Quito (AFP)
Herbivore, of "small size" (six meters long anyway) and appeared just before the fatal meteorite which decimated its congeners: the study of the first dinosaur fossils discovered in Ecuador unveils the Yamanasaurus lojaensis, a new species .
The disarticulated and incomplete skeleton uncovered by a Argentinean-Ecuadorian team shows that the specimen "seemed to have a protective cuirass", told the AFP, during a telephone interview, the Ecuadorian scientist Galo Guaman.
The animal was also "herbivorous" and "had to adapt to the type of low vegetation - no more than three meters - that grew in the area, which would have determined its size", explained Mr. Guaman, head of the Loja Technical University team (UTPL), which oversaw the research and announced this discovery on Friday.
The name of this dinosaur, never described before by the university, was chosen with reference to two localities: Yamana, where were found the bones, in the south of the Equator, with about fifty kilometers of the Peruvian border, and Loja, where this discovery was presented.
The Yamanasaurus lojaensis discovered was "small, six meters long and about two meters high" even though "with its long neck, it could reach three meters," said the specialist. He belonged to the group of titanosaurs, so called because of their imposing size.
On Friday, the UTPL claimed the discovery of "the first fossil of a large vertebrate of the Cretaceous period in the country," at a press conference in the province of Loja, where the bones were found in 2017.
It is the Argentinean paleontologist Sebastian Apesteguia who, by performing tomographies (imaging technique) and comparative analyzes, has established that the vertebrae found belonged to "a new species, different from those found in Argentina," said M. Guaman.
- Meteorite -
The fossils exhumed date from the Cretaceous and belong to the genus of saltasaurs ("lizard of Salta", named after an Argentine province), dinosaurs that lived there 85 to 65 million years ago and are considered the last to to have appeared on Earth just before the extinction of the dinosaurs.
"The age of the fossils was determined by geological correlation, thanks to the rock samples that correspond to the Maastrichtian period, the last period of the Cretaceous, before the fall of the meteorite that extinguished the dinosaurs," said M Guamán.
Further analyzes will follow to deepen the knowledge of Yamanasaurus lojaensis. "We are going to determine his relationships with other living beings, there may have been a predator" who coexisted with him.
The discovery of this skeleton is all the more exceptional as the soil characteristics in Ecuador were hardly favorable, because of erosion, says the 51-year-old expert, born in the Casanga Valley where located Yamana.
According to him, the remains were able to emerge and be found thanks to "the rise of the rivers in winter, which cleaned the zone" or movements of ground generated by mining activities at the end of the 1990s.
- "Special stone" -
At the origin of this discovery, an old inhabitant of Yamana launched Galo Guamán and his students in geology, then on an excursion in the area, on the track of the fossils, more than two years ago.
"I have a special stone," said the octogenarian named Francisco Celi, showing them the rock he had found.
"It was one of the vertebrae of the sacrum, that of the tail of the specimen, with this porosity of the bones, but petrified," said Mr. Guaman.
The octogenarian then took them to the place where he had found this "stone". Geologists found "smaller and lighter pieces" of the skeleton, before contacting foreign palaeontologists, including Mr. Apesteguia in Argentina, whom they convinced to travel to Loja.
© 2019 AFP