Homo erectus at Trinil on Java used shells for tool production and engraving
Josephine CA Joordens, Francesco d'Errico, Frank P Wesselingh, Stephen Munro cs 2015 Nature doi 10.1038/nature13962

The manufacture of geometric engravings is generally interpreted as indicative of modern cognition & behaviour.
Key questions in the debate on the origin of such behaviour are:
is this innovation restricted to H.sapiens?
does it have a uniquely African origin?("key question"?? why?? --mv)

Here we report on a fossil fresh-water shell assemblage from the Hauptknochenschicht (HKS "main bone layer") of Trinil (type locality of H.erectus, discovered by Eugène Dubois 1891).
In the Dubois collection (Naturalis museum Leiden NL) we found evidence for
- freshwater shellfish consumption by hominins,
- 1 unambiguous shell tool,
- a shell with a geometric engraving.
We dated sediment contained in the shells (40/39Ar & luminescence dating): max.age 0.54 Ma ± 0.10, min.age of 0.43 Ma ± 0.05):
the Trinil HKS is younger than previously estimated.
Our data indicate:
- the engraving was made by H.erectus,
- it is considerably older than the oldest geometric engravings described so far.
It is at present not possible to assess the function or meaning of the engraved shell, but this discovery suggests:
engraving abstract patterns was in the realm of Asian H.erectus cognition & neuromotor control.