Entelognathus primordialis: This 419-Million-Year-Old Fish Has the World’s Oldest Known Face

Friday, September 27, 2013

A reconstruction of how the creature may have looked alive. Image via Brian Choo

The ancient fossil, just discovered in China, could upend our understanding of how all vertebrates evolved over time.

Sure, it’s not much to look at. But stare long enough, and you’ll see a jaw (jutting out towards the right), a pair of nostrils (small perforations directly above the mouth cavity) and even a tiny eye socket (just above the mouth, to the left of the nostrils, staring out sideways).

This admittedly homely fish fossil, the 419-million-year old Entelognathus primordialis, was recently discovered in China and described for the first time in an article published today in Nature. What makes it remarkable is everything that’s come after it: It’s the oldest known creature with a face, and may have given rise to virtually all the faces that have followed in the hundreds of millions of years since, including our own.

The uncommonly well-preserved, three-dimensional fossil, analyzed by a group of researchers from the Chinese Academy of Sciences, was excavated near Xiaoxiang Reservoir in Southeast China, in a layer of sediment that dates to the Silurian period, which ranged from roughly 419 to 443 million years ago. All other fish specimens from this era are jawless fish (a group of more primitive creatures that still live on today as lampreys and hagfish), so this is the first one that has what we might call a face: a mouth, nose and two eyes.

It’s difficult to conclude very much about the behavior or lifestyle of the ancient creature, but we do know that it swam in water (land animals didn’t begin to evolve until the Devonian period, which spanned 359 to 419 million years ago) and was likely a top-level predator of the early ocean ecosystem.

What has scientists so excited, though, is that the particular anatomical features of this fossil could upend our understanding of how vertebrates evolved over time. “When I first saw this, I was completely blown away,” says Matt Friedman a paleobiologist at the University of Oxford that reviewed the paper and wrote an accompanying article in Nature. “It’s the kind of fossil you might see once or twice in your lifetime, as a research scientist.”

Friedman and others find the fossil so remarkable because it combines a series of characteristics from two different groups: placoderms, an ancient class of armored fish that went extinct millions of years ago, and bony fish, a lineage that gave rise to all modern fish with jaws and bone skeletons. Previously, it was assumed that placoderms died out completely (and that the other, more recent types of fish with similar armor plating had independently re-evolved it much later), while a different, shark-like group of fish called acanthodians led to the bony fishes.

“What a fossil like this shows is that maybe that’s not the case,” Friedman says. “Because if you look at just the top of the skull and the body, it looks like a placoderm. But when you look at the side, and the front, you see it has jaws that, bone for bone, closely resemble the jaws of bony fish.”

This is significant because of what happened next: bony fish gave rise to all modern vertebrate fish, along with all amphibians, reptiles, birds and mammals, including ourselves. In other words, this fossil might mean that the placoderms didn’t go extinct, but rather evolved into the tremendous diversity of animals that live on both land and sea—and that this ancient, strange-looking face belongs to one of your oldest ancestors.

Scientists won’t immediately jump to reorganize their evolutionary family trees overnight, but the new finding will prompt a period of renewed scrutiny of the previous model. “It’s going to take a while for people to digest it and figure out what it all means,” Friedman says. “From a fossil like this, you’ve got a cascade of implications, and this is just the first paper to deal with them.”

Eventually, though, this finding could help transform our understanding of just how evolution occurred in our planet’s ancient oceans—and how the primitive creatures that swam in them eventually gave rise to the faces we see everyday.


Jeff Goldblum Finally Explains His Jurassic Park Shirtless Scene

Saturday, March 17, 2018

There are few movies quite as iconic as Jurassic Park. The 1993 Steven Spielberg classic is beloved by cinephiles, and everything from the score to the beautiful visual affects have remained mainstays in popular culture. But meme culture takes no prisoners, and Jeff Goldblum has gone viral in the past few years due to one specific shot of the film: when his character Dr. Ian Malcolm lounged with his shirt open after the first attack. This scene is peak Goldblum sexiness, and has even recently been made into a Funko Pop vinyl figure. Now Goldblum has revealed what inspired him to show some skin, and become the subject of countless jokes.

