Magazine article ROM Magazine

The Making of a Pterosaur: Technicians Use Research and Technology to Build a Cast Skeleton from a Few Fossil Bones

Magazine article ROM Magazine

The Making of a Pterosaur: Technicians Use Research and Technology to Build a Cast Skeleton from a Few Fossil Bones

Article excerpt


The pterosaur Quetzalcoatlus northropi is one of the largest flying reptiles ever to have taken to the skies. In 1971, the original partial skeleton--consisting only of the bones of one wing--was discovered at Big Bend National Park in Texas. Amazingly, paleontologists in Austin and technicians in Montana were able to accurately recreate the complete skeleton of this enormous creature, a cast of which now soars above the ROM's Hyacinth Gloria Chen Crystal Court.

Peter May from Research Casting International (RCI), an Ontario-based firm that also casts museum skeletons, explains how, with a few fossil bones, a spectacular skeleton like the one unveiled at the ROM in July is produced and mounted.

The Pose

The ROM's mount shows Quetzalcoatlus swooping in for a landing above the Hyacinth Gloria Chen Crystal Court, its wings in a breaking pose that would bring it in for a smooth landing.

A great deal of scientific study has gone into how these large animals managed the skills of takeoff and landing. Quetzalcoatlus was as big as a small airplane, and probably depended on steady gusts of wind to take off. Recent research by paleontologists and aeronautical engineers has shed new light on pterosaurs, showing they were capable of flight as complex as that of modern birds; studies on the giant Quetzalcoatlus indicate it was more suited for gliding than aerobatic manoeuvres. Research Casting International used this analysis to pose the animal in a gliding rather than flapping posture, bending the hind limbs as they would have been positioned in anticipation of landing, with the wings raised, being used as brakes.



Scaffolding allowed the RCI team to reach the high anchor points from which we suspended cables to support Quetzalcoatlus. Each joint of the skeleton has a keyway machined into it and a bolt that enables the sections to be easily assembled--crucial when installing at great heights. We partially assembled the skeleton, the body and legs first, and lifted it out onto the scaffolding platform, where we loosely attached it to the cables. Then we added the other skeletal parts and the first wing section. Next we adjusted the skeleton to the specified pose, lifting the skull and neck and tightening the cables to have the pterosaur banking at about 30 degrees. Once we were satisfied with the positioning, we attached the remaining wing sections.

When we removed the scaffolding, the metal armature remained to support Quetzalcoatlus. Substantial in strength, the armature is bolted at three anchor points to secure the skeleton in its set position, taking pride of place soaring just outside the James and Louise Temerty Galleries of the Age of Dinosaurs.

Sculpting and Modelling

Having just a few existing bones, technicians needed to recreate most of the skeleton from scratch. The fossil bones suggested what size the pterosaur needed to be. …

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