Biggest ever Swiss dinosaur skeleton discovered


This video is called My Plateosaurus Tribute + my favorite Plateosaurus Pictures!

From swissinfo in Switzerland:

Triassic park: oldest Swiss dinosaur skeleton found

July 1, 2015 – 18:55

The largest dinosaur skeleton ever found in Switzerland has been uncovered in a clay pit in northern Switzerland. The eight-metre skeleton of a plateosaurus is thought to have been around 25 years old when it died.

“This herbivore lived 210 million years ago and was discovered in the Upper Triassic geologic layer,” said Ben Pabst, who has been leader of the dig in Frick, canton Aargau, since 1976. The dinosaur’s head has yet to be found.

Plateosaurus was a bipedal herbivore with a small skull on a long, mobile neck, sharp but plump plant-crushing teeth, powerful hind limbs, short but muscular arms and grasping hands with large claws on three fingers, possibly used for defence and feeding.

Unusually for a dinosaur, instead of having a fairly uniform adult size, fully grown individuals ranged from 4.8-10 metres long and weighed 600-4,000 kilograms.

The site in Frick is known around the world for the density of dinosaur skeletons.

“We have here an unbelievably large site. So far we have been able to determine an area with a diameter of three kilometres,” Pabst explained on Wednesday, adding that one hectare will yield some 500 animals and that for every 100 herbivore dinosaurs there is one carnivore.

Museum

Around 210 million years ago, Frick was flat, very hot, tropical and criss-crossed with rivers. Pabst assumes that at various times a range of dinosaurs, which weighed several tons, got stuck in the boggy land and died of thirst.

Since many complete skeletons of legs have been found, he believes the animals were mummified by the heat.

The theory that the dinosaurs sank in mud was strengthened by the fact that the plateosaurus in question was found with its legs spread.

The Frick site has an annual budget of CHF50,000 ($52,800) and the work is heavily reliant on volunteers. The latest find is too big for the Frick dinosaur museum, so a renovation is being considered.

Triassic turtle evolution, new research


This video says about itself:

Evolution of the Turtle Shell (Illustrated)

30 May 2013

Evolution of the turtle shell based on developmental and fossil data. This animation is based on the work of Dr. Tyler Lyson, currently at the Smithsonian Institution.

The animation shows how various fossils, particularly Eunotosaurus and Odontochelys, bridge the morphological gap between a generalized animal body plan to the highly modified body plan found in living turtles.

The paper, published in Current Biology, can be found here.

Animation by Stroma Studios.

From the Washington Post in the USA:

How the turtle got its shell, a not-so ‘Just So’ story

By Sarah Kaplan

June 25 at 5:22 AM

Long, long ago, in a time so far in the past it preceded the dinosaurs and the continents, lived a tiny creature named “grandfather turtle.” It had many of the qualities of the turtles we know and love today: a boxy body, plodding legs, a long neck topped by a small, round head.

It was only missing one thing: a shell.

Thanks to the newly discovered fossil of that tiny creature, scientists say they have solved the story of how the turtle got its shell. But this is no Rudyard Kipling fable. It’s science.

The not-so “Just So” story, published in the journal Nature on Wednesday, tracks the evolution of the turtle body plan through millions of years of history. By examining fossils that spanned millennia and continents, researchers were able to figure out how the modern turtle’s unique shell evolved from what was just a brief expanse of belly bones about 240 million years ago.

The origin of the turtle shell has long bewildered scientists (this was, apparently, the one natural phenomenon Kipling hadn’t written a story to explain). Though they had fossils of turtle predecessors from the beginning and the end of the Triassic period, there was little evidence of what happened to ancient turtles during the intervening years. The bones of the 260 million-year-old Eunotosaurus, a reptilian creature found in South Africa, had wide, flat ribs and a sprawling, turtle-like figure, but it was far from the armor-encased animal we know today.

The next time a turtle ancestor popped up in the fossil record, the Odontochelys about 220 million years before present, it had a fully developed belly plate called a “plastron” that would eventually expand to enclose the turtle’s whole body, protecting it from attacks from above and below. (The first turtle with a true shell wouldn’t appear on the scene until about 6 million years after that.)

But there was nothing in the yawning 40 million-year void between the two ancient species to explain where that plastron came from.

“Hopefully we’ll find more,” Robert Reisz, a paleontologist at the University of Toronto, told National Geographic after the Odontochelys was first found in 2008. “We’re closing the gap, but there is still a big morphological gap between this turtle and its non-turtle ancestors.”

Enter Pappochelys, the hero of our story, ready and willing to fill that gap.