It's supposed to be Costa Rica, right? So things are hot and I'm sure I'm in some sort of fever. So all the logic is that we gotta get some of these wet clothes off immediately. As I remember, I don't think anybody fought me on that.

It looks like Ian Malcolm wasn't just trying to show off his glorious figure during that scene in Jurassic Park. Instead, it was a mixture of the island's natural heat, the downpour of rain, and his injuries that motivated Ian to bare some skin. Take that, all you meme creators.

Jeff Goldblum's comments to Yahoo give some context and motivation behind his choice to unbutton on the set of Jurassic Park, and his logic does make sense. At that point in the film Ian barely survived a run in with the Tyrannosaurus Rex, and knows that something has gone seriously wrong within the park. It would make sense for him to be a bit overheated in the Costa Rican heat, in addition to the adrenaline that is no doubt surging through his exposed Goldblum body.

It's actually surprising that Jeff Goldblum gave such a straight up answer when asked about that infamous Jurassic Park scene. Goldblum's staying power in the business has been largely associated with his trademark wit and personality, and he's usually someone that likes to get ahead of the joke. I'd have expected him to make a joke out of the sexy Ian Malcolm meme, but it turns out that it was a conscious acting choice.

Jeff Goldblum's Ian Malcolm was a major character in the first Jurassic Park, and the only actors to return for its sequel, The Lost World: Jurassic Park. The hardcore fandom is especially excited to see him reprise the role once again in Jurassic World: Fallen Kingdom. It's currently unclear how large his part will be, but Goldblum's inclusion in the trailer definitely got excitement drummed up.

You can catch Jeff Goldblum in Jurassic World: Fallen Kingdom on June 22, 2018.


Fossils Of Pterodactyls From 66 Million Years Ago Discovered, Show Untimely Death

Friday, March 16, 2018

Artist's impression of how the pterosaurs may have looked Photo: University of Bath

Paleontologists have just discovered 66-million-year-old fossils that belong to six new species of pterosaurs, which are prehistoric flying reptiles. Pterosaurs, aka pterodactyls, were the flying cousins of dinosaurs and are considered to be the largest breed of ancient creatures that took flight.

Soaring on wings made of skin, supported by just a single finger, these prehistoric creatures were previously thought to have been slowly going extinct, before a massive dinosaur-killing asteroid wiped out most of Earth’s animal population at the end of the Cretaceous Period. However, hundreds of newly discovered pterodactyl fossils, found at sites in northern Morocco challenge the previous theory.

The fossils reveal that seven different pterosaurs species from three different families lived in the region during the late Cretaceous Period. In other words, the ancient creatures were abundant in numbers before the asteroid impact caused their mass extinction.

“To be able to grow so large and still be able to fly, pterosaurs evolved incredibly lightweight skeletons, with the bones reduced to thin-walled, hollow tubes like the frame a carbon-fiber racing bike,” Dr. Nick Longrich from the University of Bath, and the lead author of the study, said in a statement. “But unfortunately, that means these bones are fragile, and so almost none survive as fossils.”

The rarity of pterosaur fossils from the late Cretaceous Period led many to assume that they were going extinct. However, the new study reveals that the dearth of fossils can lead to misleadingly skewed theories and that pterosaurs were actually thriving and much more diverse than previously thought.

Image shows ulna (forearm) bones from two different pterosaur species - the larger one would have had a wingspan of around 10 metres. Photo: University of Bath/ pbio.2001663

"The Moroccan fossils tell the last chapter of the pterosaurs' story - and they tell us pterosaurs dominated the skies over the land and sea, as they had for the previous 150 million years,” Dr Brian Andres, research associate at The University of Texas, and also a co-author of the study, said.

