Amazing Science

Artificial intelligence has revealed that prehistoric footprints thought to be made by a vicious dinosaur predator were in fact from a timid herbivore. In an international collaboration, University of Queensland palaeontologist Dr Anthony Romilio used AI pattern recognition to re-analyse footprints from the Dinosaur Stampede National Monument, south-west of Winton in Central Queensland.

The Nobel Assembly at the Karolinska Institutet has today decided to award the 2022 Nobel Prize in Physiology or Medicine to Svante Pääbo “for his discoveries concerning the genomes of extinct hominins and human evolution.”

Humanity has always been intrigued by its origins. Where do we come from, and how are we related to those who came before us? What makes us, Homo sapiens, different from other hominins?

Through his pioneering research, Svante Pääbo accomplished something seemingly impossible: sequencing the genome of the Neanderthal, an extinct relative of present-day humans. He also made the sensational discovery of a previously unknown hominin, Denisova. Importantly, Pääbo also found that gene transfer had occurred from these now extinct hominins to Homo sapiens following the migration out of Africa around 70,000 years ago. This ancient flow of genes to present-day humans has physiological relevance today, for example affecting how our immune system reacts to infections.

Pääbo’s seminal research gave rise to an entirely new scientific discipline; paleogenomics. By revealing genetic differences that distinguish all living humans from extinct hominins, his discoveries provide the basis for exploring what makes us uniquely human.

An international team of paleontologists has discovered remarkable new evidence that pterosaurs, the flying relatives of dinosaurs, were able to control the color of their feathers using melanin pigments.The new study is based on analyses of a new 115 million year old fossilized headcrest of the pterosaur Tupandactylus imperator from north-eastern Brazil. Pterosaurs lived side by side with dinosaurs, 230 to 66 million years ago.  This species of pterosaur is famous for its bizarre huge headcrest. The team discovered that the bottom of the crest had a fuzzy rim of feathers, with short wiry hair-like feathers and fluffy branched feathers. 

“We didn’t expect to see this at all”, said Dr Cincotta. “For decades paleontologists have argued about whether pterosaurs had feathers. The feathers in our specimen close off that debate for good as they are very clearly branched all the way along their length, just like birds today”.  The team then studied the feathers with high-powered electron microscopes and found preserved melanosomes – granules of the pigment melanin. Unexpectedly, the new study shows that the melanosomes in different feather types have different shapes. 

“In birds today, feather color is strongly linked to melanosome shape.” said Prof. McNamara. “Since the pterosaur feather types had different melanosome shapes, these animals must have had the genetic machinery to control the colors of their feathers. This feature is essential for color patterning and shows that coloration was a critical feature of even the very earliest feathers.” 

Oregon State University researchers have identified the oldest known specimen of a fungus parasitizing an ant, and the fossil also represents a new fungal genus and species. “It’s a mushroom growing out of a carpenter ant,” said OSU’s George Poinar Jr., an international expert in using plant and animal life forms preserved in amber to learn about the biology and ecology of the distant past.

A mushroom is the reproductive structure of many fungi, including the ones you find growing in your yard, and Poinar and a collaborator in France named their discovery Allocordyceps baltica. They found the new type of Ascomycota fungi in an ant preserved in 50-million-year-old amber from Europe’s Baltic region. “Ants are hosts to a number of intriguing parasites, some of which modify the insects’ behavior to benefit the parasites’ development and dispersion,” said Poinar, who has a courtesy appointment in the OSU College of Science. “Ants of the tribe Camponotini, commonly known as carpenter ants, seem especially susceptible to fungal pathogens of the genus Ophiocordyceps, including one species that compels infected ants to bite into various erect plant parts just before they die.”

Doing so, he explains, puts the ants in a favorable position for allowing fungal spores to be released from cup-shaped ascomata – the fungi’s fruiting body –protruding from the ants’ head and neck. Carpenter ants usually make their nests in trees, rotting logs and stumps. The new fungal genus and species shares certain features with Ophiocordyceps but also displays several developmental stages not previously reported, Poinar said. To name the genus, placed in the order Hypocreales, Poinar and fellow researcher Yves-Marie Maltier combined the Greek word for new – alloios – with the name of known genus Cordyceps.

“We can see a large, orange, cup-shaped ascoma with developing perithecia – flask-shaped structures that let the spores out – emerging from the rectum of the ant,” Poinar said. “The vegetative part of the fungus is coming out of the abdomen and the base of the neck. We see freestanding fungal bodies also bearing what look like perithecia, and in addition we see what look like the sacs where spores develop. All of the stages, those attached to the ant and the freestanding ones, are of the same species.”

