Exploring Prehistoric Life

New Research Sheds Light on Dinosaurs of ‘Lost Landmass’ of Appalachia

Thursday, February 22, 2018

Paleogeography of North America during the late Campanian Stage of the Late Cretaceous (~75 Ma). Modified after Blakey.

Around 90 million years ago, eastern and western North America were isolated from each other by a salty sea, creating two landmasses: Appalachia and Laramidia. The ancestors of Triceratops and Tyrannosaurus strutted about on the latter in what would one day become Utah and Alberta, leaving plentiful bones behind. A lack of fossils from eastern North America, however, has obscured Appalachia, leading to it being called a ‘lost landmass.’ Now, new research is broadening our knowledge of the dinosaurs that lived and died near the major metropolises of the eastern United States and Canada.

Dinosaurs from eastern North America have always been regarded as rather strange by scientists.

One relative of Tyrannosaurus rex from New Jersey has gigantic hands tipped with giant claws, a far cry from the notoriously puny arms of its western cousin. Giant duck-billed dinosaurs, more than 35 feet long from beak to tail, left their remains in the sediments of North Carolina.

All named eastern North American dinosaurs are known only from incomplete or fragmentary skeletons. Unlike the world-class fossil deposits of the American West, eastern North American sediments usually produce only the stray bone shard or tooth.

Unfortunately, this lack of fossils from eastern North America has hindered attempts at better understanding the distribution and evolution of dinosaurs during a period known as the Cretaceous, which lasted from about 140-65 million years ago.

For the past few years, Chase Brownstein, a research associate of paleontology at the Stamford Museum & Nature Center in Stamford, Connecticut, has been investigating this issue.

The paleontologist tallied up reports of dinosaurs from across the eastern part of the continent as presented in publications spanning over 150 years of scientific inquiry.

“This is, to my knowledge, the most complete review of eastern North American dinosaurs out there,” he said.

Additionally, Brownstein compared the compiled Appalachian dinosaur faunas to each other and to those from the American West to understand how the former changed from the latter during the 30 million year period of their separation.

The results suggest that eastern North American dinosaur faunas were not only distinct from those of the west, but also that the former were by-and-large composed of species rather more ‘primitive’ than their relatives from western North America and Asia, a hypothesis that has been gaining ground in recent years.

Additionally, the new research may show that the dinosaur wildlife from different parts of Appalachia differed from that of other areas of the landmass.

“A phenomenon known as faunal provincialism, in which different regions of a larger area have distinct assortments of species, may have occurred on Laramidia, and only recently has it been proposed for Appalachian dinosaurs,” Brownstein said.

“The new data does seem to indicate limited provincialism may have occurred among Appalachian dinosaur faunas, but future research will be needed to better substantiate this hypothesis.”

This research was published in the journal Palaeontologia Electronica.


Chase D. Brownstein. 2018. The biogeography and ecology of the Cretaceous non-avian dinosaurs of Appalachia. Palaeontologia Electronica 21.1.5A: 1-56; doi: 10.26879/801

Source: www.sci-news.com

How Colourful and Feathery Were the Dinosaurs?

Saturday, February 17, 2018

Kulindadromeus: An example of a plant-eating dinosaur with feathers and scales

Dinosaurs are depicted as naked, scaly reptiles, but evidence shows they were much more bird-like

Jurassic Park (1993) featured Velociraptors hunting park visitors, depicting them as wily lizard-like predators. Time and science, however, have been unkind to the filmmakers. Velociraptors and most other dinosaurs were bird-like creatures. Even Tyrannosaurs rex is believed to have sported a plume (more “terrible emu” than “terrible lizard”).

“Over the past 10 to 15 years we have come to realise that dinosaurs possessed feathers. Not just some, but lots of them,” says Dr Maria McNamara at University College Cork. All sorts of feathered dinosaurs lived during the Jurassic – 201 to 145 million years ago (mya) – with feathers evolving first for insulation and display, not flight.

