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.

Romanian fossil Balaur, dinosaur or bird?


This 2011 video is called Ancient Reptile Tribute Three: Balaur bondoc / Dromaeosaurid – Dinosaur.

From PeerJ:

The phylogenetic affinities of the bizarre Late Cretaceous Romanian theropod Balaur bondoc (Dinosauria, Maniraptora): dromaeosaurid or flightless bird?

June 18, 2015

Abstract

The exceptionally well-preserved Romanian dinosaur Balaur bondoc is the most complete theropod known to date from the Upper Cretaceous of Europe. Previous studies of this remarkable taxon have included its phylogenetic interpretation as an aberrant dromaeosaurid with velociraptorine affinities.

However, Balaur displays a combination of both apparently plesiomorphic and derived bird-like characters. Here, we analyse those features in a phylogenetic revision and show how they challenge its referral to Dromaeosauridae. Our reanalysis of two distinct phylogenetic datasets focusing on basal paravian taxa supports the reinterpretation of Balaur as an avialan more crownward than Archaeopteryx but outside of Pygostylia, and as a flightless taxon within a paraphyletic assemblage of long-tailed birds.

Our placement of Balaur within Avialae is not biased by character weighting. The placement among dromaeosaurids resulted in a suboptimal alternative that cannot be rejected based on the data to hand. Interpreted as a dromaeosaurid, Balaur has been assumed to be hypercarnivorous and predatory, exhibiting a peculiar morphology influenced by island endemism.

However, a dromaeosaurid-like ecology is contradicted by several details of Balaur’s morphology, including the loss of a third functional manual digit, the non-ginglymoid distal end of metatarsal II, and a non-falciform ungual on the second pedal digit that lacks a prominent flexor tubercle. Conversely, an omnivorous ecology is better supported by Balaur’s morphology and is consistent with its phylogenetic placement within Avialae. Our reinterpretation of Balaur implies that a superficially dromaeosaurid-like taxon represents the enlarged, terrestrialised descendant of smaller and probably volant ancestors.

Fossil bat discovery in New Zealand


This video says about itself:

27 June 2012

On Little Barrier Island in Auckland’s Hauraki Gulf you can get a small glimpse of how New Zealand would have looked before humans arrived around 1000 years ago. Short-tailed bats (Mystacina tuberculata) are a threatened species of bat found only in NZ that are uniquely adapted for crawling on the ground… which makes them ideal pollinators for flowers that are arranged in large clusters.

From Business Insider Australia:

Scientists have discovered a giant dinosaur bat that walked on four legs

Chris Pash

17 June 2015

Fossils of a bat species which walked on four limbs and was three times larger than today’s average bat have been discovered in New Zealand.

The remains were found near Central Otago in sediment left over from a prehistoric body of water known as Lake Manuherikia which was part of warmer subtropical rainforest during the early Miocene era between 16 million and 19 million years ago

The species, Mystacina miocenalis, described in the journal PLOS ONE, is related to another bat, Mystacina tuberculata, which still lives in New Zealand’s old growth forests.

“Our discovery shows for the first time that Mystacina bats have been present in New Zealand for upwards of 16 million years, residing in habitats with very similar plant life and food sources,” says lead author and vertebrate palaeontologist, Suzanne Hand from the University of New South Wales.

New Zealand’s only native terrestrial mammals are three species of bat, including two belonging to the Mystacina genus – one of which was last sighted in the 1960s.

They are known as burrowing bats because they forage on the ground under leaf-litter and snow, as well as in the air, scuttling on their wrists and backward-facing feet, while keeping their wings tightly furled.

“This helps us understand the capacity of bats to establish populations on islands and the climatic conditions required for this to happen,” says Associate Professor Hand.

Bats are important pollinators and seed dispersers that keep forests healthy. Understanding the connectivity between the bat faunas of different landmasses is important for evaluating biosecurity threats and conservation priorities for fragile island ecosystems.”

The new species has similar teeth to its contemporary relative, suggesting a broad diet that included nectar, pollen and fruit, as well as insects and spiders.

At an estimated 40 grams, the fossil bat is roughly three times heavier than its living cousin.

Jurassic dinosaur discovery in Wales


This video says about itself:

New Welsh Dinosaur at Amgueddfa Cymru – National Museum Wales

9 June 2015

The skeleton of a new Welsh dinosaur goes on display at National Museum Cardiff.

