Tag: fossils

Fossil Teeth Reveal Recent Origin Of Human Growth Pattern

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Monash University-led research has shown that the evolution of human teeth is much simpler than previously thought, and that we can predict the sizes of teeth missing from human fossils and those of our extinct close relatives (hominins).

A new study published today in the journal Nature, led by evolutionary biologist Dr. Alistair Evans from Monash University, took a fresh look at the teeth of humans and fossil hominins.




The research confirms that molars, including wisdom teeth, do follow the sizes predicted by what is called ‘the inhibitory cascade’ – a rule that shows how the size of one tooth affects the size of the tooth next to it.

This is important because it indicates that human evolution was a lot simpler than scientists had previously thought. Dr Alistair Evans explains how our fascination with where we come from, and what our fossil ancestors were like, has fuelled our search for new fossils and how we can interpret them.

“Teeth can tell us a lot about the lives of our ancestors, and how they evolved over the last seven million years. What makes modern humans different from our fossil relatives? Palaeontologists have worked for decades to interpret these fossils, and looked for new ways to extract more information from teeth,” Dr Evans said.

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Dr Evans, a research associate at Museum Victoria, discussed how this new research has challenged the accepted view that there was a lot of variation in how teeth evolved in our closest relatives.

“Our new study shows that the pattern is a lot simpler than we first thought – human evolution was much more limited,”Dr Evans said.

Dr Evans led an international team of anthropologists and developmental biologists from Finland, USA, UK and Germany, using a new extensive database on fossil hominins and modern humans collected over several decades, as well as high resolution 3D imaging to see inside the fossil teeth.

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The team then took the research a step further by applying the findings to two main groups of hominins: the species in the genus Homo (like us and Neanderthals), and australopiths, including specimens like Lucy, the famous fossil hominin from Africa.

Dr Evans explained that while it was discovered that both groups follow the inhibitory cascade, they do so slightly differently.

“There seems to be a key difference between the two groups of hominins – perhaps one of the things that defines our genus, Homo,” Dr Evans said.

teeth

Another author on the Nature paper was Professor Grant Townsend from the University of Adelaide’s School of Dentistry. The study examined teeth of modern humans, including those in one of the world’s largest collections of dental casts housed at the Adelaide Dental Hospital.

“These collections of dental casts are critical to finding our place in the hominin evolutionary tree, and advancing knowledge in the oral health of Australians,” said Professor Townsend.

The findings of the study will be very useful in interpreting new hominin fossil finds, and looking at what the real drivers of human evolution were.

As well as shedding new light on our evolutionary past, this simple rule provides clues about how we may evolve into the future.

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The Prehistoric Puzzle Of How Plesiosaurs Swam Through The Oceans

Among the stranger creatures to roam the earth during the time of the dinosaurs was not a dinosaur at all, but a marine reptile — the plesiosaur.

This odd predator navigated Mesozoic Era waters with four flippers — two in the front and two in the back — a design unlike anything seen in modern-day swimmers.

How the plesiosaur actually used its limbs to swim has remained something of a mystery.

But in a study in the journal PLOS Computational Biology, a group of scientists has used computer modeling to pin down what those strokes might have looked like — and it turns out that they probably looked a lot like a penguin’s.




Plesiosaurs were a diverse group of swimming reptiles that thrived for 135 million years, from the Early Jurassic to the Late Cretaceous period (when they were wiped out by the same asteroid that took out the dinosaurs).

Some had long necks, others had short stubby ones, but all of them had this four-flippered body plan, where the animals’ legs had evolved into two pairs of wing-like appendages — “a unique adaptation in the animal Kingdom,” the study authors wrote.

Although plesiosaurs were a key component of Mesozoic marine ecosystems, there are no extant ‘four-winged’ analogues to provide insights into their behavior or ecology, and their locomotion has remained a topic of debate since the first complete plesiosaur skeleton was described in 1824,” the authors wrote.

Without any clear modern comparisons, how theirs flippers worked together has stumped scientists.

Some have argued that the plesiosaur had a rowing stroke, using its fins like boat oars; others argued for a “flight stroke,” rather like those of penguins and turtles, or a modified flight stroke like the ones sea lions use.

The extinct animals’ swimming motion has been equally up for grabs: Some have posited synchronous motion, with all four flippers moving in the same direction at the same time.

