New fossil species found in Spain

Washington, March 26 (ANI): Paleontologists from the University of Extremadura in Spain have discovered a new species, Cloudina carinata, the fossil of which has preserved its tridimensional shape.

“Cloudina carinata is characterised by its elaborate ornamentation and complexity of the shells and tube that are formed when inserted,” according to Ivan Cortijo, main author and researcher in the Area of Palaeontology at the University of Extremadura.

The study, which was recently published in Precambrian Research, describes various specimens of the new species.

These fossils show evidence of asexual reproduction, until now “only described in Chinese specimens of Cloudina”, and are “one of the oldest examples of reproduction in animals in the fossil register,” said Cortijo.

The fossils have been found in the archaeological site El Membrillar (Badajoz), one of the few sites in Europe where remains of Cloudina can be found.

“The specimens display exceptional preservation, they appear preserved in three dimensions, and show their original form and numerous details of the shells,” Cortijo pointed out.

The discovery of new species of Cloudina is important “for understanding the early evolution of animals,” stated Cortijo, who added that “its importance for understanding the origin of skeletons is indisputable”.

Despite the fact that its relation to other groups of animals is uncertain, Cloudina has been compared to cnidaria (medusas and corals) and annelida (polychaeta sea worms, earthworms and leeches).

According to the research team, the study of fossils from the Ediacaran period (between 630 and 540 million years ago) and of other fossils from the early Cambrian (540 million years ago) reveals the path followed by evolution at a crucial moment in the history of life, when the first animals appeared.

Scientists said that Cloudina is a fossil indicative of the terminal Ediacaran, which marks the end of the Proterozoic eon, and gives way to the Phanerozoic, when the great radiation of animals began. (ANI)

Ancient oceans yield clues to the origins of animal life on Earth

Washington, September 10 (ANI): Analysis of a rock type found only in the world’s oldest oceans has shed new light on how large animals first got a foothold on the Earth.

By analysing the isotopes of chromium in iron-rich sediments formed in the ancient oceans, a scientific team, led by Professor Robert Frei at the University of Copenhagen in Denmark, has found that a rise in atmospheric oxygen levels 580 million years ago was closely followed by the evolution of animal life.

The data offers new insight into how animal life – and ultimately humans – first came to roam the planet.

“Because animals evolved in the sea, most previous research has focussed on oceanic oxygen levels,” explained Newcastle University’s Dr Simon Poulton, one of the authors of the research paper.

“Our research confirms for the first time that a rise in atmospheric oxygen was the driving force for oxygenation of the oceans 580 million years ago, and that this was the catalyst for the evolution of large complex animals,” he added.

Distinctive chromium isotope signals occur when continental rocks are altered and weathered as a result of oxygen levels rising in the atmosphere.

The chromium released by this weathering is then washed into the seas and deposited in the deepest oceans – trapped in iron-rich rocks on the sea bed.

Using this new data, the research team has not only been able to establish the trigger for the evolution of animals, but have also demonstrated that oxygen began to pulse into the atmosphere earlier than previously thought.

“Oxygen levels actually began to rise 2.8 billion years ago,” explained Dr Poulton.

“But, instead of this rise being steady and gradual over time, what we saw in our data was a very unstable situation with short-lived episodes of free oxygen in the atmosphere early in Earth’s history, followed by plummeting levels around 2 billion years ago,” he said.

“It was not until a second rise in atmospheric oxygen 580 million years ago that larger complex animals were able to get a foothold on the Earth,” he added. (ANI)