Exploring Prehistoric Life

Study: Simple Life Forms are Common Throughout Universe

Sunday, December 24, 2017

Study: Simple Life Forms are Common Throughout Universe

A detailed analysis of 3.465-billion-year-old microbial microfossils provides evidence to support an increasingly widespread understanding that life in the Universe is common.

Professor J. William Schopf from the University of California, Los Angeles, and his colleagues analyzed 11 specimens of 5 species of prokaryotic cellular microfossils from the Apex Basalt Formation, Pilbara Craton, Western Australia.

Two of the five species the researchers studied were primitive photosynthesizers, one was an Archaeal methane producer, and two others were methane consumers.

“The evidence that a diverse group of organisms had already evolved extremely early in the Earth’s history strengthens the case for life existing elsewhere in the Universe because it would be extremely unlikely that life formed quickly on Earth but did not arise anywhere else,” they said.

The study, published in the Proceedings of the National Academy of Sciences, is the most detailed ever conducted on microorganisms preserved in such ancient fossils.

A 3.465-billion-year-old fossil microorganism from Western Australia. Image credit: J. William Schopf / Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles.

“By 3.465 billion years ago, life was already diverse on Earth; that’s clear — primitive photosynthesizers, methane producers, methane users,” Professor Schopf said.

“These are the first data that show the very diverse organisms at that time in Earth’s history, and our previous research has shown that there were sulfur users 3.4 billion years ago as well.”

“This tells us life had to have begun substantially earlier and it confirms that it was not difficult for primitive life to form and to evolve into more advanced microorganisms.”

“Scientists still do not know how much earlier life might have begun. But, if the conditions are right, it looks like life in the Universe should be widespread.”

A methane-consuming fossil microorganism from Western Australia. Image credit: J. William Schopf / Center for the Study of Evolution and the Origin of Life, University of California, Los Angeles.

Professor Schopf and co-authors analyzed the Apex specimens with cutting-edge technology called secondary ion mass spectroscopy (SIMS), which reveals the ratio of carbon-12 to carbon-13 isotopes — information scientists can use to determine how the microorganisms lived.

They used a secondary ion mass spectrometer — one of just a few in the world — to separate the carbon from each fossil into its constituent isotopes and determine their ratios.

“The differences in carbon isotope ratios correlate with their shapes. Their carbon-12 to carbon-13 ratios are characteristic of biology and metabolic function,” said co-author Professor John Valley, from the University of Wisconsin, Madison.

“The fossils were formed at a time when there was very little oxygen in the atmosphere,” Professor Schopf added.

“I think that advanced photosynthesis had not yet evolved, and that oxygen first appeared on Earth approximately half a billion years later before its concentration in our atmosphere increased rapidly starting about 2 billion years ago.”

“Oxygen would have been poisonous to these microorganisms, and would have killed them,” the scientist said.

Primitive photosynthesizers are fairly rare on Earth today because they exist only in places where there is light but no oxygen — normally there is abundant oxygen anywhere there is light.

And the existence of the rocks the team analyzed is also rather remarkable.

“The average lifetime of a rock exposed on the surface of the Earth is about 200 million years,” Professor Schopf noted.

“When I began my career, there was no fossil evidence of life dating back farther than 500 million years ago. The rocks we studied are about as far back as rocks go.”

“While the study strongly suggests the presence of primitive life forms throughout the Universe, the presence of more advanced life is very possible but less certain,” he said.


J. William Schopf et al. SIMS analyses of the oldest known assemblage of microfossils document their taxon-correlated carbon isotope compositions. PNAS, published online December 18, 2017; doi: 10.1073/pnas.1718063115

Source: sci-news.com

Protarctos abstrusus: Fossils Reveal Ancient Bear’s Weakness for Sweets

Sunday, December 24, 2017

An artist’s reconstruction shows Protarctos abstrusus in the Beaver Pond site area during the late summer. An extinct beaver, Dipoides, is shown carrying a tree branch in water. Plants include black crowberry with ripened berries, dwarf birch in foreground, sedges in water margins, and larch trees in background. (Mauricio Antón)

An international team of paleontologists has found the remains of an unusual prehistoric bear that lived 3.5 million years ago (Pliocene epoch) in Canada’s High Arctic.


The High Arctic bear is a close relative of the ancestor of modern bears. It represents an ursine bear (all living bears plus their ancestors, except the giant panda) species called Protarctos abstrusus.

The animal was the size of an Asian black bear and slightly smaller than an American black bear, with a flatter head and a combination of primitive and advanced dental characters.