“Dinosaurs were depicted as these naked, scaly reptiles. Jurassic Park did that. But discoveries in China changed our perception. They were much more bird-like,” says palaeontologist Dr Jakob Vinther at the University of Bristol. Though there are no fossils of Velociraptors with feathers, Chinese fossils prove their relatives were covered in them.

Dinosaurs experimented with feather designs and shapes. Vinther recently re-examined fossils of a dinosaur called Anchiornis, from the Jurassic. Whereas modern birds have a long central shaft, barbs and then filaments that seal feathers together, Anchiornis was different: “[It] had a short shaft, but then long barbs coming off and bundles of filaments. It would have given the dinosaur a much fluffier appearance; more like a shaggy mammal than a bird,” Vinther says.

In 2017, lasers were used to study traces of soft tissue from Anchiornis and revealed a four-winged dinosaur with drumstick shaped legs, padded feet, a slender tail and an arm similar to a modern bird’s wing. The crow-sized dinosaur may have glided through its woodland home.


Upending science

The first bird is still seen by many as Archaeopteryx (150 mya), a famous fossil discovered in the 19th century in a limestone quarry in Germany. Dublin Zoo put a cast of an Archaeopteryx fossil in its Zoorassic World gallery where visitors can see feather impressions, teeth and a long bony tail, a hodgepodge of dinosaur and bird.

But it was discoveries in China that upended dinosaur science. “We went from a dozen specimens of Archaeopteryx to tens of thousands of feathered specimens, each of which was as amazing,” says Prof Mike Benton, senior dinosaur expert at the University of Bristol. “The level of detail just blew away the field because of the richness of data.”

At the start of his career in the 1980s, Benton was taught Archaeopteryx had about 30 features that set them apart from dinosaurs, including feathers, hallowed bones, reduction of teeth and a wish bone. “All these have been now found in dinosaurs, except one: Powered flight,” says Benton. All parts of the dinosaur family tree had feathers. At a minimum, feathers evolved with early theropod dinosaurs about 200-250 mya, two-legged flesh-eating dinosaurs that gave rise to T. rex.


Feather colour

By examining the shape of granules holding the pigment melanin, scientists such as McNamara have helped decipher the colour of feathers. The first reconstruction of colour was carried out by scientists at the University of Bristol and palaeontologist Dr Patrick Orr at University College Dublin in 2010, reported in the journal Nature. It revealed Sinosauropteryx had a feather-like covering of orange and brown and a striped white and orange tail, probably for display purposes.

In 2014, McNamara co-authored a paper in the journal Science describing a Jurassic dinosaur from Siberia that resembled a flightless bird such as an emu or ostrich (except it had a long tail). This was the first ever example of a plant-eating dinosaur with feathers and scales. Before that, it was only the flesh-eating theropods that were found with feathers. Today, palaeontologists suspect large dinosaurs lacking feathers lost them during evolution, similar to how large mammals such as elephants lost fur.

“If we didn’t have all these fossils from China, our understanding of dinosaurs would be very different today,” says Vinther. “Birds are dinosaurs.”


A land of feathered dragons

Northeast China is ground zero for a revolution in how we see dinosaurs. A huge area in Liaoning province has well-preserved fossils of feathered dinosaurs and early birds, which are remarkably widespread. “The area is huge, probably about 1,000 square kilometres,” says Benton. “It is a little unclear why the fossils are so exceptionally preserved, but lots of the sediment has volcanic ash. For some locations, it seems fossils were captured in ash, a little like Pompeii.”

Most seem to be buried in lake beds or marshes, and many people dig them out to sell to museums and collectors.

The fossils have shifted scientists’ views on how dinosaurs looked and behaved. Many apparently had bright feathers, like birds today, which could have driven sexual selection. Benton says: “There are so many species of these small theropod dinosaurs. It may be that sexual selection was spinning up the number of species.”

Source: www.irishtimes.com

What we Know About Dinosaurs will Probably Change

Wednesday, February 21, 2018

Everything we know about dinosaurs is connected to fossil records and, if the last decade is anything to go by, all of that could change dramatically over the next 20 years.

