The Australian dinosaur record is one of the most misunderstood, with only a handful of species discovered in the last hundred years. But a newly identified has been in our power for decades without us knowing.
A bizarre collection of unexamined bones on display at the oldest museum in Australia for years has turned out to be a completely new species of dinosaur, and the first evidence of a herd of dinosaurs in the country, including the most complete opalized dinosaur skeleton in the country. world.
"This is unheard of in Australia," said lead author Phil Bell. The Smithsonian. "There were around 60 bones in the entire collection, which is a remarkable number for an Australian dinosaur."
Preserved in opal, the gleaming remains were first discovered in 1984 by Australian miner Bob Foster, who worked in an inland city and a fossil access point called Lightning Ridge.
Frustrated by the amount of dinosaur bones he was finding (after all, his livelihood was based on opals), Foster made the long trip to the Australian Museum in Sydney, more than 800 kilometers away.
"I was a little tired by then," he said. The New York Times. "I took these suitcases on the train, on the bus and up the stairs, I opened them, threw the bones on the table and rushed to catch them before they fell to the ground."
(Robert A Smith / Australian Opal Center)
And then, for some inexplicable reason, the largest collection of fossils of opalized dinosaurs went completely unstudied. When Foster saw some of them on display at an opal store in Sydney many years later, he recovered what he could and donated everything to the Australian Opal Center in 2015.
It was here that the first formal study really began. After years of careful research, using a CT scanner instead of physical extraction, researchers at the New England University in Armidale discovered traces of a completely unknown species of dinosaur, called Fostoria dhimbangunmal, Named for its discoverer and the traditional land in which it was found.
Nestled in opal, the remains probably belong to four herbivorous dinosaurs that are related to the iguanodontian dinosaur. Diverse during the early Cretaceous, these dinosaur taxa have so far been found mainly in Europe and North America.
Fostoria is only the second described in Australia, and also the youngest. Unlike its Australian pair, in central Queensland, the bed of bones where these fossils were found, which used to be a lush floodplain of lakes and rivers, is stratigraphically superior.
As such, the authors estimate that these dinosaurs once roamed the eastern margin of the inland sea of Australia, which existed during the Middle Cretaceous, when Australia was part of the supercontinent Gondwbadand.
Opalized fossils support previous claims that this particular dinosaur taxon, which had a horse-shaped skull and a kangaroo-like body, was more geographically widespread than we ever thought.
(Bell, paleontology of vertebrates, 2019)
When the inland sea of Australia began to disappear, about 100 million years ago, the sandstone that was drying up near Lightning Ridge began to grow in acidity, releasing silica that then hardened slowly to become opal.
When this bright substance is trapped in the cavities and cavities of decaying dinosaur bones, it creates a shiny mold of ancient remains.
Based on four of these encrusted opal fossils found near Lightning Ridge, the authors argue that the Foster collection belongs to a herd of at least four animals of different sizes, including two large individuals up to 5 meters in length (16 feet ), one medium-sized animal, and one small individual.
Apart from its size, the only clear indication of the age of these dinosaurs was a single and unmixed medullary neural arch, suggesting that one of the smaller animals had not yet reached skeletal maturity.
"We have bones from all parts of the body, but not a complete skeleton," Bell said. National Geographic. "These include the bones of the ribs, the arms, the skull, the back, the tail, the hips and the legs, so it is one of the best-known dinosaurs in Australia … [with] 15 to 20 percent of the skeleton of the species. "
Now imagine all those priceless dinosaur fossils, sitting behind glbad in an opal tent, languishing for decades.
The investigation has been published in the Vertebrate paleontology journal.