"This is a fabulous discovery of pterosaurs from Morocco - they tell us their amazing diversity while we thought them in decline,” said Moroccan paleontologist Professor Nour-Eddine Jalil from the Muséum national d'Histoire naturelle, who was not involved in this study but has worked with the authors on a previous study on fossils found in this area. "The Moroccan phosphates are an open window on a key moment in the history of the Earth, one that shortly preceded the global crisis that swept away, among others, dinosaurs and marine reptiles."

The newly discovered fossils reveal that these creatures weighed around 200 kilograms and had wingspans that ranged over two meters to up to ten meters – nearly three times bigger than the largest living bird. Researchers were also able to identify diversity in size and shape. The fossils also allowed the researchers to show that the species had significant differences in the shape of different body parts such as beak shape, neck length, and wing proportions, indicating that the newly identified species occupied distinct ecological niches.

“I believe there are many more species to find,” Dr. Longrich said.

“Exciting discoveries are being made all the time, and sometimes, just the smallest of bones can radically change our perception of the history of life on Earth,” co-author of the study, Professor David Martill from the University of Portsmouth said.

The new study has been published in the journal PLOS Biology.


Are Paleontologists Naming Too Many Species?

Friday, March 16, 2018

Ichthyosaur skeleton Niedersächsisches Landesmuseum Lower Saxony State Museum Germany (2)

A complete new examination taking a gander at varieties in Ichthyosaurus, a typical British Jurassic ichthyosaur (maritime reptile) otherwise called ‘Ocean Dragons’, has given essential data into perceiving new fossil species.

Professor Judy Massare (SUNY College at Brockport, NY, USA) and Dean Lomax (The University of Manchester) have examined many examples of Ichthyosaurus. After their most recent research project, the pair urge caution in naming new fossil species on the basis of just a few fragmentary or isolated remains.

For their examination, Prof Massare and Lomax concentrated on one specific piece of the Ichthyosaurus skeleton, the hindfin (or back oar). The reason for existing was to assess the distinctive structures among the six-known types of Ichthyosaurus. They inspected 99 examples which could give valuable data.

Ichthyosaur skeleton Niedersächsisches Landesmuseum Lower Saxony State Museum Germany (2)

Early in their research, they found different types of hindfin that initially appeared to represent different species. However, the more specimens they examined the more ‘variation’ they uncovered, such as differences in the size and number of bones. They determined that a single hindfin alone could not be used to distinguish among species of Ichthyosaurus, but that a particular variation was more common in certain species.

Their discoveries demonstrate that with just a couple of examples, highlights can be discovered that vary significantly starting with one example then onto the next and in this way show up as though there are a few animal categories. Though, as a general rule, with a significantly bigger example measure the holes in the ‘one of a kind’ varieties are filled in, demonstrating that distinctions are essentially the aftereffect of individual variation and an absence of the full picture.

Prof Massare said: “We described a few hindfins, which might have been called a new species if they were found in isolation. Instead, we had enough specimens to determine that it was just an extreme variation of a common form.”

Scientists can be categorized as one of two camps with regards to naming species, ‘lumpers’ and ‘splitters’. The previous ‘protuberance’ gatherings of comparable examples together, though the last pick to part up examples and recognize new species. Be that as it may, in this new examination, if the group picked to part up the examples in view of the variety discovered, it would propose an immense number of animal varieties.

“On the off chance that we thought about the variety as interesting, it would mean we would name around 30 new species. This would be like what was done in the Nineteenth Century when any new fossil find, from another area or skyline, was named as another species on the off chance that it varied marginally from already known examples.

“As bunches of new fossil species are named each year, at times, for example, with fragmentary or restricted remains, the choice to name another species ought to be viewed as deliberately.”

The new study has been published today in the scientific journal, Geological Magazine.


New research solves the 60-year-old paleontological mystery of a 'phantom' dicynodont

Friday, March 16, 2018

Skeleton of the dicynodont Placerias, a close relative of the newly-discovered Pentasaurus, with dicynodont trackways (Pentasauropus). Credit: Christian Kammerer  Read more at:

A new study has re-discovered fossil collections from a 19th century hermit that validate 'phantom' fossil footprints collected in the 1950s showing dicynodonts coexisting with dinosaurs.

