Tetrapodophis :Four-legged snake fossil ?

Scientists have described what they say is the first known fossil of a four-legged snake. The limbs of the 120-or-so-million-year-old, 20-centimeter-long creature are remarkably well preserved and end with five slender digits that appear to have been functional. Thought to have come from Brazil, the fossil would be one of the earliest snakes found, suggesting that the group evolved from terrestrial precursors in Gondwana, the southern remnant of the supercontinent Pangaea. But although the creature’s overall body plan—and indeed, many of its individual anatomical features—is snakelike, some researchers aren’t so sure that it is a part of the snake family tree.

The team’s scientific interpretation may be the least controversial aspect of the discovery, which they report online today in Science. The specimen’s provenance seems to be murkier than the silty waters that once buried its carcass. Whereas the team’s analyses strongly suggest the fossil came from northeastern Brazil, details of when it was unearthed and how it eventually ended up in the German museum where it now resides remain a mystery. Those details matter to many researchers and especially to some from Brazil, because it’s been illegal to export fossils from that nation since 1942.

Aptly, the new species has been dubbed Tetrapodophis amplectus. The genus name, in Greek, means “four-footed serpent.” (Previously, fossils of creatures considered to be protosnakes have only sported one set of limbs, usually hindlimbs.) The species name amplectus, which comes from Latin, means “embracing” and refers to the creature’s flexibility and presumed ability to wrap tightly around its prey. The front part of the fossil—which appears to be complete and has all bones in their original, lifelike arrangement—lies in a tight coil, a demonstration of the animal’s extreme limberness, says Nicholas Longrich, a vertebrate paleontologist at the University of Bath in the United Kingdom and co-author of the new study. Besides the tiny limbs, the specimen sports a skull the size of a human fingernail, 160 spinal vertebrae, and 112 vertebrae in the tail.

Dave Martill/University of Portsmouth  Tetrapodophis (rear limbs shown), had delicate but functional limbs that may have been used for grasping prey or used during mating.

Dave Martill/University of Portsmouth
Tetrapodophis (rear limbs shown), had delicate but functional limbs that may have been used for grasping prey or used during mating.

The fossil had resided in a private collection for several decades before it gained the attention of team member David Martill of the University of Portsmouth. He stumbled across the specimen during a field trip with students to Museum Solnhofen in Germany. No notes about when or where it was collected are available, the researchers say. But certain characteristics of the limestone that entombed the fossil, as well as the distinct orange-brown color of the bones themselves, strongly suggest it came from a particular area of northeastern Brazil, Longrich says. The sediment that became those rocks accumulated in calm waters on the floor of a lake or a lagoon sometime between 113 million and 126 million years ago, he notes.

Regarding the legality of the fossil’s collection or export from its presumed home country, Martill says “Who knows how the fossil came from Brazil”? Furthermore, he notes, to assert that the fossil was collected illegally a person would need to ascertain when it was unearthed. But such questions are irrelevant to the fossil’s scientific significance, Martill maintains. “Personally I don’t care a damn how the fossil came from Brazil or when,” he says.

Many features of Tetrapodophis point to its snakiness. Among squamates, the group of reptiles that also includes lizards, only snakes have more than 150 spinal vertebrae, the researchers note. The creature’s teeth are pointy and slightly curved. Also, the fossil includes some scales that stretch across the full width of the belly, a trait known only in snakes. The dramatically reduced size of the creature’s limbs, as well as a cylindrical rather than a flattened tail, suggest that snakes evolved from terrestrial animals that burrowed, not from marine creatures as some researchers have proposed, Longrich says.

 “This is the single most extraordinary fossil that I’ve ever seen,” says Bhart-Anjan Bhullar, a vertebrate paleontologist at Yale University who was not involved with the work. And Tetrapodophis is definitely a snake, he notes: “No other reptile has the combination of features that this creature has.”

Yet other scientists aren’t so sure. Michael Caldwell, a vertebrate paleontologist at the University of Alberta, Edmonton, in Canada, readily admits he has seen only the team’s images of the fossil, not the fossil itself. But some aspects of the creature’s spinal vertebrae don’t match that of other snakes and lizards, he notes. In particular, the front surfaces of the vertebrae of known snakes and lizards except geckoes are concave, and the rear surfaces are convex; that doesn’t appear to be the case in Tetrapodophis, he says.

Julius T. Cstonyi  Tetrapodophis (artist’s representation) is the first known snake known to have four limbs.

