Day: April 10, 2018

A jawbone fossil found on a rocky English beach belongs to one of the biggest marine animals on record, a type of seagoing reptile called an ichthyosaur that scientists estimated at up to 85 feet (26 meters) long – approaching the size of a blue whale.

Scientists said on Monday this ichthyosaur, which appears to be the largest marine reptile ever discovered, lived 205 million years ago at the end of the Triassic Period, dominating the oceans just as dinosaurs were becoming the undisputed masters on land. The bone, called a surangular, was part of its lower jaw.

The researchers estimated the animal’s length by comparing this surangular to the same bone in the largest ichthyosaur skeleton ever found, a species called Shonisaurus sikanniensis from British Columbia that was 69 feet (21 meters) long. The newly discovered bone was 25 percent larger.

“This bone belonged to a giant,” said University of Manchester paleontologist Dean Lomax.

“The entire carcass was probably very similar to a whale fall in which a dead whale drops to the bottom of the sea floor, where an entire ecosystem of animals feeds on the carcass for a very long time. After that, bones become separated, and we suspect that’s what happened to our isolated bone.”

Fossil collector Paul de la Salle, affiliated with the Etches Collection in Dorset, England, found the bone in 2016 at Lilstock on England’s Somerset coast along the Bristol Channel.

“The structure was in the form of growth rings, like that of a tree, and I’d seen something similar before in the jaws of late Jurassic ichthyosaurs,” he said.

Ichthyosaurs swam the world’s oceans from 250 million years ago to 90 million years ago, preying on squid and fish. The biggest were larger than other huge marine reptiles of the dinosaur age like pliosaurs and mosasaurs. Only today’s filter-feeding baleen whales are larger. The blue whale, up to about 98 feet (30 meters) long, is the biggest animal alive today and the biggest marine animal ever.

The researchers estimated the new ichthyosaur at 66 to 85 feet long (20 to 26 meters).

It appears to have belonged to an ichthyosaur group called shastasaurids. Because the remains are so incomplete, it is unclear whether it represents a new ichthyosaur genus or is a member of a previously identified genus, said paleontologist Judy Massare of the State University of New York College at Brockport.

The research was published in the journal PLOS ONE.

This story was written by Reuters.
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A fossil finger bone dating back about 90,000 years that was unearthed in Saudi Arabia’s Nefud Desert is pointing to what scientists are calling a new understanding of how our species came out of Africa en route to colonizing the world.

Researchers said on Monday the middle bone of an adult’s middle finger found at site called Al Wusta is the oldest Homo sapiens fossil outside of Africa and the immediately adjacent eastern Mediterranean Levant region, as well as the first ancient human fossil from the Arabian peninsula.

While the Nefud Desert is now a veritable sea of sand, it was hospitable when this individual lived – a grasslands teeming with wildlife alongside a freshwater lake.

Our species first appeared in Africa roughly 300,000 years ago. Scientists previously thought Homo sapiens departed Africa in a single, rapid migration some 60,000 years ago, journeying along the coastlines and subsisting on marine resources, said anthropologist Michael Petraglia of the Max Planck Institute for the Science of Human History in Germany.

This fossil of an intermediate phalanx bone, 1.2 inches (3.2 cm) long, suggests our species exited Africa far earlier.

“This supports a model not of a single rapid dispersal out of Africa 60,000 years ago, but a much more complicated scenario of migration. And this find, together with other finds in the last few years, suggests … Homo sapiens is moving out of Africa multiple times during many windows of opportunity during the last 100,000 years or so,” Petraglia said.

The discovery also shows these people were moving across the interior of the land, not coastlines, Petraglia added.

Numerous animal fossils were discovered, including hippos, wild cattle, antelopes and ostriches, University of Oxford archeologist Huw Groucutt said. Bite marks on fossilized bones indicated carnivores lived there, too.

Stone tools that hunter-gatherers used also were found.

“The big question now is what became of the ancestors of the population to which the Al Wusta human belonged,” Groucutt said.

“We know that shortly after they lived, the rains failed and the area dried up. Did this population die out? Did it survive further south in Arabia, where even today there are mountainous areas with quite high rainfall and coastal regions which receive monsoonal rains?” Groucutt added. “Or did the drying environment mean that some of these people were ‘pushed’ further into Eurasia, as part of a worldwide colonization?”

The research was published in the journal Nature Ecology and Evolution.

This story was written by Reuters.
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