Rukwa Rift Basin Project names new Cretaceous mammal from East African Rift System

Date:  March 18, 2019

Source:  Ohio University

Ohio University researchers announced a new species of mammal from the Age of Dinosaurs, representing the most complete mammal from the Cretaceous Period of continental Africa, and providing tantalizing insights into the past diversity of mammals on the planet.

The National Science Foundation-funded OHIO team, in collaboration with international colleagues, identified and named the new mammal in an article published today in Acta Paleontologica Polonica. This nearly complete lower jaw represents the first named mammal species from the Late Cretaceous Period (100-66 million years ago) of the entire African continent. The squirrel-sized animal was probably related to a group of southern hemisphere mammals known as gondwanatherians, yet a bizarre combination of features (including evergrowing and enamel-less peg-like teeth) make it challenging to easily place within any group of mammals yet known, living or extinct.

The new mammal is named Galulatherium jenkinsi, a name based on the Galula rock unit (itself derived from one of the local villages in the field area) and therium, Latin for beast, with the species name "jenkinsi" honoring the late Farish Jenkins, distinguished professor of anatomy and organismic biology at Harvard University and a strong supporter of the Rukwa Rift Basin Project early in its development.

The type and only specimen of Galulatherium was discovered in 2002, when Rukwa Rift Basin Project researchers found a bone fragment eroding from Cretaceous-age red sandstones in the Rukwa Rift Basin in southwestern Tanzania. After painstakingly removing the rock from the delicate specimen, the team announced the discovery of a new mammal in 2003, yet they conservatively refrained from establishing a name for the enigmatic new species until additional details of its anatomy could be revealed. In the intervening years, improvements in high-resolution x-ray computed tomography enabled the team to document detailed anatomy of the specimen and to establish Galulatherium as a species new to science.

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New dinosaur with heart-shaped tail provides evolutionary clues for African continent

Mnyamawamtuka moyowamkia fossils recovered from East African Rift System

Date:  February 13, 2019

Source:  Ohio University

A new dinosaur that wears its "heart" on its tail provides new clues to how ecosystems evolved on the African continent during the Cretaceous period according to researchers at Ohio University.

The OHIO team identified and named the new species of dinosaur in an article published this week in PLOS ONE. The new dinosaur, the third now described from southwestern Tanzania by the NSF-funded team, is yet another member of the large, long-necked titanosaur sauropods. The partial skeleton was recovered from Cretaceous-age (~100 million years ago) rocks exposed in a cliff surface in the western branch of the great East African Rift System.

The new dinosaur is named Mnyamawamtuka moyowamkia (Mm-nya-ma-wah-mm-too-ka mm-oh-yo-wa-mm-key-ah), a name derived from Swahili for "animal of the Mtuka (with) a heart-shaped tail" in reference to the name of the riverbed (Mtuka) in which it was discovered and due to the unique shape of its tail bones.

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100-Million-Year-Old Hagfish Complete with Slime Kit Discovered

By Mindy Weisberger, Senior Writer | January 21, 2019 03:39pm ET

Scientists recently discovered a rare and important hagfish fossil that includes traces of preserved slime dating to 100 million years ago.

Eyeless, jawless hagfish — still around today — are bizarre, eel-like, carrion-eating fishes that lick the flesh off dead animals using their spiky tongue-like structures. But their most well-known feature is the sticky slime that they expel for protection.

And now, scientists know that hagfish slime is robust enough to leave traces in the fossil record, finding remarkable evidence in a fossilized hagfish skeleton excavated in Lebanon. This new discovery is also prompting researchers to redefine the hagfish's relationship to other ancient fish and to all animals with backbones. [Photos: The Freakiest Looking Fish]

Hagfish fossils are scarce, and this specimen — an "unequivocal fossil hagfish" — is exceptionally detailed with lots of soft tissue preserved, scientists reported in a study published online today (Jan. 21) in the journal Proceedings of the National Academy of Sciences (PNAS).

