Ancient, scary and alien-looking specimen forms a rarity in the insect world — a new order

Researchers at Oregon State University have discovered a 100-million-year-old insect preserved in amber with a triangular head, almost-alien and “E.T.-like” appearance and features so unusual that it has been placed in its own scientific “order” — an incredibly rare event.

There are about 1 million described species of insects, and millions more still to be discovered, but every species of insect on Earth has been placed in only 31 existing orders. Now there’s one more.

The findings have been published in the journal Cretaceous Research and describe this small, wingless female insect that probably lived in fissures in the bark of trees, looking for mites, worms or fungi to feed on while dinosaurs lumbered nearby. It was tiny, but scary looking.

“This insect has a number of features that just don’t match those of any other insect species that I know,” said George Poinar, Jr., an emeritus professor of entomology in the OSU College of Science and one of the world’s leading experts on plant and animal life forms found preserved in the semi-precious stone amber.

“I had never really seen anything like it. It appears to be unique in the insect world, and after considerable discussion we decided it had to take its place in a new order.”

Perhaps most unusual, Poinar said, was a triangular head with bulging eyes, with the vertex of the right triangle located at the base of the neck. This is different from any other known insect, and would have given this species the ability to see almost 180 degrees by turning its head sideways.

The insect, probably an omnivore, also had a long, narrow, flat body, and long slender legs. It could have moved quickly, and literally seen behind itself. It also had glands on the neck that secreted a deposit that scientists believe most likely was a chemical to repel predators.

The insect has been assigned to the newly created order Aethiocarenodea, and the species has been named Aethiocarenus burmanicus, in reference to the Hukawng Valley mines of Myanmar — previously known as Burma — where it was found. Only one other specimen of this insect has been located, also preserved in Burmese amber, Poinar said.

Those two specimens, which clearly belong to the same species, now comprise the totality of the order Aethiocarenodea. The largest order of insects, by comparison, is Coleoptera, the beetles, with hundreds of thousands of known species.

Needless to say, this species from such ancient amber is long extinct. It obviously had special features that allowed it to survive in the forests of what is now Burma, 100 million years ago, but for some unknown reason it disappeared. Loss of its preferred habitat is a likely possibility.

“The strangest thing about this insect is that the head looked so much like the way aliens are often portrayed,” Poinar said. “With its long neck, big eyes and strange oblong head, I thought it resembled E.T. I even made a Halloween mask that resembled the head of this insect. But when I wore the mask when trick-or-treaters came by, it scared the little kids so much I took it off.”

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South American fossil tomatillos show nightshades evolved earlier than thought

Delicate fossil remains of tomatillos found in Patagonia, Argentina, show that this branch of the economically important family that also includes potatoes, peppers, tobacco, petunias and tomatoes existed 52 million years ago, long before the dates previously ascribed to these species, according to an international team of scientists.

Tomatillos, ground cherries and husk tomatoes — members of the physalis genus — are unusual because they have papery, lantern-like husks, known to botanists as inflated calyces that grow after fertilization to extend around their fleshy, often edible berries. They are a small portion of the nightshade family, which includes many commercially, scientifically and culturally valuable plants among its more than 2,400 living species. This entire family has had a notably poor fossil record, limited to tiny seeds and wood with little diagnostic value that drastically limited understanding of when and where it evolved.

The researchers examined two fossil lantern fruit collected at Laguna del Hunco, Chubut, Patagonia, Argentina, in an area that was temperate rainforest when the plants grew, 52 million years ago. These are the only physalis fossils found among more than 6,000 fossils collected from this remote area, and they preserve very delicate features such as the papery husk and the berry itself. The fossil site, which has been the focus of a Penn State, Museo Palentologico Egidio Feruglio, Trelew, Argentina, and Cornell University project for more than a decade, was part of terminal Gondwana, comprised of the adjacent landmasses of South America, Antarctica and Australia during a warm period of Earth history, just before their final separation.

“These astonishing, extremely rare specimens of physalis fruits are the only two fossils known of the entire nightshade family that preserve enough information to be assigned to a genus within the family,” said Peter Wilf, professor of geosciences, Penn State. “We exhaustively analyzed every detail of these fossils in comparison with all potential living relatives and there is no question that they represent the world’s first physalis fossils and the first fossil fruits of the nightshade family. Physalis sits near the tips of the nightshade family’s evolutionary tree, meaning that the nightshades as a whole, contrary to what was thought, are far older than 52 million years.”

