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

Read about the photogrammetry on this page, and access the full report here


From the perspective of paleontological science, it is important that the original fossils of ‘Barbara’ are made available in perpetuity for further academic study. It goes without saying, that once the original fossilized bones are inlayed into a fully mounted specimen for museum exhibit, these fossils are hard for paleontologists to access again. An important development from a scientific perspective is that high resolution 3D digital models have developed to such an accurate degree that they can now replace real bones for a wide variety of research scenarios. 

‘Barbara’s’ photogrammetric scans were a top priority for the team of scientists working on this specimen, and full scans of every bone were created after preparation and before the specimen was mounted for exhibit.

The most suitable scanning methodology for objects of complex shape and variable size is photogrammetry, a “Structure From Motion” scanning method based on digital photography. The scans capture the external shape as well as the color of the fossil in extremely high detail.

Photogrammetry models are created by taking high resolution digital images of an object, with either the camera, the object or both moving between shots. Overlapping photos from different angles allows the Agisoft Metashape software to calculate the relative position of camera and object for each image. A simple tie point cloud is created, which gives the base for a high density point cloud. This point cloud is meshed to produce a solid polygon model. A high resolution 2D texture is then calculated by using selected images of the object.

During the first photoset, a scale bar with two or more fix points at a known distance is added. Using a scale bar with two fix points at a distance of 10 cm for ‘Barbara’ allows the software to calculate and scale each bone to its original size. 

‘Barbara’ is an incredibly important specimen from a paleontological science perspective. Due to the high resolution of each fossilized bone’s texture, which shows important surface details, as well as the exact resizing of each bone, the Photogrammetry process using Agisoft Metashape provides an excellent approach to enable the continued study of ‘Barbara’ by academics in perpetuity.

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.