Julius T. Cstonyi
Tetrapodophis (artist’s representation) is the first known snake known to have four limbs.

And whereas the vertebrae of all living and fossil reptiles include a small bone called an intercentrum, Tetrapodophis’ vertebrae don’t have them. In fact, Caldwell notes, its vertebrae resemble those seen among a large group of extinct amphibians that died out during mass extinctions about 251 million years ago, long before Tetrapodophis appeared on the scene. Rather than being a protosnake, Tetrapodophis might be a surviving remnant of that previously presumed lost group, he suggests. “I think this creature is far more exciting for what it might be than for what [the team] says it is.”

Tetrapodophis “has a really interesting mix of characters,” says Susan Evans, a paleobiologist at University College London. Although the creature’s teeth look snakelike, she admits, “I’m trying to carefully sit on the fence as to whether this is actually a snake.” A radical elongation of the body and reduction in size or loss of limbs has occurred many times in other groups of reptiles, she notes.

Another puzzle, she adds, are why the bones at the tips of the creature’s digits are so long. Longrich and his colleagues suggest the long-fingered feet are used for grasping prey or possibly used during mating. But Caldwell notes that such feet “are remarkably unusual unless you’re a tree-climber.”

Regardless of what Tetrapodophis turns out to be, says Caldwell, “I’m looking forward to seeing the specimen.” Now permanently on loan to the Museum Solnhofen, the fossil will be made available for further scientific analysis, Longrich and his colleagues confirm.

Courtesy: Article by By Sid Perkins & additional reporting by Herton Escobar , http://news.sciencemag.org

Radiocarbon Dating may Inaccurate Due To Fossil Fuel Emissions

Fossil fuel emissions could soon start to cause headaches for archaeologists and paleontologists using radiocarbon dating to study artifacts. New research suggests the release of carbon-based gases into the atmosphere by vehicles and factories could alter radiocarbon measurements of ancient material.

Radiocarbon dating measures levels of carbon-14, a naturally radioactive form of the atom. This technique, first developed in the 1940’s, determines the age of any organic material by measuring ratios between carbon-14 and nonradioactive atoms of the element.

Researchers stated that at current rates of atmospheric carbon emissions, so much error will have been introduced into radiocarbon measurements that by the year 2050, an item 1,000 years old would be indistinguishable from a brand-new sample. Researchers could begin seeing this effect as early as the year 2020, the study determined.

Radio carbon dating process

Radio carbon dating process

Carbon-14 atoms within organic material decline over time, allowing investigators to measure the age of a given artifact. Ancient organic remains, such as oil and coal, are so old, they are nearly devoid of carbon-14. As carbon emissions from human-based activities continue, concentrations of carbon-14 will decrease, as the radioactive atoms are diluted from the pollution and the radiocarbon “age” of the atmosphere is artificially raised.

“If we did any current measurements on new products, they will end up having the same fraction of radiocarbon to total carbon as something that’s lost it over time due to decay. So if we just measure the fraction they’ll look like they have the same age for radiocarbon dating,” Heather Graven of Imperial College London, lead author of an article detailing the study, said.

This is not the first time in modern history in which human activities are altering levels of carbon-14 in relics. Carbon first began to dilute the marker material at the beginning of the Industrial Revolution, researchers state. Concentrations climbed once again during the 1950s and ’60s as nuclear tests released the radioactive atoms into the environment. Today, concentrations of carbon-14 measure about the same as they did prior to the rise of industry.

Radiocarbon dating can not only measure the age of ashes from a fire, or a bone within a knife handle, but has even been used to detect art fraud. However, within just 35 years, Graven predicts a robe worn while an anonymous writer penned Beowulf would be indistinguishable in age from a T-shirt worn last weekend by a guy watching football.

“If we reduced fossil fuel emissions, it would be good news for radiocarbon dating,” Graven said.

Study of how fossil fuel emissions affect radiocarbon dating was profiled in the Proceedings of the National Academy of Sciences.

Velociraptor ancestor was ‘winged dragon’ ?

Scientists have discovered a winged dinosaur – an ancestor of the velociraptor – that they say was on the cusp of becoming a bird.The 6ft 6in (2m) creature was almost perfectly preserved in limestone, thanks to a volcanic eruption that had buried it in north-east China and the 125-million year-old fossil suggests many other dinosaurs, including velociraptors, would have looked like “big, fluffy killer birds”. But it is unlikely that it could fly.