Before the dinosaurs, around 260 million years ago, a group of early mammal relatives called dicynodonts were the most abundant vertebrate land animals. These bizarre plant-eaters with tusks and turtle-like beaks were thought to have gone extinct by the Late Triassic Period, 210 million years ago, when dinosaurs first started to proliferate. However, in the 1950s, suspiciously dicynodont-like footprints were found alongside dinosaur prints in southern Africa, suggesting the presence of a late-surviving phantom dicynodont unknown in the skeletal record. These "phantom" prints were so out-of-place that they were disregarded as evidence for dicynodont survival by paleontologists. A new study has re-discovered fossil collections from a 19th century hermit that validate these "phantom" prints and show that dicynodonts coexisted with early plant-eating . While this research enhances our knowledge of ancient ecosystems, it also emphasizes the often-overlooked importance of trace fossils, like footprints, and the work of amateur scientists.

"Although we tend to think of paleontological discoveries coming from new field work, many of our most important conclusions come from specimens already in museums," says Dr. Christian Kammerer, Research Curator of Paleontology at the North Carolina Museum of Natural Sciences and author of the new study.

The re-discovered fossils that solved this mystery were originally collected in South Africa in the 1870s by Alfred "Gogga" Brown. Brown was an amateur paleontologist and hermit who spent years trying, with little success, to interest European researchers in his discoveries. Brown had shipped these specimens to the Natural History Museum in Vienna in 1876, where they were deposited in the museum's collection but never described.

"I knew the Brown collections in Vienna were largely unstudied, but there was general agreement that his Late Triassic collections were made up only of dinosaur fossils. To my great surprise, I immediately noticed clear dicynodont jaw and arm bones among these supposed 'dinosaur' fossils," says Kammerer. "As I went through this collection I found more and more bones matching a dicynodont instead of a dinosaur, representing parts of the skull, limbs, and spinal column." This was exciting—despite over a century of extensive collection, no  of a dicynodont had ever been recognized in the Late Triassic of South Africa.

Before this point, the only evidence of dicynodonts in the southern African Late Triassic was from questionable footprints: a short-toed, five-fingered track named Pentasauropus incredibilis (meaning the "incredible five-toed lizard foot"). In recognition of the importance of these tracks for suggesting the existence of Late Triassic dicynodonts and the contributions of "Gogga" Brown in collecting the actual fossil bones, the re-discovered and newly described dicynodont has been named Pentasaurus goggai ("Gogga's five-[toed] lizard").

"The case of Pentasaurus illustrates the importance of various underappreciated sources of data in understanding prehistory," says Kammerer. "You have the contributions of amateur researchers like 'Gogga' Brown, who was largely ignored in his 19th century heyday, the evidence from footprints, which some paleontologists disbelieved because they conflicted with the skeletal evidence, and of course the importance of well-curated museum collections that provide scientists today an opportunity to study specimens collected 140 years ago."

The paper, "The first skeletal evidence of a dicynodont from the lower Elliot Formation of South Africa," is published in the journal Palaeontologia Africana.

Provided by: North Carolina Museum of Natural Sciences


Study Sheds Light on Different Ways Dinosaurs Hatched Eggs

Sunday, March 18, 2018

This artist's image shows a hadrosaurus, a dinosaur that is thought to have used heat from microbial decay to warm its eggs. (Image by Masato Hattori, courtesy of the Nagoya University Museum)

Some dinosaurs used heat of the sunlight or microbial decay to warm their eggs, while others brooded, a study by a team including a researcher from Nagoya University suggests.

The study by the team including Japanese researcher Kohei Tanaka was published online in the British journal Scientific Reports. While the fossils of dinosaur eggs and nests have been discovered across the globe, it was not clear how dinosaurs warmed their eggs.