“This is evidence of the most northerly record for primitive bears, and provides an idea of what the ancestor of modern bears may have looked like,” said team member Dr. Xiaoming Wang, from the Natural History Museum of Los Angeles County.

Protarctos abstrusus was previously known only from a tooth found in Idaho, but Dr. Wang and colleagues found the skull, jaws, teeth and parts of the skeleton from two individuals.

“The skeletal remains of Protarctos abstrusus were collected in different years (1992-2006) from the Beaver Pond site on Ellesmere Island, Nunavut, Canadian Arctic,” the paleontologists explained.

The fossil bear lived in a northern boreal-type forest habitat, where there would have been 24-hour darkness in winter, as well as about six months of ice and snow.

“Modern bears are wide-ranging, found from equatorial to polar regions. Their ancestors, mainly found in Eurasia, date to about 5 million years ago,” the researchers said.

“The new fossil represents one of the early immigrations from Asia to North America but it is probably not a direct ancestor to the modern American black bear.”

Of further significance is that the teeth of both Protarctos abstrusus individuals show signs of dental cavities.

“Dental evidence from Protarctos abstrusus appears to be from two individuals, including an apparent young adult, and both show dental caries, suggesting their diets included high amounts of fermentable carbohydrates early in their lives,” the authors explained.

“Simple sugars, such as glucose and fructose, are readily metabolized by many bacteria found in the oral biofilm into various acids. These acids demineralize enamel and dentin and may lead to dental caries.”

“This is the first and earliest documented occurrence of high-calorie diet in basal bears, likely related to fat storage in preparation for the harsh Arctic winters,” Dr. Wang said.

“We know that modern bears consume sugary fruits in the fall to promote fat accumulation that allows for winter survival via hibernation,” added team member Dr. Natalia Rybczynski, a paleontologist fro mthe Canadian Museum of Nature.

“The dental cavities in Protarctos abstrusus suggest that consumption of sugar-rich foods like berries, in preparation for winter hibernation, developed early in the evolution of bears as a survival strategy.”

The team’s findings appear in the journal Scientific Reports.


Xiaoming Wang et al. 2017. A basal ursine bear (Protarctos abstrusus) from the Pliocene High Arctic reveals Eurasian affinities and a diet rich in fermentable sugars. Scientific Reports 7, article number: 17722; doi: 10.1038/s41598-017-17657-8

Source: sci-news.com

Los Angeles Subway Work Uncovers Array of Ice Age Fossils

Tuesday, December 19, 2017

Los Angeles Subway Work Uncovers Array of Ice Age Fossils

As part of the crew digging a subway extension under the streets of Los Angeles, Ashley Leger always keeps her safety gear close by.

When her phone buzzes, she quickly dons a neon vest, hard hat and goggles before climbing deep down into a massive construction site beneath a boulevard east of downtown.

Earth-movers are diverted, and Leger gets on her hands and knees and gently brushes the dirt from a spot pointed out by a member of her team. Her heart beats faster because there’s a chance she’ll uncover what she calls “the big find.”

Leger is a paleontologist who digs for fossils in the middle of a city rather than an open plain or desert. She works for a company contracted by Los Angeles transportation officials to keep paleontologists on hand as workers extend a subway line to the city’s west side.

“They’re making sure that they’re recovering every single fossil that could possibly show up,” Leger says of her team of monitors. “They call me anytime things are large and we need to lead an excavation.”

Since work on the extension began in 2014, fossilized remains have routinely turned up from creatures that roamed the grasslands and forests that covered the region during the last Ice Age, about 10,000 years ago.

In this Aug. 15, 2017 photo, paleontologist Ashley Leger shows a skull of a young Columbian mammoth found at the construction site of the Metro Purple Line extension in Los Angeles. The Los Angeles subway system is expanding and so too are the number of prehistoric fossils being recovered as crews dig beneath the city. Since work on one extension began in 2014, workers have routinely turned up fossilized remains of rabbits, camels, bison and other creatures that roamed the region during the last Ice Age. (AP Photo/Jae C. Hong)


They include a partial rabbit jaw, mastodon tooth, camel foreleg, bison vertebrae, and a tooth and ankle bone from a horse.

But the discovery that still makes Leger shake her head in disbelief came about a year ago, shortly after construction began on the project’s second phase. She was at home getting ready for bed when a call came in from one of her monitors.

“It looks big,” he told her.

The next morning, Leger knelt at the site and recognized what appeared to be a partial elephant skull.