The fungus could not be placed in the known ant-infecting genus Ophiocordyceps because ascomata in those species usually come out the neck or head of an ant, Poinar said, and not the rectum. “There is no doubt that Allocordyceps represents a fungal infection of a Camponotus ant,” he said.

Scientists have recovered DNA from mammoth fossils found in Siberian permafrost that are more than a million years old. This DNA—the oldest genomic evidence recovered to date—illuminates the evolutionary history of woolly mammoths and Columbian mammoths. It also raises the prospect of recovering DNA from other organisms this ancient—including extinct members of the human family.

Ever since the recovery of two short DNA sequences from a recently extinct zebra subspecies known as the quagga in 1984, researchers have been working to get ever larger amounts of DNA from ever older remains. Advances in ancient DNA extraction and sequencing methods eventually brought to light genomes of creatures from deeper time, including cave bears and Neandertals.

In 2013, investigators announced that they had retrieved DNA from a 700,000-year-old horse fossil—by far the oldest genomic data ever obtained. But as astonishingly old as that genetic material was, some experts predicted that sequenceable DNA should survive more than a million years in fossils preserved in frozen environments.

The new findings, published today in Nature, bear that prediction out. Tom van der Valk and Love Dalén of the Center for Paleogenetics in Stockholm and their colleagues obtained DNA from molar teeth belonging to three mammoths from different time periods. Mammoth species can be distinguished on the basis of dental characteristics. One tooth, discovered in deposits thought to be around 700,000 years old, looked like that of an early woolly mammoth, Mammuthus primigenius. The other two teeth—one dated to around one million years ago and the other to 1.2 million years ago or more—resembled molars of the steppe mammoth, Mammuthus trogontherii.

Fossils of bizarre, armored amphibians known as albanerpetontids provide the oldest evidence of a slingshot-style tongue, a new Science study shows.

Despite having lizardlike claws, scales and tails, albanerpetontids – mercifully called “albies” for short – were amphibians, not reptiles. Their lineage was distinct from today’s frogs, salamanders and caecilians and dates back at least 165 million years, dying out only about 2 million years ago.

Now, a set of 99-million-year-old fossils redefines these tiny animals as sit-and-wait predators that snatched prey with a projectile firing of their tongue – and not underground burrowers, as once thought. The fossils, one previously misidentified as an early chameleon, are the first albies discovered in modern-day Myanmar and the only known examples in amber.

They also represent a new genus and species: Yaksha perettii, named after treasure-guarding spirits known as yakshas in Hindu literature and Adolf Peretti, the discoverer of two of the fossils. “This discovery adds a super-cool piece to the puzzle of this obscure group of weird little animals,” said study co-author Edward Stanley, director of the Florida Museum of Natural History’s Digital Discovery and Dissemination Laboratory. “Knowing they had this ballistic tongue gives us a whole new understanding of this entire lineage.”

The extinction of prehistoric megafauna like the woolly mammoth, cave lion, and woolly rhinoceros at the end of the last ice age has often been attributed to the spread of early humans across the globe. Although overhunting led to the demise of some species, a study appearing August 13, 2020 in the journal Current Biology found that the extinction of the woolly rhinoceros may have had a different cause: climate change. By sequencing ancient DNA from 14 of these megaherbivores, researchers found that the woolly rhinoceros population remained stable and diverse until only a few thousand years before it disappeared from Siberia, when temperatures likely rose too high for the cold-adapted species.

"It was initially thought that humans appeared in northeastern Siberia fourteen or fifteen thousand years ago, around when the woolly rhinoceros went extinct. But recently, there have been several discoveries of much older human occupation sites, the most famous of which is around thirty thousand years old," says senior author Love Dalén, a professor of evolutionary genetics at the Centre for Palaeogenetics, a joint venture between Stockholm University and the Swedish Museum of Natural History. "So, the decline towards extinction of the woolly rhinoceros doesn't coincide so much with the first appearance of humans in the region. If anything, we actually see something looking a bit like an increase in population size during this period."

To learn about the size and stability of the woolly rhinoceros population in Siberia, the researchers studied the DNA from tissue, bone, and hair samples of 14 individuals. "We sequenced a complete nuclear genome to look back in time and estimate population sizes, and we also sequenced fourteen mitochondrial genomes to estimate the female effective population sizes," says co-first author Edana Lord, a PhD student at the Centre for Palaeogenetics.

