Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, India

Fossil site in Kerala, India

Fossil wood park maintained by geological survey of India at Tamilnadu

Cretaceous fossil sites india

Fossils in rack:-Cyad

Fossils in rack:-echiniderms

Fossils in rack:-Rastellum sp

Pre-historic seabed, Cretaceous period

Glaciers in East Antarctica also ‘imperiled’ by climate change

July 30th, 2018 Riffin

Source:University of California – Irvine

A team of scientists from the University of California, Irvine has found evidence of significant mass loss in East Antarctica’s Totten and Moscow University glaciers, which, if they fully collapsed, could add 5 meters (16.4 feet) to the global sea level.

In a paper published this week in the American Geophysical Union journal Geophysical Research Letters, the glaciologists estimate that between April 2002 and September 2016, the two glaciers lost about 18.5 billion tons of ice per year — equivalent to 0.7 millimeters (0.03 inches) of global sea level rise over the analyzed time period.

UCI’s researchers discovered this by applying a locally optimized technique to data from NASA’s Gravity Recovery & Climate Experiment satellite mission, combined with mass balance approximations from regional atmospheric climate models and ice discharge measurements by NASA’s Operation IceBridge and Measures projects.

“For this research, we used an improved methodology with GRACE data to retrieve the mass loss in an area undergoing rapid change,” said lead author Yara Mohajerani, a graduate student in UCI’s Department of Earth System Science. “By overlaying these data with independent measurements, we improve our confidence in the results and the conclusion that Totten and Moscow University are imperiled.”

Making up roughly two-thirds of the Antarctic continent, East Antarctica has been viewed by polar researchers as less threatened by climate change than the volatile ice sheets in West Antarctica and the Antarctic Peninsula.

“Both of these glaciers are vulnerable to the intrusion of warm ocean water and hold considerable potential for sea level rise,” said co-author Eric Rignot, Donald Bren Professor and chair of Earth system science at UCI. “This work highlights that East Antarctic glaciers are as important to our future as those in the continent’s western regions.”

According to co-author Isabella Velicogna, professor of Earth system science, it’s challenging to study the Totten and Moscow University glaciers because the signal of change is much weaker than that of their counterparts in the west.

“In this remote part of the world, the data from GRACE and other satellite missions are critical for us to understand the glacier evolution,” she said.

Citation: University of California – Irvine. “Glaciers in East Antarctica also ‘imperiled’ by climate change: Usually seen as less vulnerable, they carry the potential to add 16 feet to global sea level.” ScienceDaily. ScienceDaily, 26 July 2018. <www.sciencedaily.com/releases/2018/07/180726161009.htm>.

Yellowstone super-volcano has a different history than previously thought

July 28th, 2018 Riffin

The long-dormant Yellowstone super-volcano in the American West has a different history than previously thought, according to a new study by a Virginia Tech geoscientist.

Scientists have long thought that Yellowstone Caldera, part of the Rocky Mountains and located mostly in Wyoming, is powered by heat from the Earth’s core, similar to most volcanoes such as the recently active Kilauea volcano in Hawaii. However, new research published in Nature Geoscience by Ying Zhou, an associate professor with the Virginia Tech College of Science’s Department of Geosciences, shows a different past.

“In this research, there was no evidence of heat coming directly up from the Earth’s core to power the surface volcano at Yellowstone,” Zhou said. “Instead, the underground images we captured suggest that Yellowstone volcanoes were produced by a gigantic ancient oceanic plate that dove under the Western United States about 30 million years ago. This ancient oceanic plate broke into pieces, resulting in perturbations of unusual rocks in the mantle which led to volcanic eruptions in the past 16 million years.”

This is the location of the Yellowstone's hotspot track. The triangles indicate general locations of the Yellowstone and Snake River Plain age-progressive volcanoes with ages shown in millions of years, plotted on a topography map of the Western United States. Credit: Virginia Tech

This is the location of the Yellowstone’s hotspot track. The triangles indicate general locations of the Yellowstone and Snake River Plain age-progressive volcanoes with ages shown in millions of years, plotted on a topography map of the Western United States.
Credit: Virginia Tech

The eruptions were very explosive, Zhou added. A theoretical seismologist, Zhou created X-ray-like images of the Earth’s deep interior from USArray — part of the Earthscope project funded by the National Science Foundation — and discovered an anomalous underground structure at a depth of about 250 to 400 miles right beneath the line of volcanoes.

“This evidence was in direct contradiction to the plume model,” Zhou said.

In her study, Zhou found the new images of the Earth’s deep interior showed that the oceanic Farallon plate, which used to be where the Pacific Ocean is now, wedged itself beneath the present-day Western United States. The ancient oceanic plate was broken into pieces just like the seafloor in the Pacific today. A section of the subducted oceanic plate started tearing off and sinking down to the deep earth.

The sinking section of oceanic plate slowly pushed hot materials upward to form the volcanoes that now make up Yellowstone. Further, the series of volcanoes that make up Yellowstone have been slowly moving, achingly so, ever since. “The process started at the Oregon-Idaho border about 16 million years ago and propagated northwestward, forming a line of volcanoes that are progressively younger as they stretched northwest to present-day Wyoming,” Zhou added.

The previously-held plume model was used to explain the unique Yellowstone hotspot track — the line of volcanoes in Oregon, Idaho, and Wyoming that dots part of the Midwest. “If the North American plate was moving slowly over a position-fixed plume at Yellowstone, it will displace older volcanoes towards the Oregon-Idaho border and form a line of volcanoes, but such a deep plume has not been found.” Zhou said. So, what caused the track? Zhou intends to find out.

