Friday, January 14, 2011

Sahul Dinosaurs





A big problem with studying the Pleistocene Sahul continent is the paucity of organized scholarship addressing it all.  It really needs a center dedicated to the subject.

I have already concluded that what is the Sahul is a remnant evolved from the age of reptiles in a unique manner that provided a successor population radically different from the rest of the Earth.  Kangaroos make all that obvious but also hides it. 

The Pleistocene ended mostly 10,000 to 12,000 years ago.  As a direct result, most of Australia desertified wiping out a tropical continuum that reached far into the continent and made conditions impossible for large reptiles.  The flooding of the Asturias Sea and Carpentian Gulf eliminated most of a huge rainforest leaving a residue and refugia mostly in Papua New Guinea.  Yet this loss is incredibly recent.  That means a host of reptiles had a good chance to remain in various refugia out of sight and out of mind.


There is no gap of millions of years and we have aboriginal art depicting both theropods and apathosaurs.   I suspect that we simply do not know how to look and their home range is simply far too intimidating.

Yet we even have reports of sightings of pterosaurs.

And just how far has a kangaroo evolved from an upright reptile.  Did Tyrannosaurus Rex hop after his prey?

I think that the Sahul is n untapped gold mine of biological knowledge and isolated populations worth investigating.

Sahul

By K. Kris Hirst, About.com Guide


Definition:


Sahul is the name given to the single Pleistocene-era continent which combined Australia with New Guinea and Tasmania. At the time, the sea level was as much as 150 meters lower than it is today; and it was separated from the other great land mass (Sunda) by the Sahul Strait. The island in the photograph would have been part of Sahul.
Archaeologists care about this ancient continental shift because to get the Sahul populated, people had to actively work at getting there from the Sunda (in other words, they had to have boats or rafts and were likely to intend getting there). Currently, there are two theories about when this happened: 60,000 or 40,000 years ago. Scholars do agree that there are sites in Australia that date to at least 40,000 years ago, including Devil's LairLake Mungo, Nauwalabila, and Malakunanja. The O'Connell and Allen paper listed below is an excellent review of the recent considerations.



Sources
This glossary entry is part of the About.com Guide to Populating Australia and the Dictionary of Archaeology.
O'Connell, James F. and Jim Allen 2004 Dating the colonization of Sahul (Pleistocene Australia--New Guinea): A review of recent research. Journal of Archaeological Science31:835-853.

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