It turned out to be much more. After 15 hours of painstaking excavation, the team uncovered an intact skull of a juvenile mammoth.

In this Aug. 15, 2017 photo, paleontologist Ashley Leger navigates through the construction site of the Metro Purple Line extension in Los Angeles. Earth-movers are diverted, and Leger gets on her hands and knees and gently brushes the dirt from a spot pointed out by a member of her team. Her heart beats faster because there’s a chance she’ll uncover what she calls “the big find.” (AP Photo/Jae C. Hong)


“It’s an absolute dream come true for me,” said Leger, who spent the previous decade at a South Dakota mammoth site with no discoveries even close to the size of the one in Los Angeles. “It’s the one fossil you always want to find in your career.”

California’s stringent environmental laws require scientists to be on hand at certain construction sites.

Paleontologists have staffed all L.A. subway digs beginning in the 1990s, when work started on the city’s inaugural line, said Dave Sotero, spokesman for the Los Angeles County Metropolitan Transportation Authority.

Paying for the paleontologist staff from Cogstone Resource Management is factored into the project’s cost, he said. When scientists are brought in to see what crews might have unearthed, work on the project continues, albeit in a different location.

“Our crews try to be as mindful as possible to help them do their jobs. We get out of their way,” Sotero said, adding that when the mammoth skull was uncovered, construction workers helped deliver it to the mouth of the site.

In this Aug. 15, 2017, photo, a skull of a young Columbian mammoth found at the construction site of the Metro Purple Line extension is placed on a cart at the La Brea Tar Pits and Museum in Los Angeles. The Los Angeles subway system is expanding and so too are the number of prehistoric fossils being recovered as crews dig beneath the city. (AP Photo/Jae C. Hong)


From there, the skull was hauled a mile or so to Los Angeles’ La Brea Tar Pits and Museum, home to one of America’s most fossil-rich sites.

Assistant curator Dr. Emily Lindsey called it a “pretty remarkable find,” noting that while thousands of dire wolf and saber-toothed cat remains have been uncovered in L.A., there have been only about 30 mammoths.

A few hundred pounds and the size of an easy chair, the skull is especially rare because both tusks were attached. It’s being studied and is available for public viewing inside the museum’s glass-walled Fossil Lab.

With a nod to Hollywood, the 8- to 12-year-old Colombian mammoth was named Hayden, for the actress Hayden Panettiere, featured in the TV series “Nashville” and “Heroes.”

The Cogstone monitor at the construction site had been watching her on television before spotting the speck of bone that turned out to be the intact skull.

In this Aug. 15, 2017 photo, a worker operates a backhoe at the construction site of the Metro Purple Line extension in Los Angeles. The Los Angeles subway system is expanding and so too are the number of prehistoric fossils being recovered as crews dig beneath the city. Since work on one extension began in 2014, workers have routinely turned up fossilized remains of rabbits, camels, bison and other creatures that roamed the region during the last Ice Age. (AP Photo/Jae C. Hong)


Similar endeavors have turned up subterranean treasures during digs in other cities.

Workers at a San Diego construction site found fossils including parts of a mammoth and a gray whale and multiple layers of ancient seashells.

Last year, crews working on a development near Boston’s seaport uncovered a 50-foot (15-meter) wooden boat possibly dating as far back as the late 18th century.

Lindsey praised California’s efforts to ensure science and urban development overlap, while bemoaning what bygone treasures may have been lost before the regulations went into place in the early 1970s.

“Most of the past is below the ground, so you’re only going to find it when you dig,” she said. “As the city grows, I’m sure we’ll find more exciting fossil material.”

In this Aug. 15, 2017 photo, a skull of a young Columbian mammoth found at the construction site of the Metro Purple Line extension is placed on a cart at the La Brea Tar Pits and Museum in Los Angeles. The Los Angeles subway system is expanding and so too are the number of prehistoric fossils being recovered as crews dig beneath the city. (AP Photo/Jae C. Hong)



Source: phys.org

New Extinct Species Discovered in Australia

Tuesday, December 19, 2017

The latest addition to the family tree of masupial lions is considerably more ancient than other members, going extinct roughly 19 million years ago.

A new species has been identified from the fossilised remains of a marsupial; lion-like creature that has been unearthed in Australia.

Named Wakaleo Schouteni, the predatory animal is said to be a relative of modern marsupials such as koalas and kangaroos. Marsupials are identified by the fact they carry their offspring in pouches attached to their bodies.

The new species was squat with a flat head. It has been named after famous wildlife illustrator and paleo artist Peter Schouten.