“It has always been a problem there, and scientists have tried to come up with different ways to explain the cause of Yellowstone volcanoes, but it has been unsuccessful,” she said, adding that hotspot tracks are more popular in oceans, such as the Hawaii islands. The frequent Geyser eruptions at Yellowstone are of course not volcanic eruptions with magna, but due to super-heated water. The last Yellowstone super eruption was about 630,000 years ago, according to experts. Zhou has no predictions on when or if Yellowstone could erupt again.

The use of the X-ray-like images for this study is unique in itself. Just as humans can see objects in a room when a light is on, Zhou said seismometers can see structures deep within the earth when an earthquake occurs. The vibrations spread out and create waves when they hit rocks. The waves are detected by seismometers and used in what is known as diffraction tomography.

“This is the first time the new imaging theory has been applied to this type of seismic data, which allowed us to see anomalous structures in the Earth’s mantle that would otherwise not be resolvable using traditional methods,” Zhou said.

Zhou will continue her study of Yellowstone. “The next step will be to increase the resolution of the X-ray-like images of the underground rock,” she added.

“More detailed images of the unusual rocks in the deep earth will allow us to use computer simulation to recreate the fragmentation of the gigantic oceanic plate and test different scenarios of how rock melting and magma feeding system work for the Yellowstone volcanoes.”

Citation: Virginia Tech. “Yellowstone super-volcano has a different history than previously thought: Yellowstone super-volcano eruptions were produced by gigantic ancient oceanic plate.” ScienceDaily. ScienceDaily, 26 July 2018. <www.sciencedaily.com/releases/2018/07/180726085827.htm>.

Source: www.sciencedaily.com

Paleontologists discover largest dinosaur foot ever

July 25th, 2018 Riffin

The Black Hills region of the United States is famous today for tourist attractions like Deadwood and Mount Rushmore, but around 150 million years ago it was home to one of the largest dinosaurs known. This dinosaur was a member of the sauropod family with long necks and tails. These giant plant-eating dinosaurs like Brontosaurus and Diplodocus were the largest land animals that ever lived on this planet.

The foot described in a new scientific paper recently published in the open-access journal PeerJ — the Journal of Life and Environmental Sciences was excavated in 1998 by an expedition from the University of Kansas, with Anthony Maltese, lead author of the study, as member of the crew. As he writes, it was immediately apparent that the foot, nearly a meter wide, was from an extremely large animal — so the specimen was nicknamed “Bigfoot.”

Photograph from the excavations in 1998, with the brachiosaur foot bones below a tail of a Camarasaurus. University of Kansas expedition crew member as a scale. Credit: Photo courtesy of the KUVP archives

Photograph from the excavations in 1998, with the brachiosaur foot bones below a tail of a Camarasaurus. University of Kansas expedition crew member as a scale.
Credit: Photo courtesy of the KUVP archives

Now, after detailed preparation and study, Maltese and his international team of researchers from the USA, Switzerland, and Germany identified it as belonging to an animal very closely related to Brachiosaurus, famous for its appearance in the 1993 film Jurassic Park.

Anthony Maltese, Emanuel Tschopp, Femke Holwerda, and David Burnham used 3D scanning and detailed measurements to compare Bigfoot to sauropod feet from numerous species. Their research confirmed that this foot was unusually large. According to Holwerda, a Dutch PhD student at the Ludwig Maximilians University of Munich, Germany, comparisons with other sauropod feet showed that Bigfoot was clearly the largest dinosaur foot discovered to date.

It also confirmed that brachiosaurs inhabited a huge area from eastern Utah to northwestern Wyoming, 150 million years ago. “This is surprising,” says Tschopp, a Swiss paleontologist working at the American Museum of Natural History in New York, “many other sauropod dinosaurs seem to have inhabited smaller areas during that time.”

According to Maltese, who was part of the original University of Kansas team in 1998 but is now at the Rocky Mountain Dinosaur Resource Center in Woodland Park, Colorado, the rock outcrops that produced this fossil hold many more “fantastic dinosaur skeletons,” and the research team hopes to continue their studies on fossils from there.

Citation: PeerJ. “Paleontologists discover largest dinosaur foot ever.” ScienceDaily. ScienceDaily, 24 July 2018. <www.sciencedaily.com/releases/2018/07/180724110119.htm>.

Source: www.sciencedaily.com

The Earth’s youngest banded iron formation discovered.

July 24th, 2018 Riffin

Source:University of Alberta

The banded iron formation, located in western China, has been conclusively dated as Cambrian in age. Approximately 527 million years old, this formation is young by comparison to the majority of discoveries to date. The deposition of banded iron formations, which began approximately 3.8 billion years ago, had long been thought to terminate before the beginning of the Cambrian Period at 540 million years ago.

Earth's youngest banded iron formation in western China. Credit: Zhiquan Li

Earth’s youngest banded iron formation in western China.
Credit: Zhiquan Li

“This is critical, as it is the first observation of a Precambrian-like banded iron formation that is Early Cambrian in age. This offers the most conclusive evidence for the presence of widespread iron-rich conditions at a time, confirming what has recently been suggested from geochemical proxies,” said Kurt Konhauser, professor in the Department of Earth and Atmospheric Sciences and co-author. Konhauser supervised the research that was led by Zhiquan Li, a PhD candidate from Beijing while on exchange at UAlberta.

