Amazing Science

The oxygenation of Earth’s atmosphere was thanks, in part, to iron and silica particles in ancient seawater, according to a new study by geomicrobiologists at the University of Alberta. But these results solve only part of this ancient mystery.

Early organisms called cyanobacteria produced oxygen through oxygenic photosynthesis, resulting in the oxygenation of Earth’s atmosphere. But cyanobacteria needed protection from the sun’s UV radiation in order to evolve. That’s where iron and silica particles in ancient seawater come in, according to Aleksandra Mloszewska, a former PhD student who conducted this research under the supervision of Kurt Konhauser, professor in the Department of Earth and Atmospheric Sciences, and George Owttrim, professor in the Department of Biological Sciences.

The research team characterized the effect of UV stress on cyanobacteria and the degree of radiation through the seawater medium through a combination of microbiological, spectroscopic, geochemical and modeling techniques. Their results show that the presence of high silica and iron concentrations in early sea water allowed for the formation of iron-silica precipitates that remained suspended in the ocean for extended periods of time.

“In effect, the iron-silica particles acted as an ancient ‘sunscreen’ for the cyanobacteria, protecting them from the lethal effects of direct UV exposure,” said Konhauser, the senior author from UAlberta. “This was critical on the early Earth before a sufficiently thick ozone layer was established that could enable marine plankton to spread across the globe, as is the case today.”

Researchers in Argentina have discovered what they say is the oldest-known giant dinosaur and it’s altering the way paleontologists view the evolution of dinosaurs as a whole.

A study recently published in Nature indicates the newly-discovered Ingentia prima is three times the size of the largest previously discovered dinosaur species from the Triassic period and would have weighed up to nine tonnes as an adult.

With this discovery, researchers are now rethinking the evolution of dinosaurs, as they previously believed giant dinosaurs didn’t exist until 25 million years later.

"Before this discovery, gigantism was considered to have emerged during the Jurassic period, approximately 180 million years ago, but Ingentia prima lived at the end of the Triassic, between 210 and 205 million years ago,” Cecilia Apaldetti, researcher at the University of San Juan and the study’s principal author, said in a news release.

For most dinosaurs, gigantism proved to be an evolutionary survival tool, especially among herbivores who could use their size as a form of defence against predators.

The researchers say the Ingentia prima, which loosely translates to “first giant,” was a four-legged herbivore that grew cyclically, meaning it would grow quickly for stretches of time and then stop growing for similar stretches, kind of like a tree.

Nitrogen fixation in the surface ocean impacts global marine nitrogen bioavailability and thus microbial primary productivity. Until now, cyanobacterial populations have been viewed as the main suppliers of bioavailable nitrogen in this habitat. Although PCR amplicon surveys targeting the nitrogenase reductase gene have revealed the existence of diverse non-cyanobacterial diazotrophic populations, subsequent quantitative PCR surveys suggest that they generally occur in low abundance. Now, a team of scientists used state-of-the-art metagenomic assembly and binning strategies to recover nearly one thousand non-redundant microbial population genomes from the TARA Oceans metagenomes. Among these, they provided the first genomic evidence for non-cyanobacterial diazotrophs inhabiting surface waters of the open ocean, which correspond to lineages within the Proteobacteria and, most strikingly, the Planctomycetes. Members of the latter phylum are prevalent in aquatic systems, but have never been linked to nitrogen fixation previously. Moreover, using genome-wide quantitative read recruitment, the group of scientists were able to demonstrate that the discovered diazotrophs were not only widespread but also remarkably abundant (up to 0.3% of metagenomic reads for a single population) in both the Pacific Ocean and the Atlantic Ocean northwest.

These results extend decades of PCR-based gene surveys, and substantiate the importance of heterotrophic bacteria in the fixation of nitrogen in the surface ocean.

Sixty-six million years ago, the world burned. An asteroid crashed to Earth with a force one million times larger than the largest atomic bomb, causing the extinction of the dinosaurs. But dinosaurs weren't the only ones that got hit hard -- in a new study, scientists learned that the planet's forests were decimated, leading to the extinction of tree-dwelling birds.

