In 2016, Dr Clement and Professor Long published groundbreaking research on the beautifully preserved fossil skull of a lungfish called Rhinodipterus, from the 385-million-year-old Gogo Formation in Western Australia’s Kimberley region.
Along with colleagues from Uppsala University in Sweden, Dr Clement pioneered a ‘brain-warping’ technique, whereby she studied the brains of modern lungfish and used these insights, along with the fossil braincase of Rhinodipterus, to more accurately reconstruct its brain.
This innovation was significant, as fish brains don’t fit snugly into the braincase. The resultant gap means fossil braincases alone aren’t good guidelines for the shape of the brains that once sat inside them. The technique allowed for a prehistoric brain to be rigorously reconstructed for the first time, using computer models and data from both living animals and fossils.
In May 2018, the pair published a brain reconstruction of a second fish, called Ligulalepis, from 400-million-year-old rocks near Wee Jasper in New South Wales.
Exploring evolutionary changes in these brains could reveal when and why certain senses, such as smell or sight, took precedence and allowed some animals to succeed where others failed. “What’s really cool is that you can track changes through evolutionary time,” says Dr Clement. “You can see if there are certain regions of the brain that are increasing or decreasing in relative size.”
In the lungfish, she noticed a gradual increase in part of the forebrain called the telencephalon, likely related to the sense of smell. “This suggests to me that vision is less important in these fish, perhaps because of the murky water they live in, and that’s why they’re relying on sense of smell instead.”
While the earliest well-established fossils of land-faring limbed fish were found in Greenland and dated to 380 million years ago, Dr Clement says there are other intriguing fossil footprints in Poland that are perhaps 20 million years older. “There are plenty of trackways that are a bit ambiguous, but these ones in Poland have distinct digit impressions, so you can tell there was a foot or a hand.”