Much of what we know about dinosaurs is nascent by nature. It's difficult to study something that's been buried in the ground for 65 million years, right?

But a recent study from scientists at the University of Cambridge and Imperial College London has put some numbers behind our collective acquired knowledge of dinosaurs. It appears that much of what we know about dinosaurs could potentially change over the next 20 years.

The science is simple. Everything we know about dinosaurs is essentially derived from the fossil record. And over the last ten years there has been a dramatic increase in additions to that fossil record. In layman's terms: we're discovering more dinosaurs at rapid rate, which means we're constantly acquiring new, concrete examples of how dinosaurs actually lived.

Just take a look at this handy graph.


More dinosaur findings equals more knowledge, equals a better, broader understanding of how the scientific community understands dinosaurs as a whole.

In a blog post Jonathan P. Tennant tried to explain his findings.

"This has profound impacts on our understanding of dinosaur diversity, especially as these discoveries are unevenly spread over time and space," he wrote. "There are still huge gaps in our knowledge of the fossil record, and areas in space and geological time where the rapid pace of discovery is changing much of what we thought we knew about dinosaurs." 

Source: www.cnet.com

Paleontologists Find First Placodont Fossil in the Algarve

Friday, February 23, 2018

Paleontologists from Lisbon’s Universidade Nova have found the first placodont fossils in Portugal, they have announced.

Paleontologist Hugo Campos and Octávio Mateus told Lusa that they found the placodont “ribs and a Shell” in 2016, but only now disclosed the discovery by publishing a study in the catalogue for an exhibition “Loulé: Territories. Memories. Identities”, on display at the National Archeology Museum.

“Placodonts are a group of marine reptiles that had not been identified in Portugal, but are known in other parts of the world”, said Octávio Mateus, who supervised Hugo Campos’s paleontology Master’s thesis about Triassic vertebrates in the Algarve.

The study “Loulé more than 220 million years ago: the fossil vertebrates of the Algarve in the Triassic”, published now, describes that the placodonts lived in the sea during the Triassic period between 250 million and 200 million years ago, feeding on mollusks and they had boney plates that made them look a bit like turtles.

A large number of these boney plates, which the scientists call ‘osteoderms’, were found around Loulé and Silves in the Algarve in 2016 and 2017.

The researchers believe that these placodonts were of the ‘Henodus’ type because of the long, flat, hexagonal shape and without ornamentation of the shell and the lack of teeth.

The village of Penina, near Loulé, has what is considered to be the main deposit from the upper Triassic in Portugal and one of the most important for vertebrate paleontology in the country.

The deposit has turned up ten ‘Metoposaurus algarvensis’ (an amphibian similar to a salamander), bivalves and fish scales, phytosaurs (similar to crocodiles) and placodonts, but there may be as many as 20 animals.

The Triassic period, the first period of the Mezoic era, was a period in history when the continents were still all jo9ined together in a super-continent (Pangeia) and when the dinosaurs and other animals appeared and spread round the world.


