Jan van Es of The Netherlands writes on his web site:
"The measures of this ape head are: height 18 cm; width 17 cm; thickness 8 cm; weight 4½ kilo. It’s extremely heavy, considering the measures.
In 1991 I bought in Roermond (Holland) in a little shop a piece of fossilized wood (it was presented like this), but I saw immediately a clear ape head. Because the ape item from the pitch in Pampau was presented by Mrs. U.Benekendorff as a new addition in the sculpture series, I thought this ape head a hot item. I asked the owner of the shop about this piece of wood. He told me about an acquaintance in Indonesia, from Java, who let children search for minerals and fossils in ancient riverbeds (he used to pay them f 1,- for a good fossil or mineral).
This polymorph ape head had been presented 4 x in expositions of several collectors, including present writer. Typological this piece fits in the sculpture-sequence: male portrait – sitting mother or ape portrait – sitting ape mother. I frequently notice these images besides (also frequently) females riding on the back of animals, like Europe on the back of a bull (Zeus). Because the ape images are turning up at several places in the world, this ape portrait seems to me a suitable piece in the jig puzzle of sort (species), source, period, interpretation and presentation. Ambiguous aspects in an ape portrait, e.g. the skull of a chimp but the snout of an orang-utan, can be an indication of a (geographic) connection to the African continent and Asia. This ape head for instance has a resemblance with a male chimp (and “en profile” with an Australopithecus), but upside down one can see an ape (mother) with a long snout. For many years I’ve been collecting a typology of male portraits and sitting females (in one sculpture), of which the male portraits were to be seen on the bellies of the females. I found this item also in human-animal sculptures.
When I saw this ape head I immediately had Dr. Eugene Dubois in mind, a professor from Amsterdam, who found in 1890 and 1891 fragments from skeletons in Indonesia from a species, which he called at that time the Pithecanthropus."