To understand nesting habits, the team researched species including alligators and birds which take advantage of surrounding heat to warm their eggs, as they are similar to dinosaurs. They found that the nesters mainly used microbial decay to warm their eggs when the nesting material consisted of dirt or plants, and sunlight in sandy nesting locations. The researchers used this knowledge to analyze 192 fossilized dinosaur nests.

The nests of some sauropods -- giant herbivorous dinosaurs having a small head and a long neck -- were found in coarse-grained sediment such as sandstone. This led researchers to presume that these dinosaurs used solar radiation or geothermal heat to incubate their eggs.

For the hadrosaurus, a herbivorous dinosaur whose face is like the platypus, researchers concluded it was possible microbial decay was used for incubation because hadrosaurus nests were mainly discovered in fine-grained deposits such as mudstone.

The scientists also analyzed nests of troodontids, small carnivorous dinosaurs similar to birds, including eggs. The fossils were discovered in both fine-grained and coarse-grained deposits, indicating that the eggs were hatched in any type of environment. This supported the theory that these dinosaurs brooded.

Tanaka, who works as a special researcher at Nagoya University Museum, commented, "I want to utilize differences in the ways of warming eggs to shed light on the habitats of dinosaurs."


Kerygmachela kierkegaardi: 520-Million-Year-Old Predator’s Fossilized Brains Discovered

Thursday, March 15, 2018

Image Source: Rebecca Gelernterk, Near Bird Studios

Scientists have peered into the brain of a prehistoric creature that lived around 520 million years ago. Fifteen fossils of the ancient predator were recently discovered in Greenland, which had fortunately escaped the ravages of time and elements.

This allowed the creature’s nervous tissue to be fossilized, providing researchers with new insights into panarthropods' evolutionary developments. Panarthropods are an animal group that include creatures such as tardigrades or water bears, velvet worms and arthropods, such as insects.

“The findings shed light on the ancestral condition of the panarthropod brain and the origin of complex arthropod compound eyes. The new material, furthermore, provides novel information on the overall anatomy of Kerygmachela,” the researchers wrote in the new study, published in the journal Nature Communications.

The newly discovered fossils belonged to a now-extinct species called Kerygmachela kierkegaardi. The prehistoric creature swam across the Earth’s oceans during the Cambrian explosion — an era that saw the emergence of incredible and rapid diversity among life forms over a short period of time.

The ancient creature measures between one to ten inches and is flanked by 11 wrinkly flaps on both sides of the body. Photo: Tae-Yoon Park/Nature Communications

The ancient creature measured between one to ten inches and is flanked by 11 wrinkly flaps on both sides of the body. The predator also sported a round head and an elongated tail spine. United Kingdom-based paleontologist Jakob Vinther, who led the study along with Tae-Yoon Park of the Korea Polar Research Institute, told National Geographic the creature’s forward-facing appendages grabbed onto prey, “making lives miserable for other animals.”

The new study challenges previous theories that claimed the common ancestor of all panarthropods had complex three-part brain. Instead, the researchers argue the new evidence indicated the common ancestor of panarthropods, as well as invertebrate panarthropods and vertebrates, did not have complex brains.

Researchers believe despite its simple brain, the Kerygmachela’s eyes were likely complex enough to form images. The ancient predator’s eyes likely mirror the smaller and much simpler eyes of modern-day tardigrades and velvet worms, Science reported.

However, some scientists appear to be unconvinced of the new details.

“If they’re going to say that the brain of Kerygmachela is like that of a tardigrade, you have to be really, really careful,” Nicholas Strausfeld told National Geographic. “Because it might not be.”

“The discovery of the simple unipartite brain in stem-group euarthropods corroborates the ancestral simplicity of the panarthropod brain, and also suggests that the complex neural concentrations, such as tripartite brains in euarthropods and chordates, are the result of convergent adaptations,” the researchers concluded.


