(Arctotherium angustidens, the largest bear in history)

 
(Megatherium americanum)

 
(Glyptodon clavipes)

 
(Notiomastodon platensis, formerly known as Stegomastodon sp.)

 
(Panthera onca, the Pleistocene jaguar)


(Toxodon platensis)

 

[Notes on updated info]

●About Notiomastodon

At annual 'International Conference on Mammoth and their relatives' held on May 2014, comprehensive taxonomical revision on South American Gomphotherids was made and this rather unfamiliar genus name 'Notiomastodon' has now become the only valid one for one of two SA gomphotherids, replacing much used synonyms such as Stegomastodon.

Notiomastodon platensis and Cuvieronius hyodon were only valid proboscidea in the entire continent(according to them) and the two were very close morphologically as well as phylogenetically, except for the size, molar and tusk shapes.

The larger Notiomastodon platensis was notably shorter at the shoulders than in extant bull African elephants but had more robust bone structures and the longer torso and probably weighed just as heavy or slightly less on average(Cuvieronius hyodon was much smaller but with longer tusks). The giant ground sloth(Megatherium americanum) is often quoted as being the largest of the Pleistocene SA megafauna but the rightful title most probably belong to this powerful gomphotherid, instead.

●About the Terror Bird

There's this relatively small terror bird running towards you and you may think it's weird to find a phorusrhacid within the mid to late Pleistocene faunal assembly of South America. Well in 2009, a right tarsometatarsus bone of phorusrhacid bird was excavated from late Pleistocene sediments in Uruguay(southern South America).

The discovery of the youngest terror bird fossil rewrites the widely held notion that all phorusrhacid lineages were completely wiped out by the time of Pliocene-Pleistocene boundary, largely due to the Great American Interchange.

The bone belongs to a much smaller species than typical Miocene and Pliocene terror birds but it possesses shared similarities with that of North American Titanis walleri and its relationship with Psilopterinae, the smallest and morphologically the most distant group of Phorusrhacidae is precluded.


Illustration and text by ⓒJagroar

Morphological supervision on Notiomastodon platensis by Asier Larramendi (EoFauna)