University of Washington paleontologists discover major T. rex fossil

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Dave DeMar/Burke Museum/University of Washington

A <em>T. rex</em> tooth discovered by UW Burke Museum paleontologists in Montana.

Tom Wolken/Burke Museum/University of Washington

Paleontologists with the Burke Museum of Natural History Culture the University of Washington have discovered a Tyrannosaurus rex, including a very complete skull. The find, which paleontologists estimate to be about 20 percent of the animal, includes vertebrae, ribs, hips lower jaw bones. The team, led by Burke Museum Adjunct Curator of Vertebrate Paleontology UW biology professor Gregory P. Wilson, discovered the T. rex during an expedition to the Hell Creek Formation in northern Montana — an area that is world-famous for its fossil dinosaur sites. Two Burke Museum paleontology volunteers, Jason Love Luke Tufts, initially discovered pieces of fossilized bone protruding from a rocky hillside. The bones’ large size honeycomb-like structure indicated they belonged to a carnivorous dinosaur. Upon further excavation, the team discovered the T. rex skull along with ribs, vertebrae, parts of the jaw pelvis.

T. rex was one of the largest meat-eating dinosaurs to ever roam the Earth. Measuring an average of 40-feet long 15 to 20-feet tall, T. rex was a fierce predator with serrated teeth large jaws. Fossil evidence shows it ate other dinosaurs like Edmontosaurus Triceratops, with crushed bones from the animals even showing up in the its fossilized poop. T. rex lived about 66-68 million years ago in forested river valleys in western North America during the late Cretaceous Period.

The T. rex found by the Burke/UW team is nicknamed the “Tufts-Love Rex” in honor of the two volunteers who discovered it. The skull is about 4 feet long weighs about 2,500 pounds in its protective plaster jacket. Excavation in the field revealed the right side of the skull from base to snout, including teeth. Burke paleontologists believe it is very probable the other side of the skull is present, but will need to carefully remove the rock surrounding the fossil before they can determine its completeness.

“We think the Tufts-Love Rex is going to be an iconic specimen for the Burke Museum the state of Washington will be a must-see for dinosaur researchers as well,” said Wilson.

Based on the size of its skull, Burke paleontologists estimate this dinosaur is about 85 percent the size of the largest T. rex found to date. At the hips, the T. rex would have been nearly as tall as a city bus, as long as a bus from tail to head.

The Tufts-Love Rex is 66.3 million years old. T. rex lived at the end of the Cretaceous Period, 145-66 million years ago, became extinct during the Cretaceous-Paleogene mass extinction 66 million years ago. Burke paleontologists could determine that the Tufts-Love Rex lived at the very end of the Cretaceous because it was found at the bottom of a hill; a rock layer at the top of that hill marks the Cretaceous-Paleogene mass extinction. Based on the size of the skull — a good indicator of T. rex age — the team estimates the dinosaur was about 15 years old when it died. Adult T. rex lived up to 25-30 years.

Although arguably the most iconic well-known dinosaur, T. rex fossils are rare. This remarkable find is one of only about 25 of this level of completeness. The skull is the 15th reasonably complete T. rex skull known to exist in the world. Next summer, Burke paleontologists will search for additional parts of the dinosaur at the site.

More than 45 people helped excavate the T. rex over the course of a month this summer. The team was collecting fossils in the area for the Hell Creek Project, a multi-disciplinary project examining vertebrates, invertebrates, plants geology of the area to learn more about the final 2 million years of the dinosaur era, the mass-extinction event that killed off the dinosaurs, the first 1.5 million years post-extinction that gave rise to the age of mammals. The project, currently led by Wilson, was founded by Jack Horner Nathan Myhrvold. Burke paleontologists, volunteers, undergraduate graduate students from the UW other universities K-12 educators participating in the Burke’s DIG Field School contribute to the project.

“This is really great news. The Hell Creek Project is responsible for finding the most T. rex specimens in the world, with 11 to date,” said Myhrvold, Intellectual Ventures CEO Paleontologist. “The T. rex has always been my favorite dinosaur I’m really pleased that this one is going to make its home at the Burke Museum.”

“Having seen the ‘Tufts-Love Rex’ during its excavation I can attest to the fact that it is definitely one of the most significant specimens yet found, because of its size, is sure to yield important information about the growth possible eating habits of these magnificent animals,” said Horner, former curator of paleontology at the Museum of the Rockies current Burke Museum research associate.

