Photo © T. Keillor

Nigersaurus is a composite of partial skeletons collected during two field seasons (1997, 2000). Paleontologists almost never find complete dinosaur skeletons and often sculpt missing bones in order to reconstruct a complete skeleton for display. Once fossils are cleaned and cast and missing bones have been sculpted, it is possible to assemble a skeleton. The mounted skeleton of Nigersaurus began with an "armature" (metal framework) that was made of high-tensile steel. Casts (replicas) of the bones were then attached to the framework. The replicas were painted with acrylic paints to look like the color of the original Nigersaurus fossils discovered in the field.

Photo © M. Hettwer Sitting in the curve of its tail, expedition  team member Gabrielle Lyon excavates a partial skeleton of an adult Nigersaurus in 2000.	Photo © P. Sereno Years of careful comparison and laboratory work (fossil cleaning, molding, and casting) are needed prior to the creation of a mounted skeleton of a new species like Nigersaurus.  All of the bones on display were carefully removed from solid sandstone by technicians and students in the Fossil Lab at the University of Chicago.

Photos © S. Godfrey Foam, a soft material that is easy to mark and carve, is sculpted with hand tools and then painted to create missing bones.  Copies are made in durable plastic for mounting.

Photo © M. Hettwer

THE FLESH RECONSTRUCTION

The Nigersaurus flesh reconstruction was sculpted over a skeletal cast for accuracy.  Glass eyes were chosen based on fossilized iris bones (sclerotic plates) of the closely-related sauropod, Diplodicus. The scaly skin, built with peeling patches similar to living reptiles, is based on fossilized sauropod skin impressions.

Photo © T. Keillor Sheets of clay, simulating layers of muscle and flesh, are laid over a cast of Nigersaurus’ skull and neck bones.

A bill-like sheath probably protected the ends of the jaws. The evidence for this is the grooves for blood vessels that usually underlie a bill covering along the ends of the jaw bones. The nostril would have been small, based on living animals, despite a large opening in the skull. A muscular tongue shoveled cropped plants down the throat. Look inside its mouth for saliva drool and bits of chopped leaves!