The Early Cambrian is known for the rise of animals, so the level of oxygen in seawater should have been closer to near modern levels. “This is important as the availability of oxygen has long been thought to be a handbrake on the evolution of complex life, and one that should have been alleviated by the Early Cambrian,” says Leslie Robbins, a PhD candidate in Konhauser’s lab and a co-author on the paper.

The researchers compared the geological characteristics and geochemistry to ancient and modern samples to find an analogue for their deposition. The team relied on the use of rare earth element patterns to demonstrate that the deposit formed in, or near, a chemocline in a stratified iron-rich basin.

“Future studies will aim to quantify the full extent of these Cambrian banded iron formations in China and whether similar deposits can be found elsewhere,” says Kurt Konhauser.

Citation: University of Alberta. “Scientists discover Earth’s youngest banded iron formation in western China: Discovery provides evidence of iron-rich seawater much later than previously thought.” ScienceDaily. ScienceDaily, 11 July 2018. <www.sciencedaily.com/releases/2018/07/180711182731.htm>.

Earth’s ancient biosphere deciphered using prehistoric lake deposits.

July 23rd, 2018 Riffin

Source:McGill University

A sample of ancient oxygen, teased out of a 1.4 billion-year-old evaporative lake deposit in Ontario, provides fresh evidence of what the Earth’s atmosphere and biosphere were like during the interval leading up to the emergence of animal life.

The findings, published in the journal Nature, represent the oldest measurement of atmospheric oxygen isotopes by nearly a billion years. The results support previous research suggesting that oxygen levels in the air during this time in Earth history were a tiny fraction of what they are today due to a much less productive biosphere.

“It has been suggested for many decades now that the composition of the atmosphere has significantly varied through time,” says Peter Crockford, who led the study as a PhD student at McGill University. “We provide unambiguous evidence that it was indeed much different 1.4 billion years ago.”

The study provides the oldest gauge yet of what earth scientists refer to as “primary production,” in which micro-organisms at the base of the food chain — algae, cyanobacteria, and the like — produce organic matter from carbon dioxide and pour oxygen into the air.

A smaller biosphere

“This study shows that primary production 1.4 billion years ago was much less than today,” says senior co-author Boswell Wing, who helped supervise Crockford’s work at McGill. “This means that the size of the global biosphere had to be smaller, and likely just didn’t yield enough food — organic carbon — to support a lot of complex macroscopic life,” says Wing, now an associate professor of geological sciences at University of Colorado at Boulder.

To come up with these findings, Crockford teamed up with colleagues from Yale University, University of California Riverside, and Lakehead University in Thunder Bay, Ontario, who had collected pristine samples of ancient salts, known as sulfates, found in a sedimentary rock formation north of Lake Superior. Crockford shuttled the samples to Louisiana State University, where he worked closely with co-authors Huiming Bao, Justin Hayles, and Yongbo Peng, whose lab is one of a handful in the world using a specialized mass-spectrometry technique capable of probing such materials for rare oxygen isotopes within sulfates.

The work also sheds new light on a stretch of Earth’s history known as the “boring billion” because it yielded little apparent biological or environmental change.

“Subdued primary productivity during the mid-Proterozoic era — roughly 2 billion to 800 million years ago — has long been implied, but no hard data had been generated to lend strong support to this idea,” notes Galen Halverson, a co-author of the study and associate professor of earth and planetary sciences at McGill. “That left open the possibility that there was another explanation for why the middle Proterozoic ocean was so uninteresting, in terms of the production and deposit of organic carbon.” Crockford’s data “provide the direct evidence that this boring carbon cycle was due to low primary productivity.”

Exoplanet clues

The findings could also help inform astronomers’ search for life outside our own solar system.

“For most of Earth history our planet was populated with microbes, and projecting into the future they will likely be the stewards of the planet long after we are gone,” says Crockford, now a postdoctoral researcher at Princeton University and Israel’s Weizmann Institute of Science. “Understanding the environments they shape not only informs us of our own past and how we got here, but also provides clues to what we might find if we discover an inhabited exoplanet.”

Credit: Sciencedaily.com

Curious armoured dinosaur fossil discovered in Utah!!!!

July 22nd, 2018 Riffin

Source:University of Utah

Fossils of a new genus and species of an ankylosaurid dinosaur — Akainacephalus johnsoni — have been unearthed in the Kaiparowits Formation of Grand Staircase-Escalante National Monument (GSENM), in Kane County, southern Utah, U.S.A., and are revealing new details about the diversity and evolution of this group of armored dinosaurs. Expected to look like other North American Late Cretaceous ankylosaurid dinosaurs with smooth bony armor on the skull, the new research suggests just the opposite and indicates that the defining features of Akainacephalus, specifically the spiky bony armor covering the skull and snout, align more closely with Asian ankylosaurids, who also have more pronounced spikes covering their skulls.

Akainacephalus was announced today in the open-access scientific journal PeerJ and unveiled on exhibit in the Past Worlds Gallery of the Natural History Museum of Utah at the Rio Tinto Center in Salt Lake City, Utah. The genus name is derived from the Greek words akaina, which means ‘thorn’ or ‘spike’, and cephalus, meaning ‘head.’ The species epithet johnsoni honors Randy Johnson, a dedicated museum volunteer who skillfully prepared its skull. Other talented volunteers helped to prepare the rest of the specimen.

