Is the hominid skull discovered in Petralona 700,000 years old?

Question

Aris Poulianos, a Greek anthropologist, claims that the hominid remains (a skull) discovered in the Petralona Cave are 700,000 years old and belong to a distinct species, which he named Archanthropus europeaus petraloniensis (commonly: Archanthropus of Petralona).

The claim and Poulianos' interpretations are surprisingly popular in Greece, and a further claim that an 11 million years old calcified tibia was found in nearby Triglia also received some coverage in local news. Poulianos claimed the tribia belonged to a Homo erectus subspecies which he named Homo erectus trilliensis.

While the claim sound absurd, there are copious amount of literature re-iterating it. Some examples:

• THE 46th ANNIVERSARY SINCE THE DISCOVERY OF THE PETRALONA ARCHANTHROPUS’ SKULL, from Poulianos website,
• Petralona cave & man discovery, a Greek national tv documentary (English subtitles),
• Wikitravel article on Petralona

(Perhaps) more importantly, Poulianos effectively controls access to the cave itself, through his Anthropological Association of Greece and most tourist literature for the cave and the findings comes from the AAG operated museum.

Answer 1

According to the Smithsonian Museum of Natural History the skull is "Between 350,000 and 150,000 years" old

Some further notes on the morphology and dating of the Petralona hominid Journal of Human Evolution vol. 12, December 1983, Pages 731-742, says:

somewhat more than 350ky, but certainly less than 730 ky

However, A re-analysis of electron spin resonance dating results associated with the Petralona hominid, Journal of Human Evolution vol. 30 March 1996, Pages 227-241, says:

Two electron spin resonance (ESR) dating studies of the late 1970s and early 1980s on speleothems associated with the Petralona hominid cranium yielded age estimates of 350–700 ka and 200 ka, respectively. These dating results are re-assessed in view of more than a decade of progress in ESR dating. The re-assessed values are in reasonable agreement with some independent U-series results on the same material, suggesting an age of 150–250 ka for the speleothems bracketing the cranium