By looking at the heterozygosity, or genetic diversity, of these genomes, the researchers were able to estimate the woolly rhino populations for tens of thousands of years before their extinction. "We examined changes in population size and estimated inbreeding," says co-first author Nicolas Dussex, a postdoctoral researcher at the Centre for Palaeogenetics. "We found that after an increase in population size at the start of a cold period some 29,000 years ago, the woolly rhino population size remained constant and that at this time, inbreeding was low."

This stability lasted until well after humans began living in Siberia, contrasting the declines that would be expected if the woolly rhinos went extinct due to hunting. "That's the interesting thing," says Lord. "We actually don't see a decrease in population size after 29,000 years ago. The data we looked at only goes up to 18,500 years ago, which is approximately 4,500 years before their extinction, so it implies that they declined sometime in that gap."

The DNA data also revealed genetic mutations that helped the woolly rhinoceros adapt to colder weather. One of these mutations, a type of receptor in the skin for sensing warm and cold temperatures, has also been found in woolly mammoths. Adaptations like this suggest the woolly rhinoceros, which was particularly suited to the frigid northeast Siberian climate, may have declined due to the heat of a brief warming period, known as the Bølling-Allerød interstadial, that coincided with their extinction towards the end of the last ice age.

The largest flying animal of all time lived very near the end of the Dinosaur Age. This giant called Quetzalcoatlus was as tall as a giraffe on all fours, and its wings spanned over 10 meters, as much as a small aircraft. It probably weighed close to 250 kilograms or more. Quetzalcoatlus shared North America with the terrifying likes of Tyrannosaurus, playing second to the dinosaur on the food chain. Pterosaurs like this were the pinnacle of their evolution. It was once thought that the very biggest Quetzalcoatlus were unable to fly or had to make us of rising air thermals to even stay aloft. New research suggests that pterosaur torsos were packed to the brim with dense muscle. They launched via a push-up motion, using just their arms, and from there onward used a method known as dynamic soaring. The biggest pterosaurs could stay in the air with just a few flaps of their wings. An animal like Quetzalcoatlus could probably travel for 16,000 kilometers non-stop, relying on just a few flaps to stay airborne and then soaring the rest of the way.

All of this is a testament to their glory and their success. It was only a celestial event that could wipe out Quetzalcoatlus and its kin. In this case, it was the infamous asteroid that crashed into the Earth 66 million years ago, the one that heralded the end of the Age of the Dinosaurs, The pterosaurs and their neighbors, as well as numerous other creatures were gone for good, but their legacy still remained. Paleontology has been evolving at a breakneck speed since its origins in the 18th Century. We know more about pterosaurs and their lifestyle than we could have ever hoped to, and there is still more to be discovered.

An international team of scientists led by the University of the Witwatersrand in South Africa, has been able to reconstruct, in the smallest details, the skulls of some of the world's oldest known dinosaur embryos in 3D, using powerful and non-destructive synchrotron techniques at the ESRF, the European Synchrotron in France. They found that the skulls develop in the same order as those of today's crocodiles, chickens, turtles and lizards. The findings are published recently in Scientific Reports.

University of the Witwatersrand scientists publish 3D reconstructions of the ~2cm-long skulls of some of the world's oldest dinosaur embryos in an article in Scientific Reports. The embryos, found in 1976 in Golden Gate Highlands National Park (Free State Province, South Africa) belong to South Africa's iconic dinosaur Massospondylus carinatus, a 5-meter long herbivore that nested in the Free State region 200 million years ago.

The scientific usefulness of the embryos was previously limited by their extremely fragile nature and tiny size. In 2015, scientists Kimi Chapelle and Jonah Choiniere, from the University of Witwatersrand, brought them to the European Synchrotron (ESRF) in Grenoble, France for scanning. At the ESRF, an 844 metre-ring of electrons travelling at the speed of light emits high-powered X-ray beams that can be used to non-destructively scan matter, including fossils. The embryos were scanned at an unprecedented level of detail -- at the resolution of an individual bone cell.

With these data in hand, and after nearly 3 years of data processing at Wits' laboratory, the team was able to reconstruct a 3D model of the baby dinosaur skull. "No lab CT scanner in the world can generate these kinds of data," said Vincent Fernandez, one of the co-authors and scientist at the Natural History Museum in London (UK). "Only with a huge facility like the ESRF can we unlock the hidden potential of our most exciting fossils. This research is a great example of a global collaboration between Europe and the South African National Research Foundation," he adds.