Source: www.theportugalnews.com

10 Reasons to Celebrate Darwin Day

Wednesday, February 14, 2018

Why, each and every year, do scientists, humanists, and scholars from all around the world pay special attention to the life and work of Darwin on his birthday — February 12, 1809? (He was born the same day as Abraham Lincoln, by the way.)
Why do groups like the Hudson Valley Humanists literally make shrines to Darwin and bake evolution-themed cookies in his honor this time of year?
His work brings to our understanding of the human condition. Following are 10 reasons why you should celebrate Darwin Day.
10 Reasons to Celebrate Darwin Day
1. The field of biology did not exist until after Darwin’s ideas on natural selection were published (see Allmon, 2011).
2. Our understanding of modern medicine is improved exponentially as a result of medical professionals understanding and applying Darwinian principles (see Nesse & Williams, 1995).
3. Darwin was an abolitionist, supporting equality among people regardless of regional or ethnic background, way before being an abolitionist was in style. In fact, in many ways, he was more of an abolitionist than was his contemporary Abraham Lincoln (see Desmond & Moore, 2014).
4. Darwin’s perspective led to research that has shed extraordinary light on issues that are specific to women’s health (see Reiber, 2009).
5. Darwin’s perspective has led to advances in how we understand elementary education (see Gruskin & Geher, 2017).
6. Darwin’s ideas paved the way for the advanced understanding we now have regarding the evolutionary history of modern humans (e.g., Hodgson et al., 2010).
7. Darwin’s ideas have been applied to help us better understand how humans can live in urban settings (see Wilson, 2011).
8. Darwin’s ideas paved the way for the field of paleontology, helping us understand how fossils from across the world fit together to explain the history of the earth (e.g., Bose & Bartholomew, 2013).
9. Darwin’s ideas sparked an extraordinary number of additional academic fields, such as ethology, ecology, immunology, Darwinian Literature, evolutionary psychology, behavioral genetics, and more (see Wilson, Geher, Gallup, & Head, in production).
10. Darwinian ideas have dramatically improved our understanding of the positive aspects of the human experience, such as art, music, happiness, gratitude, spirituality, community, and love (see Geher & Wedberg, in production).
This list is incomplete in many ways; Darwin's influence on our modern world extends well beyond the 10 points demarcated here.
Darwin’s impact on our modern world is simply extraordinary and hard to quantify. Without the publication of his ideas on the nature of life, we’d be without such academic fields as biology and paleontology. Our medicine would be far behind where it is now. And our entire understanding of what it means to be human would lack a science-based foundation.
Happy Birthday, Charles Darwin. And on behalf of hominids everywhere, thank you.


Source: www.psychologytoday.com


Prehistoric Rainforest Collapse Dramatically Changed the Course of Evolution

Tuesday, February 13, 2018

Artist's recreation of Dimetrodon in its habitat | Simon Stalenhag

The collapse of rainforests during the Carboniferous period 300 million years ago triggered great changes in the evolutionary paths of plants and animals.

It is estimated that more than 150 acres of rainforest are lost each minute of every day, totaling some 78 million acres of loss annually. Should this current rate of tropical deforestation continue, NASA's Earth Observatory projects that rainforests will vanish within a century, "causing unknown effects on global climate and eliminating the majority of plant and animal species on the planet."

Although the present level of human-caused deforestation is unprecedented, this is not the first time that rainforests have dramatically shrunk in size. Tropical rainforests collapsed around 307 million years ago, toward the end of the Carboniferous period (359–299 million years ago).

New research on this prehistoric rainforest collapse, published in the journal Proceedings of the Royal Society B, finds that it forever changed the course of evolution for terrestrial species, with effects still felt today.

"There have been several studies over the last 40 years on how diversity has changed through time, but it is only in the last few years that researchers have begun to acknowledge the limitations of fossil data," lead author Emma Dunne of the University of Birmingham told Seeker.

She added, "Newly developed methods have been allowing researchers to look for genuine patterns of diversity amongst this patchy fossil data, and we thought it was time to look more closely at diversity patterns of the first vertebrates to live on land."

A key source of information for Dunne and her colleagues is the ever-growing Paleobiology Database, which is the largest international collaborative project among paleontologists all over the world. It has already supported more than 300 papers and is being used now more than ever by scientists.

Throughout her work on the new study, Dunne actually updated, and added to, the database's information on early tetrapods: vertebrates with two pairs of limbs, including those that lost one or both pairs over evolutionary time, such as whales and snakes.

Around 310 million years ago, before the early rainforest collapse, North America and Europe were part of a single landmass located at the equator. There, dense tropical rainforests flourished. This was at a time before the first dinosaurs and mammals evolved.

The ample vegetation and warm, humid climate supported amphibian-like early tetrapods, which quickly diversified into many different species. Giant dragonflies, millipedes, the first amniotes — egg-producing animals that lay them on land or within the mother — and even early cockroaches were also around then.

But the tropical paradise began to change.