Typically, researchers look for fossilized fruits or flowers as their first choice in identifying ancient plants. Because the fruits of the nightshade family are very delicate and largely come from herbaceous plants with low biomass, they have little potential to fossilize. The leaves and flowers are also unknown from the fossil record. This presents a problem for understanding when and where the group evolved and limits the use of fossils to calibrate molecular divergence dating of these plants.

Molecular dating of family trees relies on actual dates of fossils in the family to work from. Because the previous dated fossils had little diagnostic value beyond their membership in the large nightshade family, molecular dating was difficult.

The researchers note in Science that “The fossils are significantly older than corresponding molecular divergence dates and demonstrate an ancient history for the inflated calyx syndrome.”

Molecular dates calibrated with previous fossils had placed the entire nightshade family at 35 to 51 million year ago and the tomatillo group, to which the 52 million year old fossils belong, at only 9 to 11 million years ago.

Using direct geologic dating of materials found with the fossils — argon-argon dating of volcanic tuffs and recognition of two magnetic reversals of the Earth’s poles — the team had previously dated the rocks containing the fossil fruit to 52 million years ago.

“Paleobotanical discoveries in Patagonia are probably destined to revolutionize some traditional views on the origin and evolution of the plant kingdom,” said N. Rubén Cúneo, CONICET, Museo Palentológico Egidio Feruglio. “In this regard, the Penn State/ MEF/Cornell scientific partnership is showing the strength of international collaborations to bring light and new challenges to the exciting world of discovering the secrets of Earth life.”

Mónica Carvalho, former Penn State M.S. student now a Ph.D. student at the School of Integrative Plant Science, Cornell, and Wilf did the evolutionary analysis of the morphology of current members of the family and the fossils, combined with genetic analysis of the living species.

“These fossils are one of a kind, since the delicate papery covers of lantern fruits are rarely preserved as fossils,” Carvalho said. “Our fossils show that the evolutionary history of this plant family is much older than previously considered, particularly in South America, and they unveil important implications for understanding the diversification of the family.”

All members of the physalis genus are New World species inhabiting South, Central and North America. Their center of diversity is Mexico.

The researchers note that the physalis fossils show a rare link from late-Gondwanan Patagonian to living New World plants, but most other fossil plants, such as eucalyptus, found at the site have living relatives concentrated in Australasia. That pattern reflects the ancient overland connection across terminal Gondwana from South America to Australia through Antarctica. The new research raises the possibility that more, potentially much older, nightshade fossils may be found at far southern locations.

“Our results reinforce the emerging pattern wherein numerous fossil plant taxa from Gondwanan Patagonia and Antarctica are substantially older than their corresponding molecular dates, demonstrating Gondwanan history to groups conjectured to have post-Gondwanan origins under entirely different paleogeographic and paleoclimatic scenarios,” the researchers wrote.

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How long did it take to hatch a dinosaur egg? 3-6 months

A human typically gives birth after nine months. An ostrich hatchling emerges from its egg after 42 days. But how long did it take for a baby dinosaur to incubate?

Groundbreaking research led by a Florida State University professor establishes a timeline of anywhere from three to six months depending on the dinosaur.

In an article in the Proceedings of the National Academy of Sciences, FSU Professor of Biological Science Gregory Erickson and a team of researchers break down the complicated biology of these prehistoric creatures and explain how embryonic dental records solved the mystery of how long dinosaurs incubated their eggs.

“Some of the greatest riddles about dinosaurs pertain to their embryology — virtually nothing is known,” Erickson said. “Did their eggs incubate slowly like their reptilian cousins — crocodilians and lizards? Or rapidly like living dinosaurs — the birds?”

Scientists had long theorized that dinosaur incubation duration was similar to birds, whose eggs hatch in periods ranging from 11-85 days. Comparable-sized reptilian eggs typically take twice as long — weeks to many months.

Because the eggs of dinosaurs were so large — some were about 4 kilograms or the size of a volleyball — scientists believed they must have experienced rapid incubation with birds inheriting that characteristic from their dinosaur ancestors.

