. Scientific Frontline: Paleontology
Showing posts with label Paleontology. Show all posts
Showing posts with label Paleontology. Show all posts

Wednesday, April 3, 2024

In the evolution of walking, the hip bone connected to the rib bones

New reconstruction of the skeleton of Tiktaalik roseae, a 375-million-year-old fossil fish. In a new study, researchers used micro-CT imaging to reveal vertebrae and ribs of the fish that were previously hidden beneath rock. The new reconstruction shows that the fish’s ribs likely attached to its pelvis, an innovation thought to be crucial to supporting the body and for the eventual evolution of walking.
Photo Credit: Thomas Stewart / Pennsylvania State University

Before the evolution of legs from fins, the axial skeleton — including the bones of the head, neck, back and ribs — was already going through changes that would eventually help our ancestors support their bodies to walk on land. A research team including a Penn State biologist completed a new reconstruction of the skeleton of Tiktaalik, the 375-million-year-old fossil fish that is one of the closest relatives to limbed vertebrates. The new reconstruction shows that the fish’s ribs were likely attached to its pelvis, an innovation thought to be crucial to supporting the body and for the eventual evolution of walking.

A paper describing the new reconstruction, which used microcomputed tomography (micro-CT) to scan the fossil and reveal vertebrae and ribs of the fish that were previously hidden beneath rock, appeared in the journal Proceedings of the National Academy of Sciences.

“Tiktaalik was discovered in 2004, but key parts of its skeleton were unknown,” said Tom Stewart, assistant professor of biology in the Eberly College of Science at Penn State and one of the leaders of the research team. “These new high-resolution micro-CT scans show us the vertebrae and ribs of Tiktaalik and allow us to make a full reconstruction of its skeleton, which is vital to understanding how it moved through the world.”

Monday, March 25, 2024

Persian plateau unveiled as crucial hub for early human migration out of Africa

Pebdeh Cave located in the southern Zagros Mountains. Pebdeh was occupied by hunter-gatherers as early as 42,000 years ago.
Photo Credit: Mohammad Javad Shoaee

A new study combining genetic, palaeoecological, and archaeological evidence has unveiled the Persian plateau as a pivotal geographic location serving as a hub for Homo sapiens during the early stages of their migration out of Africa.  

This study sheds new light on the complex journey of human populations, challenging previous understandings of our species’ expansion into Eurasia. 

The study, published in Nature Communications, highlights a period between 70,000 to 45,000 years ago when human populations did not uniformly spread across Eurasia, leaving a gap in our understanding of their whereabouts during this time frame. 

Sunday, March 24, 2024

Research uncovers a rare resin fossil find: A spider that aspires to be an ant

Ant-mimicking spider in fossilized resin
Photo Credit: George Poinar Jr / Oregon State University

Arachnophobia can make humans flee at the sight of a brown recluse, black widow or even a daddy long legs, but animal predators of spiders know no such fear.

That’s why paleobiologist George Poinar Jr. explains, some spider species have developed the defense of deception. They masquerade as a much less desirable prey – ants – and Poinar’s recent paper in Historical Biology presents an early record of an ant-mimicking spider in fossilized resin.

“Ants are particularly good creatures for spiders to pretend to be – many animals find ants distasteful or dangerous to eat,” said Poinar, who has a courtesy appointment in the Oregon State University College of Science. “Ants are aggressive in their own defense – they have a strong bite as well as stinging venom, and they can call in dozens of nestmates as allies. Spiders, meanwhile, have no chemical defenses and are loners, which makes them vulnerable to being hunted by larger spiders, wasps and birds – predators that would rather avoid ants. So, if a spider can be like an ant, it’s more likely to be unbothered.”

Spiders that disguise themselves as ants live in many locations around the globe but until now most had been able to avoid detection from fossil researchers as well as predators. The specimen that Poinar describes, which he named Myrmarachne colombiana, was entombed in a type of fossilized resin known as copal.

Thursday, March 21, 2024

Rays were more diverse 150 million years ago than previously thought

Aellopobatis bavarica: The newly discovered species, complete fossils are only known from Germany. This species is also the largest species of all and can grow up to 170 cm in size.
Photo Credit: Türtscher et al.