The T. rex skull other bones are currently covered in a plaster jacket — similar to a cast used to cover a broken bone — in order to protect the skull during transport. The public can see the plaster-covered T. rex skull, along with other T. rex fossils paleontology field tools, in a lobby display at the Burke Museum from August 20 to October 2. Special T. rex-themed activities will take place over Labor Day Weekend on Sunday, September 25.

After removing the fossil from display, the Burke’s paleontology team will begin preparing the fossil by removing the rock surrounding the bone, which may take a year or more. The museum plans to display the T. rex skull in the New Burke Museum when it opens in 2019.

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Recent connection between North South America reaffirmed

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credit: Aaron O’Dea

Split by the Isthmus of Panama: Species of butterfly fish, sdollar cone snail that today live on the Pacific Caribbean coasts of Central America are very closely related. Genetic sequencing shows that only 4 to 3 million years ago, each pair was a single species, demonstrating that marine connections between the oceans must have existed until that time.

Simon Coppard, Alexander Medvedev, Ross Robertson, Shellnut, Bob Fenner

Zircon crystals are like fingerprints holding clues of their source. For example, zircons found in 15 million year old river sediments in Colombia possess a signature like volcanic rocks on the Isthmus of Panama, which led researchers to believe that a lbridge must have connected the two realms at that time. However, zircons with similar signatures also occur in volcanic rocks across northern Colombia casting doubts on their exclusively Panamanian origin the proposal for an old Isthmus of Panama.

Angel Barbosa

Long ago, one great ocean flowed between North South America. When the narrow Isthmus of Panama joined the continents about 3 million years ago, it also separated the Atlantic from the Pacific Ocean. If this took place millions of years earlier, as recently asserted by some, the implications for both lsea life would be revolutionary. Aaron O’Dea, staff scientist at the Smithsonian Tropical Research Institute (STRI), colleagues writing in Science Advances firmly set the date at 2.8 million years ago. “Recent scientific publications proposing the isolation of the two oceans between 23 to 6 million years ago rocked the generally held model of the continental connection to its foundations,” said Jeremy Jackson, emeritus staff scientist at the Smithsonian. “O’Dea his team set out to reevaluate in unprecedented, rigorous detail, all of the available lines of evidence–geologic, oceanographic, genetic ecological data the analyses that bear on the question of when the Isthmus formed.”

“The timing of the connection between continents the isolation of the Pacific Atlantic oceans is important for so many reasons,” O’Dea said. “Estimates of rates of evolutionary change, models of global oceans, the origin of modern-day animals plants of the Americas why Caribbean reefs became established all depend upon knowing how when the isthmus formed.”

The team of researchers from 23 institutions, including nine current or emeritus staff scientists from STRI the Smithsonian’s National Museum of Natural History 13 current or previous Smithsonian post-doctoral fellows concluded that records from marine terrestrial fossils, volcanic marine rocks the genes of marine animals split by the formation of the Isthmus all tell the same story. Three key pieces of evidence defined when the lbridge was finally in place:

Analysis of the family trees of shallow-water marine animals such as fish sdollars from the Pacific Caribbean (Atlantic) sides of the isthmus show genetic mixing until after 3.2 million years ago. Surface waters from the Pacific Caribbean mixed until about 2.8 million years ago, as seen in deep-ocean sediments. Massive migrations of lanimals between North South America began sometime before 2.7 million years ago.

The first paper to propose an earlier connection, published by Camilo Montes, professor at the Universidad de los Andes, STRI staff scientist Carlos Jaramillo in 2015, asserted that tiny particles called zircons found in northern Colombia arrived there 15 million years ago via rivers from the Panama Arc along a lbridge. The authors of the new paper reveal that, in fact, there are several possible sources for these zircons, all of which require less convoluted travel to arrive at their resting place in the Magdalena basin.

The second paper to propose an earlier isthmus by Christine Bacon, post-doctoral fellow at the University of Gothenburg, suggested that molecular data from terrestrial animals plants corresponded with geographic splits in marine animals, assuming the correspondence must have been due to a lbridge. The new study questions their use of a universal rate of evolution–“different species evolve at different rates” Harilaos Lessios, a coauthor, said. They also question their use of genetic splits for lanimals as evidence of the continental connection because “a lbridge would not cause genetic divergence, but would, on the contrary, allow greater genetic mixing between the continents.”