"Looking at the fossil record, at plants and birds, there are multiple lines of evidence suggesting that the forest canopies collapsed," says Regan Dunn, a paleontologist at the Field Museum in Chicago and a co-author on the study in Current Biology . "Perching birds went extinct because there were no more perches.  We drew on a variety of approaches to stitch this story together," said Daniel Field, the paper's lead author, of the Milner Centre for Evolution at the University of Bath.

"We concluded that the temporary elimination of forests in the aftermath of the asteroid impact explains why arboreal birds failed to survive across this extinction event. The ancestors of modern arboreal birds did not move into the trees until forests had recovered from the extinction-causing asteroid."

The project's pollen expert, Antoine Bercovici of the Smithsonian Institution and the Denver Museum of Nature and Science, helped determine that the world's forests were destroyed by looking at microscopic fossils of pollen and spores. Dunn explains, "After a disaster like a forest fire or a volcanic eruption, the first plants to come back are the fastest colonizers -- especially ferns." That's because ferns don't sprout from seeds, but from spores, which are much smaller -- just a single cell. "Spores are minuscule, the size of a grain of pollen, so they're easily dispersed. They get picked up by the wind and go further than seeds can, and all they need to grow is a wet spot.  The spores are tiny -- you could fit four across a single strand of your hair," says Dunn. "To see them, we take a sample of rock from the time frame just after the collision and dissolve it in acid. Then we purify it so that all that remains is the organic debris, like pollen, spores and little leaf bits, then we look at them under a microscope."

Immediately after the asteroid hit, the fossil record shows the charcoal remains of burnt trees, and then, tons of fern spores. An abundance of fern spores in the fossil record often comes on the heels of a natural disaster that destroyed larger plants like trees.  "Our study examined the fossil record from New Zealand, Japan, Europe and North America, which showed there was a mass deforestation across the globe at the end of the Cretaceous period," says co-author Bercovici.

And with no more trees, the scientists found, tree-dwelling birds went extinct. The birds that did survive were ground-dwellers -- birds whose fossilized remains show longer, sturdier legs like we see in modern ground birds like kiwis and emus. The Cretaceous equivalent of robins and sparrows, with delicate little legs made for perching on tree branches, had no place to live.  "Today, birds are the most diverse and globally widespread group of terrestrial vertebrate animals -- there are nearly 11,000 living species," says Field. "Only a handful of ancestral bird lineages succeeded in surviving the mass extinction event 66 million years ago, and all of today's amazing living bird diversity can be traced to these ancient survivors."

A newly found "transitional" bird fossil sheds light on a pivotal point in the pathway from dinosaurs to modern birds. Ichthyornis dispar lived in North America about 86 million years ago. The seagull-sized bird had a beak and a brain much like modern birds, but the sharp teeth and powerful jaws of dinosaurs like Velociraptor. "It shows us what the first bird beak looked like," said Bhart-Anjan Bhullar of Yale University, a study researcher. "It's a real mosaic of features, a transitional form."

It has long been known that birds evolved from dinosaurs in what was a slow gradual process, involving feathers, wings and beaks. Evidence for feathers has shown up in the fossil record, but it has proved very difficult to study the anatomy of the tiny delicate skulls of ancient birds.

The researchers combined fossil evidence from the complete skull and two previously overlooked cranial fossils with the latest CT scanning techniques to build an advanced 3D model of the skull of the primitive bird. As study researcher Daniel Field, from the University of Bath, put it, most skull fossils are "squashed flat during the fossilization process". He said the "extraordinary new specimen", which was discovered only recently, reveals similar brain proportions to that of a modern bird, while other parts of the skull more closely resemble those of predatory dinosaurs.

Half-bird, half-dinosaur
Dr Steve Brusatte of the University of Edinburgh, who is not connected with the research, described the study as a game-changer in how we understand the evolution of the bird beak and brain. "The beaks of these primitive birds were very small and seem to have been evolving to take over some of the functions of the hand, like manipulating food and cleaning the feathers, that became impossible once the hands were incorporated into the wing," he said. "This helps to show that the evolution of birds from dinosaurs was a long and gradual process - it didn't just happen overnight, and for much of the Age of Dinosaurs there would have existed these creatures that looked half-dinosaur, half-bird."