New fossil ray species discovered in Bavarica, Germany: Aellopobatis bavarica from the Late Jurassic

In a new study recently published in the journal Papers in Paleontology, an international team of scientists led by paleobiologist Julia Türtscher from the University of Vienna has explored the puzzling world of rays that lived 150 million years ago and discovered a previously hidden diversity – including a new ray species. This study significantly expands the understanding of these ancient cartilaginous fish and provides further insights into a past marine ecosystem.

In her new study, paleobiologist Julia Türtscher from the Institute of Paleontology at the University of Vienna examined 52 fossil rays from the Late Jurassic period. These rays are 150 million years old, from a time when Europe was largely covered by the sea, except for a few islands, comparable to today's Caribbean. The Late Jurassic specimens are particularly valuable to scientists because they are among the oldest known fully preserved ray specimens. As only the teeth of fossilized rays are usually preserved, such rare skeletal finds provide exciting insights into the early evolution of this group. Although the exceptionally well-preserved fossils (from Germany, France, and the UK) have been known for some time, they have been largely unexplored. Türtscher's study is the first comprehensive analysis of the variation in body shape in these rays.

Friday, February 23, 2024

Killer instinct drove evolution of mammals’ predatory ancestors

Inostrancevia, a more advanced predatory synapsid and one of the first sabertoothed carnivores, from the late Permian (~259-252 Million years ago). (Display at the Royal Ontario Museum, Canada).
Photo Credit: Suresh A. Singh

The evolutionary success of the first large predators on land was driven by their need to improve as killers, researchers at the University of Bristol and the Open University suggest.

The forerunners of mammals ruled the Earth for about 60 million years, long before the origin of the first dinosaurs. They diversified as the top predators on land between 315–251 million years ago.

Researchers studied the jaw anatomy and body size of carnivorous synapsids, using these traits to reconstruct the likely feeding habits of these ancient predators and chart their ecological evolution through time. They found a major shift in synapsid jaw function roughly 270 million years ago linked to a significant shift in predatory behavior that has important implications for the evolution of our earliest ancestors. 

As herbivores grew larger and faster, carnivores adapted to become bigger and better predators to survive.

“Earlier synapsid predators such as the famous sail backed Dimetrodon, had fairly long jaws with lots of teeth to ensure that once they ensnared their prey, it wouldn’t escape,” explained lead author Dr Suresh Singh based in Bristol’s School of Earth Sciences. “However, we saw a shift in jaw function toward shorter jaws with greater muscle efficiency and fewer teeth that were concentrated at the front of the jaw - these were jaws adapted to deliver deep, powerful bites.

Monday, February 12, 2024

Ancient air-breathing fish comes to surface

Life reconstruction of Harajicadectes zhumini, a 40 cm long lobe-finned fish that is not too distantly related to the fishes that gave rise to the earliest limbed tetrapods.
Illustration Credit: Brian Choo, Flinders University

Alice Spring’s Finke River (Larapinta), often cited as one of the oldest rivers in the world, once hosted waters teeming with bizarre animals – including a sleek predatory lobe-finned fish with large fangs and bony scales.

The newly described fossil fish has been named Harajicadectes zhumini by an international team of researchers led by Flinders University paleontologist Dr Brian Choo.

The fossil was named for the Harajica Sandstone Member where the fossils were found in Australia’s ‘Red Centre’ and the ancient Greek dēktēs (“biter”). It also pays homage to Professor Min Zhu, currently at the Chinese Academy of Sciences, Beijing, who has made some major contributions to the research of early vertebrates.

Wednesday, December 20, 2023

Insects already had a variety of defense strategies in the Cretaceous

Larva of a wedge-shaped beetle in amber, which could have lived inside other insects like its modern counterparts. 
Image Credit: © Carolin Haug

Analyses of amber show that insect larvae were already using a wide variety of tactics to protect themselves from predators 100 million years ago.

