Fossilised footprints belonging to 230-million-year-old dinosaurs have been unearthed in Brisbane, imprinted in the same sandstone used to construct some of the city's most recognisable buildings, ABC News reported on Sunday (15 November).
University of Queensland palaeontologist Dr Anthony Romilio said two separate pieces of Brisbane-mined sandstone handed over to UQ's Dinosaur Lab appeared to display the footprints of the Sauropodomorph. Both pieces were discovered during the 1950s, the ABC reported.
"Instead of walking on all four legs, they walked on their back legs. They still retained a very long neck and tail, but they were more ancient than the more typical than the Brontosaurus," Dr Romilio said.
"These buildings certainly capture my eye, and I do glance twice to see what evidence might be hidden within their own architecture," he said.
The History of Petrie's Quarry
The inner-north suburb of Albion was once Petrie's Quarry. Educator Sue-Belinda Meehan told the ABC the Petrie family opened the quarry in the 1860s, 30 years after the family settled in Brisbane, which was then known as the Moreton Bay Penal Colony.
"If the Petries hadn't recognised the quality of that sandstone, we wouldn't have the sandstone that literally built Brisbane," she said.
The General Post Office, All Hallows School and the Old Customs House were all made from the creamy, white stone, the report says, and St Stephen's Cathedral, St John's Cathedral and St Paul's Presbyterian Church are among the other buildings that feature Petrie sandstone.
"The thing that really tickles me is that there were stonemasons looking at big blocks of sandstones going, 'Oh heaven's, there's a flaw in it, there's a footprint' … and cutting it out," Ms Meehan said. She said the scar of the quarry can still be seen from Crosby Road, looking up to St Margaret's.
Dr Romilio said the white hills of Albion were made up of layers of sand deposited when the landscape was traversed by dinosaurs. "If you were to travel 230 million years ago, you would find a very flat area," he said. "It would have been shallow enough for a two-legged dinosaur to walk past."
Australia's Oldest Dinosaur Fossil
The ABC reported that one of the footprints was discovered by a teenager more than six decades ago, a fossil UQ confirmed earlier this year as Australia's oldest dinosaur fossil. A UQ release says the 18.5-centimetre footprint was discovered by a teenager at Petrie's Quarry in 1958 but remained unstudied for more than 60 years. That teenager was study co-author and UQ Honorary Professor Bruce Runnegar, who collected the fossil during a visit to the quarry with school friends and has kept it since.
"This is the only dinosaur fossil to be found in an Australia capital city and shows how globally significant discoveries can remain hidden in plain sight," Dr Romilio said in the release. UQ says the footprint was likely made by an early sauropodomorph that stood roughly 75 to 80 centimetres tall at the hip and weighed about 140 kilograms.
"At the time, we suspected the marks might be dinosaur tracks, but we couldn't have imagined their national significance," Professor Runnegar said.
The paper, published online in the journal Alcheringa on 1 February, describes the track from the Aspley Formation, where no skeletal remains of dinosaurs have yet been found, Sci.News reported. Sci.News said the footprint preserves impressions of three forward-pointing digits, and that the authors caution a possible tail trace found with it cannot be confidently attributed to a dinosaur.
"It may seem unusual in a capital city that we find evidence of dinosaurs, but really all you need is the right aged material and a keen eye, and some conviction to investigate," Dr Romilio told the ABC.