The fossils were discovered at Boodjamulla national park in Riversleigh which is located near the border of Queensland and the Northern Territory. The announcement of this find has followed 20 years of research into ancient marsupial lions after the first discoveries of fossils in the 1980’s.

This new creature is very closely related to the Thylacoleo Canifex; the least ancient known species of marsupial lion. It is said to have had giant, sword-like fangs with the strongest known jaws of any mammal species in history.

That species is believed to have gone extinct approximately 30,000 years ago and may be linked to the overhunting of ancient human beings in Australia. This new species is believed to be far more ancient than one’s previously discovered, being estimated to have gone extinct 19 million years ago.

This species is also much smaller than the other marsupial lions that have been discovered. At 130 kg the other marsupial lions may have been a significant threat to humans at the time, this creature is thought to be no larger than a common dog at 23 kg.

This latest discovery has aided researchers in understanding the decendents of marsupial lions who are believed to have lived in Australia at least 25 million years ago.

Researchers noted that the identification of this new species highlights an increased diversity between species of marsupial lion. It has been suggested that this new fossil demonstrates even deeper roots in the family tree.

Via an examination of the fossilised teeth of the creature palaeontologists have determined this to be one of the most ancient marsupial lions to have been discovered. Despite its small size in comparison to other marsupial lions this creature would still have been a vicious ambush predator in the Australian bush.

While a controversial opinion in some circles, common scientific thought is that giant marsupial species began to go extinct after the arrival of ancient humans in Australia. It is also said that changes in climate would have caused some of these species to go extinct.

Source: bestinau.com.au

This is the Oldest Fossil of a Plesiosaur From the Dinosaur Era

Tuesday, December 19, 2017

This is the Oldest Fossil of a Plesiosaur From the Dinosaur Era

Plesiosaurs were especially effective swimmers. These long extinct “paddle saurians” propelled themselves through the oceans by employing “underwater flight”—similar to sea turtles and penguins. Paleontologist from the University of Bonn, Germany, together with colleagues from Japan and France, now describe the oldest plesiosaur in the journal Science Advances. The fossil comes from the earliest part of the Triassic period and is about 201 million years old.

Instead of laboriously pushing the water out of the way with their paddles, plesiosaurs glided with limbs modified as underwater wings. They had small heads and long, streamlined necks. Their stout bodies had strong muscles to keep those wings in motion. Compared to other marine reptiles, the tail was short, because it was only used for steering. This evolutionary design was very successful, but curiously, it did not evolve again after the extinction of the plesiosaurs, according to paleontologist Prof. Martin Sander from the Steinmann Institute of Geology, Mineralogy, and Paleontology of the University of Bonn.

The long-extinct paddle saurians could easily have held their own against today’s water animals. Whereas sea turtles mainly use their strong forelimbs for propulsion, the plesiosaurs moved all four limbs together, resulting in powerful thrust. These ancient animals did not have a shell like turtles, however. Plesiosaurs fed on fish. Numerous fossils document a global distribution of the group during the Jurassic and Cretaceous periods.

The private collector Michael Mertens discovered a truly exceptional specimen during quarrying operations in a clay pit in Westphalia, Germany, in 2013. The subsequent evaluation by the LWL-Museum für Naturkunde in Münster, Germany, revealed that the find represents a marine reptile from the Triassic, the period that predates the Jurassic. This news reached Prof. Sander of the University of Bonn while on sabbatical in Los Angeles. “I could not believe that there was a plesiosaur from the Triassic, given that these animals had been studied by paleontologist for nearly 300 years, and never was there one older than Jurassic,” said Sander.

He also notes that only through the timely and efficient cooperation between the private collector, the natural heritage protection agency, the Münster museum, and the scientists, the unique find could be described and published. The detailed research by Ph.D. student Tanja Wintrich of the Steinmann Institute of the University of Bonn revealed that the find represents the oldest plesiosaur, at an age of about 201 million years, which makes it the only plesiosaur skeleton from the Triassic period.

Paleontologists Tanja Wintrich and Martin Sander from the University of Bonn inspect the skeleton of Rhaeticosaurus in the laboratory of the LWL-Museum für Naturkunde in Münster (Germany). Credit: Yasuhisa Nakajima

The reconstructed length of the skeleton is 237 cm (7′ 7″) (part of the neck was lost to quarrying). “We are looking at a relatively small plesiosaur,” says Wintrich. The scientists bestowed the name Rhaeticosaurus mertensi on the unique fossil. The first part of the name refers to its geologic age (Rhaetian) and the second part honors the discoverer. Together with scientists from Osaka Natural History Museum, the University of Osaka, the University of Tokyo and the Paris Natural History Museum, the team from Bonn studied a bone sample. First, they examined the interior of the bone using computed tomography. Then they cut thin sections for microscopic study from especially promising parts of the bone.