Erickson, FSU graduate student David Kay and colleagues from University of Calgary and the American Museum of Natural History decided to put these theories to the test.

To do that, they accessed some rare fossils — those of dinosaur embryos.

“Time within the egg is a crucial part of development, but this earliest growth stage is poorly known because dinosaur embryos are rare,” said co-author Darla Zelenitsky, assistant professor of geoscience at University of Calgary. “Embryos can potentially tell us how dinosaurs developed and grew very early on in life and if they are more similar to birds or reptiles in these respects.”

The two types of dinosaur embryos researchers examined were those from Protoceratops — a sheep-sized dinosaur found in the Mongolian Gobi Desert whose eggs were quite small (194 grams) — and Hypacrosaurus, an enormous duck-billed dinosaur found in Alberta, Canada with eggs weighing more than 4 kilograms.

Erickson and his team ran the embryonic jaws through a CT scanner to visualize the forming dentition. Then, they extracted several of the teeth to further examine them under sophisticated microscopes.

Researchers found what they were looking for on those microscope slides. Growth lines on the teeth showed researchers precisely how long the dinosaurs had been growing in the eggs.

“These are the lines that are laid down when any animal’s teeth develops,” Erickson said. “They’re kind of like tree rings, but they’re put down daily. We could literally count them to see how long each dinosaur had been developing.”

Their results showed nearly three months for the tiny Protoceratops embryos and six months for those from the giant Hypacrosaurus.

“Dinosaur embryos are some of the best fossils in the world,” said Mark Norell, Macaulay Curator for the American Museum of Natural History and a co-author on the study. “Here, we used spectacular fossils specimens collected by American Museum expeditions to the Gobi Desert, coupled them with new technology and new ideas, leading us to discover something truly novel about dinosaurs.”

The implications of long dinosaur incubation are considerable.

In addition to finding that dinosaur incubation was similar to primitive reptiles, the researchers could infer many aspects of dinosaurian biology from the results.

Prolonged incubation put eggs and their parents at risk from predators, starvation and other environmental risk factors. And theories that some dinosaurs nested in the more temperate lower latitude of Canada and then traveled to the Arctic during the summer now seem unlikely given the time frame for hatching and migration.

The biggest ramification from the study, however, relates to the extinction of dinosaurs. Given that these warm-blooded creatures required considerable resources to reach adult size, took more than a year to mature and had slow incubation times, they would have been at a distinct disadvantage compared to other animals that survived the extinction event.

“We suspect our findings have implications for understanding why dinosaurs went extinct at the end of the Cretaceous period, whereas amphibians, birds, mammals and other reptiles made it through and prospered,” Erickson said.

This research was supported by the National Science Foundation.

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No teeth? No problem: Dinosaur species had teeth as babies, lost them as they grew

Researchers have discovered that a species of dinosaur, Limusaurus inextricabilis, lost its teeth in adolescence and did not grow another set as adults. The finding, published today in Current Biology, is a radical change in anatomy during a lifespan and may help to explain why birds have beaks but no teeth.

The research team studied 19 Limusaurus skeletons, discovered in “death traps,” where they became mired in mud, got stuck and died, in the Xinjiang Province of China. The dinosaurs ranged in age from baby to adult, showing the pattern of tooth loss over time. The baby skeleton had small, sharp teeth, and the adult skeletons were consistently toothless.

“This discovery is important for two reasons,” said James Clark, a co-author on the paper and the Ronald Weintraub Professor of Biology at the George Washington University’s Columbian College of Arts and Sciences. “First, it’s very rare to find a growth series from baby to adult dinosaurs. Second, this unusually dramatic change in anatomy suggests there was a big shift in Limusaurus’ diet from adolescence to adulthood.”

Limusaurus is part of the theropod group of dinosaurs, the evolutionary ancestors of birds. Dr. Clark’s team’s earlier research of Limusaurus described the species’ hand development and notes that the dinosaur’s reduced first finger may have been transitional and that later theropods lost the first and fifth fingers. Similarly, bird hands consist of the equivalent of a human’s second, third and fourth fingers.