The fossil dates to the late Cretaceous period (145.5 million to 65 million years ago), and measures 12 inches (31 centimeters) in length. Researchers dubbed it Tethymyxine tapirostrum: Tethymyxine comes from "Tethys" (referencing the Tethys Sea) and the Latinized Greek word "myxnios," which means "slimy fish." Tapirostrom translates as "snout of a tapir," and refers to the fish's elongated nose, the study authors wrote.

Read on

Cretaceous croc had steamy past – via Herp Digest

Article from University of Queensland, Australia, 3/28/18

Contacts-Media: Dr Caitlin Syme, caitlin.syme@uqconnect.edu.au, @taphovenatrix, +61 (0)428 642 061; Dr Steven Salisbury, @implexidens, s.salisbury@uq.edu.au, +61 (0)407 788 660.

An artist’s rendering of Isisfordia duncani. Credit: Matt Herne.

March 28, 2018

The death, decay and burial of an ancient extinct crocodilian from outback Queensland has revealed more about Cretaceous Period landscapes in Australia.

Scientists from The University of Queensland have completed a forensic-style investigation into fossils of the Isisfordia duncani, and found the diminutive crocodilians lived and died in brackish-water deltas.

School of Biological Sciences Dr Caitlin Syme said it was already known that the crocodile carcasses eventually ended up in the deltas, but it was uncertain if they had lived in the delta or drifted in after death.

“A decaying animal carcass can swell or bloat, and if it is washed into a lake or river, it can float and drift along in river currents,” Dr Syme said.

“If this is what happened to individuals of Isisfordia duncani, then it is possible they were already dead by the time their carcasses drifted in to the delta.”

Dr Syme compared the crocodilian fossils to modern animal carcasses and used the science of taphonomy—the study of death, decay, burial, and preservation of animal and plant remains—to predict the movement of the carcasses before they were fossilised.

“We counted which fossil bones and how many were present, whether they were still joined together as they would be in life, and whether they were scratched or broken,” she said.

“When a carcass floats in water, it will continue to decay, and parts of the skeleton will detach and sink.

“With carcasses of modern animals, for instance, the head is often the first part of the body that falls off.

“Where a fossil specimen comprises isolated and broken leg and hip bones, it indicates that the carcass probably drifted for quite a while before parts of it sunk and were eventually buried.”

Although some Isisfordia duncani fossils were incomplete, researchers found two with a large proportion of their bones still connected and intact, indicating the crocodile died near to where they lived.

“Both juvenile and adult crocodilian fossils are found at this site, which also suggests that these crocodilians were breeding in or near to these ancient deltas,” Dr Syme said.

Dr Steven Salisbury said the findings were significant because they suggested that the central-western Queensland Cretaceous Period climate was warm and wet enough for the cold-blooded reptiles to live and breed.

“The results of this study greatly improve our understanding of this part of outback Queensland during the Age of Dinosaurs, and provides valuable information on the life and times of the one of the world’s first modern crocodilians,” Dr Salisbury said.

Fossils of Isisfordia duncani were first found by a local grazier, Ian Duncan, near the outback Queensland town of Isisford in the mid-1990s.

The species was named in 2006 and the Cretaceous crocodilian is considered to be close to the ancestry of all modern crocodilians: true crocodiles, alligators and caimans, and the Indian gharial.

Seven individual Isisfordia duncani have been found, making it the best-represented Cretaceous crocodilian in Australia.

The study is published in the Royal Society Open Science journal.

Fossils and dioramas of Isisfordia duncani are on display at the Outer Barcoo Interpretation Centre and at the Queensland Museum.

Meet the vampire ant from hell with huge jaws and a metal horn

10 September 2017

By Josh Gabbatiss

A newly discovered species of prehistoric “hell ant” had anatomy that lived up to its demonic name, including a lethal feeding apparatus reinforced with metal.

Hell ants are an extinct lineage from the Cretaceous Period. Instead of regular mouthparts, they had upward-facing blades.