Early life stages of insects fulfill important functions in our ecosystems. They decompose dead bodies and wood, forming soil and returning various elements into material cycles. Not least, they are a major food source for many larger animals such as birds and mammals. This has led to many insect larvae developing structures and strategies for reducing the danger of being eaten. These include features like spines and hairs, but also camouflage and concealment. Over millions of years, a wide variety of such adaptation strategies have developed.

Researchers at LMU and the universities of Greifswald and Rostock have studied particularly well-preserved fossils from Burmese amber and have been able to demonstrate that such anti-predator mechanisms had already evolved very diverse forms in insect larvae during the Cretaceous period 100 million years ago. This includes well-known strategies such as that employed by lacewing larvae, which carry various plant and animal materials on their back to give them camouflage, or the ploy of mimicking the appearance of certain plant parts.

Friday, December 15, 2023

Deadly chicken disease: ancient DNA reveals evolution of virulence

With the increase in poultry farming, Marek's disease virus evolved
Photo Credit: Heidi-Ann Fourkiller

Using genetic analyses, an international team led by LMU paleogeneticist Laurent Frantz has revealed the evolutionary history of the pathogen of a fatal disease in chickens.

A notifiable animal disease in Germany, Marek’s disease is caused by the globally distributed Marek’s disease virus (MDV). Over the past century, the virus, which causes tumors in chickens and has a high mortality rate, has become increasingly aggressive. Combating the disease costs the poultry industry over a billion dollars every year. With the help of ancient DNA, an international team of scientists led by LMU paleogenomicist Professor Laurent Frantz and Professor Greger Larson and Professor Adrian Smith from the University of Oxford has now decoded the evolution of MDV and shed light on what is behind the growing virulence.

The international team from the fields of paleogenetics, archeology, and biology isolated viral genomes from chicken bones up to 1,000 years old from 140 archeological sites in Europe and the Near East. “Our data shows that the virus was already widely distributed at least 1,000 years before the first description of the disease in 1907,” says Frantz. When the disease was first described, it was said to produce only mild symptoms in older chickens. With the dramatic increase in poultry farming in the 1950s and 1960s, the virus evolved and has become increasingly virulent despite the development of several vaccines.

Wednesday, December 13, 2023

This Japanese ‘dragon’ terrorized ancient seas

UC Associate Professor Takuya Konishi is an expert on ancient marine reptiles such as mosasaurs.
 Photo Credit: Joseph Fuqua II/UC

Researchers have described a Japanese mosasaur the size of a great white shark that terrorized Pacific seas 72 million years ago.

Extra-long rear flippers might have aided propulsion in concert with its long-finned tail. And unlike other mosasaurs, or large extinct marine reptiles, it had a dorsal fin like a shark’s that would have helped it turn quickly and with precision in the water.

University of Cincinnati Associate Professor Takuya Konishi and his international co-authors described the mosasaur and placed it in a taxonomic context in the Journal of Systematic Palaeontology.

The mosasaur was named for the place where it was found, Wakayama Prefecture. Researchers call it the Wakayama Soryu, which means blue dragon. Dragons are creatures of legend in Japanese folklore, Konishi said.

“In China, dragons make thunder and live in the sky. They became aquatic in Japanese mythology,” he said.

Tuesday, November 7, 2023

‘Neglected’ Dinosaur Had Super Senses

A family of Thescelosaurus emerges from safety to forage in the forests of the Hell Creek Formation, 66 million years ago.
Illustration Credit: Anthony Hutchings.

A CT scan of an often-overlooked, plant-eating dinosaur’s skull reveals that while it may not have been all that “brainy,” it had a unique combination of traits associated with living animals that spend at least part of their time underground, including a super sense of smell and outstanding balance. The work is the first to link a specific sensory fingerprint with this behavior in extinct dinosaurs.

The dinosaur in question, Willo, is a specimen housed at the North Carolina Museum of Natural Sciences. Willo is a Thescelosaurus neglectus – a small (12 feet or 3.6 meters long) but heavy (750 pounds or 340 kilograms) herbivore that lived in what is now North America just before the end-Cretaceous mass extinction event, 66 million years ago.

