Abstract

PRELIMINARY SCIENTIFIC REPORT

Abstract

A new specimen of Tyrannosaurus rex from the Lance Formation in eastern Wyoming (nicknamed ‘Peter’) is reported herein. The specimen shows taphonomical details including traces on the bones produced by teeth, accompanied by crushed and shattered bones apparently modified during feeding by another T. rex. These record events incurred at the end of the animal’s life or shortly thereafter and may represent extreme osteophagy.

Peter was undoubtedly fed upon, and most likely killed, by another Tyrannosaurus rex. There is especially severe damage to the leg bones (femur and tibia) which can only be due to the jaw mechanics of an animal with an incredible bite force and in the Late Cretaceous Period, the most powerful bite belongs to a T. rex.

SPECIMEN NUMBER AWMM-IL 2022.9

Full Report

Peter the T.rex is 47% complete

A set of parallel tooth marks, Knethichnus paralleum, found on both long bones, fits Tyrannosaurus rex tooth morphology. There is also a set of smaller parallel tooth marks on the femoral shaft suggesting feeding by a juvenile tyrannosaurid. There are no other indications of scavenging, perhaps implying that this was a kill site or due to exocannibalism whereby ‘Peter’ was killed and only partially eaten.

The specimen also preserves paleopathological details such as erosion of articular surfaces of the ischium and femur. The astragalus has two lesions on the ascending process, one penetrating the bone that is surrounded by reactive bone.

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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 As these reports are preliminary, they’re not peer-reviewed yet.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.