Tech UPTechnologyThey discover one of the oldest carnivorous dinosaurs of...

They discover one of the oldest carnivorous dinosaurs of the Jurassic

The discovery of part of a skeleton of a carnivorous dinosaur from the Jurassic period, which was eight meters long (and its skull only 80 centimeters) and, which is the oldest found so far, represents a moment of evolutionary explosion in the that dinosaurs diversified; from the pre-Late or Upper Jurassic period, which began about 165 million years ago and ended 18 million years later.

And is that the new fossil, found in the Argentine province of Chubut has revealed a mixture of lineages in this species that leads scientists to rethink its evolution , according to the authors published in the journal Scientific Reports that collects the study.

“The study of the skeleton revealed a very unusual combination of characters that mixes peculiarities of different families of the tetanur group, which is difficult to reconcile with the currently accepted image of the relationships between the three large groups of dinosaurs that comprise the tetanus . megalosauria, allosauria and celurosauria E ste analysis leads us to rethink what we know so far about the early evolution of carnivores in the Jurassic , “explained Diego Pol, a researcher at the Argentine organization CONICET and leader of the work in the Paleontological Museum Egidio Feruglio (MEF) and his colleague, the German paleontologist Oliver Rauhut from the University of Munich.

Pol is known to have found the remains of the largest dinosaur in the world, the Patagotitan mayorum, also in Chubut.

The largest predator of the time

In life, this dinosaur had to be really intimidating to look at. The specimen can be assigned to the Tetanurans, the most prominent group of bipedal dinosaurs, which includes such iconic representatives as Allosaurus, Tyrannosaurus Rex, and Velociraptor (and also from which modern birds are derived). The oldest tetanurans are found in the earliest Middle Jurassic, but most of the known Middle Jurassic fossils are extremely fragmentary. Hence the importance of this discovery.

The fossil probably represents the oldest known representative of one of the main lineages of carnosaurian theropod dinosaurs: the allosauroids.

A new piece of the puzzle

The fossils, of which 50% of the dinosaur skeleton could be recovered, with the skull and complete jaws (almost two dozen teeth were found) and the complete spine, including parts of the pelvis, all the bones of both extremities anteriors and parts of the legs), represents a previously unknown genus. Baptized as Asfaltoventor vialidadi , which includes the Latin term for hunter, the deposits in which the fossil was found and the name of the species refers to the maintenance of the Chubut road, which helped in the recovery of this ancient dinosaur.

According to the results of the phylogenetic analysis of the new species, all the species of the two major groups allosauroids and megalosauroids have a common ancestor that they do not share with coelurosaurs.

“The new taxon shows an unusual mosaic of tetanuran characters and highlights the large number of convergences in the early evolution of the group and thus the resulting phylogenetic uncertainty in its early evolution ,” the authors explain.

Rauhut links the explosive evolution of the group to a mass extinction episode that took place in the late Lower Jurassic, about 180 million years ago. Therefore, the two experts interpret the parallel development of similar external traits in different species as an example of evolutionary experimentation during the subsequent rapid expansion and diversification of tetanurans.

The previous extinction of potential competitors would have opened the way to new ecological niches for those who survived, and the Tetanurans were apparently among them.

“This is a pattern that we also see in many other groups of animals after mass extinctions. It is fulfilled, for example, for the expansion and diversification of mammals and birds after the extinction of the dinosaurs at the end of the Cretaceous 66 million years ago “, concludes Rauhut.

Referencia: Probable basal allosauroid from the early Middle Jurassic Cañadón Asfalto Formation of Argentina highlights phylogenetic uncertainty in tetanuran theropod dinosaurs, Oliver W. M. Rauhut & Diego PolScientific Reports 9, Article number: 18826 (2019). Nature DOI: https://doi.org/10.1038/s41598-019-53672-7

 

Slaves and Disabled: Forced Medical Test Volunteers

The main problem to carry out medical research is to have willing volunteers for it. And if they come out for free, much better. This is the story of unethical behavior in medical research.

How are lightning created?

Summer is synonymous with sun, but also with storms. Who has not contemplated one from the protection that the home gives that electrical display that is lightning?

How global warming will affect astronomy

Astronomical observations around the world will worsen in quality as a result of climate change, according to a new study.

New images of Saturn's rings in stunning detail

New images of Saturn's rings in stunning detail

NASA discovers more than 50 areas that emit exorbitant levels of greenhouse gases

NASA's 'EMIT' spectrometer locates has targeted Central Asia, the Middle East and the US among others.

More