91av

MOST of the beautiful Chinese fossil birds on sale have been embellished in
one way or another. Some may be assembled from broken pieces of several fossils
while others have had missing features added. 鈥淎lmost every one that I鈥檝e seen
on the commercial market has some reconstruction to make it look prettier,鈥� says
Kraig Derstler, a palaeontologist at the University of New Orleans in
Louisiana.

Many early palaeontologists saw nothing wrong with adding a missing bone or
two. Both the American Museum of Natural History and the Carnegie Museum in
Pittsburgh acquired fossil skeletons of Apatosaurus with skulls from
different dinosaurs in the 1880s. But the prices that well-preserved Chinese
bird fossils fetch have made faking extremely profitable. Over the past twenty
years, says Derstler, 鈥渁dhesives and fake rock have become very easy to make and
very difficult to spot.鈥�

The problems start with the Chinese peasants who dig up most of the bird
fossils. They quickly learned that they could make a killing from 鈥渃omplete鈥�
fossils. Fossils often split along the plane of the bones, giving them two sides
of a single animal, known as a part and counterpart. If they鈥檙e missing the
right leg, 鈥渢hey鈥檒l cut out the counterpart of the left leg and make it into a
right leg,鈥� says Larry Martin of the University of Kansas.

Some composites are even good enough to fool the professionals. Luis Chiappe
of the Natural History Museum of Los Angeles County recalls one specimen that
aroused his suspicions. 鈥淚 wasn鈥檛 sure what was wrong with it,鈥� he says. But
careful measurement showed that one leg was longer than the other. And only when
he examined it closely did he find the mortar that had glued two slabs together.
鈥淥n the surface you really couldn鈥檛 see that,鈥� says Chiappe. 鈥淎t the moment,鈥�
says Martin, 鈥淚 don鈥檛 trust any of these specimens until I see the X rays.鈥�
These reveal joints or voids within the rock.

Usually the pieces come from the same species, but in the case of
Archaeoraptor
(91av, 29 January, p 12) someone had added
a dinosaur tail to a bird body. 鈥淭he farmers do not believe this is wrong,鈥� says
Martin, 鈥渢hey look at it as restoring an art object to make it more
尘补谤办别迟补产濒别.鈥�

鈥淭he whole commercial market for fossils has gotten riddled with fakery,鈥�
complains Martin. Derstler says shrimp and fish are often painted to enhance
their appearance. The problem is particularly bad for the Chinese fossils, which
continue to be smuggled out of the country despite an official crackdown
(91av, 14 December 1996, p 12).

Smuggled specimens typically pass through many hands and middle men in
America, Italy or Germany often sculpt feet or skulls from adhesives mixed with
ground rock from the fossil itself to replace missing pieces. 鈥淵ou can鈥檛 spot it
without a microscope, or ultraviolet or X-rays,鈥� says Derstler.