When Dr Tony Martin joined MV palaeontologist Dr Tom Rich and volunteer Greg Denney on a four-week examination of Victoria's Cretaceous coastline last year, he was hoping to find dinosaur burrows. He didn't expect that he'd find the most significant dinosaur track site in southern Australia instead.
Dr Martin of Emory University, Georgia, was at Museum Victoria recently to examine some trace fossils in the collection. Trace fossils are his speciality and he's spent many years studying the burrows, tracks and trails of prehistoric animals preserved in the fossil record. Decades of searching for tracks at palaeontological sites worldwide means that he has an eye for spotting these subtle and sometimes cryptic trace fossils.
Late in the day during the third week of the Cretaceous Walk, Dr Martin saw something unusual in a slab of rock. Because of the low light he didn't trust his eyes and starting feeling the surface. "I was in awe at first," he says. "One of the things I did was I put my fingers into the indentations and thought OK, that's a track. Then I traced back and found two more, identically sized, making this the first Victorian trackway we know of where there's an actual sequence of steps."
Dr Tony Martin with the dinosaur trackway he found on Melanesia Beach.
Source: Museum Victoria
Until that moment, only four individual dinosaur tracks were known for all of Victoria. But that wasn't the only discovery of the day. Greg Denney long-time local collaborator on the Dinosaur Cove digs, spotted something else. "He saw there was another slab nearby of the same thickness, with the same layers, but upside down. He grabbed a piece of driftwood and flipped it over - and there were seven more tracks on it."
All up, the two slabs have increased the number of Victorian dinosaur tracks by 85 per cent. "They're only about 1.1 square metres but it was a busy little piece of real estate, because there are approximately 24 tracks within that." Some of the footprints are partial tracks and many are very faint but they still reveal a lot about the Victorian environment over 100 million years ago. The dinosaurs in question were small predatory dinosaurs, ranging from about the size of a rooster to the size of a cassowary. They belonged to a group of animals called the ornithomimosaurs, or bird-mimics. Dr Martin postulates that the individuals may have been different ages, and they were walking over swampy areas left on receding snowmelt floodplains in springtime.
In March 2011, Museum Victoria retrieved the two slabs for the palaeontology collection as they were at risk of being lost from erosion and burial. A scientific paper by Dr Martin, Dr Rich and three other experts that describes the amazing find was published in the journal Alcheringa: An Australasian Journal of Palaeontology yesterday. As Dr Martin summarised it, "I've made other discoveries in my life, and I wouldn't like to rank them, but this one's way up there. It's one I feel very satisfied with that it added quite a bit to what's already a huge wealth of information that's come out of this part of the world."
In this video, Tom Rich talks more about the trackway and the effort to remove the slabs from Melanesia Beach.
Watch this video with a transcript
Martin, A.J., Rich, T.H., Hall, M., Vickers-Rich, P. & Vazquez-Prokopec, G. A polar dinosaur-track assemblage from the Eumeralla Formation (Albian), Victoria, Australia. Alcheringa, 1–18.
The Age: 'Walking in their footsteps on Victoria's dinosaur trail'