 An artist's impression of Zhenyuanlong shows how strange this feathered beast may have looked

An artist’s impression of Zhenyuanlong shows how strange this feathered beast may have looked

The dinosaur has been named Zhenyuanlong, meaning “Zhenyuan’s dragon” – in honour of the man who procured the fossil for the museum in Jinzhou, allowing it to be studied. The University of Edinburgh and the Chinese Academy of Geological Sciences collaboration is published in the journal Scientific Reports.

Lead researcher Dr Steve Brusatte said it was “the single most beautiful fossil I have had the privilege to work on”.

“It has short arms, and it is covered in feathers [with] proper wings with layers of quill-pen feathers,” he said.

“So even though this is a dinosaur, even though it is a close relative of velociraptor, it looks exactly like a turkey or a vulture.”

 Zhenyuanlong is an ancestor of the infamous velociraptor

Zhenyuanlong is an ancestor of the infamous velociraptor

Dr John Nudds, a senior lecturer in palaeontology at the University of Manchester, told BBC News the find was part of an “increasingly complex picture” of emerging evidence “that certainly a lot of [dinosaurs] and possibly even all of them had feathers or at least downy hair”.

Dr Brusatte said: “It will blow some people’s minds to realise that those dinosaurs in the movies would have been even weirder, and I think even scarier – like big fluffy birds from hell.”

He said its large body made it unlikely Zhenyuanlong would have been able to fly.

“So maybe [wings] did not evolve for flight – perhaps they evolved as a display structure, or to protect eggs in the nest,” he said.

“Or maybe this animal was starting to move around in the trees and was able to glide.”

Dr Brusatte said: “China is the epicentre of palaeontology right now.

“There are [museum] storerooms full of new dinosaur fossils that have never been studied before.

He added: “This is the most exciting time maybe in the history of palaeontology.”

Courtesy:

 The complex feathers of the dinosaur's wings are beautifully preserved

The complex feathers of the dinosaur’s wings are beautifully preserved

A vanished history of skeletonization in Cambrian comb jellies

Ctenophores are traditionally regarded as “lower” metazoans, sharing with cnidarians a diploblastic grade of organization. Unlike cnidarians, where skeletonization (biomineralization and sclerotization) evolved repeatedly among ecologically important taxa (for example, scleractinians and octocorals), living ctenophores are characteristically soft-bodied animals. We report six sclerotized and armored ctenophores from the early Cambrian period. They have diagnostic ctenophore features (for example, an octamerous symmetry, oral-aboral axis, aboral sense organ, and octaradially arranged ctene rows). Unlike most modern counterparts, however, they lack tentacles, have a sclerotized framework, and have eight pairs of ctene rows. They are resolved as a monophyletic group (Scleroctenophora new class) within the ctenophores. This clade reveals a cryptic history and sheds new light on the early evolution of this basal animal phylum. Skeletonization also occurs in some other Cambrian animal groups whose extant members are exclusively soft-bodied, suggesting the ecological importance of skeletonization in the Cambrian explosion.

Science Advances  10 Jul 2015:Vol. 1, no. 6, e1500092,DOI: 10.1126/sciadv.1500092

 

Gemmactena actinala gen. et sp. nov. (A) Holotype (ELEL-SJ100756A) showing radiating flap-like structures outlined by spokes, comb rows, and oral lappets. Apical organ not preserved. (B) Close-up of small focus area in (A) showing fine striae on spoke surface. (C) Close-up of large focus area in (A) showing remains of comb rows, as well as upper and lower spokes that frame a flap. (D) Paratype (ELEL-SJ081292A). (E) Close-up of focus area in (D) showing rigidity of a spoke with a medial groove (internal view). (F) Close-up of aboral region in (D) showing an ellipsoidal statolith preserved as dark remains surrounded by apical plates. (G) Counterpart of (F) showing complete apical plates detached from each other; remains of organic carbon are partially preserved as a dark band on the statolith. (H) Paratype (ELEL-SJ081366A) showing pointed dome-like apical organ walled by rigid plates (each with a medial groove continuous with a spoke). (I) Aborally compacted specimen ELEL-SJ120375A showing an apical organ and partially dislocated upper spokes (arrows). The apex of the apical organ was truncated and retained in counterpart during splitting. (J) Close-up of focus area in (I) showing distal end of upper spoke, with the kink marked by arrow. (K) Close-up of apical organ in (I); dark, equally spaced bands (arrowheads) radiating from the base of apical organ may represent remains of underlying meridional canals. (L) Close-up of apical organ showing considerable positive relief, presumably due to its rigidity imparted by apical plates (numbered). ao, apical organ; cr, comb row; fp, flap-like structure; ls, lower spoke; ol, oral lappet; os, oral skirt; pl, apical plate; sl, statolith; us, upper spoke. Scale bars, 5 mm (A, D, H, and I); 2 mm (C, F, and G); 1 mm (B, E, and J to L).

