A preliminary report on a new specimen of Tyrannosaurus rex named 'Barbara'

Read the abstract on this page, and access the full report here


A new specimen of Tyrannosaurus rex collected from the Hell Creek Formation of northeastern Montana (nicknamed ‘Barbara’), specimen number AWMM-IL2022.21, is reported herein. The new specimen preserves an especially severe injury to the foot from an external traumatic event that happened during the animal’s life. This Tyrannosaurus rex lived for a long period after the injury as can be seen on a healed metatarsal. This was remarkable for such a massive animal that was an obligate biped, and it is incredible that it survived such an injury.

The nearly complete left metatarsal II shows massive alteration of the bone surface and additional bone growth around the location of the insertion scar for the gastrocnemius muscle, indicating a traumatic tendon injury. The metatarsal also shows extensive remodeling from a possible stress fracture. Both abnormalities indicate long term survival after the initial injury. As the injury must have limited the locomotor prowess of the individual to a large degree, long term survival can be interpreted as evidence that Tyrannosaurus rex was able to change its feeding mode entirely from predation to scavenging or perhaps lived gregariously, allowing the injured individual to gain nourishment from prey caught or abandoned by other members of the pack. In either case, ‘Barbara’ was no longer able to capture its own prey.

Left II Metatarsal

Sharing the science

We’re pleased to be able to share Preliminary Scientific Reports to help visitors who come to see these incredible T. rex understand more about them.

These reports are prepared by two of the world’s top therapod paleontologists, Dr David Burnham (University of Kansas Biodiversity Institute and Natural History Museum) and Dr John Nudds (Department of Earth and Environmental Sciences, University of Manchester), who have studied both Peter and Barbara in their university laboratories for many months. Their research has identified the unique pathologies of each specimen, such as the injury to Barbara’s leg and the marks on Peter’s leg. As these reports are preliminary, they’re not peer-reviewed yet.

It’s not standard practice for a museum to share this much information when a specimen is being exhibited for the first time, but with the benefactor’s agreement we’re keen to share the initial findings, to enhance the learning experiences that having these two specimens in our Museum provides for the people of Aotearoa New Zealand.

Updates to the Preliminary Scientific Reports will be an ongoing process and will most likely span decades, rather than years.