Prehistoric Flora & Fauna

Welcome to Gondwana: A Dinosaur Treasure Trove

Saturday, November 11, 2017

Welcome to Gondwana: A Dinosaur Treasure Trove

After the supercontinent Pangaea separated into the smaller supercontinents of Laurasia and Gondwana, evolution became dependent upon specific conditions of climate and habitat.

The dinosaur “collective” fragmented, leaving dinosaurs to evolve in isolated groups and develop traits distinctly different from their sundered cousins on other landmasses.

During the 19th century, naturalist Charles Darwin began speculating about the relationship between living and fossil species while developing his theory of natural selection and “descent with modification,” to explain why some species became extinct while others evolved.

But no one paid much attention to geology’s role in biological evolution until 1910, when geophysicist Alfred Wegener, curious about why identical plant and animal fossils were being found on separate continents, realized that the outline of the east coast of South America fit against the lower west coast of Africa like pieces in a massive jigsaw puzzle.

It was as if the two continents had once been joined — an insight later confirmed by modern geology.

Africa, the first landmass to separate from Gondwana, supported Cretaceous Period dinosaurs like Suchomimus, a three-ton, bipedal predator with a skull resembling a contemporary crocodile’s. It was also home to Nigersaurus, whose wide, flat, vacuum-cleaner-nozzle-shaped mouth was packed with 50 teeth each in its upper and lower jaws, making it perfect for gobbling low-growing plants. Each tooth position held nine replacement teeth, meaning that Nigersaurus replaced 80 to 100 teeth each month — without missing a single meal.

Meanwhile, in South America, Giganotosaurus roamed the badlands of what is now Argentina’s Patagonia region. Perhaps the largest land carnivore that ever lived, this 43-foot-long, 13,200-pound behemoth comes alive at the Denver Museum of Nature & Science special exhibition “Ultimate Dinosaurs,” where visitors can manipulate special screens to see what a creature’s skin and facial coloration might have looked like in “real life.”

Dinosaur-Killing Asteroid Could Hold the Cure for Cancer

Saturday, November 11, 2017

Dinosaur-Killing Asteroid Could Hold the Cure for Cancer

Being diagnosed with cancer doesn’t necessarily carry the same weight as it did a few decades ago, and treatments today have increased the survival rates for many types of the disease dramatically. That said, we obviously still don’t have a cure, but new research into the effects of iridium on cancer cells looks not only promising, but incredibly exciting.

The research, which was conducted by a team of scientists from both the University of Warwick and China’s Sun Yat-Sen University, tested a novel approach to combating cancer which involves flooding the cells with a toxic form of oxygen that not only kills off the cancer but leaves surrounding healthy tissue unfazed. The research was published in the journal Angewandte Chemi.

The technique the researchers used is fairly complex, but it all starts with iridium. Iridium is the second densest metal on the planet, and while it’s fairly rare to find here on Earth, it’s often found in large quantities in asteroids. The dinosaur-killing space rock that slammed into the earth some 65 million years ago is thought to have been responsible for much of the iridium found here today, and it’s a key ingredient in a cancer-fighting cocktail.

To create the cancer-conquering substance, scientists created a compound of iridium and organic matter which was then used against the cancer cells. The compound converts the oxygen found within the cells into what is called singlet oxygen, which behaves dramatically when interacting with organic compounds and is toxic to the cancer. When the proteins of the targeted cancer are attacked it dies off, while the healthy cells around it remain unaffected.

“This project is a leap forward in understanding how these new iridium-based anti-cancer compounds are attacking cancer cells, introducing different mechanisms of action, to get around the resistance issue and tackle cancer from a different angle,” Cookson Chiu, co-author of the study and postgraduate research at Warwick explained.


Humans Wouldn’t Exist if Dinosaur-Ending Asteroid Hadn’t Struck Where it Did

Friday, November 10, 2017

Humans Wouldn’t Exist if Dinosaur-Ending Asteroid Hadn’t Struck Where it Did

The catastrophic asteroid impact that wiped out the dinosaurs 66 million years ago may not have been so devastating had it hit almost anywhere else on earth. It means dinosaurs could still rule the earth and humans may never have evolved at all.

