High school student discovers skeleton of baby dinosaur

A chance find by a high school student led to the youngest, smallest and most complete fossil skeleton yet known from the iconic tube-crested dinosaur Parasaurolophus. The discovery, announced today by the Raymond M. Alf Museum of Paleontology at The Webb Schools, shows that the prehistoric plant-eater sprouted its strange headgear before it celebrated its first birthday. Three-dimensional scans of nearly the entire fossil are freely available online, making this the most digitally-accessible dinosaur to date.

This is the skeleton of the baby Parasaurolophus nicknamed "Joe"
[Credit: Raymond M. Alf Museum of Paleontology]

The fossil skeleton was discovered in 2009 by high school student Kevin Terris, within Grand Staircase-Escalante National Monument in southern Utah. Incredibly, the specimen was missed by two professional paleontologists, who walked within several feet of the exposed bones days prior to the discovery. "At first I was interested in seeing what the initial piece of bone sticking out of the rock was," commented Terris. "When we exposed the skull, I was ecstatic!" Excavation and subsequent cleaning of the fossil, nicknamed "Joe" after a long-time supporter of the Alf Museum whose family funded preparation of the fossil, revealed nearly the entire skeleton of a baby dinosaur measuring only six feet long when it died.

Detailed study of the skeleton of "Joe" identified it as the most complete specimen yet known for Parasaurolophus, a duck-billed (hadrosaurid) dinosaur that lived throughout western North America around 75 million years ago. The herbivore is notable for a long and hollow bony tube on the top of its skull, which scientists speculate was used like a trumpet to blast sound for communication, as well as a billboard for visual display. Although partial skulls and skeletons of full-grown Parasaurolophus have been known for over 90 years, scientists previously knew little about how Parasaurolophus grew up.

This image shows a comparison of the size of the baby Parasaurolophus (green) to adult
Parasaurolophus, as well as an adult and baby human [Credit: Scott Hartman, Matt
Martyniuk, and Raymond M. Alf Museum of Paleontology]

Intriguingly, the new fossil shows that baby Parasaurolophus had a low bump on top of its head, which only later morphed into the curved tube of adults. "Our baby Parasaurolophus is barely one-quarter of adult size, but it had already started growing its crest," stated lead project scientist Andrew Farke, who is Augustyn Family Curator at the Raymond M. Alf Museum of Paleontology. "This is surprising, because related dinosaurs didn't sprout their ornamentation until they were at least half-grown. Parasaurolophus had to get an early start in order to form its unique headgear."

A sample of bone from the leg helped estimate the animal's age at death. "Dinosaurs have yearly growth rings in their bone tissue, like trees. But we didn't see even one ring. That means it grew to a quarter of adult size in less than a year," commented co-author Sarah Werning of Stony Brook University. Although "Joe" was only six feet long and a year old, it would have grown to 25 feet in length as an adult.