Australia So Much to See

While local station owner Glen Seymour was fossicking for opals on the hill that now bears him name, he discovered a fossilised bone. This alone was not a startling discovery, but nearby he uncovered a footprint.  Following showing it to a station employee who believed it to be a dinosaur print, the sample was sent to the Museum of Queensland where the identification was confirmed. This was in 1962, following which farming continued on the station with little thought of what lay under the ground yet to be discovered. 

During 1971 a panel of experts ascertained that the incline with the prints would have continued past a present creek line and into the next hill.  Subsequent excavations found perfectly preserved prints of three different species.  The most successful dig was overseen by Doctor Mary Wade, and over a ten year period an elderly man by the name of Malcolm Lark was a consistent worker. Doctor Wade named Lark Quarry Conservation Park, which now covers 374 hectares, in his honour.  Lark Quarry is the largest of three excavations in the Conservation Park that have revealed dinosaur tracks. 

International research has taken place and by making comparisons with other trackways and fossil discoveries around the world, calculating the size of the animals.  They have also calculated the speed of the predator as the footprints dug deeper into the muddy surface at the water’s edge.  The predator left eleven tracks preserved in the mud, taking steps up to two metres long, leaving three toed prints up to 58 centimetres long.  The distance between the prints indicates it was walking at about eight to nine kilometres per hour.  After six steps it shortened its paces showing that it slowed to about six kilometres per hour.  Strides one to six are about sixty centrimetres long, but footprint seven is only forty centimetres.  At the tenth step, the large theropod had begun to turn right. It took one more step and then its tracks are lost. What happened after this is impossible to say because the side of the creek has been eroded away.

There were three species present at the water’s edge, with adults and young included. Many small chook sized creatures called coelurosaurs were present, panicking and running around, as were a number of sheep sized dinosaurs called ornithopods.  All these dinosaurs stood, walked on hind legs and ran on their toes, much like birds do. This type of movement is called digitigrade.

It is evident that the small dinosaurs were running because the length between successive steps is greater than leg length. These coelurosaurs moved at about nine to fifteen kilometres per hour and ornithopods at about ten to thirty kilometres per hour. The small dinosaurs crossed the quarry area in a fairly uniform spread so it is probable they were running from the big theropod.

See more about the Lark Quarry story at Lark Quarry Dinosaur Trackways

and Lark Quarry Dinosaur Stampede

Winton - We visit Lark Quarry, where the only dinosaur stampede in the world has been discovered in trackways

The site where the Lark Quarry footprints were found was once a stream bed leading into a lake. Scientists believe that the water level in this creek dropped, exposing a patch of half-dried, still pliable mud on one side. 

Once the tracks were uncovered, relentless heat and occasional rain storms eroded the exposed ‘soft’ solidified powdery mud, so a roof was erected in 1979. Kangaroos found this an ideal shelter, and tourists walked across the prints causing further degradation. 

The present climate controlled building was erected in 2002 using Government funding of $2.5 million; this being allocated for the preservation and presentation of Lark Quarry as part of the Queensland Heritage Trails Network initiative.  This building was insulated by mud brick walls, using removed rubble to form the bricks and create a climate controlled environment.  The complex was officially opened on 18^th August 2002, however following the collapse of one of the mud brick walls, it remained closed from 30^th October 2002 to 11^th April 2003. 

Similarly in October 2011 instability in a wall caused the trackways to be closed to the public until 5^th April 2012.  Funding is being sought to do further preventative maintenance on the building.

In 2004, the site was placed on the National Heritage List.

Countless studies have been done on this site – the only stampede scene discovered anywhere in the world.  Visitors to Lark Quarry can be a part this unique experience.  Whereas other dinosaur trackways have been uncovered, only here there is evidence of a chase.  This dinosaur stampede in part inspired Steven Speilberg’s story of Jurassic Park.  It has been calculated that there are around 3,300 footprints from 150 animals at the Lark Quarry site. 

The fact the footprints were preserved in the drying mud at the water’s edge rather than just washed away is one uncommon occurrence. Covered and protected for around 95 million years, and by chance discovered by a station manager to be excavated by a paleontology team is another.  We are indeed fortunate to have this discovery made in our lifetime, and have the opportunity of sharing in the 95 million year old story.

Glen Seymour also found a fossilised crocodile in a creek bed on his property, and his son is trying to re-locate it.  A number of one to one and a half metre crocodiles have been found in the wider region and these are believed to be ancestors of present day crocodiles.  The discovery of a complete skeleton without the snout, and another skull near Isisford, has placed Queensland as the original of modern crocodiles across the world.  We will learn more about this when we reach Isisford.