These fossils indicate that baby Limusaurus could have been carnivores or omnivores while the adults were herbivores, as they would have needed teeth to chew meat but not plants. Chemical makeup in the fossils’ bones supports the theory of a change in diet between babies and adults. The fossils also could help to show how theropods such as birds lost their teeth, initially through changes during their development from babies to adults.

“For most dinosaur species we have few specimens and a very incomplete understanding of their developmental biology,” said Josef Stiegler, a graduate student at George Washington University and co-author. “The large sample size of Limusaurus allowed us to use several lines of evidence including the morphology, microstructure and stable isotopic composition of the fossil bones to understand developmental and dietary changes in this animal.”

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New prehistoric bird species discovered

A team of geologists at the University of Rochester has discovered a new species of bird in the Canadian Arctic. At approximately 90 million years old, the bird fossils are among the oldest avian records found in the northernmost latitude, and offer further evidence of an intense warming event during the late Cretaceous period.

“The bird would have been a cross between a large seagull and a diving bird like a cormorant, but likely had teeth,” says John Tarduno, professor and chair of the Department of Earth and Environmental Sciences at the University and leader of the expedition.

Tarduno and his team, which included both undergraduate and graduate students, named the bird Tingmiatornis arctica; “Tingmiat” means “those that fly” in the Inuktitut language spoken in the central and eastern Canadian Arctic (Nunavut territory).

Their findings, published in Scientific Reports, add to previous fossil records Tarduno uncovered from the same geological time period and location in previous expeditions. Taken together, these fossils paint a clearer picture of an ecosystem that would have existed in the Canadian Arctic during the Cretaceous period’s Turonian age, which lasted from approximately 93.9 to 89.8 million years ago.

“These fossils allow us to flesh out the community and add to our understanding of the community’s composition and how it differed from other places in the world,” says Donald Brinkman, vertebrate paleontologist and director of preservation and research at the Royal Tyrrell Museum in Alberta, Canada.

Building historic climate records further helps scientists determine the effects of climate on various communities, ecosystems, and the distribution of species and could help predict the effects of future climatic events.

“Before our fossil, people were suggesting that it was warm, but you still would have had seasonal ice,” Tarduno says. “We’re suggesting that’s not even the case, and that it’s one of these hyper-warm intervals because the bird’s food sources and the whole part of the ecosystem could not have survived in ice.”

From the fossil and sediment records, Tarduno and his team were able to conjecture that the bird’s environment in the Canadian Arctic during the Turonian age would have been characterized by volcanic activity, a calm freshwater bay, temperatures comparable to those in northern Florida today, and creatures such as turtles, large freshwater fish, and champsosaurs — now-extinct, crocodile-like reptiles.

“The fossils tell us what that world could look like, a world without ice at the arctic,” says Richard Bono, a PhD candidate in earth and environmental sciences at the University and a member of Tarduno’s expedition. “It would have looked very different than today where you have tundra and fewer animals.”

The Tingmiatornis arctica fossils were found above basalt lava fields, created from a series of volcanic eruptions. Scientists believe volcanoes pumped carbon dioxide into Earth’s atmosphere, causing a greenhouse effect and a period of extraordinary polar heat. This created an ecosystem allowing large birds, including Tingmiatornis arctica, to thrive.

Tarduno’s team unearthed three bird bones: part of the ulna and portions of the humerus, which, in birds, are located in the wings. From the bone features, as well as its thickness and proportions, the team’s paleontologist, Julia Clarke of the University of Texas, was able to determine the evolutionary relationships of the new birds as well as characteristics that indicate whether it likely was able to fly or dive.

“These birds are comparatively close cousins of all living birds and they comprise some of the oldest records of fossil birds from North America,” Clarke says. “Details of the upper arm bones tell us about how features of the flightstroke seen in living species came to be.”

Previous fossil discoveries indicate the presence of carnivorous fish such as the 0.3-0.6 meter-long bowfin. Birds feeding on these fish would need to be larger-sized and have teeth, offering additional clues to Tingmiatornis arctica’s characteristics.

Physiological factors, such as a rapid growth and maturation rate, might explain how this line of bird was able to survive the Cretaceous-Paleogene mass extinction event that occurred approximately 66 million years ago and eliminated approximately three-quarters of the plant and animal species on Earth.