Gemmactena actinala gen. et sp. nov. (A) Holotype (ELEL-SJ100756A) showing radiating flap-like structures outlined by spokes, comb rows, and oral lappets. Apical organ not preserved. (B) Close-up of small focus area in (A) showing fine striae on spoke surface. (C) Close-up of large focus area in (A) showing remains of comb rows, as well as upper and lower spokes that frame a flap. (D) Paratype (ELEL-SJ081292A). (E) Close-up of focus area in (D) showing rigidity of a spoke with a medial groove (internal view). (F) Close-up of aboral region in (D) showing an ellipsoidal statolith preserved as dark remains surrounded by apical plates. (G) Counterpart of (F) showing complete apical plates detached from each other; remains of organic carbon are partially preserved as a dark band on the statolith. (H) Paratype (ELEL-SJ081366A) showing pointed dome-like apical organ walled by rigid plates (each with a medial groove continuous with a spoke). (I) Aborally compacted specimen ELEL-SJ120375A showing an apical organ and partially dislocated upper spokes (arrows). The apex of the apical organ was truncated and retained in counterpart during splitting. (J) Close-up of focus area in (I) showing distal end of upper spoke, with the kink marked by arrow. (K) Close-up of apical organ in (I); dark, equally spaced bands (arrowheads) radiating from the base of apical organ may represent remains of underlying meridional canals. (L) Close-up of apical organ showing considerable positive relief, presumably due to its rigidity imparted by apical plates (numbered). ao, apical organ; cr, comb row; fp, flap-like structure; ls, lower spoke; ol, oral lappet; os, oral skirt; pl, apical plate; sl, statolith; us, upper spoke. Scale bars, 5 mm (A, D, H, and I); 2 mm (C, F, and G); 1 mm (B, E, and J to L).

Wendiceratops: Horned Dinosaur Evolutionary Tale

Paleontologists say a dinosaur from 79 million years ago, known as Wendiceratops pinhornensis, could help them hook into the mysteries of how horned dinosaurs evolved.

The species’ somewhat whimsical name is inspired by the place where its fossilized bones were found (the Pinhorn Provincial Grazing Reserve in Alberta) and the person who found them (Canadian fossil hunter Wendy Sloboda) in 2010. But the lessons learned from the more than 200 bones recovered from the site are anything but whimsical.

The picture that emerges is of a 1-ton, 20-foot-long (6-meter-long) dinosaur that had a pair of horns sticking up from its brow, plus another horn on the nose. It also had a weird frill with hornlets that curled forward on themselves like hooks — which is apt for a dinosaur whose name evokes J.M. Barrie’s classic tale of Wendy, Peter Pan and Captain Hook.

Skeletal reconstruction of Wendiceratops pinhornensis gen. et sp. nov.  Elements represented in the material collected from the bonebed are indicated in blue.

Skeletal reconstruction of Wendiceratops pinhornensis gen. et sp. nov.
Elements represented in the material collected from the bonebed are indicated in blue.

That combination of characteristics hasn’t been seen in other species of that time and place — and it hints at a surprising level of diversity among horned dinosaurs, said Michael Ryan, a paleontologist at the Cleveland Museum of Natural History.

The variations in skull ornamentation suggest that the way horned dinosaurs used their heads played a big role in how they evolved. “That’s where all the evolution is happening in these animals,” Ryan said.

Life reconstruction of Wendiceratops pinhornensis gen. et sp. nov.  Illustration by Danielle Dufault.

Life reconstruction of Wendiceratops pinhornensis gen. et sp. nov.
Illustration by Danielle Dufault.

Ryan and David Evans of the Royal Ontario Museum lay out the implications in a paper published Wednesday by the open-access journal PLOS ONE.

They say Wendiceratops appears to have been one of the first dinosaurs in its evolutionary line to have a prominent nasal horn. That suggests that such horns arose separately for two different branches of the dinosaur evolutionary tree — for the branch that includes Wendiceratops, and for the branch that includes the best-known horned dinosaur, Triceratops.

What’s more, Wendiceratops’ hooklike hornlets are similar to the frill ornaments seen in Sinoceratops, a Chinese horned dinosaur that lived about 72 million years ago. That suggests that Wendiceratops’ descendants may have migrated back from the Americas to Asia, Ryan said.

