An exciting study published today in the journal Biology Letters announces the discovery of a new dinosaur species, one which turned out to be the oldest long-necked sauropod in the entire fossil record.
Dubbed Macrocollum itaquii, the newfound dinosaur species was described from three skeletons unearthed in Brazil, and represents an early ancestor of the sauropod mega-herbivores that roamed the Earth throughout the Mesozoic Era.
Classified as a sauropodomorph — a clade of dinosaurs that includes sauropods and their ancestral relatives — Macrocollum itaquii was dated to approximately 225 million years ago, reports Phys.org. This places the newfound sauropodomorph species in the Late Triassic — the first period of the Mesozoic Era, which started 251 million years ago.
According to Live Science, the Macrocollum itaquii remains were unearthed from early Norian rocks found in an outcrop in rural Agudo, a city in southern Brazil. This makes the find all the more thrilling, given that not many dinosaur fossils from the Norian Age — the middle age of the Late Triassic, spanning from 227 million to 208.5 million years ago — have endured to this day.
The three sauropodomorph skeletons are nearly complete, and are “exceptionally well-preserved,” which further adds to their scientific value — making their discovery “a boon to paleontology,” as Live Science puts it. Moreover, two of the skeletons have completely preserved skulls — a rarity for sauropodomorph fossils, particularly ones so ancient as Macrocollum itaquii.
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This incredible discovery is credited to a trio of paleontologists led by Rodrigo Temp Müller from the Center for Paleontological Research of the Fourth Colony at the Federal University of Santa Maria. Müller named the new sauropodomorph after José Jerundino Machado Itaqui, the founder of the research center.
Perhaps the most striking feature of Macrocollum itaquii is its remarkably elongated neck — an adaptation which suggests that the ancient sauropod had already developed a taste for tall vegetation, and was probably munching on the foliage of towering trees.
Up until now, this adaptation — the extreme elongation of the neck vertebrae — was first seen in the much younger sauropodomorph species known as Massospondylus (shown at the beginning of this article), which emerged during the early Jurassic.
“The new dinosaur is the oldest-known sauropodomorph with such an elongated neck, suggesting that the ability to feed on high vegetation was a key trait achieved along the early Norian,” the authors wrote in their paper.
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In case you’re wondering just how long the neck of Macrocollum itaquii really was, Müller has the answer.
“We can consider it a long neck when it is approximately as long as the trunk region. The neck of the new dinosaur is proportionally two times longer than the neck of previous sauropodomorphs, such as ‘Buriolestes schultzi’ and ‘Eoraptor lunensis.'”
This arresting feature is aptly mirrored by the species’ name, which combines the Greek word “makro” and the Latin word “collum.” Another interesting thing about Macrocollum itaquii is that this dinosaur was bipedal — unlike its more famous descendants, which walked around on four legs.
At the same time, the ancient sauropodomorph was a lot smaller than later sauropods. According to the team, Macrocollum itaquii grew to be only 11 feet long, and weighed just 200 pounds. By comparison, Patagotitan mayorum, the largest sauropod to ever walk the planet, measured 120 feet in length and weighed more than 100 tons.
Stephen Poropat — a postdoctoral researcher of paleontology at the Swinburne University of Technology in Australia — described the three Macrocollum itaquii specimens as “really rare.”
“That such an ancient, [early] sauropodomorph had such a long neck is interesting, since it suggests that Macrocollum and its kin were already experimenting with the sorts of adaptations that were evidently put to such good use by their Jurassic and Cretaceous successors, the sauropods, for more than a hundred million years,” said Poropat, who was not involved with the study.
The newly discovered sauropodomorph has been included in a specially created group of early dinosaurs known as Unaysauridae, which brings together fossils from various species of sauropodomorphs uncovered in Brazil and India. All these dinosaurs share a common trait — namely that they roamed the ancient continent of Gondwana during the Triassic Period.
“This group helps to understand the distribution of sauropodomorphs along the Triassic, indicating that they expanded from western to eastern supercontinent of Gondwana, posteriorly reaching Laurasia [current-day North America],” explained Müller.