Others have favored semi-synchronous or asynchronous motion, where the forelimbs and hindlimbs move out-of-phase relative to each other.

Researchers haven’t even been able to agree on whether it was the forelimbs or the hindlimbs producing most of the animal’s thrust.

Scientists have tried all kinds of ways to model the animals’ swimming behavior, from using experimental robots to testing out human swimmers using paddles.

These studies, although informative, are limited because they do not deal with accurate representations of the plesiosaur form,” the study authors wrote.

There is therefore still no consensus on how plesiosaurs swam, especially how they moved all four limbs relative to each other.”

To get a better handle on plesiosaur physiology, researchers from Georgia Tech decided to build a computer model — far more accurate than, say, a human with some paddles.

They based theirs on Meyerasaurus victor, a Lower Jurassic plesiosaur from what is now Germany that would have stretched about 11 feet (relatively small by plesiosaur standards).

This model also allowed researchers to test thousands of simulations to try to determine which combinations of movement allowed the animal to move most effectively through the water.

In the end, the scientists found that the plesiosaur was swimming mostly with its forelimbs; surprisingly, the hindlimbs didn’t generate much thrust and likely were used for balance and steering.

Within the biologically possible range of limb motion, the simulated plesiosaur swims primarily with its forelimbs using an unmodified underwater flight stroke, essentially the same as turtles and penguins,” the study authors wrote.

Now that the scientists have developed a working model of this plesiosaur, they can use it to further probe exactly how the hindlimbs were used — and to explore the motion of other extinct swimming animals.

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Oldest Fossils Of Homo Sapiens Found in Morocco

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Fossils discovered in Morocco are the oldest known remains of Homo sapiens, scientists reported, a finding that rewrites the story of mankind’s origins and suggests that our species evolved in multiple locations across the African continent.

Until now, the oldest known fossils of our species dated back just 195,000 years. The Moroccan fossils, by contrast, are roughly 300,000 years old.




Remarkably, they indicate that early Homo sapiens had faces much like our own, although their brains differed in fundamental ways.

Today, the closest living relatives to Homo sapiens are chimpanzees and bonobos, with whom we share a common ancestor that lived over six million years ago.

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Tiny Prehistoric Frogs Trapped In Amber Show That Death Comes At You Fast

Four pieces of amber found in Myanmar contain ancient fossilized frogs.

Life’s too short. By the time you’ve figured a few things out, the years have slipped away. All you can do is love others, let yourself be loved, and try to leave the world a better place.

Unfortunately, the same can’t necessarily be said for a group of Cretaceous frogs that got trapped in tree sap and preserved in amber, which a team of scientists described in the journal Scientific Reports on Thursday.

It’s impossible to say whether these 99-million-year-old frogs loved each other, but as the oldest frogs to be found preserved in amber and the oldest evidence of frogs inhabiting wet tropical forests, they definitely died before they got a chance to see the legacy they left the world.

These days, we’re used to picturing frogs in wet, hot climates, but we don’t know for sure when they began to occupy their preferred ecosystem.

Scientists believe that frogs emerged over 200 million years ago, but as with many animals, there exist major gaps in that fossil record, large swaths of evolutionary time for which we have no direct evidence.




In this new paper, researchers write that four small pieces of amber found in Myanmar contain evidence that could help fill in the frog’s evolutionary timeline.

These amber fossils provide direct evidence that frogs inhabited wet tropical forests before the mass extinction event at the end of the Cretaceous,” Lida Xing, an associate professor at China University of Geosciences in Beijing and first author on the paper.

By studying the remains of these four frogs, which are each about 22 millimeters long — as well as the plant, insect, and spider remains trapped in the amber with them — Xing and his colleagues established that about 99 million years ago frogs lived in an environment similar to ones that they currently inhabit.

The study’s authors dubbed the species Electrorana limoae, from the Latin words for “amber” (electrum) and “frog” (rana), as well as Mrs. Mo Li, “who purchased and provided these specimens for study,” they write.

These four pieces of amber (specimen B and D are each shown from multiple angles) are the oldest amber-preserved frogs ever found.

And while the researchers were fortunate to come into possession of the specimens, the quality of the remains did pose issues.

As you can see, the frog remains are either ripped apart or curled up, and not one of them remained intact.

