Tag: fossil

In A Lost Baby Tooth, Scientists Find Ancient Denisovan DNA

Denisovans

More than 100,000 years ago in a Siberian cave there lived a child with a loose tooth. One day her molar fell out, and fossilized over many millenniums, keeping it safe from the elements and the tooth fairy.

But she wasn’t just any child. Scientists say she belonged to a species of extinct cousins of Neanderthals and modern humans known today as the Denisovans.

And in a paper published last Friday in the journal Science Advances, a team of paleoanthropologists reported that she is only the fourth individual of this species ever discovered.

“We only have relatively little data from this archaic group, so having any additional individuals is something we’re very excited about,” said Viviane Slon, a doctoral candidate at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and lead author of the study.

Denisovans cave

The scant fossil record for these ancient hominins previously included only two adult molars and a finger bone. The Denisovans were only correctly identified in 2010 by a team of researchers led by Svante Paabo.

Scientists exploring Denisova Cave in the Altai Mountains discovered the worn baby tooth in 1984 and labeled it ‘Denisova 2.’ At the time, its origins were a mystery.

But now, after performing DNA analysis on the deciduous, or baby tooth, researchers say it was one of the elusive Denisovans.

“We think based on the DNA sequences that ‘Denisova 2’ is at least 100,000 years, possibly 150,000 years old. Or a bit more,” said Ms. Slon. “So far it makes it the oldest Denisovan.”

Denisovans

To determine the origins of ‘Denisova 2’ the team first performed a CT scan of the tooth to preserve its structure for future studies.

After sequencing the DNA she compared genetic information from the sample with genetic data already collected from Denisovans, Neanderthals and modern humans.

“We saw it was most similar to Denisovan mitochondrial genomes,” she said. “That was exciting because that was a good indication that this was another Denisovan individual.”

Bence Viola, a paleoanthropologist from the University of Toronto and an author on the paper, said there was not too much to be learned from studying the tooth’s morphology or appearance.




The genetic analysis, on the other hand, provided the keys to learning more about the species. He said the genetic study was something the team most likely could not have done five years ago without destroying the tooth.

“For a long time we didn’t want to work on it because it’s such a small specimen,” he said.

But by drilling into the tooth and performing the genetic analysis the scientists were able to not only figure out who it belonged to, but also provide relative dates for when the Denisovan lived.

The study also suggests that the species had less genetic variability than modern humans, but more genetic diversity than seen in Neanderthal nuclear DNA.

Dr. Bernard A. Wood, a professor of human origins at the Center for the Advanced Study of Human Paleobiology at George Washington University, said the paper demonstrated the power of molecular biology as a tool for paleoanthropology.

“Talk about extracting blood from a stone,” he said, “this is extracting treasure from a tooth.”

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According To Scientists, Winged Archaeopteryx Dinosaur Flew In Short Bursts Like A Pheasant

Archaeopteryx flapped its wings but was not capable of long distance flight. Nor could it soar like birds of prey.

Instead, the feathered Jurassic creature probably made short bursts of ­limited low-level flight to escape danger, say experts in Grenoble, France, after X-ray analysis of fossil bones.

Pheasants fly in a similar way to avoid predators or human hunters.




Archaeopteryx – which means “ancient wing” – lived in the Late Jurassic period in what is now southern Germany.

The first fossil skeleton of one of the creatures, known as the London Specimen, was unearthed in 1861 near Langenaltheim and is housed at London’s Natural History Museum.

Similar in size to a magpie, it shared characteristics of Earth-bound dinosaurs and modern birds, including winged feathers, sharp teeth, three fingers with claws, and a long bony tail.

However despite being thought of as the first bird, experts now view Archeopteryx as a flying dinosaur.

Nor was it a direct ancestor of modern birds. Despite sharing a common dinosaur ancestor with birds, Archaeopteryx represents a “dead end” side branch on the evolutionary tree.

Present day birds are generally believed to have evolved from a group of small meat-eating dinosaurs known as maniraptoran theropods.