These physiological characteristics are still conjecture, Tarduno emphasizes, but he says the bird’s environment gives clear indications as to why the bird fossils were found in this location.

“It’s there because everything is right,” Tarduno says. “The food supply was there, there was a freshwater environment, and the climate became so warm that all of the background ecological factors were established to make it a great place.”

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Journal Reference:

Richard K. Bono, Julia Clarke, John A. Tarduno, Donald Brinkman. A Large Ornithurine Bird (Tingmiatornis arctica) from the Turonian High Arctic: Climatic and Evolutionary Implications. Scientific Reports, 2016; 6: 38876 DOI: 10.1038/srep38876

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Fossilized water fleas: Evolution of the micro-crustacean group Cladocera

Scientists of the Senckenberg Institute have studied the evolutionary history of the so-called “water fleas.” These tiny crustaceans from the order Cladocera form the basis of the trophic pyramid and therefore play an important role in modern ecosystems. Due to the fact that they are rarely preserved as fossils, little is known about the water fleas’ evolution. In their study, which was recently published in the scientific journal “Earth-Science Reviews,” the team of scientists presents the first comprehensive inventory of all Cladocera fossils in an ecological context. The scientists show that the animals’ morphology has undergone very little change over the course of geological history. Nevertheless, the water fleas demonstrate a high adaptability to changes in environmental conditions.

A search for organisms in any lake or puddle will very likely turn up a representative of the Cladocera. With more than 700 species, these tiny animals — commonly referred to as “water fleas” due to their bouncing locomotion — inhabit almost all types of freshwater environments. “Despite this wealth of species and habitats, little is known about the evolutionary history of the Cladocera,” explains Dr. Kay Van Damme of the Senckenberg Research Institute in Frankfurt, and he continues, “Since the animals do not possess a calcareous shell or carapace, they are only rarely preserved as fossils.”

For the first time, Van Damme and his colleague, Prof. Alexey A. Kotov of the A.N. Severtsov Institute of Ecology and Evolution in Moscow, have now compiled a complete inventory of all known Cladocera species. “The Cladocera constitute a crucial group in our effort to understand the development of freshwater ecosystems throughout geological history,” says Van Damme in explanation of the team’s motivation. Even today, water fleas still form the basis of many food chains, which makes them an important component of aquatic ecosystems.

Moreover, the tiny crustaceans are very sensitive to environmental changes and can thus be used to monitor water quality — for years, the genus Daphnia has served as a model organism in this regard. “In addition, Daphnia is the first representative of the crustaceans whose genome has been published — therefore, water fleas play a similar role in aquatic environmental genomics as does the fruit fly Drosophila in terrestrial environments,” adds Van Damme.

According to the team of researchers, the first representatives of the water fleas appeared in the early Jurassic, about 180 million years ago. “Since then, the basic design of the Cladocera has hardly changed,” says the biologist from Frankfurt, and he continues, “Nevertheless, this ‘living fossil’ was able to adapt very well to a variety of different environmental conditions.” For example, the water fleas developed various defense mechanisms to escape predators. “Daphnia and company were even able to survive the massive extinction event at the Cretaceous/Tertiary boundary, which, among others, claimed all of the terrestrial dinosaurs,” says Van Damme in closing.

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Mammals in age of dinosaurs packed powerful bite

Move over, hyenas and saber-toothed cats; there’s a mammal with an even stronger bite. A new study by Burke Museum and University of Washington paleontologists describes an early marsupial relative called Didelphodon vorax that lived alongside ferocious dinosaurs and had, pound-for-pound, the strongest bite force of any mammal ever recorded.

Published in the journal Nature Communications, the team’s findings suggest mammals were more varied during the Age of Dinosaurs than previously believed. Didelphodon was able to eat a variety of foods, and was likely a scavenger-predator who could eat prey ranging from snails to small dinosaurs.

In addition, the team re-traced the origins of marsupials. Previous theories attribute South America as the origin of marsupials, but anatomical features of the Didelphodon point to marsupials originating in North America 10-20 million years earlier than originally thought, and later dispersing and diversifying in South America.