“I’m a retired chemist, but I’ve always been interested in most of the science disciplines. I never thought that I would have the opportunity to actually work on fossils that could be important for paleontologists,” said Randy Johnson. “Now that I’m a museum volunteer, I’m getting the opportunity to work on a large variety of fossils and consult with top paleontologists — it’s like a dream second career. I couldn’t believe it when they told me they are naming the ankylosaur after me, a once in a lifetime honor,” said Johnson.

Ankylosaurids are a group of four-legged herbivorous armored dinosaurs with imposing bony tail clubs. Though ankylosaurids originated in Asia between 125 — 100 million years ago, they do not appear in the western North American fossil record until ~77 million years ago. The new species Akainacephalus lived 76 million years ago during the Late Cretaceous Period and offers the most complete skeleton of an ankylosaurid dinosaur found in the southwestern US. It includes a complete skull, much of the vertebral column, including a complete tail club, several fore and hind limbs elements, and bony body armor that includes two neck rings and spiked armor plates.

The unique arrangement of bony armor in the shape of small cones and pyramids covering the snout and head is the key research finding indicating that Akainacephalus is closely related to the New Mexican ankylosaurid Nodocephalosaurus kirtlandensis. Surprisingly, Akainacephalus and Nodocephalosaurus are more closely related to Asian ankylosaurids such as Saichania and Tarchia than to other Late Cretaceous North American ankylosaurids, including Ankylosaurusand Euoplocephalus. Both of the latter taxa possess flat skull armor.

“A reasonable hypothesis would be that ankylosaurids from Utah are related to those found elsewhere in western North America, so we were really surprised to discover that Akainacephalus was so closely related to species from Asia,” remarked Randall Irmis, co-author of the study.

Though ankylosaurids originated in Asia between 125 — 100 million years ago, they do not appear in the North American fossil record until around 77 million years ago. Akainacephalus once roamed the southern part of Laramidia, a landmass on the western coast of a shallow sea that flooded the central region, splitting the continent of North America in two. This caused isolation along western and eastern portions of the North American continent during the Late Cretaceous Period, between 95-70 million years ago.

Lead author Jelle Wiersma suggests that the geographic distribution of Late Cretaceous ankylosaurids throughout the Western Interior was the result of several geologically brief intervals of lowered sea level that allowed Asian ankylosaurid dinosaurs to immigrate to North America several times during the Late Cretaceous, resulting in the presence of two separate groups of ankylosaurid dinosaurs. This lowering of sea levels exposed the Beringian land bridge, allowing dinosaurs and other animals to move between Asia and North America.

“It is always exciting to name a new fossil taxon, but it is equally exciting if that taxon also provides additional insights into the bigger picture of its life, such as its diet or aspects of its behavior, and the environment it lived in,” said Wiersma. “Such is exactly the case with Akainacephalus johnsoni; not only is this the first described and named Late Cretaceous ankylosaurid dinosaur from Utah, but this unique animal also strengthens the evidence that distinct northern and southern provincialism existed during the late Campanian stage in Laramidia, because to date, we don’t see this type of ankylosaurid dinosaurs in the fossil record of northern Laramidia,” he said.

Wiersma explained that additionally, together with its close relative Nodocephalosaurus from New Mexico, Akainacephalus looks very different compared to other North American ankylosaurids such as Ankylosaurus, but instead, look much more like Asian ankylosaurids including Saichania and Tarchia. From these observations we can conclude that at least two immigration events took place during Late Cretaceous times when lowered sea levels exposed the Beringian land bridge, connecting Asia with western North America.

Ankylosaurid dinosaurs, among many other groups of animals, eventually crossed this land bridge, emigrating from Asia into western North America, resulting into two different types of Late Cretaceous ankylosaurid dinosaurs: ones that evolved flatter skull armor like Ankylosaurus and Euoplocephalus, and ones possessing very spiky skull armor such as Akainacephalus and Nodocephalosaurus.

“It is extremely fascinating and important for the science of paleontology that we can read so much information from the fossil record, allowing us to better understand extinct organisms and the ecosystems they were a part of,” concluded Wiersma.

These new findings are part of a study funded in large part by the Bureau of Land Management, as well as the Geological Society of America, and a University of Utah Department of Geology & Geophysics Graduate Student Grant. The project was led by University of Utah M.Sc. student Jelle Wiersma, now a Ph.D. student in the Dept. of Geosciences at James Cook University, Queensland, Australia. Wiersma was advised by co-author Dr. Randall Irmis, chief curator and curator of paleontology at the Natural History Museum of Utah, and associate professor in the Dept. of Geology and Geophysics, University of Utah.

Anklysaurid Dinosaurs on the Lost Continent of Southern Laramidia

Akainacephalus johnsoni was discovered in Grand Staircase-Escalante National Monument (GSENM) which encompasses a large area of high desert terrain in south-central Utah. This vast and rugged region, part of the National Landscape Conservation System administered by the Bureau of Land Management (BLM), was the last major area in the lower 48 states to be formally mapped by cartographers.

During the Late Cretaceous, GSENM was in the southern portion of Laramidia, which stretched from the Arctic Circle to the Gulf of Mexico. Akainacephalus is part of a growing number of new dinosaur discoveries over the past 15 years demonstrating the incredible diversity of animals and plants living on Laramidia between 80-75 million years ago. One of the most exciting conclusions from this work is that nearly every species of dinosaur discovered in GSENM is new to science, and Akainacephalus is no exception. Other recently discovered species include large and small meat-eating dinosaurs (e.g., tyrannosaurs), horned dinosaurs, and duck-billed dinosaurs. “A major long-term goal of our work in southern Utah is to try and understand why the species in GSENM differ from relatives of the same geologic age found in other parts of Laramidia,” said Wiersma. Hypotheses for the differences include changes in sea level, climate differences across latitude, and physical barriers to animal movement such as mountains and large rivers.