Fortunately, micro-CT scans allowed the researchers to penetrate the amber to get a better look at the frogs’ anatomies and figure out where they sit in the evolutionary tree.

They determined that E. limoae is likely an ancestor of these existing species, as well as some that have been long extinct.

Living in a wet environment, most frog specimens from E. limoae’s home environment had no chance of being preserved as fossils, so this amber from Myanmar gave scientists a rare opportunity to glimpse into the tree of life and add one more piece to the puzzle of evolution.

I can only hope that there are more spectacular fossils to come,” Blackburn tells National Geographic. “In today’s tropical forests, there is a rich diversity of living frog species.

“So, there might be many more species to discover still in the Cretaceous amber from Myanmar.”

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The First Living Giant Ship Worm Found In The Philippines

ship worm

Mud-dwelling organism that lives head down in a tusk-like tube found alive for first time, although its existence had been known of for centuries.

About three feet long and glistening black with a pink, fleshy appendage, it looks like the entrails of an alien from a bad horror film. In fact, it is a giant ship worm.




Discovered in the mud of a shallow lagoon in the Philippines, a living creature of the species has never been described before.

Even though its existence has been known for more than 200 years thanks to fossils of the baseball bat-sized tubes that encase the creature.


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Oldest known case of dandruff found in 125m-year-old dinosaur

A fossil of a microraptor found in Liaoning province, China. The crow-sized dinosaur lived about 125m years ago.

The oldest known case of dandruff has been identified in a small feathered dinosaur that roamed the Earth about 125m years ago.

Paleontologists found tiny flakes of fossilised skin on a crow-sized microraptor, a meat-eating dinosaur that had wings on all four of its limbs.

Tests on two other feathered dinosaurs, namely beipiaosaurus and sinornithosaurus, and a primitive bird known as confuciusornis, also revealed pieces of fossilised dandruff on the animals’ bodies.

The prehistoric skin flakes are the only evidence scientists have of how dinosaurs shed their skin.

The material shows that rather than losing their outer layer in one piece, or in large sheets, as is common with modern reptiles, the feathered dinosaurs adapted to shed their skin in tiny flakes.




Images of the dandruff taken with a powerful electron microscope show that the material is extremely well-preserved and is almost identical to that found on modern birds.

Like human dandruff, the skin flakes are made of tough cells called corneocytes that are full of the protein keratin.

The work, published in Nature Communications, suggests that dinosaurs who sported feathers evolved skin to cope with their plumage as far back as the middle Jurassic.

Even though they are in the early stages of feather evolution, they have already adapted their skin to this more modern structure,” McNamara said.

Prehistoric dandruff found on the skin of a microraptor dinosaur. Photograph: Maria McNamara at University College Cork

The fossilised remains of all of the animals studied were recovered from rock formations in north-eastern China. At 2m long, beipiaosaurus and sinornithosaurus grew to more than twice the size of microraptor.

Modern birds have very fatty corneocytes that are loosely packed with keratin, a feature which helps the birds lose heat from the exertion of flying.

McNamara found that the dinosaur dandruff cells lacked such fat, suggesting that the animals did not get as warm as modern birds, perhaps because they could not fly far, or failed to get airborne at all.

Many dinosaurs that sported feathers were not competent fliers. Instead, their plumage served other purposes: to keep them warm, provide camouflage, and perhaps attract members of the opposite sex with multicoloured displays.

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180 Million-Year-Old Crocodile Had Dolphin-Like Features, Tells Tale Of ‘Missing Link’

The discovery of an ancient type of crocodile that lived during the Jurassic Period, at the height of the age of dinosaurs, has shed new light on the species.

The 180 million-year-old fossil, named Magyarosuchus fitosi, shows that some ancient crocodiles evolved to have dolphin-like features.

The fossil was analyzed recently and found to have abnormal vertebra in its tail fin, effectively combining two different families of crocodiles – one that had limbs for walking on the surface and a bone-like protective armor on its back and one that had tail fins and flippers to aid with swimming in the ancient seas.




This fossil provides a unique insight into how crocodiles began evolving into dolphin and killer whale-like forms more than 180 million years ago,” Dr. Mark Young, of the University of Edinburgh’s School of GeoSciences, said in a statement.

The presence of both bony armour and a tail fin highlights the remarkable diversity of Jurassic-era crocodiles.

