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Researchers test blood flow in athletes’ brains to find markers that diagnose concussions

Diagnosing concussions is difficult because it typically rests on subjective symptoms such as forgetfulness, wobbly gait and disorientation or loss of consciousness. A new study of college athletes investigates objective indicators using Doppler ultrasound to measure brain blood flow and blood vessel function.

A hard hit to the head typically prompts physicians to look for signs of a concussion based on symptoms such as forgetfulness, wobbly gait and disorientation.

But symptoms such as those are subjective. And youth who are anxious to get back to their sport can sometimes hide the signs in order to brush off adult concerns, says physiologist Sushmita Purkayastha, Southern Methodist University, Dallas.

Now a new study funded by the Texas Institute for Brain Injury and Repair at U.T. Southwestern Medical Center, Dallas aims to find noninvasive objective indicators to diagnose whether an athlete has suffered a concussion. Using transcranial Doppler ultrasound, the study will probe the brains of college athletes to measure blood vessel function in the brain, looking for tell-tale signs related to blood flow that help diagnose concussion, said Purkayastha, a researcher on the new study.

“We know this is an understudied area. With other health problems, when the doctor suspects diabetes or hypertension, they don’t guess, they run objective tests to confirm the diagnosis. But that’s not the case with concussion — yet,” said Purkayastha, whose research expertise is blood flow regulation in the human brain. “That’s why my research focus is to find markers that are objective and not subjective. And this method of monitoring blood flow in the brain with ultrasound is noninvasive, inexpensive and there’s no radiation.”

Purkayastha and others on the research team are working under a one-year, $150,000 pilot research grant from the Texas Institute for Brain Injury and Repair, a UT Southwestern initiative funded by the Texas Legislature to enhance the diagnosis and treatment of brain injuries.

The team will observe 200 male and female college athletes over the next two years. Half the athletes will be students playing a contact-collision sport who have recently suffered a sports-related concussion. The other half, a control group, will be students playing a contact-collision sport who don’t have a concussion. The study draws on athletes from football, soccer, equestrian sports, cheerleading and recreational sports.

The researchers began testing subjects in August. They expect to have results by the Fall of 2017.

“We are very excited at establishing this collaboration between SMU and the Physical Medicine and Rehabilitation Department at UTSW. Our work with Dr. Purkayastha promises to give meaningful insight into the role of cerebral blood flow mechanisms after concussion and will point us in the right direction for improved neurorecovery,” said physician Kathleen Bell, a leading investigator at U.T. Southwestern’s Texas Institute for Brain Injury and Repair and principal investigator on the study. Bell is a nationally recognized leader in rehabilitation medicine and a specialist in neurorehabilitation.

Diagnosing concussions by using objective, non-invasive and inexpensive markers will result in accurate diagnosis and better return-to-play decisions following a concussion, thereby preventing the long-term risk of second-impact syndrome, said Purkayastha, an assistant professor in the Department of Applied Physiology and Wellness of SMU’s Annette Caldwell Simmons School of Education and Human Development.

“Although sports-related concussions are common, the physiology of the injury is poorly understood, and hence there are limited treatments currently available,” she said.

Hemorrhage or blackouts result, for example, if autoregulation malfunctions
While the brain is the most important organ in the body, it has been very understudied, said Purkayastha, a professor in the Simmons School of Education & Human Development. But since blood vessels in the brain behave similarly to those in the rest of the body, it’s possible to measure blood vessel function in the brain by monitoring blood pressure and brain blood flow. Observing those functions could reveal a marker, she said.

In Purkayastha’s lab on the SMU campus, student athletes are being outfitted with two small ultrasound probes, one on each side of their forehead in the temple area, to test blood vessel function. Specifically, the two probes monitor the blood flow through middle cerebral artery, which supplies blood to 75 percent of the brain. The artery traverses the brain, circulating blood to the brain tissues responsible for movement, cognition and decision-making.

Branching from the middle cerebral artery is a network of blood vessels that get smaller and smaller as they get further from the artery, spreading like tree branches through the brain. The smallest vessels — via a different local regulatory mechanism — maintain constant blood flow to the brain, making microadjustments, such as constricting and dilating in the face of constant changes in blood pressure. Adjustments occur as a person’s muscles move, whether standing, sitting, exercising, or even just laughing and experiencing emotion. These continual adjustments in the vessels — called cerebral autoregulation — keep blood flow constant and regular. That prevents problems such as hemorrhaging or passing out from large fluctuations in blood pressure that is either too high or too low.