Extinct Bird with Dinosaur-Like Claw May Soon Be Resurrected

Monday, March 12, 2018

Preserved Megalapteryx (moa) foot, Natural History Museum (CC by SA 2.0)

A clawed, flightless bird that went extinct in New Zealand in the late 13th century might be brought back to life, claim scientists at Harvard University.

Nearly three decades ago, archaeologists exploring a cave system on Mount Owen in New Zealand discovered a dinosaur-like claw with flesh and scaly skin. After testing it proved to the a 3,300-year-old mummified remains of an upland moa (Megalapteryx didinus). A DNA analysis published in the  Proceedings of the National Academy of Sciences established that there were at least “ten species of moa which appeared around 18.5 million years ago” but they were all wiped from existence in what scientists call “the most rapid, human-facilitated megafauna extinction documented to date.”

Sir Richard Owen standing next to a moa skeleton and holding the first bone fragment belonging to a moa ever found. (public domain)

Using DNA recovered from the toe, Harvard scientists have now mapped and compiled the first almost complete genome of a “little bush moa,” moving closer to the possibility that extinct genomes will soon become “de-extinct.” The whole idea of bringing “vanished species back to life by slipping the genome into the egg of a living species,” has been regarded by some reviewers as equal to the dark fictional works of Dr Frankenstein, while to others, it has been described in a lighter light as being ‘Jurassic Park’-like,” according to an article on

Left: Illustration of a Moa. Right: Preserved footprint of a Moa (public domain)

Let’s not enter the moral debate, for that is wholly subjective, and look closer at the processes and innovations of Stewart Brand, the co-founder of the nonprofit conservation group Revive and Restore. Aiming to “resurrect vanished species” Brand’s team’s work on the DNA of the little bush moa was recently published in a non-peer-reviewed paper and Brand told reporters “De-extinction probability increases with every improvement in ancient DNA analysis.” The DNA was reconstructed from the sample taken from the creature’s toe but scientists know that “a lot of genetic restructuring is required before the creature can be reborn.” And with the prospects of a creature which stands as high as a teenager, scientists predict they might have to use a "6-inch long, 1-pound emu egg to incubate the moa”.

Stewart Brand had already mapped the passenger pigeon genome and the woolly mammoth, and speaking of this latest project to reporters at, Morten Erik Allentoft of the Natural History Museum of Denmark, an expert on moa DNA said it is “a significant step forward.” As well as the woolly mammoth and passenger pigeon, among the “nearly complete” extinct genomes, scientists have almost completed two of our human cousins, Neanderthals and Denisovans, the dodo, the Tasmanian tiger and the great auk, which dyed out in the North Atlantic in the mid-19th century.

Scientists have almost completed the mapping of the Tasmanian Tiger genome, another extinct species that may soon be revived (public domain).

According to Harvard’s Alison Cloutier, the little bush moa team tried to match “900 million nucleotides, scattered across millions of DNA pieces, and tried to match them to specific locations on the genome of the emu, a close relative of all nine moa species.” Bird genomes, including the eight other extinct moa species, “have similar genes for particular traits tend to be on the same chromosome and arranged relative to other genes in a similar way,” according to the article.

Similarly, according to Harvard’s George Church, who leads The Mammoth Project, “elephant chromosomes were studied to better know how mammoth DNA might be organized.” Scientists believe that herpes infections killed off the mammoth and if it was made ‘de-extinct’, its immune system could be enhanced to resist this virus. You might be asking, like I did, wasn’t all this DNA and genome mapping sorted out “before” the 1996 birth of Dolly the Sheep at the Roslin institute in Scotland?

“Kind of” is the answer, the problem is, putting DNA into an egg is infinitely more difficult than fertilizing mammals. The cloning method applied to make Dolly the Sheep is fine for a mammalian eggs, “but that doesn’t work in birds — “at least so far,” Brand told reporters.

There is no doubt the final parts in the cloning puzzle will be solved, and given enough time, maybe not in our lifetime, a country or a private enterprise will inevitably work out how to clone us.