Fact Sheet: Major Points of the Paper

(1) Akainacephalus is a remarkable new species of ankylosaurid dinosaur from the upper Campanian Kaiparowits Formation in Grand Staircase-Escalante National Monument in Kane County, southern Utah.

(2) Akainacephalus is the most complete Late Cretaceous ankylosaurid dinosaur discovered from Utah and the southwestern U.S., and is distinguished by a number of unique features, including spikes and cones of the bony exterior covering the head and snout.

(3) The spikes and cones of bony armor on the skull of Akainacephalus are similar to those found on the New Mexican ankylosaurid Nodocephelausaurus kirtlandensis but distinct from all other known Late Cretaceous Laramidian ankylosaurids such as Ankylosaurus, Euoplocephalus, and Ziapelta, indicating these two species are more closely related to some Asian ankylosaurids.

(4) The new ankylosaurid Akainacephalus suggests multiple ankylosaurid emigration events from Asia to Laramidia during the Late Cretaceous.

(5) Together with some anklylosaurid dinosaurs from northern Laramidia, including Dyoplosaurus acutossquameus and Scolosaurus cutleri (both ~ 77 Ma), Akainacephalus represents one of the oldest known ankylosaurid dinosaurs from the Late Cretaceous of western North America (~76 Ma).

New Dinosaur Name: Akainacephalus johnsoni

  • The first part of the name, Akaina, is a Greek word that can be translated to spike or thorn. The second part of the name cephalus means head, and the epithet johnsoni honors Randy Johnson, a dedicated paleontology volunteer at the Natural History Museum of Utah who prepared the specimen’s skull.

Size

  • Akainacephalus, is a medium-sized dinosaur, and was 13-16 feet long (4-5 meters) and was 3 ½ feet tall (1 — 1.5 meters) at the hips.

Relationships

  • Akainacephalus belongs to a group of herbivorous armored dinosaurs called anklosaurids that lived in Asia and western North America during the Late Cretaceous Period (100-66 million years ago). One of the unique features of ankylosaurid dinosaurs is the presence of a characteristic bony tail club.

Anatomy

  • Akainacephalus walked on four legs, which were positioned directly underneath his body.
  • Akainacephalus was covered in bony armor from head to tail, with various sized and shaped bony plates, called osteoderms, which are thought to provide protection.
  • Akainacephalus is characterized by its elaborate covering of spikes and horns on the skull, as well a large bony club at the end of its tail.
  • Akainacephalus presumably had small, leaf-shaped teeth for eating plants. These fell out of the jaw after death, but before the skeleton was buried by sediment.

Age and Geography

  • Akainacephalus lived during the upper Campanian stage of the Late Cretaceous Period, which spanned from approximately 84 million to 72 million years ago. This animal lived about 76 million years ago.
  • Akainacephalus was discovered in 76 Ma old rocks of the Kaiparowits Formation, a geological/stratigraphic unit exposed in southern Utah consisting of sedimentary rocks deposited by rivers and streams.

Discovery & Excavation

  • Akainacephalus was first discovered in 2008 during a museum-led paleontological expedition in a remote area of BLM-administered Grand Staircase-Escalante National Monument (GSENM) in Kane County, southern Utah, USA. The site was discovered by BLM employee Scott Richardson.
  • The bones of Akainacephalus that were discovered include a complete skull, bony armor that includes neck rings and spiked plates, many vertebrae, forelimb and hindlimb bones, and a near complete tail with tail club.
  • Akainacephalus was found together with skeletons of several other animals at the same site, including a duck-bill dinosaur (Gryposaurus), a recently-described species of turtle (Arvinachelys), and a yet unnamed relative of alligators and caimans).
  • Akainacephalus is permanently housed in the collections of the Natural History Museum of Utah at the Rio Tinto Center in Salt Lake City and on public display at the museum’s Past Worlds exhibit.
  • These discoveries are the result of an ongoing collaboration between the Natural History Museum of Utah and the Bureau of Land Management.

Preparation

  • It required almost four years to fully prepare all of the bones of Akainacephalus.
  • Preparation of the skull was done by museum volunteer Randy Johnson, who is honored in the new name, Akainacephalus johnsoni

Credits: Sciencedaily.com

WFS News: Plant fossils provide new insight into the uplift history of SE Tibet

July 17th, 2018 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

The Tibetan Plateau, the highest and largest plateau in the world, is well known as ‘The Third Pole’. Tibet has also been called ‘Asia’s water tower’ because so many of Asia’s major rivers such as the Ganges, Indus, Tsangpo/Brahmaputra, Mekong, Yellow and Yangse rivers originate there. Despite its importance, the uplift history of the plateau and the mechanisms underpinning its evolution are still unclear, largely because reliable measurements of past surface elevation are hard to obtain.

Plant fossils might seem an unlikely way of determining surface height and thus what is happening deep in the Earth to build mountains and plateaus. However, because plants live at the Earth’s surface and constantly interact with the atmosphere, their leaves are very good at recording their surroundings, including properties of the atmosphere that are related to height. This approach has shown that the rise of the Himalayas was a relatively recent phenomenon, and took place after parts of Tibet were already above 4.5 km. However, well-dated  are rare in Tibet.