The new finding was made after the team of paleontologists analyzed the bones, which had been kept at a museum in Budapest. The fossil was originally discovered in Hungary in the Gerecse Mountains.

With an estimated body length of 4.67–4.83 m [15 feet – 16 feet] M. fitosi is the largest known non-metriorhynchid metriorhynchoid,” the study’s abstract reads.

The abstract continues: “The combination of retaining heavy dorsal and ventral armors and having a slight hypocercal tail is unique, further highlighting the mosaic manner of marine adaptations in Metriorhynchoidea.”

In addition, the newly-discovered species had large, pointed teeth, used to grasp prey, the statement added.

The study was published on May 10, in PeerJ, a peer-reviewed scientific journal.

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Incredible Gold Metallic Colors Of Ancient Butterfly Ancestors That Lived Alongside Dinosaurs Are Revealed For The First Time

The beautiful gold metallic colors of the earliest known ancestors of moths and butterflies have been revealed for the first time.

Some of these creatures – now preserved in amber – inhabited the planet alongside dinosaurs as long as 200 million years ago.

Researchers found the structural colors of the fossils resulted from intricate light scattering, or photonic, microstructures.

This finding pushes back evidence for such light-scattering structures in the insect fossil record by more than 130 million years.

An international team of researchers, including Dr Tim Starkey from the University of Exeter, discovered the new evidence for color in Mesozoic fossils.

His team used powerful electron microscopes to detect tiny ridges and grooves in the insect’s wing scales, similar to those seen in today’s moths.




Optical models revealed these tiny features are photonic structures that would have produced metallic bronze to golden color appearances in the insects’ wings.

Dr Starkey, part of Exeter’s physics and astronomy department, said: “The structural colours exhibited by butterflies and moths have been a longstanding research interest in Exeter.

They have helped us develop biologically-inspired optical technologies for the present day.

However, in this study we’ve looked millions of years back in time to early origins of such colours in nature, to understand how and when the evolution of colours in these insects took place.”

The fossils studied are among the oldest known representatives of butterflies and moths.

Some specimens that originate from England’s Jurassic Coast date back 195 million years.

Insects have evolved an amazing range of photonic structures, experts say.

They can produce iridescence, metallic colours, and other flashy effects that are important for behaviour and ecological functions.

The fossils studied are among the oldest known representatives of butterflies and moths.

Some specimens that originate from England’s Jurassic Coast date back 195 million years.

Insects have evolved an amazing range of photonic structures, experts say.

They can produce iridescence, metallic colours, and other flashy effects that are important for behaviour and ecological functions.

However, researchers say they were surprised to find wing scales preserved, let alone microscopic structures that produce color.

They say this tells us color was an important driving force in shaping the evolution of wings even in the earliest ancestors of butterflies and moths.

Luke McDonald from University College Cork added: “Uniquely in this study, we show that impression fossils are equally as capable as compression fossils at preserving the structure of scales in sufficient detail to elucidate the moths’ 180 million‑year‑old colours.

The full findings of the study were published in the journal Science Advances.

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This Prehistoric ‘Sea Monster’ May Be Largest That Ever Lived

This reassembled jaw bone belonged to the 85-foot ichthyosaur.

The ancient remains of a gigantic marine reptile have been found in southwestern England.

Known as an ichthyosaur, the animal lived about 205 million years ago and was up to 85 feet long—almost as big as a blue whale, say the authors of a study describing the fossil published today in PLOS ONE.

Biology textbook have long touted the modern blue whale as the largest animal that ever lived, but this and other fascinating fossil finds hint that there may once have been even bigger creatures swimming Earth’s seas.

What is this animal?

Ichthyosaurs were ocean-going contemporaries of the dinosaurs, with body shapes superficially similar to dolphins.

They reached their greatest diversity about 210 million years ago in the late Triassic, but some persisted into the late Cretaceous.




They vanished from the fossil record about 25 million years before the mass extinction that wiped out the non-avian dinosaurs.

Most ichthyosaurs were much smaller than the newly discovered creature—several species in the genus Ichthyosaurus also found in the U.K. were just 5 to 11 feet long.

How did paleontologists find it?

Self-taught fossil hunter and study coauthor Paul de la Salle was combing the beach at Lilstock, Somerset, in May 2016 when he found a large and puzzling chunk of fossil bone.