That’s according to new research by Japanese scientists Kunio Kaiho and Naga Oshima, who published their findings Thursday in the journal Scientific Reports. They posit the asteroid, known as the Chicxulub Impactor, which smashed into what was then a shallow sea in modern day Mexico, would not have been so devastating if it hit about 87 percent of anywhere else on the planet.

The roughly six mile (10km) wide asteroid created a crater more 110 miles (176km) across when it smashed into our planet. The collision released more energy than 1 billion atomic bomb detonations which destroyed Hiroshima and Nagasaki at the close of WW2.

More than 75 percent of all land and sea animals, the most famous of which being dinosaurs, were wiped out as a result. Huge volumes of ash, soot and dust shot into the atmosphere, blocking as much as 80 percent of precious sunlight from reaching the surface of the planet.

The pair believe the key ingredient in the extinction is the soot, which was produced when the impact ignited rocks loaded with hydrocarbon molecules such as oil. However, the amount of hydrocarbon in rocks varies widely depending on their location.

With this in mind, the team set about analysing places on Earth where the rocks have a high hydrocarbon molecule content. They found that only about 13 percent of the planet have such an environment, essentially meaning that the dinosaurs were unlucky the asteroid hit in such a hydrocarbon rich area.

“The catastrophic chain of events could only have occurred if the asteroid had hit the hydrocarbon-rich areas occupying approximately 13 percent of the Earth’s surface,” the scientists wrote in a university press release.

It’s a good thing for humanity, however, or else we may never had evolved in the first place.


New Research Shows Dinosaur Dung Fertilizes Planet

Thursday, October 19, 2017

New Research Shows Dinosaur Dung Fertilizes Planet

Whether it started with exhibits at the Natural History Museum or fun-terrified screams watching Jurassic Park, humans have always been awestruck by dinosaurs.

But little is known about what, if any, role dinosaurs and other large animals like mammoths or elephants play in ecosystem functioning. What would the world be like if they never existed?

Christopher Doughty, faculty member in the School of Informatics, Computing and Cyber Systems at Northern Arizona University, asks that question often. He has been studying large animals for more than 10 years, specifically how these animals have increased the planet’s fertility.

“Theory suggests that large animals are disproportionately important to the spread of fertility across the planet,” Doughty said. “What better way to test this than to compare fertility in the world during the Cretaceous period—where sauropods, the largest herbivores to exist, roamed freely—to the Carboniferous period—a time in Earth’s history before four-legged herbivores evolved.”

During these two periods, plants were buried faster than they could decompose. As a result, coal was formed. Doughty gathered coal samples from mines throughout the U.S. By measuring the coal elemental concentrations, he found elements needed by plants, like phosphorus, were more abundant and much better distributed during the era of the dinosaurs than the Carboniferous. The data also revealed that elements not needed by plants and animals, such as aluminum, showed no difference, suggesting the herbivores contributed to increased global fertility.

According to Doughty, these large animals are important not for the quantity of dung they produce, but for their ability to move long distances across landscapes, effectively mixing the nutrients. By increasing the abundance and distribution of elements like phosphorus, plants grow faster, meaning large herbivores are responsible for producing their own food and contributing to their lush habitats.

But as today’s large animal populations become more in danger of extinction, the environment too is at risk. Simply put, fewer large animals may mean less plant growth.

“This is important for two reasons,” Doughty said. “First, we are rapidly losing our remaining large animals, like forest elephants, and this loss will critically impair the future functioning of these ecosystems by reducing their fertility. Second, combining the idea that large animals are disproportionately important for the spread of nutrients with the natural rule that animal size increases over time, means the planet may have a Gaia-like mechanism of increasing fertility over time.

Life makes the planet easier for more life.”