Recently, a large collection of plant fossils was made from the Lawula Formation in the Markam Basin in SE Tibet. This collection was made by Tao Su and his colleagues from Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences. Remarkably, the fossils were preserved between volcanic ash layers that allowed them to be precisely dated using 40Ar/39Ar analysis. It turned out that the fossil assemblages were much older than their relatively modern appearance would suggest.

40Ar/39Ar sample locations and dates constrain the ages of the MK1 and MK3 leaf assemblages, for which indicative selected leaf fossils are shown to scale, together with predicted palaeoelevations. A distinct reduction in leaf size is evident between MK3 and MK1, which is situated at the onset of the Eocene-Oligocene transition (E-O). Adjusted elevations are where moist enthalpy at sea level obtained from Indian fossil floras have been transposed to the palaeoposition of the Markam Basin. The most abundant taxa in terms of specimens recovered are marked with an asterisk (*). Credit: ©Science China Press Read more at: https://phys.org/news/2018-06-fossils-insight-uplift-history-se.html#jCp

40Ar/39Ar sample locations and dates constrain the ages of the MK1 and MK3 leaf assemblages, for which indicative selected leaf fossils are shown to scale, together with predicted palaeoelevations. A distinct reduction in leaf size is evident between MK3 and MK1, which is situated at the onset of the Eocene-Oligocene transition (E-O). Adjusted elevations are where moist enthalpy at sea level obtained from Indian fossil floras have been transposed to the palaeoposition of the Markam Basin. The most abundant taxa in terms of specimens recovered are marked with an asterisk (*). Credit: ©Science China Press

Tao Su and his colleagues recorded several thousand fossil leaves from four different layers, but two layers have the richest plant fossils with the best preservation. The lower layer (MK3) was deposited 34.6 million years (Ma) ago and the upper layer (MK1) at 33.4 Ma. As such they spanned the Eocene-Oligocene Transition (33.9 Ma), a time when deep sea sediments show significant cooling.

Interestingly, layer MK3 is dominated by leaves of the ring-cupped oak and members of the birch family, whereas MK1 consists almost exclusively of alpine taxa with small leaves. Assemblage composition and leaf form show clearly a transition from evergreen and deciduous broad-leaved mixed forest to alpine shrub. That climate change was quantified by Climate-Leaf Analysis Multivariate Program (CLAMP), a proxy that uses leaf form to estimate a range of climate variables such as temperature and moisture, as well as surface height, in the geological past.

Using this approach, Tao Su and colleagues showed that at the E-O transition southeastern Tibet was ~3 km high and actively rising to close its present height. Their results demonstrate clearly the early onset of uplift in this region, rather than uplift beginning some 10 million years later near the start of the Miocene. The results show that the elevation of southeastern Tibet took place largely in the Eocene, which has major implications for uplift mechanisms, landscape development and biotic evolution.

Furthermore, 40Ar/39Ar analysis of the volcanic ashes bounding the Markam fossil floras adds to a growing list of Paleogene sites in southeastern Tibet and Yunnan, which are far older than previously thought based on biostratigraphy and lithostratigraphy. It is already clear that the evolution of the modern highly diverse Asian biota is a Paleogene, not a Neogene, phenomenon and took place before the E-O transition. This implies a modernisation deeply-rooted in the Paleogene, possibly driven by a combination of complex Tibetan topography and climate change.

The Xishuangbanna group are continuing to collect spectacular plant fossils in different parts of the Tibetan Plateau. In the coming years, it would expect to see a revolution in the understanding of Tibetan uplift and its relationship to climate and biotic evolution in Asia.

Citation: Tao Su et al, Uplift, Climate and Biotic Changes at the Eocene-Oligocene Transition in Southeast Tibet, National Science Review (2018). DOI: 10.1093/nsr/nwy062
@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

 

WFS News: Scientists have discovered the oldest colors in the geological record

July 10th, 2018 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

 1.1-billion-year-old porphyrins establish a marine ecosystem dominated by bacterial primary producers.

 N. Gueneli, A. M. McKenna, N. Ohkouchi, C. J. Boreham, J. Beghin, E. J. Javaux, and J. J. Brocks.

             PNAS, 2018 DOI: 10.1073/pnas.1803866115

The average cell size of marine phytoplankton is critical for the flow of energy and nutrients from the base of the food web to higher trophic levels. Thus, the evolutionary succession of primary producers through Earth’s history is important for our understanding of the radiation of modern protists ∼800 million years ago and the emergence of eumetazoan animals ∼200 million years later. Currently, it is difficult to establish connections between primary production and the proliferation of large and complex organisms because the mid-Proterozoic (∼1,800–800 million years ago) rock record is nearly devoid of recognizable phytoplankton fossils. We report the discovery of intact porphyrins, the molecular fossils of chlorophylls, from 1,100-million-year-old marine black shales of the Taoudeni Basin (Mauritania), 600 million years older than previous findings. The porphyrin nitrogen isotopes (δ15Npor = 5.6–10.2‰) are heavier than in younger sedimentary sequences, and the isotopic offset between sedimentary bulk nitrogen and porphyrins (εpor = −5.1 to −0.5‰) points to cyanobacteria as dominant primary producers. Based on fossil carotenoids, anoxygenic green (Chlorobiacea) and purple sulfur bacteria (Chromatiaceae) also contributed to photosynthate. The low εpor values, in combination with a lack of diagnostic eukaryotic steranes in the time interval of 1,600–1,000 million years ago, demonstrate that algae played an insignificant role in mid-Proterozoic oceans. The paucity of algae and the small cell size of bacterial phytoplankton may have curtailed the flow of energy to higher trophic levels, potentially contributing to a diminished evolutionary pace toward complex eukaryotic ecosystems and large and active organisms.