He said the different twists in the skulls of horned dinosaurs probably had to do with sexual signaling and head-butting competitions between the males of the species — analogous to what Bighorn sheep do today.

Whatever the reason, horned dinosaurs appear to have evolved more quickly than the norm for the Cretaceous Period. Ryan said vertebrate species usually arose, had their day and went extinct over a span of 2 million to 4 million years. “We’re finding that these horned dinosaurs replaced each other every half-million years,” he said.

There could be a lesson in that for modern times. Ryan noted that the era when Wendiceratops lived was marked by environmental change in North America, including warmer temperatures and the rise of the Western Interior Seaway.

“Maybe the rapid evolution we’re looking at is related to climate change,” Ryan said.

Ref: Evans DC, Ryan MJ (2015) Cranial Anatomy of Wendiceratops pinhornensis gen. et sp. nov., a Centrosaurine Ceratopsid (Dinosauria: Ornithischia) from the Oldman Formation (Campanian), Alberta, Canada, and the Evolution of Ceratopsid Nasal Ornamentation. PLoS ONE 10(7): e0130007. doi:10.1371/journal.pone.0130007

Editor: Peter Dodson, University of Pennsylvania, UNITED STATES

Great Karoo rocks reveals mass extinction

An international team led by researchers from the Evolutionary Studies Institute (ESI) at the University of the Witwatersrand, Johannesburg, has obtained an age from rocks of the Great Karoo that shed light on the timing of a mass extinction event that occurred around 260 million years ago.

WFS : Great Karoo ,South Africa

WFS : Great Karoo ,South Africa

This led to the disappearance of a diverse group of early mammal-like reptiles called dinocephalians, which were the largest land-living animals of the time.

The project was led by Dr Michael Day, a postdoctoral fellow at Wits University, and the findings are contained in paper, titled: When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa, published today, 8 July 2015, in the latest issue of the Royal Society’s biological journal, Proceedings of the Royal Society B.

This is an illustration of the Guadalupian extinction. Credit: Wits University

This is an illustration of the Guadalupian extinction.
Credit: Wits University

The Karoo is very rich in fossils of terrestrial animals from the Permian and Triassic geological periods, which makes it one of the few places to study extinction events on land during this time. As a result South Africa’s Karoo region provides not only a historical record of biological change over a period of Earth’s history but also a means to test theories of evolutionary processes over long stretches of time.

By collecting fossils in the Eastern, Western and Northern Cape Provinces the team was able to show that around 74-80% of species became extinct along with the dinocephalians in a geologically short period of time.

The new date was obtained by high precision analyses of the relative abundance of uranium and lead in small zircon crystals from a volcanic ash layer close to this extinction horizon in the Karoo.

This provides a means of linking the South African fossil record with the fossil record in the rest of the world. In particular, it helps correlate the Karoo with the global marine record, which also records an extinction event around 260 million years ago.

“A mid-Permian extinction event on land has been known for some time but was suspected to have occurred earlier than those in the marine realm. The new date suggests that one event may have affected marine and terrestrial environments at the same time, which could mean its impact was greater than we thought,” says Day.

The mid-Permian extinction occurred near the end of what geologists call the Guadalupian epoch that extended from 272.3 to around 259.1 million years ago. It pre-dated the massive and much more famous end-Permian mass extinction event by 8 million years.

“The South African Karoo rocks host the richest record of middle Permian land-living vertebrate animals. This dataset, the culmination of 30 years of fossil collecting and diligent stratigraphic recording of the information, for the first time provides robust fossil and radioisotopic data to support the occurrence of this extinction event on land,” says Day.

“The exact age of the marine extinctions remains uncertain,” says Jahandar Ramezani of Massachusetts Institute of Technology and who was responsible for dating the rocks, “but this new date from terrestrial deposits of the Karoo, supported by palaeontological evidence, represents an important step towards a better understanding of the mid-Permian extinction and its effect on terrestrial faunas.”

REF: Michael O. Day, Jahandar Ramezani, Samuel A. Bowring, Peter M. Sadler, Douglas H. Erwin, Fernando Abdala, Bruce S. Rubidge. When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa. Proceedings of the Royal Society B, Courtesy:ScienceDaily, 7 July 2015.