In addition, the new paper mentions that Bacon et al.’s study omitted several important published genetic analyses, which skewed their results when included, eliminate the main line of evidence that marine terrestrial events coincided.

The authors concluded, “Our review new analyses aims to clarify the issue by bringing together expertise from a wide array of different lines of evidence. Given all the available evidence, we strongly caution against the uncritical acceptance of the old isthmus hypothesis.”

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is a part of the Smithsonian Institution. The Institute furthers the understanding of tropical nature its importance to human welfare, trains students to conduct research in the tropics promotes conservation by increasing public awareness of the beauty importance of tropical ecosystems. Website. Promo video.

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Pre-Hispanic Mexican civilization may have bred managed rabbits hares

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F. Botas

Hispanic Mexican city of Teotihuacan may have bred rabbits hares for food, fur bone tools, according to a study published August 17, 2016 in the open-access journal PLOS ONE by Andrew Somerville from the University of California San Diego, US, colleagues. Human-animal relationships often involve herbivore husbandry have been key in the development of complex human societies across the globe. However, fewer large mammals suitable for husbandry were available in Mesoamerica. The authors of the present study looked for evidence of small animal husbandry in the pre-Hispanic city of Teotihuacan, which existed northeast of what is now Mexico City from A.D. 1-600. The authors performed stable carbon oxygen isotope analysis of 134 rabbit hare bone specimens from the ancient city 13 modern wild specimens from central Mexico to compare their potential diets ecology.

Compared to modern wild specimens, the authors found that Teotihuacan rabbit hare specimens had carbon isotope values indicating higher levels of human-farmed crops, such as maize, in their diet. The specimens with the greatest difference in isotope values came from a Teotihuacan complex that contained traces of animal butchering a rabbit sculpture.

While the ancient rabbits hares included in this study could have consumed at least some farmed crops through raiding of fields or wild plants, the authors suggest their findings indicate that Teotihuacan residents may have provisioned, managed, or bred rabbits hares for food, fur, bone tools, which could be new evidence of small mammal husbandry in Mesoamerica.

“Because no large mammals such as goats, cows, or horses were available for domestication in pre-Hispanic Mexico, many assume that Native Americans did not have as intensive human-animal relationships as did societies of the Old World,” said Andrew Somerville. “Our results suggest that citizens of the ancient city of Teotihuacan engaged in relationships with smaller more diverse fauna, such as rabbits jackrabbits, that these may have been just as important as relationships with larger animals.”

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Scientists on the prowl for ‘the ultimate Pokémon’

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Steven Heritage

David Fernandez, study co-author, is treating the first whole-body specimen of&nbsp;<em>Zenkerella</em> that has been found.

Grainne McCabe

Researchers are on a real-life search for what one calls “the ultimate Pokémon”: Zenkerella, an elusive scaly-tailed squirrel that has never been spotted alive by scientists. However, biologists recently found three newly dead specimens that hint at how the “living fossil” has evolved over the past 49 million years. Zenkerella insignis, a mysterious rodent from central Africa, is among the least studied of all living mammals, said Erik Seiffert, study senior author a professor of cell neurobiology at the Keck School of Medicine of USC. The last time scientists heard about Zenkerella in the wild was two decades ago. Notably, only 11 Zenkerella specimens are curated in museums around the world. The three new rodents bring the count to 14.

Zenkerella could be seen as the ultimate Pokémon that scientists have still not been able to find or catch alive,” Seiffert said. “After all, it probably only shows up in the middle of the night, deep in the jungles of central Africa, might spend most of its time way up in tall trees where it would be particularly hard to see.”

Using the three whole-body specimens, scientists sampled Zenkerella‘s DNA for the first time. The study, published in the journal PeerJ on Aug. 16, details how researchers analyzed Zenkerella‘s genes using cells from cheek swabs. Then they compared the scaly-tailed squirrels’ DNA with a large sample of other rodents in an online database called GenBank, which includes all rodent suborders families.

A family divided

Based on DNA results, the researchers determined that, contrary to expectation, Zenkerella is a very distant cousin of two scaly-tailed squirrels with webbing between their legs elbows that allows them to glide from tree to tree. Thus, Zenkerella, who cannot glide, should be placed in the newly named Zenkerellidae family, researchers said. All three cousins are part of the superfamily of Anomaluroidea, partially because they all have a set of scales on the bottom of their tails that reportedly provide support traction for tree climbing.