Willo’s scientific name roughly translates to “wonderful, overlooked lizard.” But David Button, a former Brimley Postdoctoral Scholar at the North Carolina Museum of Natural Sciences and North Carolina State University, decided to look more closely at this “overlooked” dinosaur’s skull. Button is currently a research associate at the University of Bristol in the U.K.

Friday, October 13, 2023

Boom in “ice ivory” trade of mammoth tusks presents new threat to elephants and environment

A new study warns the close similarities between the tusks of elephants and mammoths poses threats to conservation and environment efforts

Conservationists fear a rise in the buying and selling of mammoth tusks, known as the “ice ivory” trade, poses a new threat to elephants.

A UK-wide ban on the sale of ivory came into force in 2018, following a University of Portsmouth led investigation into the British antiques trade of the material.

Earlier this year, it was announced the Ivory Act would be extended to protect five more endangered CITES-listed species, including the hippopotamus, walrus, narwhal, orca and sperm whale.

However, a new study has warned that the sale of mammoth tusks is an unregulated aspect of the ivory trade that needs to be addressed. The species falls outside of the regulation of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES); a multi-government agreement set up to ensure the survival of animals and plant species.

Thursday, October 5, 2023

New type of tiny wasp comes with mysterious, cloud-like structures at ends of antennae

Fossil researchers have discovered a novel genus and species of tiny wasp with a mysterious, bulbous structure at the end of each antenna.
Photo Credit: George Poinar Jr.

Fossil researchers have discovered a novel genus and species of tiny wasp with a mysterious, bulbous structure at the end of each antenna.

The female micro-wasp was described from 100-million-year-old Burmese amber in a study led by George Poinar Jr., who holds a courtesy appointment in the Oregon State University College of Science.

Poinar and Fernando Vega, an independent researcher based in Silver Spring, Maryland, have some ideas about the “clouds” on the antennae, but they don’t know for sure what they are.

“We could find no fossil or extant insect with such antennal structures,” said Poinar, an international expert in using plant and animal life forms preserved in amber to learn about the biology and ecology of the distant past. “We wondered how it could still fly with that weight.”

Feather-tailed possums in New Guinea were originally Aussies: fossil study

The New Guinean feather-tailed possum, Distoechurus pennatus, never developed gliding.
Photo Credit: UNSW Sydney

Scientists have long known that the miniature feather-tailed possums in Australia and the island of New Guinea – members of the marsupial family Acrobatidae – were evolutionary cousins, but where they started their long evolutionary journey has been a bit of a mystery – until now.

According to recently published research in Alcheringa: An Australasian Journal of Paleontology, paleontologists from UNSW Sydney say the modern-day animals on either side of the Torres Strait came from common ancestors in Australia before diverging into their living gliding and non-gliding descendants, known as Acrobates pygmaeus in Australia and Distoechurus pennatus in New Guinea.

Professor Mike Archer from UNSW’s School of Biological Earth and Environmental Sciences says that in an analysis of extinct species found at Riversleigh World Heritage Area fossil deposits in north-western Queensland revealed that ancestors of both groups of possums were present in Australia by at least 25 million years ago.

“As Riversleigh started revealing its prehistoric treasures, we discovered four different species of feathertail possums, the first ‘deep-time’ fossil record known for the whole family,” he says.

Wednesday, June 14, 2023

Paleontologists Discovered Unique Remains of Paleogene Reptiles in the Urals

Rare remains have been found in the Sverdlovsk and Kurgan Regions
Photo Credit: Courtesy of Ural Federal University

At the river Miass (Kurgan Region) paleontologists of the Ural Branch of the Institute of Ecology of Animals and Plants of the Russian Academy of Sciences and the Ural Federal University discovered rare for the Urals and Siberia finds - vertebrae of a sea snake and a piece of a turtle shell. Approximate dating of bones - 45-35 million years, but the exact figures have not yet been established. The findings were sent to the Paleontological Institute of the Russian Academy of Sciences in Moscow for further research.