Biogeochemistry Lab Manager Janet Hope from the ANU Research School of Earth Sciences holds a vial of pink colored porphyrins representing the oldest intact pigments in the world. Credit: The Australian National University

Biogeochemistry Lab Manager Janet Hope from the ANU Research School of Earth Sciences holds a vial of pink colored porphyrins representing the oldest intact pigments in the world.
Credit: The Australian National University

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

WFS News: Evidence for arboreal radiation of stem primates in the Palaeocene

July 6th, 2018 Riffin
@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev
Oldest skeleton of a plesiadapiform provides additional evidence for an exclusively arboreal radiation of
stem primates in the Palaeocene

Stephen G. B. Chester, Thomas E. Williamson, Jonathan I. Bloch, Mary T. Silcox, Eric J. Sargis

Hypothesis of evolutionary relationships of Torrejonia wilsoni and other eutherian mammals. (Left) Resulting single most parsimonious cladogram based on modified morphological dataset of Bloch et al. [4], sampling a total of 240 morphological characters (68 postcranial, 45 cranial and 127 dental) with Primates sensu lato indicated in blue and Torrejonia wilsoni supported as a stem primate and indicated in orange. Numbers below branches represent Absolute Bremer Support values. See the electronic supplementary material for detailed methods, descriptions of morphological characters, specimens examined (also see [5]), and the taxon-character matrix in TNT format. (Bottom) Simplified subset of resulting tree topology focused on Primates. Boxes (a–f) illustrate tarsals of select primates with great mobility at the upper ankle joint (yellow: lateral tibial facet extends distally onto neck of astragalus in dorsal view), lower ankle joint (red: sustentacular facet extends distally onto body of calcaneus in dorsal view) and transverse tarsal joint (orange: round, concave cuboid facet of calcaneus in distal view) indicating arboreality. Boxes (a–f) also illustrate micro X-ray CT scan reconstructions of (a) purgatoriid Purgatorius unio p4-m3 (UCMP 107406) with tall molar cusps in buccal view, (b) micromomyid Dryomomys szalayi cranium (UM 41870) in right lateral view with large IOF, (c) Torrejonia wilsoni partial skeleton (NMMNH P-54500), (d) paromomyid Ignacius graybullianus cranium (USNM 421608) in right lateral view with relatively large olfactory bulbs (OB) of endocast (violet), (e) carpolestid Carpolestes simpsoni cranium (USNM 482354) in right lateral view and tarsals (UM 101963) and (f) notharctid Notharctus tenebrosus cranium (AMNH 127167) in right lateral view. Some elements reversed for clarity. See figure 3 legend for specimen numbers of tarsals not listed above. See the electronic supplementary material for institutional abbreviations.

Hypothesis of evolutionary relationships of Torrejonia wilsoni and other eutherian mammals. (Left) Resulting single most parsimonious cladogram based on modified morphological dataset of Bloch et al. [4], sampling a total of 240 morphological characters (68 postcranial, 45 cranial and 127 dental) with Primates sensu lato indicated in blue and Torrejonia wilsoni supported as a stem primate and indicated in orange. Numbers below branches represent Absolute Bremer Support values. See the electronic supplementary material for detailed methods, descriptions of morphological characters, specimens examined (also see [5]), and the taxon-character matrix in TNT format. (Bottom) Simplified subset of resulting tree topology focused on Primates. Boxes (a–f) illustrate tarsals of select primates with great mobility at the upper ankle joint (yellow: lateral tibial facet extends distally onto neck of astragalus in dorsal view), lower ankle joint (red: sustentacular facet extends distally onto body of calcaneus in dorsal view) and transverse tarsal joint (orange: round, concave cuboid facet of calcaneus in distal view) indicating arboreality. Boxes (a–f) also illustrate micro X-ray CT scan reconstructions of (a) purgatoriid Purgatorius unio p4-m3 (UCMP 107406) with tall molar cusps in buccal view, (b) micromomyid Dryomomys szalayi cranium (UM 41870) in right lateral view with large IOF, (c) Torrejonia wilsoni partial skeleton (NMMNH P-54500), (d) paromomyid Ignacius graybullianus cranium (USNM 421608) in right lateral view with relatively large olfactory bulbs (OB) of endocast (violet), (e) carpolestid Carpolestes simpsoni cranium (USNM 482354) in right lateral view and tarsals (UM 101963) and (f) notharctid Notharctus tenebrosus cranium (AMNH 127167) in right lateral view. Some elements reversed for clarity. See figure 3 legend for specimen numbers of tarsals not listed above. See the electronic supplementary material for institutional abbreviations.