"Carbon dioxide levels dropped in the late Carboniferous, and this led to the cooling and drying of the climate," Dunne explained.

Artist's recreation of a forest during the Carboniferous period |Mark Ryan

The event proved to be catastrophic to plants, and rainforests began to disappear. What happened to animals has been debated for many decades.

A prevailing theory has been that tetrapod diversity reduced markedly before endemism occurred. Endemism refers to species evolving in defined geographic locations, such as on an island, in a particular country, or in some other defined zone. In short, the species are basically confined to a certain place where they evolve to live.

Source: www.seeker.com

A Method for Studying Dinosaurs Can Also Help Fight the Spread of the Flu

Sunday, February 11, 2018

Mark Garlick/Science Photo Library via Getty Images

Dinosaurs and influenza would seem to have nothing in common, but a powerful new method of analyzing biogeographical data can be applied to both — helping to solve mysteries about long-extinct animals, while also preventing flu's spread.

Non-avian dinosaurs and flu viruses would appear to share few, if any, characteristics. After all, one group consisted of large animals that went extinct millions of years ago, while the other includes pathogenic particles that are unfortunately still very much with us.

The evolutionary histories of dinosaurs and viruses have more in common than one might expect. And a new method for studying the animals is already being recruited in the fight against influenza and additional viruses that can infect humans and other species. The groundbreaking technique is described in the journal Nature Ecology & Evolution.

The breakthrough involves projecting shifting rates of evolutionary change onto the surface of a sphere, instead of on a flat plane. This allows biogeographical data to be analyzed within an Earth-resembling model that captures speed, direction, and distance moved over short to long periods of time.

"As long as a group of organisms can be placed in a phylogenetic tree, which describes how species are related to each other, or a single species of interest can be placed in the context of its close relationships within a phylogenetic tree, and has geographical data — longitudes and latitudes of where the organisms have occurred on the Earth — the method we develop can reconstruct where the organisms’ ancestors existed on the globe," co-author Andrew Meade of the University of Reading told Seeker.

On the dinosaur side of the research, the technique has already revealed new insights concerning the origin and dispersal of dinosaurs.

Meade, lead author Ciara O'Donovan, and senior author Chris Venditti plugged extensive information on dinosaurs and their fossil record into their model. The data came from the Paleobiology Database, an online resource curated by numerous scientists around the world.

The information shows that dinosaurs first evolved in what is now South America at close to the beginning of the Mesozoic Era, which lasted in its entirety from about 252–66 million years ago.

"Prior to the dinosaurs’ origination there was an extreme extinction event," O'Donovan told Seeker. "This happened 252 million years ago, at the Permian-Triassic boundary and is the largest extinction event to have occurred in Earth’s history."

"This decimated the majority of life on Earth and therefore may well have provided the dinosaurs with a blank canvas to colonize," she added. "This fairly ‘empty Earth’ would have been totally open and up for grabs, and the dinosaurs were able to spread across the globe quickly, taking every ecological opportunity in their path."

Pangea — the single, giant landmass that later broke up to form the continents — was additionally whole when the dinosaurs originated about 231 million years ago. This meant that there were few, if any, geographical barriers preventing the dinosaurs' movement.

O'Donovan and her team suspect that the dinosaurs must have had some beneficial biological predisposition, enabling them to take advantage of the "blank canvas" they found themselves on. This aided their moving, dispersing, and colonizing new habitats. The remains of dinosaurs have remarkably been found on every continent, from what are now the polar regions to nearly every place in between.

The researchers tracked the movements through evolutionary time of the four major groups of dinosaurs — Ornithischians, Sauropods, Theropods, and birds — as well as certain individual species, like Tyrannosaurus rex.

Six reconstructed evolutionary paths for the dinosaur species a) Rhoetosaurus brownei, b) Archaeopteryx lithographica, c) Stegosaurus stenops, d) Andesaurus delgadoi, e) Dromaeosaurus albertensis, f) Tyrannosaurus rex. | Ciara O'Donovan et al., Nature Ecology & Evolution

At the start of their research, the scientists thought that each of the four dinosaur groups would exhibit different dispersal patterns. They especially thought that would be the case for birds.