"This is the second such unique find, and we were lucky to study both of them. The fact is that fossil remains of Paleogene snakes from the territory of Western and Eastern Europe, the Caucasus, and Central Asia are quite well described, but such finds are not known in the Urals and Western Siberia. Last year we managed to find a vertebra of a sea snake on the Dernei River in the Sverdlovsk Region. This year, our friend and paleontology enthusiast Alexey Sofrygin showed us a snake vertebra from a new spot - the Miass River. Unfortunately, we did not find any other vertebrae when we conducted a complete study of the Miass River sediments. However, we did find a piece of a turtle shell. This is also an extremely rare find," says Dmitry Gimranov, Head of Research, Senior Researcher at the Laboratory of Natural Science Methods in Humanities of the Ural Federal University.

Tuesday, June 13, 2023

First side-necked turtle ever discovered in UK

The fossil was found on a National Trust beach on the Isle of Wight
Photo Credit: Courtesy of University of Portsmouth

The first side-necked turtle ever to be found in the UK has been discovered by an amateur fossil collector and paleontologists at the University of Portsmouth.

The fossil remains are the earliest of a so-called side-necked pan-pleurodiran turtle, named as such because they fold their neck into their shell sideways when threatened. This does mean they can only see out with one eye.

Originally found on a beach on the Isle of Wight, the turtle fossil is an almost complete shell with cervical, dorsal and caudal vertebrae, scapulae, pelvic girdle and appendicular bones. Sadly, the skull was missing.

Lead author, Megan Jacobs, said: “This is an amazing discovery because it’s the first time this type of turtle has been found in the UK. Even more exciting is that we used a new technique of radiometric dating to determine the age of the fossil beyond any doubt. And to top it off, CT scanning revealed all the tiny bones inside. It’s really incredible for what looks like a rolled beach pebble!”

Dynamic plants: Origin and geographic evolution of cycads clarified

The African cycad Encephalartos altensteinii Lehm is widely cultivated in botanical gardens around Europe (like this one in the Botanical Garden of the University of Naples "Federico II"), including one specimen that was brought from South Africa to the UK in 1775 and that is still alive today. Large Encephalartos are highly prized as ornamental plants, and unfortunately many species have been brought to the brink of extinction by poaching.
Photo Credit: Mario Coiro

Paleobotanist Mario Coiro of the Institute of Paleontology at the University of Vienna and colleagues at the University of Montpellier (France) have made an important breakthrough in understanding the origin and geographic distribution of cycads. By combining genetic data with leaf morphological data from both fossil and living species for the first time, the researchers created a phylogenetic tree of these fascinating and endangered plants. The results of the study, which was funded by the Austrian Science Fund FWF, have now been published in the journal New Phytologist.

Cycads (order Cycadales) are an evolutionarily very old and once very diverse group of palm-like plants that were widespread worldwide at the time of the dinosaurs. Now their distribution is limited to subtropical regions of the earth with low latitudes, and some of them have been considered as "living fossils". Until now, little was known about the origin of these plants, which are also highly valued by garden lovers and collectors, and their evolutionary distribution paths – a fact that Mario Coiro's team have actively challenged. To this end, the researchers developed an innovative research approach that actually makes a significant contribution to clarifying the biogeographical distribution of cycads.

Friday, June 9, 2023

Ancient herbivore’s diet weakened teeth leading to eventual starvation

Reconstruction of the rhynchosaur Bentonyx from the Middle Triassic of Devon, about 245 million years ago.
Illustration Credit: Reconstruction artwork by Mark Witton

A team of researchers from the University of Bristol have shed light on the life of the ancient reptile Rhynchosaur, which walked the earth between 250-225 million years ago, before being replaced by the dinosaurs.

Rhynchosaurs are a little-understood group of roughly sheep-sized ancient reptiles that thrived during the Triassic Period, a time of generally warm climates and tough vegetation.  

In the new study, the researchers studied specimens found in Devon and used CT scanning to see how the teeth wore down as they fed, and how new teeth were added at the backs of the tooth rows as the animals grew in size.