No living species have such facial anatomy. However, the hairs around hell ants’ mouths are reminiscent of hairs on modern trap-jaw ants that cause their mouths to snap shut when triggered. This has led to speculation that the hell ants’ mouthparts worked in a similar way.

Some also had a horn-like appendage that jutted out over their tusk-like mandibles. This includes the new species, Linguamyrmex vladi, which Phillip Barden at the New Jersey Institute of Technology in Newark and his colleagues found preserved in 98-million-year-old amber.

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300 Teeth: Duck-billed dinosaurs would have been dentist’s dream

Date: August 25, 2016

Source: University of Toronto]

Imagine how much dental care you'd need if you had 300 or more teeth packed together on each side of your mouth.

Duck-billed dinosaurs (hadrosaurs), who lived in the Cretaceous period between 90 million and 65 million years ago, sported this unique dental system, which had never been fully understood until it was examined at the microscopic level through recent research conducted by Aaron LeBlanc, a University of Toronto Mississauga PhD candidate; his supervisor, Professor Robert Reisz, the University of Toronto Mississauga vice-dean, graduate, and colleagues at the Royal Ontario Museum and the Museum of the Rockies.

Rather than shedding teeth and replacing them with new ones like other reptiles, hadrosaurs' mouths contain several parallel stacks of six or more teeth apiece, forming a "highly dynamic network" of teeth that was used to grind and shear tough plant material. Although hadrosaur teeth appear to be fused in place, LeBlanc and his colleagues show that the newest teeth were constantly pushed towards the chewing surface by a complex set of ligaments. When viewed under the microscope, the columns of teeth are not physically touching and are held together by the sand and mud that can get in between the teeth following the decay of the soft ligaments after the animals died.

"Hadrosaur teeth are actually similar to what we have because our teeth are not solidly attached to our jaws. Like us, hadrosaur teeth would have had some fine-scale mobility as they chewed thanks to this ligament system that suspended the teeth in place," says Reisz.

As they reached the grinding surface, hadrosaur teeth were essentially dead, filled with hard tissue -- unlike humans, whose teeth have an inner core filled with blood vessels and nerves.

"Since the teeth were already dead, they could be ground down to little nubbins," Reisz says.

LeBlanc says this tooth structure -- with its tough grinding surface -- was "well-adapted to break down tough plant material for digestion," through both shearing and grinding. This adaptation may have contributed to the hadrosaurs' longevity and proliferation.

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Mammals almost wiped out with the dinosaurs

Date: June 20, 2016

Source: University of Bath

Over 90 per cent of mammal species were wiped out by the same asteroid that killed the dinosaurs in the Cretaceous period 66 million years ago, significantly more than previously thought.

A study by researchers at the Milner Centre for Evolution at the University of Bath and published in the Journal of Evolutionary Biology, reviewed all mammal species known from the end of the Cretaceous period in North America. Their results showed that over 93 per cent became extinct across the Cretaceous-Paleogene (K-Pg) boundary, but that they also recovered far more quickly than previously thought.

The scientists analysed the published fossil record from western North America from two million years before the Cretaceous-Paleogene boundary, until 300,000 years after the asteroid hit. They compared species diversity before and after this extinction event to estimate the severity of the event and how quickly the mammals recovered. The extinction rates were much higher than previous estimates based on more limited data sets.

Dr Nick Longrich from the Milner Centre for Evolution, in the University of Bath's Department for Biology & Biochemistry, explained: "The species that are most vulnerable to extinction are the rare ones, and because they are rare, their fossils are less likely to be found. The species that tend to survive are more common, so we tend to find them.

"The fossil record is biased in favour of the species that survived. As bad as things looked before, including more data shows the extinction was more severe than previously believed."

The researchers say this explains why the severity of the extinction event was previously underestimated. With more fossils included, the data includes more rare species that died out.

Following the asteroid hit, most of the plants and animals would have died, so the survivors probably fed on insects eating dead plants and animals. With so little food, only small species survived. The biggest animals to survive on land would have been no larger than a cat. The fact that that most mammals were small helps explain why they were able to survive.