Pappochelys, whose name means “grandfather turtle,” lived about 240 million years ago in a warm sub-tropical lake, Hans-Dieter Sues, a co-author of the Nature study and curator at the Smithsonian Museum of Natural History in D.C., told NPR. Discovered in a limestone quarry near Stuttgart, Germany, it is the precise chronological and morphological midpoint between the two previously known fossils: about eight inches from tip to tail, it had slender legs and an oddly boxy body with a rib cage that looked like the beginnings of a “little bony house.”

This physiological setup was good for protection and also worked as “bone ballast,” according to Smithsonian, allowing the animal to control its buoyancy in the water.

In addition, the Pappochelys had a series of hard, shell-like bones lining its belly — the beginnings of the plastron that would turn up 20 million years later.

“It has real beginnings of the belly shell developing, little rib-like structures beginning to fuse together into larger plates and then ultimately making up the belly shell,” Sues told NPR.

Sues’s co-author, Rainer R. Schoch, a paleontologist at the Staatliches Museum für Naturkunde in Stuttgart, called Pappochelys a “transitional creature,” one that illustrates how ancient lizards became modern turtles.

“Transitional creatures are the most important contribution that paleontology can make to the study of evolution,” Schoch told Voice of America. “They are often unexpected and show surprising features.”

And, in Pappochelys case, they tell pretty good stories.

Triassic dinosaurs avoided the tropics


This video from the USA says about itself:

15 January 2009

A team of paleontologists from the University of California, Berkeley, the American Museum of Natural History and The Field Museum discovered fossils in northern New Mexico that show for the first time that dinosaurs coexisted with their non-dinosaur ancestors for tens of millions of years towards the end of the Triassic Period. This discovery, made at the Hayden Quarry in Ghost Ranch, New Mexico, disproves previous notions that dinosaurs rapidly replaced their supposedly outmoded predecessors.

From the National Science Foundation in the USA:

Big dinosaurs steered clear of the tropics

Climate swings lasting millions of years too much for dinos

June 15, 2015

For more than 30 million years after dinosaurs first appeared, they remained inexplicably rare near the equator, where only a few small-bodied meat-eating dinosaurs made a living.

The long absence at low latitudes has been one of the great, unanswered questions about the rise of the dinosaurs.

Now the mystery has a solution, according to scientists who pieced together a detailed picture of the climate and ecology more than 200 million years ago at Ghost Ranch in northern New Mexico, a site rich with fossils.

The findings, reported today in the journal Proceedings of the National Academy of Sciences (PNAS), show that the tropical climate swung wildly with extremes of drought and intense heat.

Wildfires swept the landscape during arid regimes and reshaped the vegetation available for plant-eating animals.

“Our data suggest it was not a fun place,” says scientist Randall Irmis of the University of Utah.

“It was a time of climate extremes that went back and forth unpredictably. Large, warm-blooded dinosaurian herbivores weren’t able to exist close to the equator–there was not enough dependable plant food.”

The study, led by geochemist Jessica Whiteside, now of the University of Southampton, is the first to provide a detailed look at climate and ecology during the emergence of the dinosaurs.

Atmospheric carbon dioxide levels then were four to six times current levels. “If we continue along our present course, similar conditions in a high-CO2 world may develop, and suppress low-latitude ecosystems,” Irmis says.

“These scientists have developed a new explanation for the perplexing near-absence of dinosaurs in late Triassic [the Triassic was between 252 million and 201 million years ago] equatorial settings,” says Rich Lane, program director in the National Science Foundation’s (NSF) Division of Earth Sciences, which funded the research.

“That includes rapid vegetation changes related to climate fluctuations between arid and moist climates and the resulting extensive wildfires of the time.”

Reconstructing the deep past

The earliest known dinosaur fossils, found in Argentina, date from around 230 million years ago.

Within 15 million years, species with different diets and body sizes had evolved and were abundant except in tropical latitudes. There the only dinosaurs were small carnivores. The pattern persisted for 30 million years after the first dinosaurs appeared.

The scientists focused on Chinle Formation rocks, which were deposited by rivers and streams between 205 and 215 million years ago at Ghost Ranch (perhaps better known as the place where artist Georgia O’Keeffe lived and painted for much of her career).

The multi-colored rocks of the Chinle Formation are a common sight on the Colorado Plateau at places such as the Painted Desert at Petrified Forest National Park in Arizona.

In ancient times, North America and other land masses were bound together in the supercontinent Pangea. The Ghost Ranch site stood close to the equator, at roughly the same latitude as present-day southern India.

The researchers reconstructed the deep past by analyzing several kinds of data: from fossils, charcoal left by ancient wildfires, stable isotopes from organic matter, and carbonate nodules that formed in ancient soils.

Fossilized bones, pollen grains and fern spores revealed the types of animals and plants living at different times, marked by layers of sediment.