The Asteroid That Killed the Dinosaurs Caused Catastrophic Climate Change

Saturday, October 14, 2017

The Asteroid That Killed the Dinosaurs Caused Catastrophic Climate Change

Most of us learned the demise of the dinosaurs went something like this: monster asteroid head-butted Earth, everything exploded with fire, and whatever was alive perished and ended up a fossil to be unearthed millions of years later.

The phenomenon sort of went like that, but the impact of this asteroid was infinitely more monstrous. Like, global thermonuclear war monstrous.

Think of an object from space about the size of San Francisco (about 6 miles wide) slamming into Mexico’s Yucatan peninsula during the late Cretaceous period—and spreading its influence far beyond the point of impact. It wasn’t just the dinosaurs that descended into extinction, either. Try 75% of anything that breathed. Besides the massive volcanic eruptions that are pictured in so many dinosaur-mageddon visions, the asteroid Chicxulub also rocked the planet with massive earthquakes and tsunamis. It vaporized rock that shot miles above the earth and rained down as searing dust hot enough to send wildfires blazing across the surface.

The only living thing that could possibly survive breathing fire is a dragon, and dragons don’t exist outside fantasy epics like Game of Thrones.

That was just the opening act. So much soot blasted back into the sky from the wildfires that it blacked out the sun. Total darkness lasted two years, and in the absence of sunlight, plants wither when photosynthesis cannot occur. These plants were the main food source of many species of dinosaurs and the last edible thing around for any that weren’t obliterated by the initial blast. But even if an extended dust eclipse hadn’t meant the end of most plant life, average land temperatures of 50° Fahrenheit that plummeted to 20° over the oceans would have. The effect of hundred Hiroshima-sized nuclear weapons wouldn’t come remotely close to that.

Fires created by an asteroid impact and fires created by a nuclear war can put large amounts of soot high up above where the rain happens, so they can exist for a longer period of time and have these global consequences,” said Charles Bardeen of the National Center of Atmospheric Research, whose team’s research was recently published in Proceedings of the National Academy of Sciences. “As long as that soot gets injected above where the rain would happen, it can stay in the atmosphere for a long time.”

It took seven years for temperatures on land to have some semblance of normality again. With colleagues from NASA and the University of Colorado Boulder, Bradeen simulated the post-collision climate using advanced technology. He believes that the plunge in temperature and the impact on Earth’s climate was so extreme that next to this kind of destruction, nuclear war would be nothing.

This also explains why prehistoric creatures like the coelacanth have been found to exist in the depths of the ocean. So long as you could survive in depths past 1,600 feet, you were pretty much protected from extinction-level chaos.

At least we won’t have to worry about another such apocalypse for at least 200 million years.

(via / Seeker)

Dinosaur-Killing Asteroid Aftermath: Years-Long Darkness

Sunday, August 27, 2017

Dinosaur-Killing Asteroid Aftermath: Years-Long Darkness

The recent solar eclipse plunged a swath of the U.S. into two minutes of gloom, but it’s nothing compared to the years-long night that almost wiped out life on Earth 66 million years ago.

Planet-wide wildfires killed land-dwelling creatures like dinosaurs after a six-mile asteroid struck the Yucatan peninsula, kicking off one of Earth’s five known mass-extinctions.

But it was the long night that fell as 15,000 million tons of fine soot rose into the stratosphere, shutting down global photosynthesis for two years and destroying the ozone layer. The long night likely doomed the rest of the three-quarters of species that died.

Chuck Bardeen of the National Center for Atmospheric Research led the PNAS study, published this week.

“This would have had a great impact on life that might have survived the immediate effects of the impact, because there wouldn’t have been a primary food source,” Bardeen said. “So, plants wouldn’t have grown, and phytoplankton in the ocean would likely have died.”

The soot layer initially shielded the already-stressed survivors from the effects of the global ozone hole, but rain drove the particulates from the sky before the O3 layer could repair itself. This only deepened the disaster, Bardeen said.