Suspecting it might be an ichthyosaur, he sent images to marine reptile experts Dean Lomax at the University of Manchester in the U.K. and Judy Massare at SUNY Brockport in New York.

Further searching revealed five fossil pieces that fitted together to form a 3.2-foot-long bone, which the scientists identified as being from the lower jaw of an ichthyosaur.

Based on the size of the bone, the scientists think this ichthyosaur was bigger than any previously known to science.

Reconstructions of the giant ichthyosaur Shonisaurus show its skeletal structure and what it might have looked like in life.

Why is this discovery important?

Lomax says the discovery has led them to reinterpret a whole series of isolated bones found near the village of Aust in Gloucestershire, England.

Some collected as early as 1850, these fragments had long been interpreted to be the limb or other bones of terrestrial dinosaurs, but this never quite made sense.

The scientists realized these pieces also belonged to giant ichthyosaurs—and possibly to ones even bigger than the newly identified animal.

Darren Naish, a paleontologist at the University of Southampton in the U.K., agrees that the sizes of all these bones are astounding.

He is part of a different team that recently examined the Aust bones and similarly concluded that they belonged to enormous ichthyosaurs.

He concurs with the size estimates of the study authors, and says that these animals were “approaching or exceeding various giant baleen whales in size.

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170-Million-Year-Old Dinosaur Footprints Found On Skye

It’s now a windswept island boasting pine martens, red deer and puffins. But 170 million years ago, some very different beasts were leaving their mark on the Isle of Skye.

Researchers have unearthed a new site of about 50 tracks, some as big as a car tyre, from dinosaurs that roamed the island during the Middle Jurassic.

The study, published in the Scottish Journal of Geology, builds on previous dinosaur finds on the island – not least a huge array of tracks discovered in the north of Skye in 2015 by the same team.

That site showed hundreds of footprints, almost all from enormous, long-necked, plant-eating dinosaurs known as sauropods.

But the newly discovered site at Rubha nam Brathairean, or Brothers’ Point, reveals that these hefty beasts were sharing their spot with another type of dinosaur: a meat-eater.

Around 170 million years ago, shortly after the supercontinent Pangaea began to break up, the land that is now Skye was part of a smaller subtropical island, far closer to the equator, and replete with beaches, rivers and lagoons.




One of Brusatte’s students stumbled across the tracks in 2016 while on a field trip along Skye’s coast. “The tide went out and we noticed them,” said Brusatte.

We knew that you could find these things in Scotland and if you were walking on tidal platforms and you saw holes in the rock, they could, possibly, be footprints.”

Mapping the site with drones and other camera equipment revealed about 50 dinosaur prints at the site in total, including what appears to be two lines of tracks.

Brusatte said the conclusion that the depressions were produced by dinosaurs came down to a number of factors.

There was a kind of a left-right, left-right patterning,” he said.

They were all kind of the same shape, they were all generally the same size – they were pretty circular but they had little bits sticking out at the front and those are marks of toes.

Some of the footprints, said Brusatte, were as big as a car tyre.

There were also handprints associated with those tracks – so these were made by a dinosaur walking all fours, a big dinosaur, and the dinosaur that fits the bill is a sauropod – one of these long-necked, pot bellied, brontosaurus-type dinosaurs,” said Brusatte.

They were the biggest things living on land at the time,” he said.

But the team also found impressions made by three-toed dinosaurs, probably theropods.

These are the tracks of the meat eaters,” said Brusatte.

[There were] only footprints, no handprints: this was a dinosaur just walking on its hind legs,” he added, saying the creature would have weighed about a tonne and was around five or six metres in length.

Paleontologists Steve Brusatte and Tom Challands near the dinosaur track marks on the Isle of Skye.

Kind of a primitive cousin of a T-Rex,” said Brusatte.

Brusatte said the prints back up evidence from the 2015 site that suggests dinosaurs spent time pottering around lagoons.

We think of dinosaurs as thundering across the land, which of course they did, but in the Jurassic dinosaurs had become dominant, they had spread all over the world and they were living in all sorts of environments, even on the beaches, even in the lagoons,” he said.

These dinosaurs look like they were just lingering, they were just kind of loitering. This seems to be a snapshot into a day in the life of some dinosaurs and I think that is just pretty cool.”

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