Ground-based atomic clocks for monitoring volcanoes

An international team led by scientists from the University of Zurich finds that high-precision atomic clocks can be used to monitoring volcanoes and potentially improve predictions of future eruptions. In addition, a ground-based network of atomic clocks could monitor the reaction of Earth’s crust to solid Earth tides.

Atomic clocks measure time with unbelievable accuracy. The best atomic clocks are so precise that they would lose less than one second over a period of 10 billion years. However, they are generally only used in laboratories. Science and industry have yet to take full advantage of their unprecedented ability to measure time. An international team including Dr. Ruxandra Bondarescu, Andreas Schärer and Prof. Philippe Jetzer from the Institute of Physics from the University of Zurich discusses potential applications for atomic clocks.

Subterranean objects influence the tick rate of local clocks that are located above the Earth’s surface. New lava filling a magma chamber beneath a volcano makes a clock located above that volcano tick more slowly than a clock that is located further away.

Subterranean objects influence the tick rate of local clocks that are located above the Earth’s surface. New lava filling a magma chamber beneath a volcano makes a clock located above that volcano tick more slowly than a clock that is located further away.

Their analysis shows that the slow down of time predicted by general relativity can be measured by local clocks and used to monitor volcanoes. General relativity states that clocks positioned at different distances from a massive body like Earth have different tick rates. The closer a clock is to a massive object, the slower it ticks. In a similar manner, subterranean objects influence the tick rate of local clocks that are located above Earth’s surface. New lava filling a magma chamber beneath a volcano makes a clock located above that volcano tick more slowly than a clock that is located further away. Volcanoes are currently monitored using GPS receivers. The resulting data often has to be integrated over a period of several years before an estimate of the volume of new magma can be made. A network of local, highly precise atomic clocks may provide the same information within a few hours. This would make it possible to monitor processes inside volcanoes more closely and to make better predictions for future volcanic eruptions.

Monitoring the solid Earth tides with a global network of atomic clocks

Atomic clocks can also be used to monitor the solid Earth tides. Tides occur because Earth moves in the gravitational field of the Sun and the Moon. It reacts to this outer field by deforming, which in turn leads to ocean tides and to the ground on the continents lifting and falling regularly. The ground can rise as much as 50 cm. A global network of atomic clocks that are connected via fiber optic cables used for internet, could provide continuous measurements of Earth tides and check existing theoretical models. It would also be possible to examine any local differences in the response of Earth’s crust to Earth tides.

The researchers hope that high precision clocks could be deployed in volcanic areas in the next few years. This is, however, subject to sufficient interest and investment from industry. “We need this additional tool to monitor magma movement under volcanoes such as the Yellowstone supervolcano, which is overdue for an explosion that would alter life on Earth as we known it,” explains Bondarescu.

REf: Ruxandra Bondarescu, Andreas Schärer, Andrew P. Lundgren, György Hetényi, Nicolas Houlié, Philippe Jetzer, and Mihai Bondarescu. Atomic Clocks as a Tool to Monitor Vertical Surface Motion. Geophysical Journal International, June 2015


A New Eocene Casquehead Lizard from North America

A new fossil showing affinities with extant Laemanctus offers the first clear evidence for a casquehead lizard (Corytophanidae) from the Eocene of North America. Along with Geiseltaliellus from roughly coeval rocks in central Europe, the new find further documents the tropical fauna present during greenhouse conditions in the northern mid-latitudes approximately 50 million years ago (Ma). Modern Corytophanidae is a neotropical clade of iguanian lizards ranging from southern Mexico to northern South America.

Citation: Conrad JL (2015) A New Eocene Casquehead Lizard (Reptilia, Corytophanidae) from North America. PLoS ONE 10(7): e0127900. doi:10.1371/journal.pone.0127900

Academic Editor: Ulrich Joger, State Natural History Museum, GERMANY

 

 

Photographs (A-C) and line drawings (D-F) of the skulls of selected corytophanid species in left lateral view.  (A) Corytophanes cristatus (AMNH R 16390), (B) Laemanctus serratus (photograph; AMNH R 44982), (C) Basiliscus vittatus (AMNH R 147832), (D) Laemanctus serratus (line drawing), (E) Geiseltaliellus maarius, and (F) Babibasiliscus alxi taxon nov. (UWBM 89090). Note that it is unclear whether Babibasiliscus alxi taxon nov. had a parietal crest. Reconstructed areas are represented as semi-opaque areas and/or dotted lines. Scale bars equal 10mm.  doi:10.1371/journal.pone.0127900.g005