Up until now, it was believed that the embryos in those eggs had died just before hatching. However, during the study, lead author Chapelle noticed similarities with the developing embryos of living dinosaur relatives (crocodiles, chickens, turtles, and lizards). By comparing which bones of the skull were present at different stages of their embryonic development, Chapelle and co-authors can now show that the Massospondylus embryos were actually much younger than previously thought and were only at 60% through their incubation period.

The team also found that each embryo had two types of teeth preserved in its developing jaws. One set was made up of very simple triangular teeth that would have been resorbed or shed before hatching, just like geckos and crocodiles today. The second set were very similar to those of adults, and would be the ones that the embryos hatched with. "I was really surprised to find that these embryos not only had teeth, but had two types of teeth. The teeth are so tiny; they range from 0.4 to 0.7mm wide. That's smaller than the tip of a toothpick!," explains Chapelle.

The conclusion of this research is that dinosaurs developed in the egg just like their reptilian relatives, whose embryonic developmental pattern hasn't changed in 200 million years. "It's incredible that in more than 250 million years of reptile evolution, the way the skull develops in the egg remains more or less the same. Goes to show -- you don't mess with a good thing!," concludes Jonah Choiniere, professor at the University of Witwatersrand and also co-author of the study.

When a gigantic asteroid struck the Earth some 66 million years ago, it triggered an “impact winter” that extinguished over 75 percent of all species on Earth. New research suggests it was the resulting low light, and not frigid temperatures, that drove this horrific mass extinction.

The Cretaceous–Paleogene (K–Pg) mass extinction event was so bad that no terrestrial species larger than a rat managed to survive—and it stayed that way for hundreds of thousands of years. It was the resulting impact winter that did the damage, as the atmosphere became inundated with dust, sulfuric compounds, and soot, which caused low temperatures and a dramatic lack of sunlight.

As to which factor—the low light or low temperatures—contributed the most to the impact winter and the ensuing mass extinction is a matter of debate. New research published in Geophysical Research Letters attributes the low light—as caused by excessive soot in the atmosphere—as the primary factor. The new paper was co-authored by geoscientist Clay Tabor from the University of Connecticut, and his colleagues from the University of Colorado, Boulder, and the National Center for Atmospheric Research.

For the study, the researchers ran multiple simulations showing how the Earth’s climate reacted to the dramatic addition of all that stuff in the atmosphere. When the asteroid struck, it spewed an unspeakable amount of molten material into the sky, which fell down as fiery rain across much of the globe. This kindled massive wildfires around the world, the byproduct of which was soot, and lots of it. As for the dust and sulfates, those elements came from the collision itself (asteroids are packed with sulfur). To create the simulations, the researchers used the Community Earth System Model (DESM) which is “able to accurately simulate present‐day climate and has been widely used for paleoclimate applications,” according to the study.

Consistent with other research, the models showed that the reduced sunlight caused global cooling at the Earth’s surface. Yes, this cooling was bad, the researchers admit, but not enough to tip the scales towards a mass extinction.

As for the low light impacting on the Earth’s biosphere, that’s another story. According to the models, the soot hung out in the atmosphere for a protracted period of time. And unlike dust and sulfur, soot sucks up the Sun’s life-giving rays like a sponge.

For more than a century, biologists have wondered what the earliest animals were like when they first arose in the ancient oceans over half a billion years ago. Searching among today’s most primitive-looking animals for the earliest branch of the animal tree of life, scientists gradually narrowed the possibilities down to two groups: sponges, which spend their entire adult lives in one spot, filtering food from seawater; and comb jellies, voracious predators that oar their way through the world’s oceans in search of food.

In a new study published this week in the journal Nature, researchers use a novel approach based on chromosome structure to come up with a definitive answer: Comb jellies, or ctenophores (teen’-a-fores), were the first lineage to branch off from the animal tree. Sponges were next, followed by the diversification of all other animals, including the lineage leading to humans. Although the researchers determined that the ctenophore lineage branched off before sponges, both groups of animals have continued to evolve from their common ancestor. Nevertheless, evolutionary biologists believe that these groups still share characteristics with the earliest animals, and that studying these early branches of the animal tree of life can shed light on how animals arose and evolved to the diversity of species we see around us today.