Based on the growth marks in the bones, the researchers recognized that Rhaeticosaurus was a fast-growing youngster. They compared the thin sections with those from young plesiosaurs from the Jurassic and Cretaceous. “Plesiosaurs apparently grew extremely fast before reaching sexual maturity,” says Sander. The paleontologists interprets this as a clear indication that plesiosaurs were warm-blooded. Since plesiosaurs spread quickly all over the world, “they must have been able to regulate their body temperature to be able to invade cooler parts of the ocean,” says the paleontologist. Because of their warm-bloodedness and their efficient locomotion, plesiosaurs were extremely successful and widespread—until they disappeared from the face of the earth. Sander says, “At the end of the Cretaceous, a meteorite impact together with volcanic eruptions lead to an ecosystem collapse, of which plesiosaurs were prominent victims.”

More information: Tanja Wintrich, Shoji Hayashi, Alexandra Houssaye, Yasuhisa Nakajima, P. Martin Sander: A Triassic plesiosaurian skeleton and bone histology inform on evolution of a unique body plan, Science AdvancesDOI: 10.1126/sciadv.1701144 , http://advances.sciencemag.org/content/3/12/e1701144

Journal reference: Science Advances

Provided by: University of Bonn

Source: www.newscientist.com

Back From the Dead? Jurassic Park Gene Technology Could CLONE Extinct Tasmanian Tiger

Monday, December 18, 2017

Back From the Dead? Jurassic Park Gene Technology Could CLONE Extinct Tasmanian Tiger

AN extinct marsupial “tiger” is to be brought back into existence by an Australian scientists who successfully mapped its genetic sequence.


The tantalising prospect of resurrecting the Tasmanian tiger, or thylacine – once the stuff of science fiction movies like Jurassic Park – has taken one step nearer reality following a pioneering study, which as based on examination of the DNA of a female cub preserved in ethanol since 1909.

Andrew Pask, a researcher from the University of Melbourne, which undertook the study, said sequencing the thylacine’s code was a first step in cloning the animal.He explained: “As this genome is one of the most complete for an extinct species, it is technically the first step to ‘bringing the thylacine back’.”

However, Mr Pask sounded a note of caution, adding: “We are still a long way off that possibility. We would need to develop a marsupial model to host the thylacine genome, like work conducted to include mammoth genes in the modern elephant.”

One of the last surviving Tasmanian tigers, pictured in 1930. GETTY

The thylacine – which despite the name, was not closely related to the tiger – became extinct on mainland Australia 3,000 years ago, but survived on the island of Tasmania until the 20th century. It was hunted there relentlessly by European settlers who regarded the animals as a threat to their sheep, with the government offering a bounty of £1 per carcass. The last known specimen, a male known as Benjamin, died in Hobart Zoo in 1936, although the species was not officially declared extinct until 1982.

Scientists have sequenced theTasmanian thylacine’s genetic code, paving the way to clone it. GETTY

However, the study also found that the thylacine was at risk of extinction as a result of a lack of genetic diversity, which meant it had difficulty adapting to changing environmental circumstances. Mr Pask said: “They were actually in pretty bad genetic shape and it wasn’t because of their isolation on Tasmania. It was a longer-term decline in their history. “We certainly made them go extinct — there’s no question about that. But we now know even if [thylacines] were still around today they’d probably be in the same genetic dire circumstances as the Tasmanian devil [another species which is under threat].”

The study – which was published in the scientific journal Nature Ecology and Evolution – suggests that the thylacine’s genetic health became compromised 70,000 to 120,000 years ago, and that the Tasmanian population became isolated when the island became cut off from the mainland 14,000.On the mainland, its extinction has been blamed on extreme weather conditions and drought.

Thylacines were hunted to extinction on Tasmania by European settlers. GETTY

It could take many years – and a great deal of money – to bring back the thylacine, but Mr Pask still thinks there is a moral responsibility to try.He said: “I think we were responsible for hunting [the species] to extinction – in that case, we almost owe it to the species to bring it back.”Even if they fail however, all may not be completely lost – for, despite being extinct, officially at least, there have been frequent reports of sightings, leading some to claim that small numbers of thylacine may still exist in remote parts of Tasmania.

