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

Read the report's conclusion on this page, and access the full report here


The metatarsus on ‘Barbara’ probably has the worst injury that a massive bipedal animal could suffer. There are three major metatarsals in the foot of a Tyrannosaurus rex. They act in conjunction as a significant weight-bearing element, although there is a partial shock-absorbing mechanism inherent in the structure of the metatarsus (Holtz 1995, Snively and Russell 2003). These three bones are tightly appressed against one another and bound by ligaments, but the middle metatarsal is a bit longer and its shock-absorbing attributes indicate that the foot was designed for massive stress (due to its own mass and the mass of its prey or attacker). On the plantar side of metatarsal II is the severe pathology that indicates ‘Barbara’ suffered horrific pain from the physical trauma that ripped the tendon from the bone; moreover, the extensive remodeling of this bone indicates that the healing process would have extended for perhaps six months and possibly longer (Rothschild and DePalma 2013). Histological studies indicate tendon to bone healing may take 26 weeks or longer (Larson and Donnan 2002, Bunker et al. 2014). Perhaps T. rex was able to heal quite rapidly, more like reptiles than modern birds as suggested by Anné et al. (2014).

Soon after the trauma occurred, ‘Barbara’s’ prey-capturing ability was less than adequate; however, since the metatarsal bone became increasingly deformed over time suggests it continued to locomote adequately enough to at least scavenge. It is doubtful that ‘Barbara’ ever successfully hunted again as a predator unless its prey was in close proximity. 

If ‘Barbara’ was totally immobile, the only way to gain nourishment, would require feeding from a cohort (Hearns and Williams 2019). This is vaguely supported by trackway evidence that has been used to imply tyrannosaur group hunting (Barbara, et al., 2021), as had already been suspected by Currie (1998). The long-term survival of ‘Barbara’ may lend some credibility to this hypothesis, as pack behavior would allow an injured individual to gain nourishment from prey caught and abandoned by other members of the pack. But direct evidence of behavior, such as being fed by confamilials, is lacking in the fossil record. Unfortunately, the injury relegated ‘Barbara’ to a subjugate lifestyle by having to eat carrion at any opportunity. It is also likely ‘Barbara’ scavenged for its food supply until her death.

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.