“The most recent common ancestor of all animals probably lived 600 or 700 million years ago. It’s hard to know what they were like because they were soft-bodied animals and didn’t leave a direct fossil record. But we can use comparisons across living animals to learn about our common ancestors,” said Daniel Rokhsar, University of California, Berkeley professor of molecular and cell biology and co-corresponding author of the paper along with Darrin Schultz and Oleg Simakov of the University of Vienna. “It’s exciting — we’re looking back deep in time where we have no hope of getting fossils, but by comparing genomes, we’re learning things about these very early ancestors.”

Understanding the relationships among animal lineages will help scientists understand how key features of animal biology, such as the nervous system, muscles and digestive tract, evolved over time, the researchers say. “We developed a new way to take one of the deepest glimpses possible into the origins of animal life,” said Schultz, the lead author and a former UC Santa Cruz graduate student and researcher at the Monterey Bay Aquarium Research Institute (MBARI) who is now a postdoctoral researcher at the University of Vienna. “This finding will lay the foundation for the scientific community to begin to develop a better understanding of how animals have evolved.”

What is an animal?
Most familiar animals, including worms, flies, mollusks, sea stars and vertebrates — and including humans — have a head with a centralized brain, a gut running from mouth to anus, muscles and other shared features that had already evolved by the time of the famed “Cambrian Explosion” around 500 million years ago. Together, these animals are called bilaterians.

Other bona fide animals, however, such as jellyfish, sea anemones, sponges and ctenophores, have simpler body plans. These creatures lack many bilaterian features — for example, they lack a defined brain and may not even have a nervous system or muscles — but still share the hallmarks of animal life, notably the development of multicellular bodies from a fertilized egg.

The evolutionary relationships among these diverse creatures — specifically, the order in which each of the lineages branched off from the main trunk of the animal tree of life — has been controversial. With the rise of DNA sequencing, biologists were able to compare the sequences of genes shared by animals to construct a family tree that illustrates how animals and their genes evolved over time since the earliest animals arose in the Precambrian Period. But these phylogenetic methods based on gene sequences failed to resolve the controversy over whether sponges or comb jellies were the earliest branch of the animal tree, in part because of the deep antiquity of their divergence, Rokhsar said. “The results of sophisticated sequence-based studies were basically split,” he said. “Some researchers did well-designed analyses and found that sponges branched first. Others did equally complex and justifiable studies and got ctenophores. There hasn’t really been any convergence to a definitive answer.”

About 300 million years ago, Earth didn't have seven continents, but instead one massive supercontinent called Pangea, which was surrounded by a single large ocean called Panthalassa. The explanation for Pangea's formation ushered in the modern theory of plate tectonics, which posits that the Earth's outer shell is broken up into several plates that slide over Earth's rocky shell, the mantle. Over the course of the planet's 4.5 billion-year history, several supercontinents have formed and broken up, a result of churning and circulation in the Earth's mantle, which makes up 84% of the planet's volume, according to the U.S. Geological Survey. This breakup and formation of supercontinents has dramatically altered the planet's history. "This is what's driven the entire evolution of the planet through time. This is the major backbeat of the planet," said Brendan Murphy, a geology professor at the St. Francis Xavier University, in Antigonish, Nova Scotia.

PANGEA'S HISTORY

More than a century ago, the scientist Alfred Wegener proposed the notion of an ancient supercontinent, which he named Pangea, after putting together several lines of evidence. The first and most obvious was that the "continents fit together like a tongue and groove," something that was quite noticeable on any accurate map, Murphy said. Another telltale hint that Earth's continents were all one land mass comes from the geologic record. Coal deposits found in Pennsylvania have a similar composition to those spanning across Poland, Great Britain and Germany from the same time period. That indicates that North America and Europe must have once been a single landmass. And the orientation of magnetic minerals in geologic sediments reveals how Earth's magnetic poles migrated over geologic time, Murphy said.

In the fossil record, identical plants, such as the extinct seed fern Glossopteris, are found on now widely disparate continents. And mountain chains that now lie on different continents, such as the Appalachians in the United States and the Atlas Mountains spanning Morocco, Algeria and Tunisia were all part of the Central Pangaea Mountains, formed through the collision of the supercontinents Gondwana and Laurussia.