Source: express.co.uk


Dinosaur Tracks at Government Canyon

Sunday, December 17, 2017

Over 100 million years ago, beach-bound dinosaurs left their permanent marks on San Antonio’s landscape.

About 110 million years ago, prehistoric creatures strolled across a muddy beach in what is now San Antonio, Texas. The beach and coast have long since relocated. But the dinosaur tracks remain, stamped into now-solid earth by the passage of time.

The tracks are within the Government Canyon State Natural Area. As of right now, they’re Bexar County’s only known dinosaur tracks on public land.

Dino tracks by satxwdavis

Park officials first uncovered the tracks in 2014. They’d previously been buried beneath pools of water and layers of sediment. Local paleontologists originally believed there were only a couple dozen tracks. However, they were delighted to discover hundreds more.

Scientists have studied the prints and theorize that they were made by two different types of dinosaurs. The three-tip prints were made by three-toed, two-legged theropods (meat eaters), while the larger, rounder tracks were made by giant four-legged sauropods (plant eaters).

In addition to its paleontological treasure, the park offers over 40 miles of trails, camping areas, educational displays, and even an aquifer recharge zone. Though the dinosaur tracks are only a small section of this 12,000-acre natural area, they are a must-see for any science and outdoor enthusiast.

Know Before You Go

Get a map at the visitor’s center and start out on trail three. Follow the signs to the dino tracks. Wear a good pair of hiking shoes/boots and take plenty of water. Also, always stay on the trails, because rattlesnakes do live in this part of Texas.

Source: www.atlasobscura.com

Ticks Trapped in Amber Were Likely Sucking Dinosaur Blood

Sunday, December 17, 2017

An image of a 99-million-year-old tick, enlarged at inset, grasping a dinosaur feather, preserved in amber found in Myanmar. Credit Nature Communications; Peñalver et al.

Paleontologists have found entombed in amber a 99-million-year-old tick grasping the feather of a dinosaur, providing the first direct evidence that the tiny pests drank dinosaur blood.

Immortalized in the golden gemstone, the bloodsucker’s last supper is remarkable because it is rare to find parasites with their hosts in the fossil record. The finding, which was published Tuesday, gives researchers tantalizing insight into the prehistoric diet of one of today’s most prevalent pests.

“This study provides the most compelling evidence to date for ticks feeding on feathered animals in the Cretaceous,” said Ryan C. McKellar, a paleontologist at the Royal Saskatchewan Museum in Canada who was not involved in the study. “It demonstrates just how much detail can be obtained from a few pieces of amber in the hands of the right researchers.”

Adult ticks, extant and preserved in ancient amber, compared to the tick nymph found attached to the dinosaur feather, above left. Scientists concluded that the tick nymph fed on a nanoraptor, a fledgling dinosaur no bigger than a hummingbird. CreditE. Peñalver

David Grimaldi, an entomologist at the American Museum of Natural History and an author of the paper published in the journal Nature Communications, was inspecting a private collection of amber from northern Myanmar when he and his colleagues spotted the eight-legged stowaway.

“Holy moly this is cool,” he recounted thinking at the time. “This is the first time we’ve been able to find ticks directly associated with the dinosaur feathers.”

Upon further inspection, he and his colleagues concluded that the tick was a nymph, similar in size to a deer tick nymph, and that its host was most likely some sort of fledgling dinosaur no bigger than a hummingbird, which Dr. Grimaldi referred to as a “nanoraptor.” The parasites were most likely unwanted roommates living in the dinosaurs’ nests and sucking their blood.

“These nanoraptors were living in trees and fell into these great big blobs of oozing resin and were snagged,” he said. Trapped too were the ticks. “We’re looking at a microcosm here of life in the trees 100-million years ago in northern Myanmar.”

They determined that the host was more likely a nonavian dinosaur and not a modern bird based on molecular dating, which suggested the specimen was at least 25 million years older than modern birds.

The team also reported finding a few more ticks in amber, including two that were covered in microscopic hairs belonging to a beetle. The team traced the origins of the beetle hair to a particular type of insect known as a skin beetle, which today lives in nests and scavenges on molted feathers as well as shedded skin and hair. In prehistoric times they most likely bothered dinosaurs in their nests.

The beetle hair suggested that the ticks lived in the same nests as the skin beetles. It provided indirect evidence that the prehistoric ticks infested dinosaurs, according to Ricardo Pérez-de la Fuente a paleobiologist at the Oxford University Museum of Natural History and an author on the paper.