Dinosaurs remained rare among the fossils, accounting for less than 15 percent of vertebrate animal remains.

They were outnumbered in diversity, abundance and body size by reptiles known as pseudosuchian archosaurs, the lineage that gave rise to crocodiles and alligators.

The sparse dinosaurs consisted mostly of small, carnivorous theropods.

Big, long-necked dinosaurs, or sauropodomorphs–already the dominant plant-eaters at higher latitudes–did not exist at the study site nor any other low-latitude site in the Pangaea of that time, as far as the fossil record shows.

Abrupt changes in climate left a record in the abundance of different types of pollen and fern spores between sediment layers.

Fossilized organic matter from decaying plants provided another window on climate shifts. Changes in the ratio of stable isotopes of carbon in the organic matter bookmarked times when plant productivity declined during extended droughts.

Drought and fire

Wildfire temperatures varied drastically, the researchers found, consistent with a fluctuating environment in which the amount of combustible plant matter rose and fell over time.

The researchers estimated the intensity of wildfires using bits of charcoal recovered in sediment layers.

The overall picture is that of a climate punctuated by extreme shifts in precipitation and in which plant die-offs fueled hotter fires. That in turn killed more plants, damaged soils and increased erosion.

Atmospheric carbon dioxide levels, calculated from stable isotope analyses of soil carbonate and preserved organic matter, rose from about 1,200 parts per million (ppm) at the base of the section, to about 2,400 ppm near the top.

At these high CO2 concentrations, climate models predict more frequent and more extreme weather fluctuations consistent with the fossil and charcoal evidence.

Continuing shifts between extremes of dry and wet likely prevented the establishment of the dinosaur-dominated communities found in the fossil record at higher latitudes across South America, Europe, and southern Africa, where aridity and temperatures were less extreme and humidity was consistently higher.

Resource-limited conditions could not support a diverse community of fast-growing, warm-blooded, large dinosaurs, which require a productive and stable environment to thrive.

“The conditions would have been something similar to the arid western United States today, although there would have been trees and smaller plants near streams and rivers, and forests during humid times,” says Whiteside.

“The fluctuating and harsh climate with widespread wildfires meant that only small two-legged carnivorous dinosaurs could survive.”

Dinosaurs and their exaggerated structures: species recognition aids, or sexual display devices? Here.

Mid-Permian extinction of animals, new study


This 2013 video says about itself:

Animal Armageddon The Great Dying – Episode 5

The Permian-Triassic extinction event, informally known as the Great Dying, was an extinction event that occurred 252 million years ago, forming the boundary between the Permian and Triassic geologic periods, as well as the Paleozoic and Mesozoic eras. It is the Earth’s most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects. Some 57% of all families and 83% of all genera became extinct. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after any other extinction event, possibly up to 10 million years.

Researchers have variously suggested that there were from one to three distinct pulses, or phases, of extinction. There are several proposed mechanisms for the extinctions; the earlier phase was likely due to gradual environmental change, while the latter phase has been argued to be due to a catastrophic event. Suggested mechanisms for the latter include large or multiple impact events, increased volcanism, coal/gas fires and explosions from the Siberian Traps, and sudden release of methane from the sea floor; gradual changes include sea-level change, increasing aridity, and a shift in ocean circulation driven by climate change.

From the Geological Society of America:

15 April 2015

New evidence adds the Capitanian extinction to the list of major extinction crises

Boulder, Colo., USA – Since the Cambrian Explosion, ecosystems have suffered repeated mass extinctions, with the “Big 5″ crises being the most prominent. Twenty years ago, a sixth major extinction was recognized in the Middle Permian (262 million years ago) of China, when paleontologists teased apart losses from the “Great Dying” at the end of the period. Until now, this Capitanian extinction was known only from equatorial settings, and its status as a global crisis was controversial.

David P.G. Bond and colleagues provide the first evidence for severe Middle Permian losses amongst brachiopods in northern paleolatitudes (Spitsbergen). Their study shows that the Boreal crisis coincided with an intensification of marine oxygen depletion, implicating this killer in the extinction scenario.

The widespread loss of carbonates across the Boreal Realm also suggests a role for acidification. The new data cements the Middle Permian crisis’s status as a true “mass extinction.” Thus the “Big 5″ extinctions should now be considered the “Big 6.”

An abrupt extinction in the Middle Permian (Capitanian) of the Boreal Realm (Spitsbergen) and its link to anoxia and acidification: David P.G. Bond et al., University of Hull, Hull, UK. Published online ahead of print on 14 Apr. 2015; http://dx.doi.org/10.1130/B31216.1. This article is OPEN ACCESS (available for free online).