Some 66 million years ago, a 10-kilometer asteroid hit Earth, triggering a firestorm engulfing most of the North American continent, a tsunami with mountain-sized waves, and an earthquake so massive that it shook the planet for weeks to months after the collision. The amount of energy released in this "mega-earthquake" is estimated at 10^23 joules, which is about 50,000 times more energy than was released in the magnitude 9.1 Sumatra earthquake in 2004 - one of the most powerful earthquakes ever experienced by humankind.

In 2014, while doing fieldwork on Colombia's Gorgonilla Island, Bermúdez found spherule deposits—layers of sediment filled with small glass beads and shards known as "tektites" and "microtektites" that were ejected into the atmosphere during an asteroid impact. These glass beads formed when the heat and pressure of the impact melted and scattered the crust of the Earth, ejecting small, melted blobs up into the atmosphere, which then fell back to the surface as glass under the influence of gravity.

The rocks exposed on the coast of Gorgonilla Island tell a story from the bottom of the ocean—roughly 2 kilometers down. There, about 3,000 kilometers southwest of the site of the impact, sand, mud, and small ocean creatures were accumulating on the ocean floor when the asteroid hit. Layers of mud and sandstone as far as 10–15 meters below the sea floor experienced soft-sediment deformation that is preserved in the outcrops today, which Bermúdez attributes to the shaking from the impact.

Faults and deformation due to shaking continue up through the spherule-rich layer that was deposited post-impact, indicating that the shaking must have continued for the weeks and months it took for these finer-grained deposits to reach the ocean floor. Just above those spherule deposits, preserved fern spores signal the first recovery of plant-life after the impact.

Bermúdez explains, "The section I discovered on Gorgonilla Island is a fantastic place to study the Cretaceous–Paleogene boundary, because it is one of the best-preserved and it was located deep in the ocean, so it was not affected by tsunamis." Evidence of deformation from the mega-earthquake is also preserved in Mexico and the United States. At the El Papalote exposure in Mexico, Bermúdez observed evidence of liquefaction—when strong shaking causes water-saturated sediments to flow like a liquid. In Mississippi, Alabama, and Texas, Bermúdez documented faults and cracks likely associated with the mega-quake. He also documented tsunami deposits at several outcrops, left by an enormous wave that was part of the cascading catastrophes resulting from the asteroid collision.

Bermúdez will deliver a talk about his team's research at the GSA Connects meeting on Sunday, October 9. He will also present a poster about his observations of tsunami deposits and earthquake-related deformation on Monday, October 10th, 2022.

A newly discovered impact crater below the seafloor hints at the possibility that more than one asteroid hit Earth during the time when dinosaurs went extinct.

Scientists have found evidence of an asteroid impact crater beneath the North Atlantic Ocean that could force researchers to rethink how the dinosaurs reached the end of their reign.

The team believes the crater was caused by an asteroid colliding with Earth around 66 million years ago – around the same time that the Chicxulub asteroid hit Earth off the coast of today's Yucatan, Mexico, and wiped out the dinosaurs.

Spanning more than 5 miles in diameter, the crater was discovered using seismic measurements, which allow scientists to probe what lies deep below Earth's surface.

Veronica Bray, a research scientist in the University of Arizona Lunar and Planetary Laboratory, who specializes in craters found throughout the solar system, is a co-author of a study in Science Advances detailing the discovery.

Named after a nearby seamount, the Nadir crater is buried up to 1,300 feet below the seabed about 250 miles off the coast of Guinea, West Africa. The team believes the asteroid that created the newly discovered Nadir crater could have formed by breakup of a parent asteroid or by a swarm of asteroids in that time period. If confirmed, the crater will be one of less than 20 confirmed marine impact craters found on Earth.

Bray used computer simulations to determine what kind of collision took place and what the effects might have been. The simulations suggest the crater was caused by the collision of a 1,300 foot-wide asteroid in 1,600 to 2,600 feet of water. "This would have generated a tsunami over 3,000 feet high, as well as an earthquake of more than magnitude 6.5," Bray said. "Although it is a lot smaller than the global cataclysm of the Chicxulub impact, Nadir will have contributed significantly to the local devastation. And if we have found one 'sibling' to Chicxulub, it opens the question: Are there others?”

The estimated size of the asteroid would put it roughly on par with asteroid Bennu, the target of the UArizona-led NASA asteroid sample return mission OSIRIS-REx.  According to Bray's calculations, the energy released from the impact that caused the Nadir crater would have been around 1,000 times greater than the tsunami caused by the underwater eruption of the Hunga Tonga-Hunga Ha'apai volcano in the Polynesian country of Tonga on Jan. 15. 