The researchers determined, however, that all of the animals shared a rapid initial expansion whereby the dinosaurs speciated quickly and moved over great distances. This was followed by a continual and gradual slow-down as the animals approached the critical Cretaceous-Tertiary boundary 66 million years ago.

Venditti explained: "As time went on, dinosaurs both moved less, and fewer new species were produced. The less they could move, the more likely it would have been that any speciation that did occur would be by specialization in the environment the dinosaurs were already living in."

"The idea that the dinosaurs were running out of space fits here," he continued. "The lack of space explains why the dinosaurs were less able to speciate to replace species that were going extinct. And species may have been going extinct owing to becoming specialized and therefore being vulnerable to changes within the environment."

The new information supports the conclusions of a prior University of Reading study that was published in 2016 in the journal Proceedings of the National Academy of Sciences. It found that 50 million years before the asteroid impact that occurred in the Yucatan peninsula 66 million years ago, dinosaurs were already in decline.

Nevertheless, the ancestors of today's birds survived.

"Where avian ancestors were not able to move to new environments owing to the lack of space by that time, they specialized to take advantage of a type of space previously unoccupied by dinosaurs — aerial space," O'Donovan said. "They were able to do this because they had feathered wings. In doing this, they would have been able to explore ecological opportunities that were previously inaccessible and would have been able to evade competition with their relatives on the ground."

It is possible that birds benefitted from the die-off in the same way that non-avian dinosaurs did after the Permian-Triassic extinction event.


Source: www.seeker.com

New Study Findings: Dinosaur-killing Asteroid Also Triggered Massive Magma Releases Beneath the Ocean

Saturday, February 10, 2018

Scientists Say Dinosaur-Killing Asteroid Made Earth's Surface Act Like Liquid

The asteroid that hit Earth 66 million years ago appears to have caused huge amounts of magma to spew out of the bottom of the ocean, a new study of seafloor data finds.

The discovery, described in the journal Science Advances, adds to the portrait of an extinction event that was as complex as it was deadly.

For decades, researchers have pointed to a cataclysmic asteroid smashing into the planet as the reason the dinosaurs, and many other species of life on Earth, were wiped out during what's formally known as the Cretaceous-Paleogene extinction event (named for the periods that came before and followed after it). That impact, which scientists think left the roughly 110-mile-wide Chicxulub crater in the Gulf of Mexico, would have vaporized living things nearby and sent choking clouds of debris into the air, obscuring the sun.

But scientists have also pointed to another culprit: the Deccan Traps in present-day India, one of the largest volcanic provinces in the world, which just happened to be going gangbusters at the time of the extinction event. The ash and noxious gases from the Deccan Traps are really what killed the dinosaurs, some scientists say, downplaying the asteroid's role.

"People still argue about which one was actually the primary driver of environmental changes that resulted in the death of dinosaurs," said senior author Leif Karlstrom, an earth scientist at the University of Oregon in Eugene.

Researchers have also suggested that perhaps the two were connected — perhaps the asteroid triggered Deccan Trap volcanism, producing a brutal one-two punch that ultimately knocked out roughly three-quarters of the Earth's plant and animal species. But recent work has shown that the traps started spewing roughly a quarter-million years before the asteroid hit, Karlstrom said.

Still, scientists have wondered if there might indeed be some kind of connection between the two. And lead author Joseph Byrnes, a geophysicist at the University of Minnesota in Minneapolis, realized something: If the asteroid impact had had a major impact on volcanism at the time, that effect should have shown up in the activity along the Earth's mid-ocean ridges. So he and Karlstrom went looking for it.

The mid-ocean ridges are long cracks in the Earth's crust at the bottom of the ocean floor where tectonic plates meet. As the plates pull apart, hot magma rises up between them, flowing out on either side of the crack before cooling, creating new seafloor in the process. With more than 40,000 miles of ridges, this network of cracks forms the longest mountain chain on Earth.

