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.

Cambrian fossil spiky worm discovery


Illustration showing the many legs and spikes covering the early Cambrian creature, Collinsium ciliosum. Credit: Javier Ortega-Hernández

From LiveScience:

Armored Spiky Worm Had 30 Legs, Will Haunt Your Nightmares

by Laura Geggel, Staff Writer

June 29, 2015 03:00pm ET

A spiky, wormlike creature with 30 legs — 18 clawed rear legs and 12 featherlike front legs that likely helped it filter food from the water — once lived in the ancient oceans of the early Cambrian period, about 518 million years ago, a new study finds.

The critter is one of the first known animals on Earth to develop protective armor and to sport specialized limbs that likely helped it catch food, the researchers said. This newfound species lived during the Cambrian explosion, a time of rapid evolutionary development, they said.

“It’s a bit of a large animal for this time period,” said one of the study’s lead researchers, Javier Ortega-Hernández, a research fellow in paleobiology at the University of Cambridge. “The largest specimen is just under 10 centimeters [4 inches], which, for a wormy thing, is quite mighty.” [See Images of the Spiky Worm & Other Cambrian Creatures]

The creature likely used its rear clawed legs to anchor to sponges or other penetrable surfaces, and waved its feathery front limbs to and fro in the current to catch nutrients in the water, Ortega-Hernández said. This technique is still used by modern animals, such as bamboo shrimp, that capture passing meals with their fanlike forearms.

But, because the Cambrian critters were “soft and squishy,” it’s likely they waved their limbs in a gentle motion, Ortega-Hernández told Live Science. “I don’t imagine they would have quick muscle control.”

A squishy creature that didn’t move quickly needed a steadfast defense strategy, and that’s likely why it had so many spikes, he said. Other Cambrian wormlike creatures, such as the bizarre Hallucigenia, also sported spines.

Hallucigenia has two sets of spines per leg,” Ortega-Hernández said. “This one has up to five, which means it was a much more heavily armored creature.”

Collins’ monster

Researchers have dubbed the new creature Collinsium ciliosum, or Hairy Collins’ Monster, named after Desmond Collins, a paleontologist who discovered a fossil of a similar Cambrian wormlike creature in Canada in the 1980s. Since then, researchers have found five species of Collins’ Monster (in the family Luolishania), including one from Australia.

But, unlike earlier fossils, the newfound specimens offer researchers a spectacular view of the prehistoric creature. One fossil displays much of Collinsium ciliosum’s body, including its digestive tract and even the delicate, featherlike structures on its front limbs. Based on the fossils, when it was alive, the worm likely didn’t have any eyes or teeth, Ortega-Hernández said.

Over the past three years, scientists at Yunnan University in China and the University of Cambridge have uncovered and studied 29 C. ciliosum fossils from the early Cambrian Xiaoshiba biota, a deposit in southern China that contains a rich collection of fossilized Cambrian creatures, he said.

An analysis of C. ciliosum‘s anatomy indicates it’s a distant ancestor of modern-day velvet worms, also known as onychophorans — a small group (just 180 species) of squishy worms that live in tropical forests, shoot slime at their prey and resemble legged worms.

Interestingly, the Collins’ Monsters were likely a more diverse group that “came in a surprising variety of bizarre shapes and sizes” than today’s onychophorans, Ortega-Hernández said in a statement.

This isn’t the first time that an ancestral group has displayed more diversity than its modern-day relatives. Sea lilies (crinoids) and lamp shells (brachiopods) also follow this trend. But Collins’ Monsters are the first example of this evolutionary pattern playing out in a mostly soft-bodied group, the researchers said. [See Images of Another Bizarre Cambrian Creature]

The study is “a superb description based on absolutely exquisite fossils,” said Greg Edgecombe, a researcher of arthropod evolution at the Natural History Museum in London, who was not involved in the new study.

The new finding drives home that Cambrian wormlike animals such as Hallucigenia and the new Collinsium are the ancestors of Onychophora, Edgecombe said.

“That means they are more closely related to Onychophora than to any other living groups (such as arthropods or tardigrades),” Edgecombe told Live Science in an email. “Rather than floating around on the tree of life without an exact home,” these creatures can be pinpointed to a living group, Edgecombe said.

The findings were published online today (June 29) in the journal Proceedings of the National Academy of Sciences.

See also here.

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.

Cambrian fossil Hallucigenia, new study


This video says about itself:

Hallucigenia: The worm with the missing head

The remains of an ancient worm species called ‘Hallucigenia’ were so bizarre looking that scientists originally reconstructed it upside down and back to front. Now Martin Smith reveals the most complete picture so far of this peculiar marine worm.