Palaechthonid plesiadapiforms from the Palaeocene of western North America have long been recognized as among the oldest and most primitive euarchontan mammals, a group that includes extant primates, colugos and treeshrews. Despite their relatively sparse fossil record, palaechthonids have played an important role in discussions surrounding adaptive scenarios for primate origins for nearly a half-century. Likewise, palaechthonids have been considered important for understanding relationships among plesiadapiforms, with members of the group proposed as plausible ancestors of Paromomyidae and Microsyopidae. Here, we describe a dentally associated partial skeleton of Torrejonia wilsoni from the early Palaeocene (approx. 62 Ma) of New Mexico, which is the oldest known plesiadapiform skeleton and the first postcranial elements recovered for a palaechthonid. Results from a cladistic analysis that includes new data from this skeleton suggest that palaechthonids are a paraphyletic group of stem primates, and that T. wilsoni is most closely related to paromomyids. New evidence from the appendicular skeleton of T. wilsoni fails to support an influential hypothesis based on inferences from craniodental morphology that palaechthonids were terrestrial. Instead, the postcranium of T. wilsoni indicates that it was similar to that of all other plesiadapiforms for which skeletons have been recovered in having distinct specializations consistent with arboreality.

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

 

 

WFS News: Early African Fossils Elucidate the Origin of Embrithopod Mammals

July 1st, 2018 Riffin

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

Long before rhinoceros, giraffes, hippos, and antelopes roamed the African savannah, a group of large and highly specialized mammals known as embrithopods inhabited the continent. The most well known is Arsinoitherium, an animal that looked much like a rhinoceros but was in fact more closely related to elephants, sea cows, and hyraxes. Now, researchers reporting in Current Biology on June 28 offer a glimpse into this ancient past with the discovery of the earliest and most ancient embrithopod yet described.

The approximately 55-million-year-old fossilized dental remains found in the first lower Eocene levels of the Ouled Abdoun phosphate basin in Morocco represent two new species in the genus Stylolophus, the researchers report. The earliest embrithopods were previously known from 48-million-year-old fossils collected in Africa and Turkey.

This figure show the lower jaw of Stylolophus minor, holotype of the new species. C is 3-D model reconstructed from CT scans. It shows by transparency the teeth roots, and especially those of the anterior incisors that are enlarged and oriented (tilted) horizontally as in the early proboscidean Phosphatherium. Length of M1-3 series: 38.5 mm. Scale bar, 10 mm. Credit: Photographs by Philippe Loubry (MNHN). Drawing by Charlène Letenneur (MNHN)

This figure show the lower jaw of Stylolophus minor, holotype of the new species. C is 3-D model reconstructed from CT scans. It shows by transparency the teeth roots, and especially those of the anterior incisors that are enlarged and oriented (tilted) horizontally as in the early proboscidean Phosphatherium. Length of M1-3 series: 38.5 mm. Scale bar, 10 mm.Credit: Photographs by Philippe Loubry (MNHN). Drawing by Charlène Letenneur (MNHN)

“The embrithopods were large and strange extinct mammals that belonged, together with hyraxes and elephants, to the early megaherbivorous mammalian fauna that inhabited the island Africa, well before the arrival about 23 million years ago of the Eurasian ungulate lineages such as the artiodactyls, including giraffes, buffalos, hippopotamus, and antelopes, and the perissodactyls, including zebras and rhinoceros,” says Emmanuel Gheerbrant of CNRS-MNHN in Paris, France. “They belong to the old endemic African fauna.”

Gheerbrant said that the origins of embrithopods had been uncertain, with two known co-existing families: one in Africa and the other in Turkey and Romania. It’s been unclear what the exact relationships of the embrithopods were with respect to sea cows and elephants.

The new phylogenetic study of the two species of Stylolophus found in Morocco confirms that they are basal embrithopods. It also shows that the extinct Embrithopod order is ancient, predating the divergence of the sea cows and elephants.

“Comparative anatomy of the new Moroccan species shows that the highly specialized embrithopod teeth derived from the ancestral dental morphology of all paenungulates, a clade including elephants, sea cows, and hyraxes, with the W-crested molars seen in some of the oldest hyracoids,” the group including hyraxes, Gheerbrant says. “The specialized design of the teeth with two transverse ridges, known in the most advanced forms such as Arsinoitherium, is a convergence of the embrithopods and the extant group of tethytheres, including manatees and elephants, towards leaf eating, which was favored by the ancient herbivorous niches available on the African island.”

The new species S. minor — which was unusually small at about the size of a sheep — is also the first to show the presence in embrithopods of enlarged and anteriorly inclined incisors, in the form of incipient tusks, as seen in the early ancestors of the group including elephants.

The early age and primitive state of Stylolophus, together with the high-level relationships (paenungulate and afrotherian), all support an African origin of the order Embrithopoda, the researchers say. The findings suggest that the Paleoamasiidae family found in Turkey arrived on the Eurasian shores of the Tethys Ocean (an ocean during much of the Mesozoic Era and the Paleogene period located between the ancient continents of Gondwana and Laurasia), after an early dispersal of an African ancestor resembling Stylolophus across the sea.

The researchers say that they’ll continue to search for paleontological evidence elucidating the evolutionary history and relationships of African ungulate-like mammals and insectivore-like afrotherian mammals, including golden moles, elephant shrews, tenrecs, aardvarks, and hyraxes. They’ll also continue the search for the enigmatic early roots of all placental mammals in Africa, going back even further in time to the Cretaceous Period.

  1. Emmanuel Gheerbrant, Arnaud Schmitt, László Kocsis. Early African Fossils Elucidate the Origin of Embrithopod Mammals. Current Biology, 2018; DOI: 10.1016/j.cub.2018.05.032

@WFS,World Fossil Society,Riffin T Sajeev,Russel T Sajeev

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