This graph shows a spike in the creation of new seafloor about 66 million years ago. That's when the Chicxulub asteroid struck the Earth, wiping out the dinosaurs. The impact also instigated the release of massive amounts of magma, a new study argues. (Byrnes and Karlstrom / Science Advances)

The youngest rock is always right at the ridge (where fresh magma keeps producing new rock) and gets older the farther away it is from the ridge on either side. And scientists can date the age accurately thanks to the Earth's magnetic field, which reverses itself every so often, as it has throughout the planet's history. That magnetic polarity gets locked into a newly formed rock as it cools and solidifies. By tracking the sequence of polarity flips in the rock near these ridges, researchers are able to tell how old a given section of the seafloor must be.

The two scientists used this data compiled by other researchers and combined it with another data set showing the gravitational field of the surface beneath the ocean. The stronger the gravitational field in a given spot, the more mass there is. (It's a substitute for actually being able to see the surface topography of the ocean floor, much of which still remains a mystery, the researchers pointed out.)

"We have a topographic map of the Earth's surface and we have topographic maps of Mars and Venus, but we don't have that for the ocean floor," Byrnes said. "We have it for places where people have taken ships, but it would take something like 900 years to survey the whole ocean floor. It's just too resource-intensive — so we have to use the gravitational anomalies as a proxy."

Sure enough, the scientists found that at the time the asteroid hit the Earth, there was a sudden surge in the magma pouring out of these mid-ocean ridges, which put out on the order of a hundred thousand to a million cubic kilometers of volcanic material. That's not too far behind the estimated several million cubic kilometers or so of magma produced by the Deccan Traps.

It's possible that the powerful seismic waves produced by the impact triggered the release of reservoirs of magma beneath the surface, Karlstrom said. And if it affected the mid-ocean ridges this way, it could have played a similar role in the Deccan Traps, triggering even more volcanism than before.

The mid-ocean ridges, then, could be a bellwether for a similar phenomenon occurring in the already-active Deccan Traps.

But did that marine magma release do any damage of its own? While it's unclear whether this extra load of ocean floor magma worsened the extinction event, it could potentially have played a role by further acidifying the oceans. Previous work indicates that marine species that were more sensitive to ocean acidification were worse hit by the extinction event. But probing that possibility will take more research, the scientists added.

"That's what we need to work on next, I would say: trying to tease out what the effects on the environment were of the volcanic activity," Byrnes said.

Colored and black points mark portions of the seafloor that may have spread faster than usual as a result of the impact of the Chicxulub asteroid. (Byrnes and Karlstrom / Science Advances)

Source: www.latimes.com

Dinosaurs Were so Good at Living that it Might Have Caused Their Demise

Saturday, February 10, 2018

Image Source: Camera Man

When you think of the end of the dinosaurs you likely envision an asteroid striking Earth, creating a massive explosion and plunging the planet into a dark, cold haze from which the mighty creatures had no chance of emerging. New research suggests that the biggest challenge in the history of the dinosaurs might have gone a bit differently if they hadn’t been so darn good at living in the first place.

The study, which was published in Nature Ecology and Evolution, proposes that the incredibly rapid spread of dinosaurs across all of the Earth was actually a major reason for their ultimate fate. The idea being that, because dinosaurs had pushed into every corner of the planet, they had very little room for adaptation which stunted the emergence of new species, and ultimately forced the creatures to become one-trick ponies, so to speak.

“The dinosaurs exploded out of South America in a frenzy of movement to cover the planet. It was during this time that diverse forms evolved and eventually led to species such as the fearsome Tyrannosaurus rex, Archaeopteryx (the earliest bird) and the gigantic, long necked Diplodocus,” lead author Ciara O’Donovan of the University of reading explains. “This honeymoon period could not last forever though, and the dinosaurs eventually filled every available habitat on Earth.”

When that happened, the various dinosaur species gradually stopped exploring and became very, very good at living in their own specific areas. Over many generations, the creatures may have lost their ability to adapt, and a lack of new species hampered the progress of the dinosaurs as a whole.