Yet the researchers found that mammals also recovered more rapidly than previously thought, not only gaining back the lost diversity in species quickly but soon doubling the number of species found before the extinction. The recovery took just 300,000 years, a short time in evolutionary terms.

Read more … 

Ants were socializing -- and sparring -- nearly 100 million years ago, study finds

Several species of ants, well-preserved in ancient Burmese amber, were studied

Date: February 12, 2016

Source: Rutgers University

Like people, ants have often fought over food and territory.

But ants began fighting long before humans: at least 99 million years ago, according to Phillip Barden, a fossil insect expert who works in the Insect and Evolution Lab of Jessica L. Ware, an assistant professor in the Department of Biological Sciences at Rutgers University-Newark.

"That's a trait of ants," Barden said. "Many ant species do that all the time. They're always warring with either other individuals of the same species from different colonies or with different species."

The ant wars began in the Cretaceous period, when enormous dinosaurs thrived on Earth, according to a study published online in the journal Current Biology. Barden, the lead author, is affiliated with the American Museum of Natural History in New York City. Co-author David A. Grimaldi is a curator at the museum and is also affiliated with Cornell University and the City University of New York.

The fighting ants and others trapped in ancient Burmese amber from Myanmar are among the earliest known ants.

"These early ants belong to lineages distinct from modern ants," he said. "That is, they aren't necessarily the direct ancestors of modern ants. They're kind of their own branch doing their own thing."

The study also provides strong evidence that ancient ants -- like modern ants -- were social, according to Barden, who began a two-year, National Science Foundation Postdoctoral Fellowship in biology at Rutgers-Newark in September.

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Fossil discovery: Extraordinary 'big-mouthed' fish from Cretaceous Period

February 8, 2016

An international team of scientists have discovered two new plankton-eating fossil fish species of the genus called Rhinconichthys (Rink-O-nik-thees) from the oceans of the Cretaceous Period, about 92 million years ago, when dinosaurs roamed the planet.

One of the authors of the study, Kenshu Shimada, a paleobiologist at DePaul University, said Rhinconichthys are exceptionally rare, known previously by only one species from England. But a new skull from North America, discovered in Colorado along with the re-examination of another skull from Japan have tripled the number of species in the genus with a greatly expanded geographical range. According to Shimada, who played a key role in the study, these species have been named R. purgatoirensis and R. uyenoi, respectively.

"I was in a team that named Rhinconichthysin 2010, which was based on a single species from England, but we had no idea back then that the genus was so diverse and so globally distributed," said Shimada.

The new study, "Highly specialized suspension-feeding bony fish Rhinconichthys (Actinopterygii: Pachycormiformes) from the mid-Cretaceous of the United States, England and Japan," will appear in the forthcoming issue of the international scientific journal Cretaceous Research.

The research team includes scientists from government, museum, private sector and university careers. They include Bruce A. Schumacher from the United Sates Forest Service who discovered the new specimen. It also includes researchers, Jeff Liston from the National Museum of Scotland and Anthony Maltese from the Rocky Mountain Dinosaur Resource Center.

Read more at:

Leaf-mining Insects Completely Disappeared With The Dinosaurs

July 28, 2014

By A’ndrea Eluse Messer, Penn State

After the asteroid impact at the end of the Cretaceous period that triggered the dinosaurs’ extinction and ushered in the Paleocene, leaf-mining insects in the western United States completely disappeared. Only a million years later, at Mexican Hat, in southeastern Montana, fossil leaves show diverse leaf-mining traces from new insects that were not present during the Cretaceous, according to paleontologists.

“Our results indicate both that leaf-mining diversity at Mexican Hat is even higher than previously recognized, and equally importantly, that none of the Mexican Hat mines can be linked back to the local Cretaceous mining fauna,” said Michael Donovan, graduate student in geosciences, Penn State.

Insects that eat leaves produce very specific types of damage. One type is from leaf miners — insect larvae that live in the leaves and tunnel for food, leaving distinctive feeding paths and patterns of droppings.

