Rowe i in., 2001- The Archaeoraptor Forgery

The Archaeoraptor fossil was announced as a ‘missing link’ and purported to be possibly the best evidence since Archaeopteryx that birds did, in fact, evolve from certain types of carnivorous dinosaur1. It reportedly came from Early Cretaceous beds of China that have produced other spectacular fossils transitional between birds and extinct non-avian dinosaurs2,3. But Archaeoraptor was revealed to be a forgery in which bones of a primitive bird and a non-flying dromaeosaurid dinosaur had been combined4–6. Here we  use high-resolution X-ray computed tomography (CT)7 to determine the nature and extent of the forgery, as well as how it was built, by imaging the fracture pattern and distribution of materials through the entire specimen. The Archaeoraptor specimen, which was reportedly collected from the Early Creta-ceous Jiufotang Formation of Liaoning, was smuggled out of China and later sold in the United States on the commercial market4. Before repatriation5, the specimen, which
was alleged to contain a single complete skeleton, was brought to us for CT analysis. The slab had obviously been reassembled from numerous broken pieces, and the
skeleton presented a unique combination of features, including teeth, feathers, a more flight-capable wing than Archaeopteryx, and the tail of a non-flying dromaeosaur. The
entire bone-bearing portion of the slab was scanned in 422 consecutive 1-mm-thick slices, spaced at 0.9 mm (for the full dataset and description of scanning protocols, see
supplementary information). Computed tomography alone cannot distinguish genuine and fraudulent mistakes, but it provides criteria for evaluating whether pairs of adjacent pieces lie in natural relation to one another. These include comparison of adjacent fracture-face geometries, thickness and density of adjacent pieces, cross-cutting relationships among four generations of fractures, the distribution of grout, and continuity across fractures of bones, natural moulds of bones, and invertebrate burrows. The textural signature of the grout is its relatively low density, inclusion of air bubbles and metallic particles, a unique fracture pattern, and dark green fluorescence under ultraviolet light. Overlapping relationships among blobs of grout and different pieces, which can be observed in CT cross-section, reveal the general sequence of assembly.
The Archaeoraptor slab was built in three layers. The top ‘layer’ is a heterogeneous mosaic of 88 separate pieces, some of which contain bone (Fig. 1). The bottom layer is a
single, unbroken plate of shale used for backing. Between the two is a layer of grout, which was spread over the face of the backing plate and between ruptured edges of the
top pieces, as they were set into place. Many Liaoning fossils have undergone this same style of repair. The top layer was built in three phases. The first to be assembled were 23 pieces that lie together in natural relationships and contain the anterior half of an articulated bird skeleton (to be described as a new species; X. Xu et al., manuscript in preparation). In the next phase, 26 pieces containing bones and a few contiguous pieces were sequentially articulated against the rear half of the skeleton to ‘complete’ it. None of these pieces preserves evidence of a natural attachment to the bird skeleton pieces, and in only a few cases are these pieces naturally associated with one another. Also, the ‘paired’ tibiae/fibulae and feet are split parts and counterparts from a single side, positioned as if they were right and left. The third phase of construction involved
placement of 39 ‘shims’. The shims lack bone, are usually separated from the other pieces by broad seams of grout, and preserve no evidence of a natural association
with any piece in the first two groups. Shims were probably added at various times during assembly to secure the secondary bones into position around the bird skeleton
and to make the slab more presentable. In addition to the discrepancies revealed by the CT information, the tail of a nonvolant dromaeosaur also presented character
conflicts with the ornithurine features of the bird skeleton and with the foot, which lacks the characteristic enlarged second claw of dromaeosaurids8. We found no evidence
that the left femur, the split tibiae/fibulae, the split foot, or the tail belonged to the same individual or to the same species. We conclude that Archaeoraptor represents
two or more species and that it was assembled from at least two, and possibly five, separate specimens. Additional work in China verified that the tail is from an
entirely different specimen, which has been described as a new species of dromaeosaur9.
Sadly, parts of at least two significant new specimens were combined in favour of the higher commercial value of the forgery, and both were nearly lost to
science. Palaeontology was also badly damaged by the Piltdown forgery10 and the “lying stones” of Johann Beringer11, and many fossils have been unwittingly or
deliberately subjected to misleading reconstruction. Knowing the history of human handling can be critical to proper evaluation and scientific interpretation of specimens.
Fortunately, a growing array of techniques can now be applied to forensic analysis of fossils.
Timothy Rowe*, Richard A. Ketcham*,
Cambria Denison*, Matthew Colbert*,
Xing Xu†, Philip J. Currie‡
*High-Resolution X-ray Computed Tomography
Facility, Department of Geological Sciences, C1100,
The University of Texas at Austin, Austin, Texas 78712, USA
e-mail: rowe@mail.utexas.edu †Institute of Vertebrate Paleontology and Paleoanthropology, Academia Sinica, PO Box 643, Beijing 100044, PR China
‡Royal Tyrrell Museum of Paleontology, Box 7500, Drumheller, Alberta T0J 0Y0, Canada
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Supplementary information is available on Nature’s website at http://www.nature.com or as a paper copy from the London editorial office of Nature.