As Dinosaurs Died, New Species Of Fish Filled The Ocean

Thursday, March 15, 2018

Section of fish evolution tree

As dinosaurs and huge ocean predators disappeared 66 million years ago in a mass extinction event, lineages that comprise the bulk of marine fish species diversity began evolving and filled the seas, a new, multi-institution analysis shows.

The findings by researchers from Yale, the University of California-Los Angeles, Louisiana State University, and the University of Michigan were published March 12 in the journal Nature Ecology and Evolution.

About 18,000 species of spiny-rayed fishes exist today, a diverse group that includes basses, tunas, deep sea anglerfishes, pufferfishes, and seahorses, and that comprises more than 25% of all living vertebrate species.

The research team analyzed more than 1,000 genes in living fish species and the spiny-rayed fish fossil record in order to estimate the timing of the evolutionary origin of the lineages that account for most of the species diversity of modern marine fishes. They found the evolutionary origin of these species’ lineages occurred at what scientists called Cretaceous and Paleogene boundary 66 million years ago.

“These lineages diversified just as dinosaurs were going extinct and placental mammals on land were emerging,” said Thomas Near, professor ecology and evolutionary biology, the Bingham Oceanographic Curator at the Peabody Museum of Natural History, head of Saybrook College, and senior author of the study.

The work was primarily supported by the National Science Foundation.


Ash From Dinosaur-Era Volcanoes Linked With Shale Oil, Gas

Thursday, March 15, 2018

Nutrient-rich ash from an enormous flare-up of volcanic eruptions toward the end of the dinosaurs' reign kicked off a chain of events that led to the formation of shale gas and oil fields from Texas to Montana.

That's the conclusion of a new study by Rice University geologists that appears this week in Nature Publishing's online journal Scientific Reports.

"One of the things about these shale deposits is they occur in certain periods in Earth's history, and one of those is the Cretaceous time, which is around the time of the dinosaurs," said study lead author Cin-Ty Lee, professor and chair of Rice's Department of Earth, Environmental and Planetary Sciences. "This was about 90 million to 100 million years ago, which is about the same time as a massive flare-up of arc volcanoes along what is today the Pacific rim of the Western United States."

Advances in horizontal drilling and hydraulic fracturing over the past 20 years led to a U.S. energy boom in "unconventionals," a category that includes the shale gas and "tight" oil found in shale fields like the Cretaceous Eagle Ford and Mowry and older ones like the Barnett and Bakken.

An enormous volcanic flare-up at the end of the dinosaurs’ reign kicked off a chain of events that led to the formation of the U.S. shale oil and gas fields from Texas to Montana. Rice University geologists said older shale gas fields, like the Marcellus in Pennsylvania and Ohio, may have formed from similar volcanic flare-ups hundreds of millions of years earlier. Credit: Wikimedia Commons

"These types of natural gas and oil are in tiny, tiny pores that range from a few millionths of a meter in diameter to a few thousandths of a meter," Lee said. "The deposits are in narrow bands that can only be accessed with horizontal drilling, and the oil and gas are locked in these little pockets and are only available with techniques like hydraulic fracturing."

Lee said that there have always been hints of a connection between ancient volcanic eruptions and unconventional shale hydrocarbons. During field trips out to West Texas, he and Rice students noticed hundreds of ash layers in exposed rock that dated to the Cretaceous period when much of western North America lay beneath a shallow ocean.

One of these trips happened in 2014 while Lee and Rice colleagues also were studying how a flare-up of Cretaceous-era arc volcanoes along the U.S. Pacific rim had impacted Earth's climate through enhanced volcanic production of carbon dioxide.

"We had seen ash layers before, but at this site we could see there were a lot of them, and that got us thinking," Lee said. Lee, graduate student Hehe Jiang and Rice undergraduates Elli Ronay, Jackson Stiles and Matthew Neal decided to investigate the ash beds in collaboration with Daniel Minisini, a colleague at Shell Oil who had been doing extensive work on quantifying the exact number of ash beds.