"These are preliminary simulations and need to be refined when we get more data," Bray said, "but they provide important new insights into the possible ocean depths in this area at the time of impact."

Rare fossils preserving the brains of creatures living more than half a billion years ago shed new light on the evolution of arthropods such as insects and crustaceans.

Exquisitely preserved fossils left behind by creatures living more than half a billion years ago reveal in great detail identical structures that researchers have long hypothesized must have contributed to the archetypal brain that has been inherited by all arthropods. Arthropods are the most diverse and species-rich taxonomic group of animals and include insects, crustaceans, spiders and scorpions, as well as other, less familiar lineages such as millipedes and centipedes.

The fossils, belonging to an arthropod known as Leanchoilia, confirm the presence -- predicted by earlier studies in genetics and developmental biology of insect and spider embryos -- of an extreme frontal domain of the brain that is not segmented and is invisible in modern adult arthropods. Despite being invisible, this frontal domain gives rise to several crucial neural centers in the adult arthropod brain, including stem cells that eventually provide centers involved in decision-making and memory. This frontal domain was hypothesized to be distinct from the forebrain, midbrain and hindbrain seen in living arthropods, and it was given the name prosocerebrum ("proso" meaning "front").

Described in a recent paper in the journal Current Biology, the fossils provide the first evidence of the existence of this discrete prosocerebral brain region, which has a legacy that shows up during the embryonic development of modern arthropods, according to paper lead author Nicholas Strausfeld, a Regents Professor of Neuroscience at the University of Arizona. "The extraordinary fossils we describe are unlike anything that has been seen before," Strausfeld said. "Two nervous systems, already unique because they are identically preserved, show that half a billion years ago this most anterior brain region was present and structurally distinct before the evolutionary appearance of the three segmental ganglia that denote the fore-, mid- and hindbrain."

The term ganglion refers to a system of networks forming a nerve center that occurs in each segment of the nervous system of an arthropod. In living arthropods, the three ganglia that mark the three-part brain condensed together to form a solid mass, obscuring their evolutionary origin as segmented structures.

For the past 150 years or so, scientists have theorized that the life cycle of the present-day lamprey mirrors the evolution of all fish – and thus of all vertebrates. Newly analyzed fossils, however, indicate that such is not the case.

The lamprey is a long eel-like fish, which latches onto the bodies of other fish using its sucker-like mouth. A ring of teeth within that mouth then rasps away the skin of the host fish, so the lamprey can feed on its blood. And while adult lampreys are free-swimming, sighted fish, their larvae are tiny blind worm-like creatures that burrow into the riverbed, then filter-feed on food particles carried past in the current.

Because previously discovered fossils indicated that adult lampreys have changed very little over the past 360 million years (or more), it was thought that their life cycle was just as ancient. Scientists thus theorized that the animals' transition from bottom-dwelling filter-feeders to free-swimming predators was a remnant of the process in which wormy invertebrates eventually evolved into the first vertebrate fishes.

Now, though, fossils of lamprey hatchlings discovered in Illinois, South Africa and Montana are challenging that theory. Some of the fossilized remains include an egg sac, indicating that the creatures had only recently hatched. And importantly, they looked very much like miniature adult lampreys, complete with eyes and tooth-lined sucker mouths. In other words, they were not similar to today's riverbed-burrowing larvae.

Based on these findings, it is now thought that the filter-feeding larval stage may have subsequently evolved as a means of adapting to life in freshwater lakes and rivers – originally, lampreys were strictly marine animals.

Stop The Wildlife Trade: ‘Extinction breeds extinction’, says grim new study revealing more than 500 species are on course to go extinct in next two decades - around the same figure for the whole of the twentieth century.

To date only the length of the legendary giant shark Megalodon had been estimated but now, a new study led by the University of Bristol and Swansea University has revealed the size of the rest of its body, including fins that are as large as an adult human. There is a grim fascination in determining the size of the largest sharks, but this can be difficult for fossil forms where teeth are often all that remain.

Today, the most fearsome living shark is the Great White, at over six meters (20 feet) long, which bites with a force of two tonnes.

Microbes found themselves buried in the dirt 101.5 million years ago, back before even Tyrannosaurus rex when Earth’s biggest meat-eating dinosaur, called Spinosaurus roamed the planet. Time passed, continents shifted, oceans rose and fell, great apes emerged, and eventually human beings evolved with the curiosity and skills to dig up those ancient cells. And now, in a Japanese lab, researchers have brought the single-celled organisms back to life.