“What I love about Didelphodon vorax is that it crushes the classic mold of Mesozoic mammals,” Dr. Gregory P. Wilson, Burke Museum Adjunct Curator of Vertebrate Paleontology and University of Washington Associate Professor of Biology, said. “Instead of a shrew-like mammal meekly scurrying into the shadows of dinosaurs, this badger-sized mammal would’ve been a fearsome predator on the Late Cretaceous landscape — even for some dinosaurs.”

All of these findings are made possible by four fossil specimens recently discovered in the 69-66 million-year-old deposits of the Hell Creek Formation in Montana and North Dakota. Prior to these discoveries, the 60 known species of metatherians (marsupials and their closest relatives) from the Cretaceous of North America — including Didelphodon — were almost all identified through fragments of jaw bones or teeth, providing a limited glimpse into marsupials’ closest relatives. These four fossils include a nearly-complete skull from the North Dakota Geological Survey State Fossil collection, a partial snout and an upper jaw bone from the Burke Museum’s collections, and another upper jaw from the Sierra College Natural History Museum.

By analyzing never-before-seen parts of Didelphodon’s anatomy, Dr. Wilson and his colleagues were able to determine these marsupial relatives were about the size of today’s Virginia opossum and were the largest metatherian from the Cretaceous. With a nearly complete skull to measure, they were able to estimate the overall size of Didelphodon, which ranged from 5.3-11.5 pounds. To test the bite force of Didelphodon, Abby Vander Linden, a UW Biology research technician in Burke Museum Curator of Mammalogy Dr. Sharlene Santana’s lab and now a graduate student at University of Massachusetts Amherst, CT-scanned the fossils and compared the gaps in reconstructed skulls where jaw muscles would go to present-day mammals with known bite forces. Bite force measurements indicate that pound-for-pound, Didelphodon had the strongest bite force of any mammal that has ever lived. In addition to the bite force, Didelphodon’s canines were similar to living felines and hyenas — suggesting they could handle biting into bone, biting deep and killing prey. Its shearing molars and big rounded premolars, combined with powerful jaws and jaw muscles indicate it had a specific niche in the food web as a predator or scavenger capable of crushing hard bone or shells, and was capable of eating prey as big as it was — even possibly small dinosaurs.

“I expected Didelphodon to have a fairly powerful bite based on the robust skull and teeth, but even I was surprised when we performed the calculations and found that, when adjusted for body size, it was capable of a stronger pound-for-pound bite than a hyena,” Vander Linden said. “That’s a seriously tough mammal.”

Co-author Dr. Jonathan Calede, former UW Biology graduate student and now a visiting assistant professor at Bucknell University, also examined “microwear” patterns, or tiny pits and scratches on the specimens’ teeth, to indicate what the animals were eating as their “last suppers” (most likely one-to-two days before the animals died). By comparing the microwear patterns from Didelphodon to the teeth of other fossilized species and current-day mammals with known diets from the Burke’s mammal collection, Calede found Didelphodon was an omnivore that likely consumed a range of vertebrates, plants and hard-shelled invertebrates like molluscs and crayfish, but few insects, spiders and annelids (earthworms and leeches).

“The interesting thing about these fossils is that they allowed us to study the ecology of Didelphodon from many angles,” Calede said. “The strength of the conclusions come from the convergence of microwear with bite force analysis, studies of the shape and breakage of the teeth, as well as the shape of the skull as a whole.”

In addition to learning much more about the biology of Didelphodon, the newly-described skull features on these fossils provide clues that help clarify the origin of all marsupials. The team found five major lineages of marsupial ancestors and marsupials themselves diverged in North America 100-85 million years ago. Marsupial relatives also got larger and ate a wider variety of foods, coinciding with an increase in diversity of other early mammals and flowering plants. Most of this North American diversity was then lost gradually from the late Campanian to Maastrichtian (79-66 million-years-ago) and then abruptly during the Cretaceous-Palaeogene (66 million-years-ago) mass extinction that also killed all dinosaurs except birds. Around this time, marsupials’ diversity and evolution shifted to South America.

“Our study highlights how, despite decades of paleontology research, new fossil discoveries and new ways of analyzing those fossils can still fundamentally impact how we view something as central to us as the evolution of our own clade, mammals,” Dr. Wilson said.

