Reconstructing Edmontosaurus

Sculpting, with an adult specimen in the background.

  Edmontosaurus was a hadrosaur, or commonly known as a “duck billed” ornithischian dinosaur from the late Cretaceus of N. America. Edmontosuarus would have coexisted with animals like Tyrannosaurus, Triceratops, Thescelosaurus, Pachycephalosaurus, Ankylosaurus, Ornithomimus, and Toodon, among others. Full grown this herbivore would have measured around 30 to 40 feet long, and weighed in the area of 4 to 6 tons.

Two dimensional life reconstruction by the artist

  Charged with reconstructing the skull of a juvenile approximately half the size of an adult, Doyle is using various reference materials such as science publications, photographs illustrations and a very complete adult Edmontosaurus skull, to inform his work.

  As with his previous projects, the reference must not simply be copied, but reinterpreted when applied to the proportions of a young dinosaur. Like the baby T. rex, Doyle will need to consider the proportional transitions of juvinile to adulthood that take place in animals, and specifically hadrosaurs. Fortunately, hadrosaurs are very well represented in the fossil record, and Edmontosaurus is one of the largest of this group. Some specimens of this genus were found preserved in the round with skin impressions, or soft tissue stains, for example the notable specimen AMNH 5060, also known as the "Trachodon mummy" found by Charles Hazelius Sternberg in 1908.

  The goal of this project is not to simply recreate the skull as it would have been seen idealistically, but in a way that is harmonious with the specimen. This is a bit of a challenge because correct anatomical structures must be laid down first and then the distortion must follow only after considering how the bones moved during fossilization. Its a little like making a model car that has crashed, rolled over and now badly rusted but the make and model remains recognizable. In essence the formal qualities must survive the distortion enough to place it as Edmontosaurus, but not so much so that it fails to blend with the specimen.

LACM 23504 in dorsal (top) view

  The specimen itself, LACM 23504, was collected in 1965 from the Hell Creek formation of Montana by Harely Garbani, an extremely talented field paleontologist and major contributor to the Museum's Mesozoic collection. Although this is a fine specimen and preserved in the round with much of the post cranial intact, the skull is quite mangled and what remains is weathered and crushed. The neck is curled back, putting the top of the skull perpendicular with the ground plane. Essentially this means that the jaw, and palate will be in clear view, and only one side of the skull will be really viewable, but when reconstructions are produced for museum exhibition they are also used as research and education materials. It is common that an animal, especially a rare one, is shared with other institutions in the form of cast reproductions for this purpose. Although nothing is planed as of yet, many of specimens that Doyle has worked on don't just go into exhibits, they are reproduced for other applications.

Cranial reconstruction. Gray material is a cast of the specimen.
The brown material is the clay reconstruction.

This specimen will be exhibited in the Tyrannosaurus tableau as a carcass, and potential meal of the fearsome three in the new Dinosaur galleries at the Natural History Museum of Los Angeles.