Big Triassic amphibian fossil discovery in Portugal


This video says about itself:

24 March 2015

Excavation in Portugal of giant Triassic fossil amphibian Metoposaurus algarvensis – Paleontology dig.

From Associated Press:

Researchers Find Fossil of ‘Super Salamander’ Species

LONDON — Mar 24, 2015, 11:01 AM ET

Fossil remains of a previously unknown species of a crocodile-like “super salamander” that grew as long as a small car and was a top predator more than 200 million years ago have been found in southern Portugal, researchers announced Tuesday.

The species grew up to two meters (six feet) in length and lived in lakes and rivers, University of Edinburgh researchers said.

The team said the species, given the name Metoposaurus algarvensis, was part of a wider group of primitive amphibians that were widespread at the time but became extinct. They are the ancestors of modern amphibians such as frogs, and are believed by paleontologists to have lived at the same time the dinosaurs began their dominance.

Steve Brusatte of the University of Edinburgh’s School of GeoSciences, who led the study, said the new species, which had hundreds of sharp teeth, is “weird compared to anything today.”

It was at the top of the food chain, feeding mainly on fish, but it was also a danger for newly appeared dinosaurs and mammals that strayed too near the water, Brusatte said.

The team says the find establishes that this group of amphibians lived in a more diverse geographic area than had been thought.

Andrew Milner, an expert on early amphibians at the Natural History Museum in London who was not involved in the study, said the find “is another piece of the picture.” The Portuguese site has “very good potential to give us more and different types of animal” from the Upper Triassic period, he added.

The dig in Portugal began in 2009 and took several years. The “super salamander” bones were uncovered in a half-meter thick layer of rock in a hillside that is “chock-full” of bones, Brusatte said. The team hopes to raise funds to continue excavating the site.

See also here.

The scientific description of this newly discovered species is here.

Pre-dinosaur carnivorous reptile discovery in Tanzania


This 2010 video says about itself:

Just testing out some software that records cursor movements. This is a Photoshop sketch of an extinct archosaur called a rauisuchian. They were related to crocodilians and distant cousins of the dinosaurs.

From Science, Space & Robots:

Partial Skel[e]ton of Ancient Croc-like Predator Species Discovered

Nundasuchus was a 9-foot long predator croc-like species that lived before the dinosaurs. It had steak knife-teeth and bony plates on its back. A partial skeleton of the species was discovered in 2007.

Nundasuchus songeaensis was named by Sterling Nesbitt, an assistant professor of geological sciences and member of the Virginia Tech paleontology team. Nesbitt says the name is “Swahili mixed with Greek.” Nunda means predator in Swahili and suchus refers to a crocodile in Greek. Songeaensis is named for the town of Songea where the creature’s bones were discovered.

Nesbitt says in a statement, “The reptile itself was heavy-bodied with limbs under its body like a dinosaur, or bird, but with bony plates on its back like a crocodilian.”

The fossil of Nundasuchus was found in southwestern Tanzania. The bones were in thousands of pieces and Nesbitt says over 1,000 hours were spent cleaning them and putting them together.

Nesbitt also says, “There’s such a huge gap in our understanding around the time when the common ancestor of birds and crocodilians was alive – there isn’t a lot out there in the fossil record from that part of the reptile family tree. This helps us fill in some gaps in the reptile family tree, but we’re still studying it and figuring out the implications.”

A research paper on the reptile can be found here in the Journal of Vertebrate Paleontology.

Posted on January 20, 2015

Triassic fossil reptile discovery in Dutch museum


This video says about itself:

21 March 2013

An overview of reptiles found in Triassic marine ecosystems.

Translated from daily De Gelderlander in the Netherlands:

Prehistoric marine reptile from Winterswijk ‘discovered’

January 9, 2015

ENSCHEDE WINTERSWIJK – Researchers from the Universities of Bonn and Zurich have recently ‘discovered’ a placodont in the collection of Museum TwentseWelle. The remains of the marine reptile were found in the late 1980’s in the quarry in Winterswijk by Gerben Diepenbroek from Varsseveld.

Diepenbroek gave his collection in 2008 to the museum in Enschede. Since then the collection is a subject of investigation by various universities in Europe.

According to Dennis Nieweg, nature department curator of TwentseWelle, it is a very special discovery. “Worldwide but a few placodonts are known.”

245 million years

The placodont is a marine reptile that lived some 245 million years ago in shallow waters, ”grazing’ seabeds looking for small animals such as sea urchins and crabs. According to Nieweg the discovery of this placodont improves our understanding of how the Netherlands was like 245 million years ago. The region around Winterswijk was under water then and was part of an inland sea covering the Netherlands.

The fossil remains of this sea reptile are again in Enschede after all investigations. Museum TwentseWelle shows them in a special showcase.