The study adds to a growing body of evidence: Extreme anatomical adaptations that evolved enabled some mammals to perform tasks such as gliding, flying or swimming are unlikely to be lost or reversed over the course of evolution.

One of only a few ancient ‘living fossils’

Of the about 5,400 mammal species alive today, only Zenkerella insignis five others are the “sole surviving members of ancient lineages” dating all the way back to the early part of the Eocene epoch, 49 million years ago or more, Seiffert said. Within this select group, only Zenkerella, the monito del monte (Dromiciops gliroides) the pen-tailed tree shrew (Ptilocercus lowii) have been given the medal “living fossil.” They closely resemble what is observed in their species’ fossil record. In other words, although they have evolved over time, the changes were minimal.

“It’s an amazing story of survival,” Seiffert said. “In strong contrast to Zenkerella, all of these five other ‘sole survivor’ mammal species have been fairly well studied by scientists. We are only just starting to work on basic descriptions of Zenkerella‘s anatomy. It’s fun to think that there might be other elusive mammalian species out there, deep in the rainforests of central Africa that will be new to science.”

Hunters caught the three Zenkerella specimens in ground snares near the southern tip of Bioko Isloff the west coast of Africa. Villagers there said they catch Zenkerella in forest floor traps once or twice a year, but the meat is not desirable. Eyewitnesses said the rodent is nocturnally active sleeps in tree hollows.

The mystery remains

Scientists still know almost nothing about the unique rodent’s way of life: how it moves, whether it spends most of its time in the trees or on the ground, or what it eats. Future studies will detail Zenkerella‘s anatomy, behavior, diet, ecology locomotion on Bioko Island.

The lack of knowledge about Zenkerella‘s life history ecology has led the International Union for Conservation of Nature to categorize the species as “least concern” because it is thought to be distributed over a broad geographical region in central Africa, said Drew Cronin, study co-author postdoctoral researcher with the Bioko Biodiversity Protection Program at Drexel University.

“This rating belies the fact that threats such as habitat loss degradation are intense widespread in central Africa,” Cronin said. “Zenkerella may be under greater threat. The more information visibility for the species that we can generate, the more likely we are to facilitate the research conservation attention a unique species like Zenkerella requires.”

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New study: Are voters influenced by campaign visits?

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Wood 2016

Los Angeles, CA (August 17, 2016) Despite their extensive national press coverage, campaign visits might not be worth presidential candidates’ time resources. A new study out today finds that voters are largely unaware of unresponsive to campaign visits. The study was published as part of a special issue of The ANNALS of the American Academy of Political Social Science (a journal from SAGE Publishing) titled “Elections in America.” “Of all the tools in a campaigns’ strategic arsenal, the campaign visit is distinguished by its unchanging nature,” wrote study author campaign consultant Dr. Thomas Wood. “The observed pattern of visits within the swing states — where the most politically pivotal markets were not more frequently visited — suggests campaign consultants intend visits to affect the national media narrative rather than local coverage. Visits’ effects on voters themselves, however, are much more modest than consultants often claim.”

Wood looked at voter data to assess the impact of specific candidate visits during the 2012 presidential election. Comparing survey responses from 64,312 voters whose local TV channels aired the visits, did not air the visits, or did not air the visits but had access to non-local channels that did, Wood found:

In areas visited by both Romney Ryan, 36% to 45% of respondents were unaware of the visits. In areas visited by either Romney or Ryan, 56% to 57% of respondents were unaware. The visits’ impact did not spread to outside of the areas visited; awareness of the visits was similar for respondents who had not received local visits, even when they had access to local channels that aired the visits. Visits increased Democrat Republican support for their parties’ candidates by 2% to 3%, with this effect starting one day after the visit ending by the third day after the visit. While Independents were 5% more likely to vote for Romney after the visits were the only group affected by visits for longer than two days, Wood concluded that such a modest response would only matter in marginal elections.

Wood also found that the relationship between candidate visits local media coverage to be modest, with no more than three extra stories from a visit than what would occur from general campaign coverage.

“Taken together, these findings invite a thought experiment: if visits have only a moderate impact on voters but consume vast amounts of the candidates’ their staff’s time, attention, resources, why not neglect visits instead redouble candidates’ attention to fundraising?,” continued Wood. “New resources could then be spent on those activities that have been shown to more reliably influence voters–advertising, building out campaign infrastructure at the local level, providing more resources for voter contact–especially inspire turnout.”

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