Remains of world’s oldest recorded platypus have been discovered in Santa Cruz

paleontologists from Conicet and some National Museum of Nature and Science, Tokyo, Japanfound remains of the first relative of the current platypus Australian rocks in the Cretaceous of 70 million years about 30 kilometers southeast of the town of El Cafayate, Holy Cross.

The “new” species has been named Patagorhynchus pascuali and it became oldest known platypus in the world. Indeed, it turns out to be the first close relative of the Australian platypus (Ornithorhynchus anatinus) known from the Mesozoic era, known as the “age of the dinosaurs”.

His presentation took place at the Provincial Cultural Complex and his discovery was published this Thursday in the magazine Communications Biology of the group Nature.

The name Patagorhynchus means “Patagonian muzzle” in Latin, alluding to the duck-billed snout of living and fossil platypus, while “pascuali” pays homage to the Argentine paleontologist Rosendo Pascualwho was the first to find platypus remains in Patagonia, albeit in younger sites.

The expedition was co-led by Fernando Novasresearcher at Conicet and director of the Laboratory of Comparative Anatomy and Evolution of Vertebrates (Lacev) of the Argentine Museum of Natural Sciences Bernardino Rivadavia (Macnbr, Conicet), and his colleague Makoto Manabeof the National Museum of Nature and Science in Tokyo.

While the person responsible for the discovery is Nicolas Chimentoresearcher Conicet at Macnbr, who found a small tooth five millimeters in diameter on the surface of the soil explored.

After the discovery, the paleontologist pointed out that due to the weight of the fossil remains, they will need an army helicopter “to transfer it to the ranch and be able to transport it for study”.

“We believe this skeleton may be complete, as there are several hinged vertebrae, which gives us an indication that there may be more under the ground, so we will continue to open it up to see if more a skeleton of an insect which It is about 20 meters long.they said in the presentation.

The intricate shape of the crown and roots made it easy to determine that the tooth belongs to a relative of today’s platypus. “The teeth of living platypuses, as well as those of a fossil found in Australia, are distinguished by two short ‘V’-shaped structures. So when I found the Patagorhynchus tooth and saw that it had the same shape, which is unique to these animals, I immediately knew it was a platypus,” Chimento said.

Platypus are monotremes, a group of mammals that are characterized by very primitive traits, such as the fact that their young are born from eggs that are incubated in the same way as birds. This reproductive behavior differentiates them from the vast majority of living mammals, which give birth to their young from the womb.

For this reason, the lineage of these primitive animals has always aroused the interest of researchers, “since they represent something like ‘missing links’ of a very old stadium”, underlined the Conicet. Patagorhynchus is the first Late Cretaceous (last period of the Mesozoic era) monotreme known from South America.

Nicolás Chimento is part of the campaign called “Jurassic and Cretaceous Vertebrates from Santa Cruz” led by paleontologist Fernando Novas.

In this regard, Novas underlined the importance of “the discovery of the tooth of the ancestor of the current platypus, which tells us a 70 million year history of this very strange line of mammals that reproduce by egg. and have a very strange muzzle”. so that they can detect where their prey is.

“It’s transcendental for Argentine science, because it’s not just the discovery of one more tooth, of a mammal, but it speaks for the first time, in terms of the age of dinosaurs, close intercontinental relations, the extreme south of Patagonia to Australia, mediator of the Antarctic continent”said the Conicet researcher.

The discovery of remains of an Australian platypus ancestor in southern Argentina highlights the importance that the southern territory of America had in the evolution of mammals, according to the researchers who participated in the discovery. .

According to paleontologists, the discovery of Patagorhynchus supports the hypothesis that at the end of the Cretaceous the same fauna composed of mammals and dinosaurs extended from southern Patagonia to Australia via Antarcticawhich at the time was wedged between the two continents.

70 million years ago, southern Patagonia and Australia were territories with climates ranging from temperate to cold and were home to lush forests in humid environments.

A characteristic feature of the platypus is the presence of a broad, soft snout, which represents an evolutionary derivative of the plump, moist nose possessed by other mammals. This enlarged snout or nose, enlarged outwards and backwards, is a very sensitive electroreceptor and mechanoreceptor organ with which platypuses detect insect larvae and aquatic snails that serve them as food, the scientists explained during of a press conference.

Federico Agnolín, researcher at Conicet and one of the authors of the work, added that “it has always been thought that these primitive lineages of mammals were limited to Australia. In the 1990s, a relative of the Cenozoic Platypus appeared in Patagonia and it was considered that it must correspond to a later migration and that it did not question the fact that all these groups had evolved on the Australian mainland. “The present discovery demonstrates that relatives of the platypus already inhabited South America much earlier than previously thought,” he noted.

With information from the Telam Agency.

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