Photographs (A-C) and line drawings (D-F) of the skulls of selected corytophanid species in left lateral view.
(A) Corytophanes cristatus (AMNH R 16390), (B) Laemanctus serratus (photograph; AMNH R 44982), (C) Basiliscus vittatus (AMNH R 147832), (D) Laemanctus serratus (line drawing), (E) Geiseltaliellus maarius, and (F) Babibasiliscus alxi taxon nov. (UWBM 89090). Note that it is unclear whether Babibasiliscus alxi taxon nov. had a parietal crest. Reconstructed areas are represented as semi-opaque areas and/or dotted lines. Scale bars equal 10mm.
doi:10.1371/journal.pone.0127900.g005

 

 

Holotype (UWBM 89090) specimen for Babibasiliscus alxi nov. taxon.  Photographs in (A) right lateral, (B) dorsal, and (C) ventral views. Digital reconstructions derived from HRXCT in (D) left lateral view and (E) transverse section. The vertical red line in (D) indicates the plane of section in (E).  doi:10.1371/journal.pone.0127900.g001

Holotype (UWBM 89090) specimen for Babibasiliscus alxi nov. taxon.
Photographs in (A) right lateral, (B) dorsal, and (C) ventral views. Digital reconstructions derived from HRXCT in (D) left lateral view and (E) transverse section. The vertical red line in (D) indicates the plane of section in (E).
doi:10.1371/journal.pone.0127900.g001

Helium leakage from Earth’s mantle ?

UC Santa Barbara geologist Jim Boles has found evidence of helium leakage from Earth’s mantle along a 30-mile stretch of the Newport-Inglewood Fault Zone in the Los Angeles Basin. Using samples of casing gas from two dozen oil wells ranging from LA’s Westside to Newport Beach in Orange County, Boles discovered that more than one-third of the sites — some of the deepest ones — show evidence of high levels of helium-3 (3He).

Considered primordial, 3He is a vestige of the Big Bang. Its only terrestrial source is the mantle. Leakage of 3He suggests that the Newport-Inglewood fault is deeper than scientists previously thought. Boles’s findings appear in Geochemistry, Geophysics, Geosystems (G-Cubed), an electronic journal of the American Geophysical Union and the Geochemical Society.

The Newport-Inglewood fault was responsible for the 4.9 magnitude Inglewood earthquake in 1920 and the 6.4 magnitude Long Beach earthquake in 1933. Credit: Sonia Fernandez

The Newport-Inglewood fault was responsible for the 4.9 magnitude Inglewood earthquake in 1920 and the 6.4 magnitude Long Beach earthquake in 1933.
Credit: Sonia Fernandez

“The results are unexpected for the area, because the LA Basin is different from where most mantle helium anomalies occur,” said Boles, professor emeritus in UCSB’s Department of Earth Science. “The Newport-Inglewood fault appears to sit on a 30-million-year-old subduction zone, so it is surprising that it maintains a significant pathway through the crust.”

When Boles and his co-authors analyzed the 24 gas samples, they found that high levels of 3He inversely correlate with carbon dioxide (CO2), which Boles noted acts as a carrier gas for 3He. An analysis showed that the CO2 was also from the mantle, confirming leakage from deep inside Earth.

Blueschist found at the bottom of nearby deep wells indicates that the Newport-Inglewood fault is an ancient subduction zone — where two tectonic plates collide — even though its location is more than 40 miles west of the current plate boundary of the San Andreas Fault System. Found 20 miles down, blueschist is a metamorphic rock only revealed when regurgitated to the surface via geologic upheaval.

“About 30 million years ago, the Pacific plate was colliding with the North American plate, which created a subduction zone at the Newport-Inglewood fault,” Boles explained. “Then somehow that intersection jumped clear over to the present San Andreas Fault, although how this occurred is really not known. This paper shows that the mantle is leaking more at the Newport-Inglewood fault zone than at the San Andreas Fault, which is a new discovery.”

The study’s findings contradict a scientific hypothesis that supports the existence of a major décollement — a low-angle thrust fault — below the surface of the LA Basin. “We show that the Newport-Inglewood fault is not only deep-seated but also directly or indirectly connected with the mantle,” Boles said.

“If the décollement existed, it would have to cross the Newport-Inglewood fault zone, which isn’t likely,” he added. “Our findings indicate that the Newport-Inglewood fault is a lot more important than previously thought, but time will tell what the true importance of all this is.”

Study co-authors include Grant Garven of Tufts University; Hilario Camacho of Occidental Oil and Gas Corp.; and John Lupton of the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory.