Read the Nature paper ‘Hallucigenia’s head and the pharyngeal armature of early ecdysozoanshere.

Find out more about Hallucigenia and other finds from the Burgess Shale at www.burgess-shale.rom.on.ca.

24th June 2015

From daily The Independent in Britain:

Hallucigenia: Significance of bizarre extinct creature revealed as it finally bares its teeth

The fossil’s bizarre appearance had mystified scientists for more than a century

Steve Connor, Science Editor

Wednesday 24 June 2015

A bizarre extinct creature that has mystified scientists since its 500m-year fossil was first unearthed more than a century ago has finally revealed its teeth – placing it centre stage in the evolution of many complex life-forms living today.

Hallucigenia, which owes its name to its unworldly appearance, was so odd that scientists initially confused its top from its bottom and its head from its tail. However, a study has now unequivocally identified its mouth, complete with a fearsome ring of sharp teeth.

Researchers from the University of Cambridge have also identified a pair of simple eyes on Hallucigenia’s head and have determined that it was a close relative of the last common ancestor of everything from tiny velvet roundworms to huge lobsters.

“The early evolutionary history of this huge group is pretty much uncharted. While we know that the animals in this group are united by the fact that they moult, we haven’t been able to find many physical characteristics that unite them,” said Martin Smith of Cambridge University, the lead author of the study in Nature</em>.

Read more: Bat-like dinosaur fossil found after 160 million years

176-million-year old dinosaur vertebra discovered in Yorkshire

New Jurassic-era dinosaur species discovered in Wales

“Prior to our study there was still some uncertainty as to which end of the animal represented the head, and which the tail,” Dr Smith said.

“A large balloon-like orb at one end of the specimen was originally thought to be the head, but we can now demonstrate that this actually wasn’t part of the body at all, but a dark stain representing decay fluids or gut contents that oozed out as the animal was flattened during burial,” he said.

Film Jurassic World’s depiction of dinosaurs criticized


This video says about itself:

Jurassic Park was ahead of its time. Jurassic World is not.

10 June 2015

A lot has changed in paleontology since Jurassic Park first came out in 1993.

For more information about this topic:

National Geographic: A Velociraptor Without Feathers Isn’t a Velociraptor

The Guardian: Siberian dinosaur spreads feathers around the dinosaur tree

Science Mag: Earliest dinosaurs may have sported feathers

See also here.

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.

Human with Neanderthal ancestry discovery


This video says about itself:

16 September 2014

Nova – Decoding Neanderthals (PBS Documentary)

By Jennifer Viegas:

Ancient Human With 10 Percent Neanderthal Genes Found

June 22, 2015 11:00 AM ET

DNA from a man who lived 40,000 years ago in Romania reveals that up to 11 percent of his genome came from Neanderthals.

Because large segments of the individual’s chromosomes are of Neanderthal origin, a Neanderthal was among the man’s ancestors as recently as four generations back in his family tree, reports a study published in the latest issue of the journal Nature.

The finding reveals that some of the first members of our species who came to Europe interbred with the local Neanderthals.

To this day, individuals of European and Asian heritage retain Neanderthal DNA in their genomes, but whether or not Neanderthals went extinct or simply were absorbed into the modern human population remains a matter of definition, senior author Svante Pääbo told Discovery News.

“Some Neanderthals clearly became incorporated in modern human societies,” said Pääbo, director of the Department of Evolutionary Genetics at the Max Planck Institute for Evolutionary Anthropology. “It is still unclear exactly how much of the complete Neanderthal genome exists today in people, but it seems to approach something like 40 percent.”

“But, of course, the Neanderthals are clearly extinct in the sense that they do not exist as an independent, separate group since some 30,000 or 40,000 years.”

David Reich from Harvard Medical School coordinated the population genetic analysis of the study, which was an international effort. At the center of the research were the remains of the man, named “Oase 1,” unearthed at a cave system called Peștera cu Oase in Romania.

The researchers believe that the man derived from the same expansion out of Africa as other modern people, but was likely to have been part of an early “pioneer foray into Europe,” ahead of other migrations that were to come later.

Under what conditions his relatives, and those of other early Neanderthal-human hybrids, interbred is a big question.

Chris Stringer, an expert on early humans at the Natural History Museum in London, posed some intriguing questions about the matings.

“Were these peaceful exchanges of partners, raids which stole women or girls, or even the adoption of orphaned babies?” he asked, adding that the answer remains a mystery.

What is clear is that the interbreeding took place at different times and locations. This particular individual, Oase 1, did not contribute much, if at all, to later modern human populations, however. Pääbo explained that whatever population he represented seems to have “disappeared,” leaving behind no known tools or other artifacts.