The dinosaur is approximately 200 million years old, the oldest Jurassic dinosaur ever found in the UK. It belongs to the theropod group of dinosaurs and is related to Tyrannosaurus rex, although our dinosaur was walking the earth about 130 million years earlier than its more well known cousin.

The new Welsh dinosaur is a completely new species, previously unknown to scientists, making this discovery even more exciting.

See also here.

From daily The Independent in Britain:

The T-Rex has a Welsh cousin: New Jurassic-era dinosaur species discovered in Wales

The theropod, discovered by two brothers, dates back 200 million years

Pat Hurst

Tuesday 09 June 2015

A new dinosaur species has been discovered in Wales dating back 200 million years to the earliest Jurassic period, scientists say.

The fossilised skeleton of the dog-sized creature, a theropod dinosaur, is described as a cousin of the giant Tyrannosaurus rex and is believed to be the earliest specimen of a Jurassic era dinosaur ever to walk the Earth.

Described as the “find of a life-time” it was discovered on Lavernock beach near Penarth in the Vale of Glamorgan by two fossil-hunting brothers, Nick and Rob Hanigan after storms in spring 2014.

A cliff fall on the beach, revealed several loose blocks containing part of the skeleton of the dinosaur, including razor sharp teeth and claws.

It was analysed by experts from The University of Manchester, University of Portsmouth and the National Museum Wales who concluded it lived at the very earliest part of the Jurassic Period, 201 million years ago.

Dr John Nudds, senior lecturer in palaeontology at The University of Manchester said: “It is very rare to find this type of dinosaur at all and never before in Wales. In fact it is only the second dinosaur ever found in Wales.

“Theropods were vicious hunters who would prey on others. They were evolving rapidly at the start of the Jurassic period, but are only known from a few specimens worldwide.

“So this is a very exciting finding that could tell us a lot about how these species were evolving.”

It is thought that the fossil was from a juvenile animal as some of its bones are not yet fully formed. Research is still under way, with a scientific paper in progress which will reveal the name of this new species in the next few months.

The fossil will be donated to the National Museum Wales by the Hanigan brothers.

The new dinosaur’s name has yet to be revealed, although the Hanigan brothers revealed their idea of “RobandNick-A-Saurus” was turned down by palaeontologists.

Bank worker Rob joked: “Choosing a name was harder than picking one for my son.”

Dr David Martill, reader in palaeobiology at University of Portsmouth, said: “The new dinosaur was brought to my attention last year and I went up to Lancashire to see the specimen.

“There, laid out on the table, was the most beautiful little theropod dinosaur ever found in Europe.

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“Although the bones were scattered on a few slabs of limestone, they were in excellent condition, and much of the skull appeared to be there.

“The teeth were small, but needle sharp, slightly curved and with the most wonderful steak-knife serrations on their edges.

“I then went to visit the discovery site, which showed that the dinosaur came from strata deposited exactly at the end of the Triassic and the start of the Jurassic. I now had the job to determine if this was a Triassic or Jurassic dinosaur. That took a lot of effort, but we are now convinced it is the first ever Jurassic dinosaur.”

The Welsh dinosaur was a small, slim, agile dinosaur, probably only about 50cm tall, which had a long tail to help it balance. It lived at the time when south Wales was a coastal region, offering a warm climate.

It had lots of small, blade-like, sharp, serrated teeth suggesting that it would have eaten insects, small mammals and other reptiles.

The dinosaur also probably had a fuzzy coating of simple proto-feathers, as did many theropod dinosaurs, and this would have been used for insulation and possibly display purposes. It may also have had simple quill-like structures for defence.

The rocks that contain the dinosaur fossil date back to a time immediately after the start of the Jurassic period, 201.3 million years ago.

At that time, the dinosaurs were just starting to diversify and the Welsh specimen is almost certainly the earliest Jurassic dinosaur in the world.

It is related to Coelophysis that lived approximately 203 to 196 million years ago in what is now the southwestern part of the United States of America. It also could be said to be a distant cousin of the much later Tyrannosaurus rex.

Nick Hanigan said: “This is a once in a lifetime find – preparing the skull and to seeing the teeth of a theropod for the first time in 200 million years was absolutely fantastic – you just can’t beat that sort of thing!”

The fossil will be on display at the main hall of National Museum Cardiff from June 9, until September 6, 2015.