The Fifth Mass Extinction - The K-T Extinction

“You start out with broiling the surface. Then you cool things down, precipitation goes away, it gets dark, you don’t have photosynthesis,” Bardeen said. “Then, as you start to warm back up and precipitation comes back, and maybe things start growing, then you get this burst of ultraviolet radiation, which could cause mutations and death.”

Dust, not soot, was the prime suspect initially investigated after physicist Luis Alvarez and his son, geologist Walter Alvarez, proposed in 1980 that a giant asteroid strike had killed the dinosaurs.

In more recent years, and using more advanced models, scientists have investigated the effects of other particulates, such as sulfates that might have erupted from volcanoes or from the impact itself.

“For a while, we have thought that soot was one of the things that went into the atmosphere from the impact, but recently there’s been a renewed interest in looking at it in climate models to understand what the climate effects of that soot would be,” said Bardeen.

The NCAR Community Earth System Model (CESM) is among the most sophisticated simulations ever to tackle the Cretaceous−Paleogene extinction. It incorporates oceanic, land and sea-ice effects, as well as chemistry and advanced microphysics.

Scientists will now apply the model to additional Cretaceous research and to simulating nuclear winter scenarios.


Cretaceous Flowers Found Preserved in Burmese Amber

Thursday, August 17, 2017

Tropidogyne pentaptera, holotype. Scale bars -1 mm. Image credit: George O. Poinar, Jr. / Kenton L. Chambers.

In a paper published recently in the journal Palaeodiversity, U.S. paleontologists described a new species of angiosperm flower, Tropidogyne pentaptera, found in seven pieces of 99-million-year-old (mid-Cretaceous) amber excavated from a mine in Myanmar (also known as Burma).

The amber fossils came from the Noije Bum 2001 Summit Site mine excavated in the Hukawng Valley and located southwest of Maingkhwan in Kachin State.

The flowers range from 3.4 to 5 mm in diameter, necessitating study under a microscope.

“The amber preserved the floral parts so well that they look like they were just picked from the garden,” said Professor George Poinar Jr., of Oregon State University.

“Dinosaurs may have knocked the branches that dropped the flowers into resin deposits on the bark of an araucaria tree, which is thought to have produced the resin that fossilized into the amber.”

“Araucaria trees are related to kauri pines found today in New Zealand and Australia, and kauri pines produce a special resin that resists weathering.”

Tropidogyne pentaptera, paratypes. Scale bars ~1 mm. Image credit: George O. Poinar, Jr. / Kenton L. Chambers

The new study builds on earlier research also involving Burmese amber in which the same team described another species in the same genus, Tropidogyne pikei.

Tropidogyne pentaptera has spreading, veiny sepals, a nectar disc, and a ribbed inferior ovary like T. pikei,” Professor Poinar noted.

“But it’s different in that it’s bicarpellate, with two elongated and slender styles, and the ribs of its inferior ovary don’t have darkly pigmented terminal glands like T. pikei.”

Both Tropidogyne pentaptera and T. pikei belong to the extant family Cunoniaceae, a widespread Southern Hemisphere family of 27 genera and about 330 species of woody plants.

Tropidogyne pentaptera was probably a rainforest tree,” Professor Poinar said.

“In their general shape and venation pattern, the fossil flowers closely resemble those of the genus Ceratopetalum that occur in Australia and Papua-New Guinea,” he added.

“One extant species is Ceratopetalum gummiferum, which is known as the New South Wales Christmas bush because its five sepals turn bright reddish pink close to Christmas.”

“Another extant species in Australia is the coach wood tree (Ceratopetalum apetalum), which like the new species has no petals, only sepals.”

“The towering coach wood tree grows to heights of greater than 120 feet, can live for centuries and produces lumber for flooring, furniture and cabinetwork.”

So what explains the relationship between a mid-Cretaceous Tropidogyne from Myanmar and an extant Ceratopetalum from Australia, more than 4,000 miles and an ocean away to the southeast?

“That’s easy, if you consider the geological history of the regions,” Professor Poinar said.

