A 95m-year-old dinosaur cranium found in Winton, Queensland, has been recognized by palaeontologists as the primary almost full sauropod cranium ever present in Australia.
The cranium belongs to a Diamantinasaurus matildae dinosaur, nicknamed Ann, that lived between 95m and 98m years in the past. It is just the fourth specimen of this species ever found.
The research’s lead researcher, Dr Stephen Poropat of Curtin College, mentioned it was “actually superb to have the ability to discover a cranium in any respect – they’re fairly uncommon, and much more so to get a lot of 1 that had been preserved”.
Sauropods have been a bunch of long-necked dinosaurs that included Brachiosaurus and Brontosaurus. They’d small skulls relative to their physique dimension, with delicate cranium bones.
“They’d have been goal for a predatory dinosaur or perhaps a scavenging animal,” Poropat mentioned. “They’d have checked out a sauropod carcass and [thought]: ‘The best factor to remove is their head.’”
He mentioned that with earlier sauropod discoveries, “You’ll typically comply with a string of neck vertebrae and are available to nothing on the finish of it as a result of the pinnacle had gone.”
Diamantinasaurus matildae was a titanosaur, a kind of sauropod that included the most important land animals in historic existence. The invention of the Diamantinasaurus cranium allows scientists to recreate for the primary time what the dinosaur’s face might have appeared like.
“In some methods, the pinnacle appears to be like very very like that of Brachiosaurus,” Poropat mentioned, noting there have been some variations in form and its tooth.
“As a result of [Diamantinasaurus] has a rounded snout as an alternative of a squared-off snout, we will say it was a generalist browser – it was not feeding near the bottom habitually.”
“After we see sauropods that have been low feeders, they have an inclination to have a lot narrower tooth, they have an inclination to have snouts which might be kind of squared-off, nearly like vacuum cleaners.”
The Diamantinasaurus cranium had many similarities to a different titanosaur, Sarmientosaurus musacchioi, which lived in South America across the identical time. “You could possibly nearly put Sarmientosaurus’s head on Diamantinasaurus’s physique and barely have the ability to inform the distinction,” Poropat mentioned.
The researchers consider the invention reinforces a speculation that throughout the mid-Cretaceous interval – 95m to 100m years in the past – sauropods traversed between South America and Australia, utilizing Antarctica as a pathway.
“As a result of the world was extraordinarily heat … the poles have been vegetated, not lined in ice,” Poropat mentioned. “It will appear that sauropods took benefit of this actually heat interval.”
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Ann doubtless measured 15 metres to 16 metres lengthy from head to tail. The utmost dimension for Diamantinasaurus is about 20 metres lengthy, 3 to three.5 metres excessive on the shoulders, with a weight of 23 to 25 tonnes.
“So far as sauropods go, they’re medium-sized,” Poropat mentioned. “The biggest [sauropods] push 40 metres in size and 80 tonnes in mass.”
The Diamantinasaurus cranium was discovered throughout a dig in 2018 however has remained unreported till now. The method concerned taking off topsoil after discovering bone fragments on the floor.
“We began discovering largely limb bones and vertebrae, however round one of many limb bones there have been scattered small bones and … it was arduous to put what they have been,” Poropat mentioned.
Mel O’Brien, a volunteer, then discovered “a very weird-looking little bit of bone that we ultimately realised needed to be a mind case. That then made all the opposite bits fall into place – we realised that we had a cranium that had principally exploded and the bits have been scattered across the again leg bones.”
The excavation was carried out in collaboration with the Australian Age of Dinosaurs Museum of Pure Historical past, citizen scientists and volunteers.
The research was revealed within the journal Royal Society Open Science.