The famous naturalist Charles Darwin read about the fossil and said the work on "old birds" afforded support for the theory of evolution. A century or so on, the strange bird is filling in the gaps in our knowledge of these "extraordinary flying machines".

Homo sapiens, Neanderthals and other recent human relatives may have begun hunting large mammal species down to size — by way of extinction — at least 90,000 years earlier than previously thought, says a new study published in the journal Science.

Elephant-dwarfing wooly mammoths, elephant-sized ground sloths and various saber-toothed cats highlighted the array of massive mammals roaming Earth between 2.6 million and 12,000 years ago. Prior research suggested that such large mammals began disappearing faster than their smaller counterparts — a phenomenon known as size-biased extinction — in Australia around 35,000 years ago.

With the help of emerging data from older fossil and geologic records, the new study estimated that this size-biased extinction started at least 125,000 years ago in Africa. By that point, the average African mammal was already 50 percent smaller than those on other continents, the study reported, despite the fact that larger landmasses can typically support larger mammals. But as humans migrated out of Africa, other size-biased extinctions began occurring in regions and on timelines that coincide with known human migration patterns, the researchers found. Over time, the average body size of mammals on those other continents approached and then fell well below Africa’s. Mammals that survived during the span were generally far smaller than those that went extinct.

The magnitude and scale of the recent size-biased extinction surpassed any other recorded during the last 66 million years, according to the study, which was led by the University of New Mexico’s Felisa Smith. “It wasn’t until human impacts started becoming a factor that large body sizes made mammals more vulnerable to extinction,” said the University of Nebraska-Lincoln’s Kate Lyons, who authored the study with Smith and colleagues from Stanford University and the University of California, San Diego. “The anthropological record indicates that Homo sapiens are identified as a species around 200,000 years ago, so this occurred not very long after the birth of us as a species. It just seems to be something that we do.

“From a life-history standpoint, it makes some sense. If you kill a rabbit, you’re going to feed your family for a night. If you can kill a large mammal, you’re going to feed your village.” By contrast, the research team found little support for the idea that climate change drove size-biased extinctions during the last 66 million years. Large and small mammals seemed equally vulnerable to temperature shifts throughout that span, the authors reported.

A newly discovered ancient sea monster from the dinosaur age was nearly the size of a blue whale.

About 205 million years ago, a ginormous sea monster — so large it was nearly the size of a modern blue whale — swam through the ocean, fueling its colossal body by preying on prehistoric squid and fish, a new study finds.

The recent discovery of this creature's immense jawbone has helped researchers identify a previously unknown species and to solve a nearly 170-year-old mystery. In 1850, beachgoers in southern England found Late Triassic fossils by the shore that were so massive, they were thought to be the limb bones of giant dinosaurs, such as the long-necked sauropods. 

But now, thanks to the newfound jawbone finding, researchers think those bones likely belonged to the largest-known ichthyosaur (ik-thee-o-saur) ever found. These creatures, marine reptiles resembling modern-day dolphins, went extinct at the end of the dinosaur age, around 66 million years ago [Ancient Monsters of the Sea]. In May 2016, while walking on a beach in Lilstock, England, study co-researcher and fossil collector Paul de la Salle found pieces of a jawbone that, when pieced together, measured an astounding 3.1 feet (96 centimeters) long.

After connecting with ichthyosaur researchers, including Dean Lomax, a paleontologist at The University of Manchester in England, and Judy Massare, professor emerita of geology at SUNY College at Brockport in New York, de la Salle determined that the specimen belonged to a giant ichthyosaur known as a shastasaurid from the Triassic, which lasted from 251 million to 199 million years ago. The researchers have yet to name the new species and are calling it the Lilstock specimen for now.

Based on the jawbone's length, the researchers estimated that the Lilstock ichthyosaur measured more than 85 feet (26 meters) long, making it the largest ichthyosaur on record — up to 25 percent larger than the previous shastasaurid record holder, Shonisaurus sikanniensis, a 69-foot-long (21 m) beast found in British Columbia, the researchers said.

A scientist has finally confirmed with 3D models that legendary ice man Ötzi was indeed killed 5,300 years ago by an arrow.