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Scientists Find Jawbone Fossil From Oldest Modern Human Out Of Africa In A Cave In Israel

Scientists on Thursday announced the discovery of a fossilized human jawbone in a collapsed cave in Israel that they said is between 177,000 and 194,000 years old.

If confirmed, the find may rewrite the early migration story of our species, pushing back by about 50,000 years the time that Homo sapiens first ventured out of Africa.

Previous discoveries in Israel had convinced some anthropologists that modern humans began leaving Africa between 90,000 and 120,000 years ago. But the recently dated jawbone is unraveling that narrative.

This would be the earliest modern human anyone has found outside of Africa, ever,” said John Hawks, a paleoanthropologist from the University of Wisconsin, Madison who was not involved in the study.




The upper jawbone — which includes seven intact teeth and one broken incisor, and was described in a paper in the journal Science — provides fossil evidence that lends support to genetic studies that have suggested modern humans moved from Africa far earlier than had been suspected.

Dr. Hawks and other researchers advised caution in interpreting the discovery.

Although this ancient person may have shared some anatomical characteristics with present-day people, this “modern human” would have probably looked much different from anyone living in the world today.

Early modern humans in many respects were not so modern,” said Jean-Jacques Hublin, director of the department of human evolution at the Max Planck Institute for Evolutionary Anthropology in Germany.

Dr. Hublin said that by concluding the jawbone came from a “modern human,” the authors were simply saying that the ancient person was morphologically more closely related to us than to Neanderthals.

 

That does not mean that this person contributed to the DNA of anyone living today, he added. It is possible that the jawbone belonged to a previously unknown population of Homo sapiens that departed Africa and then died off.

That explanation would need to be tested with DNA samples, which are difficult to collect from fossils found in the arid Levant.

The upper jawbone, or maxilla, was found by a team led by Israel Hershkovitz, a paleoanthropologist at Tel Aviv University and lead author of the new paper, while excavating the Misliya Cave on the western slopes of Mount Carmel in Israel.

The jawbone was discovered in 2002 by a freshman on his first archaeological dig with the group.

The team had long known that ancient people lived in the Misliya Cave, which is a rock shelter with an overhanging ceiling carved into a limestone cliff.

By dating burned flint flakes found at the site, archaeologists had determined that it was occupied between 250,000 to 160,000 years ago, during an era known as the Early Middle Paleolithic.

Evidence, including bedding, showed that the people who lived there used it as a base camp. They hunted deer, gazelles and aurochs, and feasted on turtles, hares and ostrich eggs.

Dr. Hershkovitz and Mina Weinstein-Evron, an archaeologist at the University of Haifa, felt that the jawbone looked modern, but they needed to confirm their hunch.

The Misliya finding is just the latest in a series of discoveries that are changing the story of our evolutionary past.

One study, not yet confirmed, suggested that modern humans may have interbred with Neanderthals in Eurasia about as far back as 220,000 years ago.

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The Evolution Of Forests And Trees In Devonian Period

The vascular plant emerged around 400 million years ago and started Earth’s forest-building process during the Silurian geologic period.

Although not yet a “true” tree, this new member of the terrestrial plant kingdom became the perfect evolutionary link (and the largest plant species) with developing tree parts and considered the first proto-tree.

Vascular plants developed the ability to grow large and tall with massive weight needed for the support of a vascular internal plumbing system.




The First Trees

The earth’s first real tree continued to develop during the Devonian period and scientists think that tree was probably the extinct Archaeopteris.

These tree species followed later by other tree types became the definitive species comprising a forest during the late Devonian period.

As mentioned, they were the first plants to overcome the biomechanical problems of supporting additional weight while delivering water and nutrients to fronds (leaves) and roots.

Entering the Carboniferous period around 360 million years ago, trees were prolific and a major part of the plant life community, mostly located in coal-producing swamps.

Trees were developing the parts that we immediately recognize today. Of all the trees that existed during the Devonian and Carboniferous, only the tree fern can still be found, now living in Australasian tropical rainforests.

If you happen to see a fern with a trunk leading to a crown, you have seen a tree fern.

During that same geologic period, now extinct trees including clubmoss and giant horsetail were also growing.