“There was nowhere new for species to move to, which may have prevented new species from arising, contributing to the dinosaurs’ pre-asteroid decline,” O’Donovan says. “In essence, they were perhaps too successful for their own good.”

Then, when the asteroid struck, the planet changed almost overnight. Species which had known nothing but one way of living for millions of years were suddenly forced into an unfamiliar world of darkness and cold. Needless to say, the vast majority of dinosaurs simply couldn’t deal with the change and were wiped off the face of the Earth.

Source: http://bgr.com

Chimerarachne yingi: Spider-like Arachnid With a Tail Sheds New Light on Origin of Spiders

Wednesday, February 7, 2018

The new animal resembles a spider in having fangs, male pedipalps, four walking legs and silk-producing spinnerets but also bears a long flagellum or tail. Credit: Dinghua Yang

Paleontologists have identified an ancient and peculiar spider-like arachnid with a whip-like tail. Although this 100-million-year-old creature has eight legs, fangs, and could spin silk, it was not a spider, but rather a relative that lived alongside spiders. Scientists believe that the ancient species may resolve many loose ends in arachnid evolution.

Specimens belonging to the newly identified species called Chimerarachne yingi were collected from the amber markets of Myanmar, where paleontologists have time and time again come across invaluable fossils. Amber is nature’s time capsule, providing a glimpse of whatever plants or animals became trapped in resin before it fossilized. What’s amazing is that the amber process preserves parts that wouldn’t be conserved through regular fossilization. This is why scientists have been able to find, for instance, things like ticks dining on the feathers of dinosaurs, insects during a courtship dance, 30-million-year-old pristine-looking flowers, or even the oldest mammal blood still preserved in a chubby, 30-million-year-old tick.

“There’s been a lot of amber being produced from northern Myanmar and its interest stepped up about ten years ago when it was discovered this amber was mid-Cretaceous; therefore, all the insects found in it were much older than first thought,” said co-author Paul Selden, a paleontologist at the University of Kansas. “It’s been coming into China where dealers have been selling to research institutions. These specimens became available last year to Nanjing Institute of Geology and Paleontology.”

The C. yingi amber fossils are exquisitely preserved, allowing two different teams of researchers to identify the creature’s morphological features in striking details.

The dorsal view of entire Chimerarachne yingi specimen. Note the long tail-like appendage. Credit: University of Kansas.

Very much like today’s black widows and huntsman spiders, C. yingi had silk-producing spinnerets. And like modern spiders (the Araneae),  C. yingi males had two modified appendages called pedipalps near the head which were used to inseminate females. Unlike the Araneae, however, these creatures possessed a long tail, similar to those of modern scorpions.

It’s this peculiar feature that led the researchers to suspect that C. yingi belongs to a long-extinct arachnid order, known as the Uraraneida, which are differentiated by their tail-like appendage called a telson. Another distinctive feature is that uraraneids had plates on their bellies instead of the squishy abdomens seen in spiders.

These are tiny arachnids, measured about 2.5 millimeters body length, excluding the nearly 3-millimeter-long tail. Selden says the flagelliform appendage acted like a sort of antenna, allowing the creature to sense the environment.

But it’s not entirely certain that C. yingi is a Uraraneid, judging from the silk-producing organs which were more similar to those of modern spiders. The 100-million-year-old spider-like creature may actually belong to its own branch of the evolutionary tree, positioned between spiders and uraraneids. A rather unexpected way scientists could confirm this hunch is by discovering some of C. yingi‘s tailed descendents in the jungle.

“We know a lot about the Burmese biota during the Cretaceous,” he said. “It was a pretty good tropical rainforest, and there are a great many other arachnids we know were there, particularly spiders, that are very similar to the ones you find today in the southeast Asian rainforest. It makes us wonder if these may still be alive today. We haven’t found them, but some of these forests aren’t that well-studied, and it’s only a tiny creature.”

The two studies were published the journal Nature Ecology and Evolution.

Source: www.zmescience.com