They also found one tick that was engorged with blood, making it about eight times larger than its normal size. Dr. Pérez-de la Fuente said it was impossible to determine the host animal for that tick, and alas, he added there was no chance they could perform any Jurassic Park shenanigans by extracting its stolen blood.

Source: nytimes.com

Fossil Orphans Reunited With Their Parents After Half a Billion Years

Sunday, December 17, 2017

This is an image of Pseudooides. Credit: University of Bristol

Everyone wants to be with their family for Christmas, but spare a thought for a group of orphan fossils that have been separated from their parents since the dawn of animal evolution, over half a billion years ago.

For decades, paleontologists have puzzled over the microscopic fossils of Pseudooides, which are smaller than sand grains.

The resemblance of the fossils to animal embryos inspired their name, which means ‘false egg’.

The fossils preserve stages of embryonic development frozen in time by miraculous processes of fossilisation, which turned their squishy cells into stone.

Pseudooides fossils have a segmented middle like the embryos of segmented animals, such as insects, inspiring grand theories on how complex segmented animals may have evolved.

A team of paleontologists from the University of Bristol’s School of Earth Sciences and Peking University have now peered inside the Pseudooides embryos using X-rays and found features that link them to the adult stages of another fossil group.

It turns out that these adult stages were right under the scientists’ noses all along: they have been found long ago in the same rocks as Pseudooides.

Surprisingly, these long-lost family members are not complex segmented animals at all, but ancestors of modern jellyfish.

Dr Kelly Vargas from the University of Bristol said: “It seems that, in trying to classify these fossils, we’ve previously been barking up the wrong branch of the animals family tree.”

Professor Philip Donoghue, also from the University of Bristol, co-led the research with Professor Xiping Dong of Peking University.

Professor Donoghue added “We couldn’t have reunited these ancient family members without the amazing technology which allowed us to see inside the fossilized bodies of the embryos and adults.”

The team used the Swiss Light Source, a gigantic particle accelerator near Zurich, Switzerland, to supply the X-rays used to image the inside of the fossils.

This showed that the details of segmentation in the Pseudooides embryos to be nothing more than the folded edge of an opening, which developed into the rim of the cone-shaped skeleton that once housed the anemone-like stage in the life cycle of the ancient jellyfish.

Luis Porras, who helped make the discovery while still a student at the University of Bristol, said: “Pseudooides fossils may not tell us about how complex animals evolved, but they provide insights into the how embryology of animals itself has evolved.

“The embryos of living jellyfish usually develop into bizarre alien-like larvae which metamorphose into anemone-like adults before the final jellyfish (or ‘medusa’) phase.

“Pseudooides did things differently and more efficiently, developing directly from embryo to adult. Perhaps living jellyfish are a poor guide to ancestral animals.”

Professor Donoghue added: “It is amazing that these organisms were fossilised at all.

“Jellyfish are made up of little more than goo and yet they’ve been turned to stone before they had any chance to rot: a mechanism which some scientists refer to as the ‘Medusa effect’, named after the gorgon of Greek mythology who turned into stone anyone that laid eyes upon her.”

The Bristol team are still looking for fossil remains of the rest of Pseudooides life cycle, including the ‘medusa’ jellyfish stage itself. However, jellyfish fossils are few and far between, perhaps ironically because the ‘Medusa effect’ doesn’t seem to work on them.

In the interim, the embryos of Pseudooides have been reunited with their adult counterparts, just in time for Christmas.


Ancient Penguins Were Giant Waddling Predators

Sunday, December 17, 2017

An artist’s rendering compares Kumimanu biceae, an extinct giant penguin, to a human diver. Kumimanu stood 5 feet 7 inches and weighed 220 pounds. It is among the earliest known penguin species. Credit G. Mayr/Senckenberg Research Institute

The 57 million-year-old fossil is both fearsome and comical: a long-beaked penguin that stood 5 feet 7 inches tall and weighed about 220 pounds.

“It was as tall as a medium-sized man,” said Gerald Mayr, a paleontologist at the Senckenberg Research Institute in Frankfurt, Germany, and lead author of a report in Nature Communications on Tuesday announcing the discovery.

By comparison, the tallest living species, the emperor penguin, reaches about four feet in height. Kumimanu biceae, as the fossil was named, would have towered above the emperor, and above just about all other known ancient penguins.

(In 2014, another team of researchers estimated that a 34-million-year-old species stood six feet tall, but they based that estimate only on two bone fragments.)