Ötzi, a 5,300-year-old mummified man, was found in 1991 in a glacier in the Alps between what is now Austria and Italy. Since the discovery, Ötzi has been examined by multiple teams of scientists, with new discoveries coming to light each time. Now an expert claims it was the arrow that delivered the fatal blow, severing the nerve to his shoulder and hitting his major vessels.

Since his discovery on 19 December 1991 by German hikers, Ӧtzi has provided window into early human history. His mummified remains were uncovered in melting glacier in the mountainous border between Austria and Italy. Analysis of the body has told us that he was alive during the Copper Age and died a grisly death.

Ötzi, who was 46 at the time of his death, had brown eyes, relatives in Sardinia, and was lactose intolerant. He was also predisposed to heart disease. Recent research focused on the DNA in the nuclei of Ötzi's cells, and it could yield further insights into the famous ice mummy's life.

In a discovery that seems straight out of Jurassic Park, researchers have identified a 99-million-year-old fossilized tick on a dinosaur feather. In a significant divergence from the Hollywood storyline, the fossils will not be yielding any dinosaur DNA. The tick’s last meal was not preserved, and even if it had been, the lifespan of DNA is too short for it to be successfully extracted.

However, because they were trapped together, the fossils offer the first direct evidence of ticks feeding on dinosaur blood.The study also examined other ticks trapped in amber, including a previously unknown species that is thought to have also fed on feathered dinosaurs. 

A pair of researchers at Tohoku University has found evidence suggesting that if the asteroid that struck the Earth near Chicxulub 66 million years ago had landed almost anywhere else, it would not have been as devastating to the biosphere.

30,000 years ago, a ground squirrel burrowed out a spot for itself, about 10 inches in diameter at its widest, where it brought back seeds and other grassy and fruited plants to nibble on. The place where the squirrel chose to make its burrow is now known as Siberia, and the burrow is close to 100 feet below the surface and in a layer of permafrost.

The squirrel, of course, is long gone. But tiny roundworms, a type of nematode, that also made their home there have lasted those tens of thousands of years, frozen and immobile. Now, though, scientists in Russia have revived them, making these worms—all of them female worms—the first multicellular organisms to have survived being frozen in Arctic permafrost.

The permafrost layer of the polar parts of the world contains all sorts of tiny creatures, including bacteria, algae, yeasts, and amoebas, as well as moss spores and seeds. After spending thousands of years in deep freeze, these bits of life are thawing out, as the poles heat up and the permafrost softens. Previously, scientists found that a giant virus that they named Pithovirus was still viable after 30,000 years.

In a new paper, published in Doklody Biological Sciences, the scientists describe how they analyzed 300 samples of permafrost. Of those, only two samples had viable nematodes in them. One came from the squirrel burrow; another came from a different permafrost deposit, part of a core drilling near the Alazeya River. That sample was about 42,000 years old.

The samples contained two different types of roundworms, Panagrolaimus detritophagus and Plectus parvus. The scientists let them thaw out, and once they had, the worms seemed ready to go on with their lives, eating and moving, which is about the extent of what ringworms do with themselves.

Earth’s oxygen levels rose and fell more than once hundreds of millions of years before the planetwide success of the Great Oxidation Event about 2.4 billion years ago, new research from the University of Washington shows.

The evidence comes from a new study that indicates a second and much earlier “whiff” of oxygen in Earth’s distant past — in the atmosphere and on the surface of a large stretch of ocean — showing that the oxygenation of the Earth was a complex process of repeated trying and failing over a vast stretch of time.

The finding also may have implications in the search for life beyond Earth. Coming years will bring powerful new ground- and space-based telescopes able to analyze the atmospheres of distant planets. This work could help keep astronomers from unduly ruling out “false negatives,” or inhabited planets that may not at first appear to be so due to undetectable oxygen levels.

“The production and destruction of oxygen in the ocean and atmosphere over time was a war with no evidence of a clear winner, until the Great Oxidation Event,” said Matt Koehler, a UW doctoral student in Earth and space sciences and lead author of a new paper published the week of July 9 , 2018 in the Proceedings of the National Academy of Sciences (PNAS).

Scientists are preparing to create “miniature brains” that have been genetically engineered to contain Neanderthal DNA, in an unprecedented attempt to understand how humans differ from our closest relatives.

