The large 3D printout before you is the skeleton of a chameleon from the collections of the UCL Grant Museum of Zoology, specimen number X1209.
We are not entirely sure which species this is – most likely it is either a common chameleon (Chamaeleo chamaeleo, from the Mediterranean Basin) or a flap-necked chameleon (Chamaeleo dilepsis, from sub-Saharan Africa).
The live chameleon – along with two others – was received from HM Customs after being seized at Heathrow Airport and was kept in the warm lab at UCL until it died. It was prepared by Rosina Down (curator of the Grant Museum 1971-1994) and Jenny Thompson in the 1980’s through freeze-drying. Freeze-drying of zoological specimens was pioneered by Reg Harris (curator of the Grant Museum 1945-1956), who published many articles on this technique. Freeze-drying involves freezing remains, then removing the water via sublimation. An advantage of this technique is that specimens are preserved with virtually no deformation unlike the more artistic method of taxidermy.
In early 2026, we were searching for a chameleon specimen for our Royal Society Summer Science Exhibit and chose this individual. The specimen was scanned using UCL Bioscience’s microcomputed tomography scanner, which allows us to visualise internal detail in high resolution. The images from the scanned specimen were processed to create a 3D digital model of the skeleton.
The physical model of the skeleton was created by B-Made at UCL’s Bartlett School of Architecture and printed at 7.37 times its original size in several large sections. The team used two 3D-printing methods: FFF (Fused Filament Fabrication) and SLS (Selective Laser Sintering), which builds objects by fusing layers of fine powder with a high-powered laser. The printed sections were then assembled to form the skeleton displayed here.
The scan revealed previously unknown information on this specimen. First, we now know it was a female, as evidenced by the 19 eggs preserved inside of her! We also found that over the course of her life, this chameleon had broken 10 ribs – five on the left and five on the right – all of which subsequently healed, as evidenced by bony calluses at the break points. (Chameleons have very slender ribs that are commonly broken through falls and rough handling.)
The freeze-drying process resulted in excellent preservation – scans clearly showed soft tissues such as the brain, individual muscles and tendons in the head and limbs, the heart, liver and the entire digestive tract, with high-density insect pieces still inside.
From a nearly forgotten specimen to a rediscovered past, new information from cutting-edge technology, and an exhibit centrepiece viewed by over 10,000 people, we hope to show how every museum specimen has a fascinating story to tell.