Our Present Evolutionary Forest

Few dinosaurs ever made a meal on hardwood leaves because they were rapidly disappearing before and during the beginning of the new “age of hardwoods” (95 million years ago).

Magnolias, laurels, maples, sycamores and oaks were the first species to proliferate and dominate the world.

Hardwoods became the predominant tree species from mid-latitudes through the tropics while conifers were often isolated to the high-latitudes or the lower latitudes bordering the tropics.

Not a lot of change has happened to trees in terms of their evolutionary record since the palms made their first appearance 70 million years ago.

Fascinating are several tree species that simply defy the extinction process and show no indication that they will change in another dozen million years.

Ginkgo was mentioned earlier but there are others: dawn redwood, Wollemi pine, and monkey puzzle tree.

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Ancient Fossilized Salamander Reveals Its Last Meal

Accessing the complete anatomy of an extinct animal, i.e. both its external and internal aspects, has often been the dream of palaeontologists.

Indeed, in 99% of cases, fossils are only represented by hard parts: bones, shells, etc. Fossils preserving soft tissues exist, but they are extremely rare.

However, their significance for science is enormous. What did the animal look like?

What did they eat? How did they live? Most of these questions can be answered by exceptionally preserved fossils.

The newly studied fossil externally looks like a present-day salamander, but it is made of stone.




This fossil “mummy” is the only known specimen of Phosphotriton sigei, a 40-35 million years old salamander and belongs to the same family as the famous living fire salamander.

It is unfortunately incomplete: only the trunk, hip and part of hind legs and tail are preserved.

Until very recently, the only thing palaeontologists could tell about this specimen was visible anatomical details, such as the cloaca, the orifice used for reproduction and by digestive and urinary canals.

Indeed, though it was discovered in the 1870s, it was never studied in detail.

The quality of preservation is such that looking at the tomograms feels like going through an animal in the flesh.

At least six kinds of organs are preserved in almost perfect condition, in addition to the skin and skeleton: muscles, lung, spinal cord, digestive tract, nerves, and glands.

But the most incredible is the preservation of frog bones within the stomach of the salamander. Salamanders almost never eat frogs or other salamanders, though they are known to be quite opportunistic.

Was it a last resort meal or a customary choice for this species? This, unfortunately, will probably never be known.

These new results are described by Jérémy Tissier from the Jurassica Museum and the University of Fribourg in Switzerland, and Jean-Claud Rage and Michel Laurin, both from the CNRS/Museum national d’histoire naturelle/UPMC in Paris.

Author Michel Laurin notes, “This fossil, along with a few others from the same lost site, is the most incredibly well-preserved that I have seen in my entire career. And now, 140 years after its discovery, and 35 million years after the animal died, we can finally study it, thanks to modern technology. The mummy returns!

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A Newly Discovered Skull Reveals What The Common Ancestor Of Humans And Apes May Have Looked Like

An infant ape cranium named as “Alesi”, excavated from the site of an archaeological dig at Napudet, west of Lake Turkana in Kenya.

Scientists have named a new species of ape based on a 13-million-year-old skull fossil.

It belonged to a new species called Nyanzapithecus alesi that was closely related to the common ancestor of people and modern apes although that ancestor likely was even older, University College London paleontologist Fred Spoor said.




The sole specimen is that of an infant that would have grown to weigh about 11 kilogrammes (24 pounds) in adulthood. Its adult brain volume would have been nearly three times larger than that of known African monkeys from the same time, the researchers estimate.

If you compare to all living things, it looks most like a gibbon“, study co-author Isaiah Nengo of the Stony Brook University in NY told AFP. The same probably held for N. alesi, making it an unlikely direct ancestor of living gibbons, they conclude.

The skull may answer a long-standing question about the origin of the lineage that led to people and modern apes such as chimpanzees, gorillas, orangutans and gibbons, indicating their common ancestor evolved in Africa, not Eurasia, the scientists said.

The lemon-sized skull was found in Kenya by an global team of researchers, and was dated to the middle of the Miocene era, a little-understood time when many species of ape arose in Africa, including common ancestors of both modern apes and humans.