Amber specimen offers rare glimpse of feathered dinosaur tail

Researchers from China, Canada, and the University of Bristol have discovered a dinosaur tail complete with its feathers trapped in a piece of amber.

The finding reported today in Current Biology helps to fill in details of the dinosaurs’ feather structure and evolution, which can’t be surmised from fossil evidence.

While the feathers aren’t the first to be found in amber, earlier specimens have been difficult to definitively link to their source animal, the researchers say.

Ryan McKellar, from the Royal Saskatchewan Museum in Canada, said: “The new material preserves a tail consisting of eight vertebrae from a juvenile; these are surrounded by feathers that are preserved in 3D and with microscopic detail.

“We can be sure of the source because the vertebrae are not fused into a rod or pygostyle as in modern birds and their closest relatives. Instead, the tail is long and flexible, with keels of feathers running down each side. In other words, the feathers definitely are those of a dinosaur not a prehistoric bird.”

The study’s first author Lida Xing from the China University of Geosciences in Beijing discovered the remarkable specimen at an amber market in Myitkyina, Myanmar in 2015.

The amber piece was originally seen as some kind of plant inclusion and destined to become a curiosity or piece of jewellery, but Xing recognized its potential scientific importance and suggested the Dexu Institute of Palaeontology buy the specimen.

The researchers say the specimen represents the feathered tail of a theropod preserved in mid-Cretaceous amber about 99 million years ago. While it was initially difficult to make out details of the amber inclusion, Xing and his colleagues relied on CT scanning and microscopic observations to get a closer look.

The feathers suggest the tail had a chestnut-brown upper surface and a pale or white underside. The specimen also offers insight into feather evolution. The feathers lack a well-developed central shaft or rachis. Their structure suggests that the two finest tiers of branching in modern feathers, known as barbs and barbules, arose before a rachis formed.

Professor Mike Benton from the School of Earth Sciences at the University of Bristol, added: “It’s amazing to see all the details of a dinosaur tail — the bones, flesh, skin, and feathers — and to imagine how this little fellow got his tail caught in the resin, and then presumably died because he could not wrestle free.

“There’s no thought that dinosaurs could shed their tails, as some lizards do today.”

The researchers also examined the chemistry of the tail inclusion where it was exposed at the surface of the amber. The analysis shows that the soft tissue layer around the bones retained traces of ferrous iron, a relic left over from haemoglobin that was also trapped in the sample.

The findings show the value of amber as a supplement to the fossil record. Ryan McKellar added: “Amber pieces preserve tiny snapshots of ancient ecosystems, but they record microscopic details, three-dimensional arrangements, and labile tissues that are difficult to study in other settings.

“This is a new source of information that is worth researching with intensity, and protecting as a fossil resource.”

The researchers say they are now “eager to see how additional finds from this region will reshape our understanding of plumage and soft tissues in dinosaurs and other vertebrates.”

Paleontology: A monster put in its place

An analysis of the fossil known as the Minden Monster has enabled paleontologists to assign the largest predatory dinosaur ever found in Germany to a previously unknown genus, among a group that underwent rapid diversification in the Middle Jurassic.

This huge dinosaur dates to about 163 million years ago, in the Middle Jurassic. And it is not only the first carnivorous dinosaur from this period to be unearthed in Germany, it is also the largest ever found in the country: Based on the remains so far recovered, the specimen is estimated to have been between 8 and 10 meters in length. In comparison with other carnivorous dinosaurs, the animal was very sturdily built, weighed more than 2 tons — and was probably not fully grown when it died. Now Oliver Rauhut, a paleontologist in the Department of Earth and Environmental Sciences at LMU (who is also affiliated with the Bavarian State Collection for Paleontology and Geology in Munich), together with Tom Hübner and Klaus-Peter Lanser of the LWL Museum of Natural History in Münster, have undertaken a detailed study of the fossil material, and concluded that the specimen represents a previously unknown genus and species to which they have given the name Wiehenvenator albati.

Dinosaur archipelago

The first fossilized bones and teeth were discovered in 1999 during a routine surface survey in an abandoned quarry in the Wiehengebirge, a range of low hills south of Minden. Although the fossil clearly represents a terrestrial form, the remains were embedded in marine sediments. It is however known that, in the Middle Jurassic, large areas of what is now Central Europe lay below sea level, and the shallow waters of this sea were dotted with islands. These islands appear to have been the home of a broad spectrum of carnivorous dinosaurs, some of which reached very large sizes, Rauhut explains.