Kumimanu wasn’t just exceptionally big; it also ranks among the oldest penguin fossils yet found. Both its age and its size make Kumimanu important to understanding the astonishing transformation that turned a lineage of flying birds into flightless swimmers.

The 18 modern species of penguin, ranging from the coast of Antarctica to the Galápagos Islands at the Equator, are impressively adapted to aquatic life. Rigid, blade-shaped wings enable them to shoot through the water at up to 22 miles an hour. Record-setting human swimmers don’t even reach six m.p.h.

But their adaptations to water have also left them unable to fly. When penguins haul out to rest or rear their young, they can only waddle about on stumpy legs. “They’re so unbirdlike that many people would not know they are birds,” Dr. Mayr said.

While penguins may look profoundly different from other birds, their DNA points to a close kinship to such species as albatrosses and petrels. These birds all fly over water to hunt for prey, hinting that the ancestors of penguins may have, too.

Auks, which can dive over a hundred feet underwater, may be a living model of the first penguins.

Birds accumulate mutations in their DNA at a roughly clocklike rate, allowing scientists to estimate when their lineages branched apart. Studies suggest that penguins diverged around the time of the mass extinction that struck the planet about 66 million years ago.

A combination of massive volcanic eruptions and an asteroid impact are believed to have been responsible for the global catastrophe. Among the victims were giant marine reptiles and dinosaurs (with the exception of birds, which are feathered dinosaurs). The mass extinctions marked the end of the Mesozoic Era and the beginning of the Cenozoic, which continues today.

The first penguin fossils were uncovered in 1859, and since then more than 50 species have been identified. The oldest of these, found in New Zealand, date back about 60 million years. Known as Waimanu, the oldest known penguins lived just a few million years after the mass extinctions.

The new fossil penguin, Kumimanu, was discovered from bones packed in a rock on a New Zealand beach. Realizing that it was almost as old as Waimanu, Dr. Mayr and his colleagues eagerly studied Kumimanu for a better picture of early penguin evolution.

To see how it was related to other species, the scientists drew an evolutionary tree and found that Kumimanu and Waimanu belonged to its farthest branches. Their lineages have been extinct for tens of millions of years.

By contrast, all living penguins belong to a young branch of the tree. They share a common ancestor that lived only about 15 million years ago.

Kumimanu and Waimanu were already flightless, but they still held onto some primitive traits not found in living penguins.

“Their beak looked much more like a stork’s,” Dr. Mayr said. “Probably they speared their prey.”

The early penguin wing was not yet the short, stiff blade found on living penguins. “They were probably able to bend it a little farther than penguins can today,” Dr. Mayr said. “There was more possibility for flexing.”

Where Waimanu and Kumimanu differ from each other is in their height. Waimanu stood just two and a half feet high. Kumimanu was more than twice as tall.

“We already knew penguins were around, and flightless, just a few million years after the extinction,” said Daniel T. Ksepka, a paleontologist at the Bruce Museum in Greenwich, Conn., who was not involved in the new study. “The new fossil shows they achieved immense sizes very rapidly as well, which is cool.”

Dr. Mayr speculates that the dramatic origin of penguins was sparked by the mass extinctions that marked the dawn of the Cenozoic. Suddenly the oceans were emptied of many of their biggest predators. Penguins could adapt to catching prey underwater without much competition, or fear.

“It’s an educated guess that makes sense, but there’s no rock-solid evidence,” said Dr. Mayr.

One way to test that hypothesis would be to uncover earlier fossils. “What would be cool would be to have a flying ancestor of penguins,” Dr. Mayr said.

The early Cenozoic oceans didn’t just open up the way for the evolution of flightless aquatic birds, Dr. Mayr speculated. It may have also fostered the evolution to big sizes.

Natural selection favors lightweight flying birds because they have to work so hard to stay aloft. Penguins don’t pay that cost. Getting bigger might have brought advantages, as well. A large body makes prey harder to kill.

The tree drawn by Dr. Mayr and his colleagues also shows that penguins became giants many times over. While Kumimanu belonged to an early lineage of big penguins, other lineages produced their own giants as recently as 27 million years ago.

The rise of marine mammals may have doomed giant penguins. As mammals moved into the oceans and evolved into whales and seals, they may have outcompeted the birds.

Both seals and penguins need to find safe beaches where they can mate and raise their young, for example. It’s possible that the seals pushed the giant penguins out, while smaller penguins survived.

“The big question for me is not why there were so many penguins in the early Cenozoic, but why there are no giant penguins today?” Dr. Mayr said.

Source: nytimes.com