Donovan, Peter Wilf, professor of geosciences, Penn State, and colleagues looked at 1,073 leaf fossils from Mexican Hat for mines. They compared these with more than 9,000 leaves from the end of the Cretaceous, 65 million years ago, from the Hell Creek Formation in southwestern North Dakota, and with more than 9,000 Paleocene leaves from the Fort Union Formation in North Dakota, Montana and Wyoming. The researchers present their results in PLOS ONE.

Read more at

Little Bitty Ancient Mammal Unearthed in Japan

Tia Ghose, LiveScience Staff Writer

Date: 26 March 2013 Time: 08:01 PM ET

Paleontologists in Japan have unearthed the jaw of a primitive mammal from the early Cretaceous period.

The pint-size creature, named Sasayamamylos kawaii for the geologic formation in Japan where it was found, is about 112 million years old and belongs to an ancient clade known as Eutherian mammals, which gave rise to all placental mammals. (A clade is a group of animals that share uniquely evolved features and therefore a common ancestry.)

The jaw sports pointy, sharp teeth and molars in a proportion similar to that found in modern mammals, said paleontologist Brian Davis of Missouri Southern State University, who was not involved in the study.

"This little critter, Sasayamamylos, is the oldest Eutherian mammal to demonstrate what paleontologists consider the modern dental formula in placental mammals," Davis told LiveScience.

The new mammal fossil, described today (March 26) in the journal Proceedings of the Royal Society B, suggests that these primitive creatures were already evolving quickly, with diverse traits emerging, at this point in the Cretaceous Era, he added.

Continued:  http://www.livescience.com/28206-cretaceous-mammal-jaw-unearthed-japan.html

Tough Turtles survive Cretaceous meteorite impact

New fossil localities from North Dakota and Montana have produced the remains of a turtle that survived the 65 million-year-old meteorite impact that wiped out the dinosaurs. The resulting study, published in the latest issue of the Journal of Vertebrate Paleontology, suggests that Boremys, a turtle that belongs to a group known as the baenids (bay-een-ids) survived the extinction event unharmed. Baenids are a group of extinct river turtles native to North America that flourished from approximately 80 million to 42 million years ago.


The lead author, Tyler Lyson from Yale University, has been collecting turtles from the western United States for years, and immediately realized the importance of these new specimens, "This find further confirms that turtles were not fazed by the meteorite that killed the dinosaurs 65 million years-ago."


The survival of turtles during this massive extinction event appears counterintuitive with what we know about other organisms. While other groups of animals show high rates of extinction at the Cretaceous/Paleocene (K/T) boundary 65-million-years ago, this new discovery provides more data indicating that turtles were largely unaffected by the meteorite impact. Lyson and colleagues found that if you just looked at turtles during this time, you would not even notice that one of the largest extinction events in Earth’s history had occurred.

The researchers recovered the new Boremys turtle remains from rocks in southwestern North Dakota and eastern Montana. These rock formations, known as the Hell Creek and Fort Union, respectively, have been actively collected for fossils by paleontologists for more than 100 years. This new study proves that even in well-searched localities, new fossil discoveries can still be uncovered. Co-author Dr. Walter Joyce acknowledged his surprise with the new discovery, "At first I did not believe Tyler when he told me that he had found Boremys in Paleocene deposits."


Lyson and his co-authors believe that features of the shell of Boremys did not help its chances of preservation in the fossil record. The turtle had very thin shell bones relative to other baenids, and they remained unfused throughout the turtle’s life. These features likely led to its skeleton being scattered after death, making the chances of a whole shell being preserved very low. The authors also noted that the features of the shell were very similar to another turtle species living at the same time, which lead to initial misidentification.

With the discovery of this turtle, Lyson and his colleagues can now say that at least eight types of baenid turtles survived the meteorite impact that killed so many other animals.

http://archaeologynewsnetwork.blogspot.com/2011/07/tough-turtles-survive-cretaceous.html

How flowers conquered the world

The great explosion in flowering plants during the Cretaceous Period is one of the great enigmas of evolution.