“Moreover, most of them belonged to the group known as the megalosaurids.” Wiehenvenator albati was a megalosaur and other representatives of the group have been found in France and England. In fact, the megalosaurids are the earliest large carnivorous dinosaurs we know of.

The remains of W. albati that have so far been discovered do not constitute a complete skeleton. The material is, however, very well preserved, and anatomical details can be clearly discerned which unequivocally prove that this individual not only represents a new species, but a new genus. Some of the teeth that have been found are as big as bananas, and have a recurved shape, pointing backwards into the pharynx. Like Allosaurus and the much younger Tyrannosaurus rex, W. albati was bipedal, standing on its hindlegs, while its forelimbs were much reduced in length.

A phylogenetic analysis of the morphology of the specimen revealed that Wiehenvenator can be assigned to a group of dinosaurs that underwent a rapid adaptive radiation during the Middle Jurassic, giving rise to a diverse array of species in a relatively short time. “Practically all the major groups of predatory dinosaurs originated during this period, including the tyrannosaurs — which, however, only gave rise to their really gigantic representatives some 80 million years later — and the first direct ancestors of the birds,” says Rauhut. This huge burst of speciation was probably made possible by the preceding extinction of a large proportion of the more primitive forms of predatory dinosaurs at the end of Lower Jurassic, which may in turn have been precipitated by a change in the climate due to widespread volcanic activity.

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Fossil pollen ‘sneeze’ caught by research team

Like capturing a sneeze, researchers including a University of Guelph scientist have recorded the only known example of prehistoric pollen caught in explosive mid-discharge from a fossil flower.

The team describes this “freeze-frame” fossilized pollen release — preserved in amber more than 20 million years ago — in a paper describing a new genus of fossil nettle plants.

The researchers captured on camera pollen explosions.

The paper is co-authored by Peter Kevan, emeritus professor in the School of Environmental Sciences. It appears in the journal Botany alongside another paper by a second team that also includes the U of G researcher.

That second paper looks at a modern-day plant relative in Latin America that is surprising researchers with its use of explosive pollen release, a fair-weather dispersal method seemingly ill-suited to its home in humid tropical rainforests.

In their fossil paper, Kevan and his co-authors describe a new genus (Ekrixanthera, meaning “explosive anther”) containing two new species of extinct plants related to modern-day nettles.

These fossil plants were preserved during the mid-Tertiary period, said Kevan. By then, dinosaurs were long-extinct and non-human mammals roamed Earth.

The samples came from the Dominican Republic and Mexico.

One Mexican sample has preserved pollen grains caught in mid-discharge from the male plant’s anther.

This pollen burst normally takes less than one-tenth of a second, said Kevan. “It’s remarkable that it was captured. It’s like catching a sneeze.”

He was asked to help identify the plants by lead author George Poinar Jr., an expert on amber fossils at Oregon State University.

“We ended up with the new genus because the flowers do not match those of any modern species,” said Kevan. “This tells us something about how old that group of plants is, and that this pollination mechanism goes back a long way.”

That form of pollen dispersal is also described in the second paper about modern-day tropical nettles. Boehmeria caudata grows from southern North America to northern Argentina.

Explosive pollen release is “something you don’t expect in the rainforest. Pollen blasted into the air is likely to get rained out.”

Most tropical plants rely instead on such creatures as insects, bats and birds rather than wind pollination, said Kevan.

In this group of nettles, the male plant disperses its pollen during short dry periods. Even during the rainy season, short sunny periods of high heat and low humidity trigger pollen release.

Drying causes parts of its stamens to shrink unevenly. Physical tension ruptures the anther to release an explosive burst of pollen.

That quick-release mechanism propels pollen into air currents and allows the male flowers to react to short-term weather conditions.

Kevan’s co-authors are students at the University of Sao Paulo led by Paula Maria Montoya-Pfeiffer. They studied Boehmeria during a pollination course taught in Brazil by Kevan in late 2014.

He and colleagues have taught that course in several Latin American countries for decades.