With this we put the root of the hominoidea in Africa more firmly“, said Nengo.

Scientists assigned it to a new species, Nyanzapithecus alesi. If an evolutionary relationship existed with the older N. alesi, the first members of the Oreopithecus genus probably originated in Africa, Nengo proposes.

That group, which has no official name yet, lived and died millions of years ago.

As well as dating to the “dark ages” of human origins, it is also the most complete extinct ape skull in the fossil record.

Alesi is the one that has allowed us to. know who is in that group. and when we take a close look we see that most of the group are found in Africa“.

The record of African fossil hominoids (primates that include apes, humans and their ancestors) lacked a almost complete cranium from between 17 million and 7 million years ago, the study notes.

We have a handsome ape cranium from a period that we knew virtually nothing about and this is one of those wonderful cases where discovery leads to all sorts of new and interesting perspectives“, Craig Feibel, who chairs Rutgers’ Department of Anthropology and is a professor of geology and anthropology, said in a statement.

The skull resembles a baby gibbon’s. But the balance organ inside its inner ear differed from gibbons and suggested Alesi’s species moved through trees more cautiously and had shorter arms than gibbons, which swing through trees with acrobatic ease.

Growth lines on the adult teeth showed Alesi was one year and four months old at death.

Commenting on the study, anthropologist Brenda Benefit of the New Mexico State University described this as a fossil find “that I never thought would be made during my lifetime“.

It’s a major finding that fills a large gap in the evolutionary record“.

This is an exceptional discovery“, agreed Paul Tafforeau of the European Synchrotron Radiation Facility in Grenoble, France, who helped examine the skull.

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‘World’s Largest Dinosaur’ Discovered In Argentina

Fossilised bones of a dinosaur believed to be the largest creature ever to walk the Earth have been unearthed in Argentina, palaeontologists say.

Based on its huge thigh bones, it was 40m (130ft) long and 20m (65ft) tall.

Weighing in at 77 tonnes, it was as heavy as 14 African elephants, and seven tonnes heavier than the previous record holder, Argentinosaurus.




Scientists believe it is a new species of titanosaur – an enormous herbivore dating from the Late Cretaceous period.

A local farm worker first stumbled on the remains in the desert near La Flecha, about 250km (135 miles) west of Trelew, Patagonia.

The fossils were then excavated by a team of palaeontologists from the Museum of Palaeontology Egidio Feruglio, led by Dr Jose Luis Carballido and Dr Diego Pol.

They unearthed the partial skeletons of seven individuals – about 150 bones in total – all in “remarkable condition”.

By measuring the length and circumference of the largest femur (thigh bone), they calculated the animal weighed 77 tonnes.

dino bone

Given the size of these bones, which surpass any of the previously known giant animals, the new dinosaur is the largest animal known that walked on Earth,” the researchers said.

Its length, from its head to the tip of its tail, was 40m. Standing with its neck up, it was about 20m high – equal to a seven-storey building.

This giant herbivore lived in the forests of Patagonia between 95 and 100 million years ago, based on the age of the rocks in which its bones were found.

But despite its magnitude, it does not yet have a name.

It will be named describing its magnificence and in honour to both the region and the farm owners who alerted us about the discovery,” the researchers said.

There have been many previous contenders for the title “world’s biggest dinosaur”.

The most recent pretender to the throne was Argentinosaurus, a similar type of sauropod, also discovered in Patagonia.

Originally thought to weigh in at 100 tonnes, it was later revised down to about 70 tonnes – just under the 77 tonnes that this new sauropod is thought to have weighed.

Argentinosaurus was estimated from only a few bones. But the researchers here had dozens to work with, making them more confident that they really have found “the big one”.

Dr Paul Barrett, a dinosaur expert from London’s Natural History Museum, agreed the new species is “a genuinely big critter. But there are a number of similarly sized big sauropod thigh bones out there,” he cautioned.

Without knowing more about this current find it’s difficult to be sure.

One problem with assessing the weight of both Argentinosaurus and this new discovery is that they’re both based on very fragmentary specimens – no complete skeleton is known, which means the animal’s proportions and overall shape are conjectural.

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