“Probably the amber site in Myanmar was part of Greater India that separated from the southern hemisphere, the supercontinent Gondwana, and drifted to southern Asia.”

“Malaysia, including Burma, was formed during the Paleozoic and Mesozoic eras by subduction of terranes that successfully separated and then moved northward by continental drift.”


George O. Poinar, Jr. & Kenton L. Chambers. 2017. Tropidogyne pentaptera, sp. nov., a new mid-Cretaceous fossil angiosperm flower in Burmese amber. Palaeodiversity 10 (1): 135-140; doi: 10.18476/pale.v10.a10


Study Reveals Link between Mass Extinction Events and Comet/Asteroid Showers

Sunday, August 13, 2017

Study Reveals Link between Mass Extinction Events and Comet/Asteroid Showers

According to a study, published in the journal Monthly Notices of the Royal Astronomical Society, mass extinctions occurring over the past 260 million years were likely caused by comet/asteroid showers.

For more than three decades, researchers have argued about a controversial hypothesis relating to periodic mass extinctions and asteroid/comet impact craters on Earth.

Dr Ken Caldeira of Carnegie Institution and Dr Michael Rampino of New York University offer new support linking the age of these craters with recurring mass extinctions of life, including the demise of the dinosaurs.

Specifically, they show a cyclical pattern over the studied period, with both impacts and extinction events taking place every 26 million years.

This cycle has been linked to periodic motion of the Sun and planets through the dense mid-plane of our Milky Way Galaxy.

Scientists have theorized that gravitational perturbations of the distant Oort comet cloud that surrounds the Sun lead to periodic comet showers in the inner Solar System, where some comets strike our planet.

To test their hypothesis, the team performed time-series analyses of impacts and extinctions using available data offering more accurate age estimates.

A graph showing how the rate of cratering has changed on Earth over time; the arrows indicate the dates of mass extinctions. Image credit: Michael Rampino / New York University.

“The correlation between the formation of these impacts and extinction events over the past 260 million years is striking and suggests a cause-and-effect relationship,” said Dr Rampino, who is the lead author on the study.

The scientists found that six mass extinctions of life during the studied period correlate with times of enhanced impact cratering on Earth.

“One of the craters considered in the study is the Chicxulub impact structure in the Yucatan, which dates to about 65 million years ago – the time of a great mass extinction that included the dinosaurs.”

“Moreover, five out of the six largest impact craters of the last 260 million years on Earth correlate with mass extinction events,” they said.

“This cosmic cycle of death and destruction has without a doubt affected the history of life on our planet,” Dr Rampino concluded.


Michael Rampino & Ken Caldeira. Periodic impact cratering and extinction events over the last 260 million years. MNRAS, published online October 20, 2015

Source:, 2015

Clues to Rocky Mountain Formation in South America

Sunday, August 13, 2017

South American example illustrates Rocky Mountain formation

New work from an international team of researchers including Carnegie’s Lara Wagner improves our understanding of the geological activity that is thought to have formed the Rocky Mountains. It was published by Nature in August 2015.

Subduction is a geological process that occurs at the boundary between two of the many plates that make up the Earth’s crust. An oceanic crustal plate sinks and slides under another plate—either oceanic or continental—and is plunged deep into Earth’s mantle.

Usually the lower plate slides down into the mantle at a fairly steep angle, sinking rapidly into the warmer, less-dense mantle material. However, in a process called “flat-slab” subduction, the lower plate moves nearly horizontally underneath the upper plate, sometimes for great distances.

 The revised geometry of the downgoing Nazca plate beneath the Andean mountains in southern Peru and northern Bolivia. Seismic stations are shown as colored cubes. Vertical lines show the location of these stations projected onto the slab.

Flat-slab subduction is used to explain volcanism and mountain formation that occurs far from plate boundaries, because the lower, “flat” slab moves inland beneath the surface of a landmass and thereby transmits the friction of the plates sliding against one another far inland. The formation of the Rocky Mountains between 55 and 80 million years ago, according to sedimentary and volcanic records that have been studied in detail since the 1970s, often is attributed to flat-slab subduction as the plate beneath the Pacific Ocean at that time slid beneath the North American continent.

