Sydney, Oct 2 (IANS): Researchers have found three-dimensional prints of a 400 million year old fish fossil that can reveal the possible evolutionary origins of human teeth.

The printed fish fossil was found around Lake Burrinjuck in southeast Australia, by researchers from The Australian National University (ANU) and Queensland Museum in Australia.

The team digitally dissected the jaws of a fossil Buchanosteus -- an armoured fish from the extinct placoderm group -- and used the 3-D prints to learn how the jaws moved and whether the fish had teeth.

"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," said Gavin Young, palaeontologist at The Australian National University (ANU).

In the study, the team used high-resolution CT scan to investigate the internal structure of very fragile fossil skulls and braincases that have been acid-etched from limestone rock.

"It's great that we are able to use recent technology, such as micro-CT scanning and 3-D printing, to examine some of the earliest known evidence of tooth-like structures in the most primitive jawed fishes," noted Carole Burrow from Queensland Museum.

The study helped determine when and how teeth -- a characteristic feature of all animal species with jaws, including humans -- had originated in evolutionary history.

The results were published in the journal Biology Letters.