Allosaurus fragilis

Scale 1:12
L 720, H 230, W 95 (mm)
Hand-cast polyurethane resin
click to enlarge
My Ants Allosaurus model rebuild progress photo Nov 2008
 

A rebuild and update of the Allosaurus fragilis skeleton model produced in the mid-1990's by the Ants company (Albuquerque, New Mexico, USA). I consider this my "Holy Grail" as it took over five years to obtain one, eventually from a private collector in New York. It was worth the wait however as the copy I secured in June 2008 was as-new, unbuilt, and untouched since invoiced in March 1994. An early edition, it consists of 150 parts (later editions had fewer separate parts).

This model is a perfect compliment to Phil Platt's Apatosaurus model; it's the same scale, very accurate, and a contemporary predator of Apatosaurus. This model was also made entirely by one man; Steven Wagner. He sculpted the model largely from technical drawings in the classic monograph Allosaurus fragilis A Revised Osteology (Madsen, 1976) (pdf here). Madsen's 160+ page publication is unique in that virtually every bone of the animal is reconstructed and drawn to scale.

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Original Ants Inc. model

The original model, while spectacular in most respects, had room for improvement; some parts did not match the technical drawings closely and because knowledge of Allosaurus has advanced some bones were missing or in need of an update. The original model was designed to be glued together and mounted on a cast metal stand. To improve on that I used an invisible brass armature to connect all vertebrae and joined remaining elements with brass connectors, using no glue whatsoever.

I elected not to build the original Ants kit as it is probably one of the last mint copies in existence. Instead, I reproduced it, being extremely careful not to damage the original. After much experimentation I learned to use pressure casting equipment, silicon molds, and polyurathane resin to copy the model.

The photo above is the half-completed rebuild and many bones are not finalized. Belly gastralia, which were not part of the original kit, are yet to be fabricated. The furcula (wishbone) has been added along with the last ten vertebrae of the tail as these were also not part of the original kit. The entire pelvic girdle was scratch built to better match the drawings of Madsen. Unfortunatley, nine parts were missing from the kit as shipped from Ants, specifically neck (cervical) vertebrae 7, 8 and 9 and their respective ribs. These were also fabricated according to Madsen.