Today, the largest flat slab is found beneath Peru, where the oceanic Nazca Plate is being subducted under the continental South American Plate. An undersea mountain belt, called the Nazca Ridge, sits on the Nazca Plate, and has been subducted along with the rest of the plate for the past 11 million years, according to previous studies

Although scientists knew that a flat slab existed in this region, much about how and when it was formed has remained a mystery. Using an array of seismometers placed over the region of flat-slab subduction, the team was able to image the structure of the subducted plate in unprecedented detail. This allowed the team to study the evolution of the Peruvian flat slab over time and to better understand the forces that created and sustain it.

What they found is that the angle of subduction is shallowest where the Nazca Ridge is being subducted beneath Peru. The portion of the plate containing this ridge sinks about 90 kilometers (56 miles) down and then flattens out. Away from the ridge, older portions of the flat slab that are no longer supported by the thick crust of the Nazca Ridge are found to be sagging, and younger, more recently subducted oceanic crust has torn free of the old, flat slab and is subducting at a normal dip angle.

“This was surprising as we expected to image large, older flat slab to the north. Instead, we found that the flat slab north of the subducting Nazca Ridge tears and reinitiates normal, steep subduction,” said lead author Sanja Knezevic Antonijevic, a student at the College of Arts and Sciences at the University of North Carolina at Chapel Hill.

Suction and trench retreat previously were theorized to be sufficient to create a flat slab. Suction is created between the upper plate and the downgoing slab, because the surrounding mantle is too viscous to creep into the narrow space between the two plates. Trench retreat occurs when the subducting oceanic plate moves dominantly downward, not laterally forward, resulting in an oceanward migration of the continent and trench.

However the team’s model shows that the subduction of the ridge is necessary for the flat slab’s formation, presumably because the buoyancy of the volcanically thickened Nazca Ridge keeps this portion of the plate from plunging steeply into the mantle. What’s more, removing the ridge from the model causes the flat slab to become unstable.

“Our model provides insights into the way that the Peruvian flat slab formed and evolved over time that can be applied to the studies of other flat-slab subduction events, such as the one that formed the Rocky Mountains,” Wagner said.

The other team members were: Abhash Kumar, also a student in the College of Arts and Sciences at the University of North Carolina at Chapel Hill; Susan Beck and George Zandt of University of Arizona; Maureen Long of Yale University; and Hernando Tavera and Cristobal Condori of Instituto Geofisico del Peru.


Devonian Period: Climate, Animals & Plants

Wednesday, August 9, 2017

Devonian period--Prehistoric amphibians. The one looks very gatorish. By Masato Hattori

The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 419.2 Mya (million years ago), to the beginning of the Carboniferous Period, about 358.9. It is named after Devon, England, where rocks from this period were first studied. The Devonian period experienced the first significant adaptive radiation of terrestrial life. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the “Age of Fish”. The first ray-finned and lobe-finned bony fish appeared, while the placoderms began dominating almost every known aquatic environment.

Early Devonian Earth

The ancestors of all tetrapods began adapting to walking on land, their strong pectoral and pelvic fins gradually evolving into legs. In the oceans, primitive sharks became more numerous than in the Silurian and the late Ordovician. The first ammonite mollusks appeared. Trilobites, the mollusk-like brachiopods and the great coral reefs, were still common. The Late Devonian extinction which started about 375 million years ago severely affected marine life, killing off all placoderms, and all trilobites, save for a few species of the order Proetida.

Devonian by atrox1

The paleogeography was dominated by the supercontinent of Gondwana to the south, the continent of Siberia to the north, and the early formation of the small continent of Euramerica in between.

Late Devonian landscape. Artwork of wetland plants, and fumaroles during the ate Devonian Period (385 to 360 million years ago). The plants shown here include club mosses such as Aglaophyton. Bacterial mats (orange) surround the hot pools. A large millipede is at lower right.