This research was supported by the U.S. Department of Energy’s Office of Science and Office of Basic Energy Sciences and by the NOAA Pacific Marine Environmental Laboratory.

Courtesy: University of California – Santa Barbara. “Helium leakage from Earth’s mantle in Los Angeles Basin: New discoveries about Newport-Inglewood Fault Zone in Los Angeles Basin.” ScienceDaily. ScienceDaily, 29 June 2015.


Sefapanosaurus — SA’s new Sesotho dinosaur.

South African and Argentinian palaeontologists have discovered a new 200-million-year-old dinosaur from South Africa, and named it Sefapanosaurus, from the Sesotho word “sefapano.”

The researchers from South Africa’s University of Cape Town (UCT) and the University of the Witwatersrand (Wits University), and from the Argentinian Museo de La Plata and Museo Paleontológico Egidio Feruglio made the announcement in the scientific journal Zoological Journal of the Linnaean Society. The paper, titled: “A new basal sauropodiform from South Africa and the phylogenetic relationships of basal sauropodomorphs,” was published online on Tuesday, 23 June 2015.

Sefapanosaurus -- SA's new Sesotho dinosaur. Credit: Image courtesy of University of the Witwatersrand

Sefapanosaurus — SA’s new Sesotho dinosaur.
Credit: Image courtesy of University of the Witwatersrand

The specimen was found in the late 1930s in the Zastron area of South Africa’s Free State province, about 30km from the Lesotho border. For many years it remained hidden among the largest fossil collection in South Africa at the Evolutionary Studies Institute (ESI) at Wits University.

A few years ago it was studied and considered to represent the remains of another South African dinosaur, Aardonyx. However, upon further study, close scrutiny of the fossilised bones has revealed that it is a completely new dinosaur.

One of the most distinctive features is that one of its ankle bones, the astragalus, is shaped like a cross. Considering the area where the fossil was discovered, the researchers aptly named the new dinosaur, Sefapanosaurus, after the Sesotho word “sefapano,” meaning “cross.”

Anusuya Chinsamy-Turan, co-author and Professor in the Department of Biological Sciences at UCT, says: “The discovery of Sefapanosaurus shows that there were several of these transitional early sauropodomorph dinosaurs roaming around southern Africa about 200 million years ago.”

Dr Alejandro Otero, Argentinian palaeontologist and lead author, says Sefapanosaurus helps to fill the gap between the earliest sauropodomorphs and the gigantic sauropods. “Sefapanosaurus constitutes a member of the growing list of transitional sauropodomorph dinosaurs from Argentina and South Africa that are increasingly telling us about how they diversified.”

Says Dr Jonah Choiniere, co-author and Senior Researcher in Dinosaur Palaeobiology at the ESI at Wits University: “This new animal shines a spotlight on southern Africa and shows us just how much more we have to learn about the ecosystems of the past, even here in our own ‘backyard’. And it also gives us hope that this is the start of many such collaborative palaeo-research projects between South Africa and Argentina that could yield more such remarkable discoveries.”

Argentinian co-author, Dr Diego Pol, says Sefapanosaurus and other recent dinosaur discoveries in the two countries reveal that the diversity of herbivorous dinosaurs in Africa and South America was remarkably high back in the Jurassic, about 190 million years ago when the southern hemisphere continents were a single supercontinent known as Gondwana.

Finding a new dinosaur among old bones

Otero and Emil Krupandan, PhD-student from UCT, were visiting the ESI collections to look at early sauropodomorph dinosaurs when they noticed bones that were distinctive from the other dinosaurs they were studying.

Krupandan was working on a dinosaur from Lesotho as part of his studies when he realised the material he was looking at was different to Aardonyx. “This find indicates the importance of relooking at old material that has only been cursorily studied in the past, in order to re-evaluate past preconceptions about sauropodomorph diversity in light of new data.”

The remains of the Sefapanosaurus include limb bones, foot bones, and several vertebrae. Sefapanosaurus is represented by the remains of at least four individuals in the ESI collections at Wits University. It is considered to be a medium-sized sauropodomorph dinosaur — among the early members of the group that gave rise to the later long necked giants of the Mesozoic.

  1. Alejandro Otero, Emil Krupandan, Diego Pol, Anusuya Chinsamy, Jonah Choiniere. A new basal sauropodiform from South Africa and the phylogenetic relationships of basal sauropodomorphs. Zoological Journal of the Linnean Society, 2015; 174 (3): 589 DOI: 10.1111/zoj.12247