In the next few months the small blobs of tissue, known as brain organoids, will be grown from human stem cells that have been edited to contain “Neanderthalized” versions of several genes.

The lentil-sized organoids, which are incapable of thoughts or feelings, replicate some of the basic structures of an adult brain. They could demonstrate for the first time if there were meaningful differences between human and Neanderthal brain biology.

“Neanderthals are the closest relatives to everyday humans, so if we should define ourselves as a group or a species it is really them that we should compare ourselves to,” said Prof Svante Pääbo, director of the genetics department at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, where the experiments are being performed.

Pääbo previously led the successful international effort to crack the Neanderthal genome, and his lab is now focused on bringing Neanderthal traits back to life in the laboratory through sophisticated gene-editing techniques.

The lab has already inserted Neanderthal genes for craniofacial development into mice (heavy-browed rodents are not anticipated), and Neanderthal pain perception genes into frogs’ eggs, which could hint at whether they had a different pain threshold to humans. Now the lab is turning its attention to the brain.

“We’re seeing if we can find basic differences in how nerve cells function that may be a basis for why humans seem to be cognitively so special,” said Pääbo.

The research comes as the longstanding stereotype of Neanderthals as gormless and thuggish is being rewritten by emerging evidence that they buried their dead, produced cave art and had brains that were larger than our own.

“Another megafauna to fall victim to the ending of an ice age was the Irish elk. Calling this animal an elk is actually a misnomer, as recent DNA analysis has shown that it was actually a deer — in fact, the largest deer to have ever lived,” the website writes. “Its antlers alone measured as much as 12 feet across. As with other animals that lived in the icy north during the Pleistocene, preserved specimens of the Irish elk can be readily found in melting permafrost, making it a prime candidate for being cloned.” The skulls, with their colossal antlers, are often mounted on the walls of castles and hunting lodges.

While the science of cloning is still in its infancy, many scientists now believe it's only a matter of time before it becomes a viable option. According to Mother Nature Network, to “successfully clone an extinct animal, scientists need to find animal DNA that is almost entirely intact.”Thus, some species will make better candidates for resurrection than others.

Because of the many well-preserved fossils of this majestic seven foot tall creature that exist around the world, it makes an obvious candidate for scientists experimenting with the cloning process.  According to the University of California Museum of Paleontology, the Irish elk with its "arresting size and singular appearance is of great significance to paleontologists because of the way in which the animal has become involved in evolutionary debates down through the years."

The website lists a theory that the Irish elk finally went extinct when the antlers became so large that the animals could no longer hold up their heads, or got entangled in the trees. To read more about the Irish elk, visit here.

It is commonly understood that the dinosaurs disappeared with a bang – wiped out by a great meteorite impact on the Earth 66 million years ago.

But their origins have been less understood. In a new study, scientists from MUSE - Museum of Science, Trento, Italy, Universities of Ferrara and Padova, Italy and the University of Bristol show that the key expansion of dinosaurs was also triggered by a crisis – a mass extinction that happened 232 million years ago.

In the new paper, published today in Nature Communications, evidence is provided to match the two events – the mass extinction, called the Carnian Pluvial Episode, and the initial diversification of dinosaurs.

Dinosaurs had originated much earlier, at the beginning of the Triassic Period, some 245 million years ago, but they remained very rare until the shock events in the Carnian 13 million years later.

The new study shows just when dinosaurs took over by using detailed evidence from rock sequences in the Dolomites, in north Italy – here the dinosaurs are detected from their footprints.

Pioneering new research has given an illuminating new insight into the metallic, iridescent colors found on the earliest known ancestors of moths and butterflies, which habited the earth almost 200 million years ago.

An international team of researchers, including Dr Tim Starkey from the University of Exeter, have discovered new evidence for colour in Mesozoic fossils. The structural colors of the fossils studied resulted from light scattering by intricate microstructures, extending the evidence for these light-scattering structures in the insect fossil record by more than 130 million years.

The research team examined fossilized remains dating back 180 million years, with some specimens originating from the Jurassic Coast, only a short distance from Exeter. Using powerful electron microscopes and using optical models, the team found microscopic ridges and grooves in the insect's wing scales, similar to those seen in today's moths. Models revealed these tiny features are photonic structures that would have produced metallic bronze to golden color appearances in the insect wings.