"It's almost continuous," Lee said. "There's an ash layer at least every 10,000 years."

The eruption of Alaska’s Pavlof Volcano as seen from the International Space Station May 18, 2013. The volcano’s ash cloud rose to 20,000 feet and extended over hundreds of miles of the northern Pacific Ocean. Credit: NASA/ISS Crew Earth Observations experiment and Image Science and Analysis Laboratory, Johnson Space Center

Lee said the team determined that ash had come from hundreds of eruptions that spanned some 10 million years. The layers had been transported several hundred miles east of their volcanic source in California. The ash was deposited on the seafloor after being blown through plumes that rose miles into the atmosphere and drifted over the ocean. Lee and students analyzed samples of the ash beds in the geochemical facilities at Rice.

"Their chemical composition didn't look anything like it would have when they left the volcano," he said. "Most of the original phosphorus, iron and silica were missing."

That brought to mind the oceanic "dead zones" that often form today near the mouths of rivers. Overfertilization of farms pumps large volumes of phosphorus down these rivers. When that hits the ocean, phytoplankton gobble up the nutrients and multiply so quickly they draw all the available oxygen from the water, leaving a "dead" region void of fish and other organisms.

Lee suspected the Cretaceous ash plumes might have caused a similar effect. To nail down whether the ash could have supplied enough nutrients, Lee and his team used trace elements like zirconium and titanium to match ash layers to their volcanic sources. By comparing rock samples from those sources with the depleted ash, the team was able to calculate how much phosphorus, iron and silica were missing.

"Normally, you don't get any deposition of organic matter at the bottom of the water column because other living things will eat it before it sinks to the bottom," Lee said. "We found the amount of phosphorus entering the ocean from this volcanic ash was about 10 times more than all the phosphorus entering all the world's oceans today. That would have been enough to feed an oxygen-depleted dead zone where carbon could be exported all the way down to the sediment."

The combination of the ashfall and oceanic dead zone concentrated enough carbon to form hydrocarbons.

Oxygen-depleted “dead zones” often form in the northern Gulf of Mexico due to nutrient-rich runoff from the Mississippi and Atchafalaya rivers, which are seen here as tan and greenish-brown plumes visible from the International Space Station in 2012. Nutrient-rich volcanic ash may have fed similar dead zones that produced shale oil and gas fields from Texas to Montana. Credit: NASA/GSFC/Aqua MODIS

"To generate a hydrocarbon deposit of economic value, you have to concentrate it," Lee said. "In this case, it got concentrated because the ashes drove that biological productivity, and that's where the organic carbon got funneled in."

Lee said shale gas and tight oil deposits are not found in the ash layers but appear to be associated with them. Because the layers are so thin, they don't show up on seismic scans that energy companies use to look for unconventionals. The discovery that hundreds of closely spaced ash layers could be a tell-tale sign of unconventionals might allow industry geologists to look for bulk properties of ash layers that would show up on scans, Lee said.

"There also are implications for the nature of marine environments," he said. "Today, phosphorus is also a limiting nutrient for the oceans, but the input of the phosphorus and iron into the ocean from these volcanoes has major paleoenvironmental and ecological consequences."

While the published study looked specifically at the Cretaceous and North America, Lee said arc volcano flare-ups at other times and locations on Earth may also be responsible for other hydrocarbon-rich shale deposits.

"I suspect they could," he said. "The Vaca Muerta field in Argentina is the same age and was behind the same arc as what we were studying. The rock record gets more incomplete as you go further back in time, but in terms of other U.S. shales, the Marcellus in Pennsylvania was laid down more than 400 million years ago in the Ordovician, and it's also associated with ashes."

More information: Cin-Ty A. Lee et al. Volcanic ash as a driver of enhanced organic carbon burial in the Cretaceous, Scientific Reports (2018). DOI: 10.1038/s41598-018-22576-3

Journal reference: Scientific Reports

Provided by: Rice University