Deluge of Atlantis

Deluge of Atlantis
Deluge of Atlantis

Thursday, August 30, 2012

That New Fossil Skull from Laos

By Way of Don Jeffrey Meldrum on Facebook:

Here is a scan of the Laos skull from the appendices of the PNAS paper. There are reportedly numerous caves in the region and future research will be directed at conducting surveys of additional caves. Can't wait to see what is recovered. ( D J Meldrum comment)

Actually the skull is very like a series of skulls already known to be very ancient, probably of Neanderthal age, and found in China: these skulls are also very much like some early Australian skulls.

A uranium date of 67 000 years was reported but has been questioned on the basis of its exact location in relation to dated geological strata. In December 2002 a Chinese group headed by geologist Shen Guanjun reported their reinvestigation of the stratigraphy of the cave and dating of the skull (extending to several neighbouring caves) and claim it should be placed in a time bracket between 70 000 and 130 000 and not less than 68 000 years ago.
The skull was found in a so-called intrusive breccia a secondary flow of debris containing jumbled material of different ages. From their paper in the prestigious Journal of Human Evolution the lower date bracket of 68 000 years seems solid since it comes from multiple date estimates of the flowstone above and covering the breccia. (A flowstone forms when flowing water deposits calcite down a wall or across a floor.) Their preferred dating of 111 000–139 000 years ago based on unstratified fragments of flowstone and calcite within the breccia seems more speculative.

Text from:

So it would seem this skull is merely one more in an already-recognised population

In the meantime, here is also another statement about another recent new find with an over-inflated claim to unique species status:

 The Pleistocene Scene – A.P. Van Arsdale Blog

Longlin fossils

I said in a post the other day that I am largely unsympathetic to arguments for excessive speciation throughout the Pleistocene. The news this week from “Red Deer Cave” or Longlin Cave in SW China does not change that. These discoveries (actually documentation of fossils recovered in 1979) have gotten a lot of attention in the news media, and I am a little baffled. As an example, The New Scientist story on the PLOSone paper describing the fossils is titled, “Chinese human fossils unlike any known species.” But they are. They are like recent modern humans from East Asia. Something the paper’s analysis also seems to strongly suggest. Here are two photos of LL1 (on the right) alongside a late Pleistocene/Holocene skull from the Upper Cave of Zhoukoudian, another Chinese fossil locality (on the left).

I should caution that these photos are necessarily not to scale, my attempt is only to highlight relative similarity. But much of the variation above parallels the kind of variation we see between male (on the left) and female (on the right) modern human crania.
In this second photo I have highlighted several regions of the maxillary/zygomatic that appear, based on the picture, to have fractures which potentially disrupt the reconstruction. I highlight these, because in the paper’s analysis, it is measurements that focus heavily on this part of the skull that provide the primary metric argument for this specimen being anything other than an early modern human skull from East Asia.

I am open to ideas about high levels of population structure and complex and changing regional population dynamics and the more fossil evidence we have to demonstrate this complexity late in the Pleistocene the better. But I am skeptical of quotes like this:
“These new fossils might be of a previously unknown species, one that survived until the very end of the Ice Age around 11,000 years ago,” says Professor Curnoe.
1. Curnoe D , Xueping J , Herries AIR , Kanning B , Ta├žon PSC , et al. (2012) Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians. PLoS ONE 7(3): e31918. doi:10.1371/journal.pone.0031918

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