The findings, published today in Palaeontology, show that these early herbivores likely eventually starved to death in old age, the vegetation taking its toll on their teeth.

“I first studied the rhynchosaurs years ago,” said team-leader Professor Mike Benton from Bristol’s School of Earth Sciences, “and I was amazed to find that in many cases they dominated their ecosystems. If you found one fossil, you found hundreds.

Wednesday, June 7, 2023

New Dino, ‘Iani,’ Was Face of a Changing Planet

Illustration Credit: Jorge Gonzalez
(CC BY-NC 4.0)

A newly discovered plant-eating dinosaur may have been a species’ “last gasp” during a period when Earth’s warming climate forced massive changes to global dinosaur populations.

The specimen, named Iani smithi after Janus, the two-faced Roman god of change, was an early ornithopod, a group of dinosaurs that ultimately gave rise to the more commonly known duckbill dinosaurs such as Parasaurolophus and Edmontosaurus. Researchers recovered most of the juvenile dinosaur’s skeleton – including skull, vertebrae and limbs – from Utah’s Cedar Mountain Formation.

Iani smithi lived in what is now Utah during the mid-Cretaceous, approximately 99 million years ago. The dinosaur’s most striking feature is its powerful jaw, with teeth designed for chewing through tough plant material.

The mid-Cretaceous was a time of big changes, which had big effects on dinosaur populations. Increased atmospheric carbon dioxide during this time caused the Earth to warm and sea levels to rise, corralling dinosaurs on smaller and smaller landmasses. It was so warm that rainforests thrived at the poles. Flowering plant life took over coastal areas and supplanted normal food sources for herbivores.

Thursday, May 18, 2023

Fossil of mosasaur with bizarre “screwdriver teeth” found in Morocco

The strange ridges on the teeth indicate a specialised feeding strategy, however its diet remains a mystery.
Photo Credit: Dr Nick Longrich

Scientists have discovered a new species of mosasaur, a sea-dwelling lizard from the age of the dinosaurs, with strange, ridged teeth unlike those of any known reptile. Along with other recent finds from Africa, it suggests that mosasaurs and other marine reptiles were evolving rapidly up until 66 million years ago, when they were wiped out by an asteroid along with the dinosaurs and around 90% of all species on Earth.

The new species, Stelladens mysterious, comes from the Late Cretaceous of Morocco and was around twice the size of a dolphin.

It had a unique tooth arrangement with blade-like ridges running down the teeth, arranged in a star-shaped pattern, reminiscent of a cross-head screwdriver.

Most mosasaurs had two bladelike, serrated ridges on the front and back of the tooth to help cut prey, however Stelladens had anywhere from four to six of these blades running down the tooth.

“It’s a surprise,” said Dr Nick Longrich from the Milner Centre for Evolution at the University of Bath, who led the study. “It’s not like any mosasaur, or any reptile, even any vertebrate we’ve seen before.”

Wednesday, May 10, 2023

Giants of the Jurassic seas were twice the size of a killer whale

An artist’s impression of the pliosaur
Illustration Credit: Megan Jacobs, University of Portsmouth

Over 20 years ago, the BBC’s "Walking with Dinosaurs" TV documentary series showed a 25-meter long Liopleurodon. This sparked heated debates over the size of this pliosaur as it was thought to have been wildly overestimated and more likely to have only reached an adult size of just over six meters long.

The speculation was set to continue, but now a chance discovery in an Oxfordshire museum has led to University of Portsmouth paleontologists publishing a paper on a similar species potentially reaching a whopping 14.4 meters - twice the size of a killer whale. 

Professor David Martill from the University of Portsmouth’s School of the Environment, Geography and Geosciences, said: “I was a consultant for the BBC’s pilot program ‘Cruel Sea’ and I hold my hands up - I got the size of Liopleurodon horrendously wrong. I based my calculations on some fragmentary material which suggested a Liopleurodon could grow to a length of 25 meters, but the evidence was scant and it caused a lot of controversy at the time.

“The size estimate on the BBC back in 1999 was overdone, but now we have some evidence that is much more reliable after a serendipitous discovery of four enormous vertebrate.”

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