Imagine that you’re a voracious carnivore who sinks its teeth into the tail of a small reptile and anticipates a delicious lunch, when, in a flash, the reptile is gone and you are left holding a wiggling tail between your jaws.

A new study by the University of Toronto Mississauga research team led by Professor Robert Reisz and PhD student Aaron LeBlanc, published March 5 in the open source journal, Scientific Reports, shows how a group of small reptiles who lived 289 million years ago could detach their tails to escape the grasp of their would-be predators — the oldest known example of such behaviour. The reptiles, called Captorhinus, weighed less than 2 kilograms and were smaller than the predators of the time. They were abundant in terrestrial communities during the Early Permian period and are distant relatives of all the reptiles today.

As small omnivores and herbivores, Captorhinus and its relatives had to scrounge for food while avoiding being preyed upon by large meat-eating amphibians and ancient relatives of mammals. “One of the ways captorhinids could do this,” says first author LeBlanc, “was by having breakable tail vertebrae.” Like many present-day lizard species, such as skinks, that can detach their tails to escape or distract a predator, the middle of many tail vertebrae had cracks in them.

It is likely that these cracks acted like the perforated lines between two paper towel sheets, allowing vertebrae to break in half along planes of weakness. “If a predator grabbed hold of one of these reptiles, the vertebra would break at the crack and the tail would drop off, allowing the captorhinid to escape relatively unharmed,” says Reisz, a Distinguished Professor of Biology at the University of Toronto Mississauga.

Because Bangiomorpha pubescens is nearly identical to modern red algae, scientists have previously determined that the ancient alga, like green plants, used sunlight to synthesize nutrients from carbon dioxide and water. Scientists have also established that the chloroplast, the structure in plant cells that is the site of photosynthesis, was created when a eukaryote long ago engulfed a simple bacterium that was photosynthetic. The eukaryote then managed to pass that DNA along to its descendants, including the plants and trees that produce most of the world's biomass today.

“Extraordinary.” “Stellar.” “Truly awesome.” “A world-class find.”

That’s how paleontologists are reacting to the discovery of several hundred ridiculously well-preserved pterosaur eggs in China, some of them still containing the remains of embryos. “My first thought was extreme jealousy,” said David Unwin, a pterosaur expert and paleobiologist at the University of Leicester. “Really.”

To understand why Unwin and others are freaking out about the discovery, published Thursday in the journal Science, you have to first appreciate how rare pterosaur eggs are.

The pterosaurs were an order of flying reptiles that went extinct some 66 million years ago. They were not actually dinosaurs, but they went extinct at the same time. Along with bats and birds, they are the only vertebrates to truly fly. And though these creatures lorded over the skies for around 162 million years, only a handful of pterosaur egg fossils have ever been unearthed. And of those, paleontologists have just six three-dimensional eggs – that is, eggs not completely flattened by millions of years of being crushed under younger sediments.

But now, we have a pterosaur egg extravaganza. According to the new research, a site in China’s Turpan-Hami Basin in Xinjiang has coughed up 215 beautiful, pliable and miraculously three-dimensional eggs – 16 of which contain embryonic remains. The researchers also suspect there could be as many as 300 more eggs within the same sandstone block. No wonder Xiaolin Wang, the study’s lead author and a paleontologist at the Chinese Academy of Sciences, said the discovery could be described as a sort of “pterosaur Eden.”

Aside from breaking records, Unwin said there are practical reasons for why having more eggs is better. “When you have a really unique find, you basically can’t do anything to it because that’s all you’ve got.” But now that we have literally hundreds of eggs to work with, we have more options – such as cutting different eggs into cross-sections to study growth rates.

What’s more, the egg treasure trove also boasts skeletons from what appear to be hatchlings, juveniles and adults. This, too, is an embarrassment of riches because it means scientists now have more information about how pterosaurs progressed from egg to adult than ever before. “This is by far the most exciting discovery that I know of,” said Alexander Kellner, co-author of the new study and paleontologist at the National Museum of the Federal University of Rio de Janeiro in Brazil.