Lark Quarry in Australia is the site of the world's only known record of a dinosaur stampede. Fossilised footprints have been interpreted as a predator stalking and causing a chaotic stampede of around 150 two-legged dinosaurs.
A group of perhaps 180 chicken-sized Coelurosaurs (Skartopus) and Bantam to emu-sized Wintonopus were disturbed by the arrival of a single much larger carnivore - a theropod named Tyrannosauropus, which may have been up to 10 metres long with 50-centimetre feet. Skartopus and Wintonopus are thought to have stampeded past Tyrannosauropus, leaving thousands of footprints in the surrounding mudflat.
Not long after the incident, the water level began to rise, covering the tracks with sandy sediments before the mud had dried. The footprints were buried beneath sand and mud as the lake and river levels continued to rise and fall. Over thousands of millennia, the rich river plain with sandy channels, swamps and lush lowland forest dried up. The sediment covering the footprints was compressed to form rock.
The footprints were first discovered in the 1960s by station manager in the nearby Seymour Quarry.
Palaeontologists from the Queensland Museum and the University of Queensland excavated Lark Quarry during 1976–77 (the quarry was named after Malcolm Lark, a volunteer who removed a lot of the overlying rock.) Altogether they removed more than 60 tonnes of rock, and uncovered about 210 square metres of the layer with the fossils. This shows about 3300 dinosaur footprints.
A sheltering roof was built over the site but did not stop the gradual damage caused by exposure to the weather. The present Conservation Building that covers the trackways was constructed in 2002. This building protects the main collection of footprints from damage by stabilising temperature and humidity fluctuations, stops water running over the footprints and keeps people and wildlife off the footprints themselves.
The Lark Quarry site is about 110 km south west of the western Queensland town of Winton.
The Dinosaur Stampede National Monument was included in the Australian National Heritage List on 20 July 2004, for values of rarity and research.
- ^ http://www.epa.qld.gov.au/projects/park/index.cgi?parkid=186 Queensland Parks and Widelife Service: Lark Quarry Conservation Park
- ^ Australian National Heritage list: Department of the Environment, Water, Heritage and the Arts
- ^ Lark Quarry: Australian heritage database