Charles Darwin had no explanation, calling it an "abominable mystery".

But now scientists think they have solved the riddle of how flowers came to dominate the conifers and ferns that preceded them.

The flowers' secret, they say, was to exploit a change in soil fertility, and create a feedback loop that allowed new flowers to feed off dead ones.

The relative explosion of flowering plants greatly worried Darwin.

In a letter written on 8 March 1875 to palaeobotanist Oswald Heer, he said: "The sudden appearance of so many Dycotyledons in the Upper Chalk appears to me a most perplexing phenomenon to all who believe in any form of evolution."

In a later letter to botanist Joseph Hooker, head of the Royal Botanic Gardens at Kew, Darwin described it as an "abominable mystery".

The great problem for Darwin and others at that time was that the Late Cretaceous was very rich in fossil angiosperm (flowering plant) species, while the Early Cretaceous was almost devoid of any early examples.

This rapid bloom in flowering plant species did not fit Darwin's belief that evolution was an extremely gradual process.

Since then, many more fossils of flowering species have been discovered, showing that they emerged over a longer period.

Today scientists believe that at the start of the Cretaceous Period, 125 million years ago, gymnosperms, the group of plants that contains cycads and conifers, dominated the globe.
Just a few groups of angiosperms had evolved, and these were rather small fragile plants that probably grew in aquatic environments, or alongside streams.

Some are also thought to have colonised extremely dry, possibly salty places, since they had quite thick leaves which would have helped conserve water.

But then, between 125 and 65 million years ago, these flowering plants exploded into life.
For example, around 105 million years ago between five and 20% of all plant species were angiosperms. By 65 million years ago, over 80% were flowering plants.

"The change from a gymnosperm- and fern-dominated world to a world dominated by fast-growing angiosperms is one of the most important changes in the history of the biosphere of our Earth, with enormous consequences for the opportunities of mammals," says Frank Berendse, an ecologist at Wageningen University in The Netherlands.

"Although the change in diversity occurred much more gradually than thought at Darwin's time, the change in abundance occurred very fast," Berendse says.

Berendse and Wageningen University colleague Marten Scheffer now think they can explain how it happened.

They outline their idea in the journal Ecology Letters.

Initially, gymnosperms flourished in poor soils. Such plants have longer-lived leaves which are capable of squeezing more nutrients out of the ground, but the litter they create tends not to decompose very fast. So while gymnosperms benefit from poor soils, they also do little to improve soil quality.

But then came some subtle changes in soil fertility. Angiosperms started colonising more fertile soils, gaining a foothold.

These early flowering plants then began changing the ecology of the soil. As they perished, they create a greater turnover in litter that replenished the soil, allowing yet more flowers to grow.
"From that time a positive feedback developed, where an increase in angiosperm dominance led to an increase in soil fertility and an increase in soil fertility led to a further accelerated expansion of the angiosperms," says Berendse.

The idea that such sudden shifts in vegetation can occur is supported by evidence from the modern day.

Over the past 30 years, heathlands in western Europe have gone from being dominated by dwarf shrubs to perennial grasses, the researchers say.

Like gymnosperms, the shrubs have long-lived leaves and stems which minimise the loss of nutrients but prevent the plants growing fast.

But once the grasses took hold, their faster growth rates created a feedback loop which added more nutrients to the soil, allowing yet more grass to grow.

A similar shift has also taken place in raised bogs, in which peat mosses can quickly be out-competed by vascular plants, say the researchers.

Berendse's and Scheffer's idea remains a hypothesis for now.

But it is one that "could explain the very fast expansion of angiosperms around the globe," says Berendse.

They hope to test the idea further by examining the geological record for tell-tale signs that soil fertility did increase during the rise of the angiosperms, and that flowering plants initially came to dominate at lower latitudes, which should have had more nutrient-rich soils.


Matt Walker Editor, Earth News
http://news.bbc.co.uk/earth/hi/earth_news/newsid_8143000/8143095.stm