Can 3D Imagery of crocodile limb anatomy shed new light on dinosaur movement?

Published 10 April 2017

PhD student at the University of New England’s FEARLab, Ada Klinkhamer believes so.

Ms Klinkhamer recently completed a 3D investigation into the limb muscles of the Australian estuarine crocodile, more commonly known as a saltwater crocodile.

Forelimb model of a saltwater crocodile.

Forelimb model of a saltwater crocodile.

The ‘digital dissection’ was done at Armidale Radiology and involved getting CT and MRI images of a 2.1m crocodile. Specialised software was used to digitally dissect out all the muscles in the forelimb and hindlimb of the reptile.

“It was a time-consuming and often difficult process, but the final result was worth it,” Ms Klinkhamer said.

The project is part of Ms Klinkhamer’s larger study designed to better understand how giant long-necked dinosaurs lived and moved.

Although the Australian estuarine crocodile is the largest living reptile species, very little is known about the anatomy of this group. Using freely available 3D technology to scan the limbs allows Ms Klinkhamer to digitally manipulate the images to improve understanding of the form and function of muscle groups.

“Crocodile and alligator species look very similar, but they employ different behaviours in the way they move about and capture prey. These differences are often reflected in the arrangement of limb muscles which are used for powering movement. Therefore, the more we know about the limb anatomy of different species of crocodile, the better we can understand their lifestyles and evolutionary history.”

Hindlimb model of a saltwater crocodile

Hindlimb model of a saltwater crocodile

By combining information gathered on crocodile limb muscles with that of bird limb muscles, it is possible to reconstruct the muscles of dinosaurs.  After reconstructing dinosaur muscles Ms Klinkhamer will use specialised software to investigate how these muscles in dinosaurs functioned, which would also reveal more about how they lived.

The UNE FEARlab (Function, Evolution and Anatomy Research) investigates the relationship between shape and function in both living and extinct animals. It uses cutting-edge digital techniques to explore a whole range of animal features and behaviours.

Ms Klinkhamer’s findings were published in PLOS ONE – a peer-reviewed open access scientific journal published by the Public Library of Science – last week. Included in the paper are two 3D PDFs. This type of PDF allows the reader to move and interact with the digital 3D model.

“Using 3D PDFs means the results are easier to visualise compared to traditional 2D illustrations and using digital data also means the final results are easily shareable with other researchers and the public”.

The paper entitled “Digital dissection and three-dimensional interactive models of limb musculature in the Australian estuarine crocodile (Crocodylus porosus)” can be accessed here: