How did our teeth evolve? A 3D printed fish fossil might have a clue

30 Sep 2016

ANU PhD student Yuzhi Hu with a 3D print of the 400m-year-old fish fossil that is six times the size of the specimen. Image: Stuart Hay/ANU

By analysing a 3D print of a 400m-year-old fish fossil, Australian researchers believe they will find a big clue to the evolutionary origin of our own teeth.

The fish fossil was a dissected jaw of a species called buchanosteus – an armoured fish from the extinct placoderm group.

By running a scanner across the ancient find and creating a digital model of the jaw, the team from the Australian National University (ANU) and Queensland Museum were able to 3D print a replica.

Future Human

By determining when and how the teeth of this ancient species formed, the researchers could shed light on the origins of jaws across many land species – including humans – and their evolutionary stages throughout history.

Found about 50km north-west of the Australian capital of Canberra, the ancient fossil was run through a high-resolution CT scanner to create a much larger version of the fossil for the researchers to inspect.

3D printed fish jaw

The 3D-printed jaw of the ancient fish. Image: Stuart Hay/ANU

Placoderm group will reveal the tooth

When the 3D print was produced, it measured six times that of the original sample.

Choosing a fish in the placoderm group was no accident as it has been the focus of the tooth origin story for some time, according to Queensland Museum’s Dr Carole Burrow.

“Our team has been able to examine the gnathal plates of placoderms from the Early Devonian period, and compare their internal and external structure with those of younger placoderms as well as with the true teeth in other jawed fishes,” she said.

Meanwhile, ANU’s Dr Gavin Young spoke about the team’s next steps in determining what connection the species has with modern day humans. “We are conducting further research on the internal tissue structure of tooth-like denticles in the mouth of the fish fossil, to determine whether they represent a transitional stage in the evolution of teeth.”

Colm Gorey was a senior journalist with Silicon Republic