Researchers aboard the drill ship JOIDES Resolution collected sediment samples from the bottom of the ocean 10 years ago. The samples came from 328 feet (100 meters) below the 20,000-foot-deep (6,000 m) bottom of the South Pacific Gyre. That's a region of the Pacific Ocean with very few nutrients and little oxygen available for life to survive on, and the researchers were looking for data on how microbes get along in such a remote part of the world.

"Our main question was whether life could exist in such a nutrient-limited environment or if this was a lifeless zone," Yuki Morono, a scientist at the Japan Agency for Marine-Earth Science and Technology and lead author of a new paper on the microbes, said in a statement. "And we wanted to know how long the microbes could sustain their life in a near-absence of food.

Their results indicate that even cells found in 101.5 million-year-old sediment samples are capable of waking up when oxygen and nutrients become available. "At first, I was very skeptical, but we found that up to 99.1% of the microbes in sediment deposited 101.5 million years ago were still alive and were ready to eat," Morono said. The microbes had ceased all noticeable activity. But when offered nutrients and other necessities of life they became active again.

A team of researchers led by Arizona State University School of Earth and Space Exploration Professor Lindy Elkins-Tanton has provided the first ever direct evidence that extensive coal burning in Siberia is a cause of the Permo-Triassic Extinction, the Earth’s most severe extinction event.

A team of researchers led by Arizona State University School of Earth and Space Exploration Professor Lindy Elkins-Tanton has provided the first ever direct evidence that extensive coal burning in Siberia is a cause of the Permo-Triassic Extinction, the Earth’s most severe extinction event. The results of their study have been recently published in the journal Geology.

For this study, the international team led by Elkins-Tanton focused on the volcaniclastic rocks of the Siberian Traps, a region of volcanic rock in Russia. The massive eruptive event that formed the traps is one of the largest known volcanic events in the last 500 million years. The eruptions continued for roughly 2 million years and spanned the Permian-Triassic boundary. Today, the area is covered by about 3 million square miles of basaltic rock.

This is ideal ground for researchers seeking an understanding of the Permo-Triassic extinction event, which affected all life on Earth approximately 252 million years ago. During this event, up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct.

Calculations of sea water temperature indicate that at the peak of the extinction, the Earth underwent lethally hot global warming, in which equatorial ocean temperatures exceeded 104 degrees Fahrenheit. It took millions of years for ecosystems to be re-established and for species to recover.

Among the possible causes of this extinction event, and one of the most long-hypothesized, is that massive burning coal led to catastrophic global warming, which in turn was devastating to life. To search for evidence to support this hypothesis, Elkins-Tanton and her team began looking at the Siberian Traps region, where it was known that the magmas and lavas from volcanic events burned a combination of vegetation and coal.

While samples of volcaniclastics in the region were initially difficult to find, the team eventually discovered a scientific paper describing outcrops near the Angara River. “We found towering river cliffs of nothing but volcaniclastics, lining the river for hundreds of miles. It was geologically astounding,” Elkins-Tanton said.

Four fossilized monkey teeth discovered deep in the Peruvian Amazon provide new evidence that more than one group of ancient primates journeyed across the Atlantic Ocean from Africa, according to new USC research just published in the journal Science.

The teeth are from a newly discovered species belonging to an extinct family of African primates known as parapithecids. Fossils discovered at the same site in Peru had earlier offered the first proof that South American monkeys evolved from African primates.

The monkeys are believed to have made the more than 900-mile trip on floating rafts of vegetation that broke off from coastlines, possibly during a storm. “This is a completely unique discovery,“ said Erik Seiffert, PhD, the study’s lead author and Professor of Clinical Integrative Anatomical Sciences at Keck School of Medicine of USC. “It shows that in addition to the New World monkeys and a group of rodents known as caviomorphs – there is this third lineage of mammals that somehow made this very improbable transatlantic journey to get from Africa to South America.”

Researchers have named the extinct monkey Ucayalipithecus perdita. The name comes from Ucayali, the area of the Peruvian Amazon where the teeth were found, pithikos, the Greek word for monkey and perdita, the Latin word for lost.

Three new species of toothed pterosaurs — flying reptiles of the Cretaceous period, some 100 million years ago — have been identified in Africa by an international team of scientists led by Baylor University.