Researchers suspect concussion diminishes a vessels ability to properly regulate blood flow
In the current study, ultrasound probes on the temples record the vessels’ microadjustments as digital data. That information is processed through a WinDaq data acquisition software and analyzed to examine cerebral autoregulation with spontaneous changes in blood pressure during that period of time.

Unlike at the doctor’s office, when a cuff is used to measure blood pressure at a rate of single measurements during 30 seconds, Purkayastha’s ultrasound monitoring of blood pressure provides continuous blood pressure recording throughout each heartbeat. As sound waves bounce into the artery and send back an echo, they measure the speed of red blood cells and other blood components moving through the artery.

“We collect 10 minutes of very high frequency data points collecting information on beat-to-beat changes in blood pressure and blood flow to the brain for every single heartbeat,” said Purkayastha. “Then we analyze and post-process and examine how well the blood vessels were able to maintain constant blood flow to the brain. We suspect in people with concussion that the autoregulation function isn’t operating properly which leads to impairments in function such as wobbly gait, disorientation or forgetfulness. This is a noninvasive way to see if there’s a flaw in the autoregulation.”

Athletes with confirmed diagnosis of concussions will be tested three times during the course of the study. The first test is three days after a suspected concussion, the second is 21 days afterward, and the third is three months afterward.

“The pilot studies so far look promising and our goal is to better understand the mechanism behind injury and design objective markers detecting concussion,” said Purkayastha.

The Texas Institute for Brain Injury and Repair at U.T. Southwestern Medical Center, a component of the Harold and Annette Simmons Comprehensive Center for Research and Treatment in Brain and Neurological Disorders, is a collaborative initiative involving local and national organizations, including the National Institutes of Health, University of Texas Dallas and its Center for BrainHealth, Children’s Medical Center, Dallas VA Medical Center, and Parkland Health and Hospital System, as well as Texas Health Resources and Texas Health Ben Hogan Sports Medicine. — Margaret Allen, SMU

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SMU biochemists, students probe membrane proteins that thwart cancer chemotherapies

“Recurring cancers have ‘learned’ how to evade chemotherapy by pumping it out of the cancer cells so that only sub-therapeutic concentrations remain in the cell, making the drug useless.” — SMU biochemist Pia Vogel

The SMU undergraduate students and Dallas-area high school students get hands-on experience working on cancer research in the combined SMU Department of Biological Sciences laboratories of Wise and Vogel.

The researchers and students are working to find ways to treat cancer patients whose cancer has either returned after initial chemotherapy or was initially hard to treat using chemotherapeutics. The research is funded in part by the National Institutes of Health.

SMU Cancer Research

Students recently in the lab included Victoria Bennet, Hockaday School, and Shaffin Siddiqui and Robert Luo, both from Highland Park High School. SMU undergraduates included Hamilton Scholar Alexis Sunshine, Clinton Osifo, Stefanie Lohse, Brianna Ramirez, Henry Thornton, Shirely Liu, Justin Musser, Jake Oien and Michael Fowler. Also currently working in the lab are M.S. student and Hamilton Scholar Collette Marchesseau (2016 SMU graduate), and Ph.D. students Amila Nanayakkara, Mike Chen, Courtney Follit, Maisa Oliveira and James McCormick.

“Often, recurring cancers have ‘learned’ how to evade chemotherapy by pumping the therapeutic out of the cancer cells so that only sub-therapeutic concentrations remain in the cell, making the drug useless,” said Vogel, a professor and director of the SMU interdisciplinary research institute, the Center for Drug Discovery, Design and Delivery.

The pumps that do the work are proteins that span the cell membranes and use the biological fuel ATP to actively pump chemotherapeutics and other toxins out of the cells.

“We like to compare these proteins to biological sump pumps,” said Wise, associate professor.

Wise and Vogel use a combination of computational, biochemical and human cell-based techniques to find new drug-like compounds that inhibit the action of the pumps. If successful, the novel drugs — or derivatives of them — will be given to patients with therapy-resistant cancer together with the chemotherapeutic.

“Since our novel compounds block the pumps, the chemotherapeutic will remain in the cell and kill the cancer that had not been treatable previously,” Vogel said.

The researchers have discovered drug-like compounds that can be modified and developed into medicines that target the protein, called P-glycoprotein.

The SMU researchers discovered the compounds after virtually screening more than 10 million small drug-like compounds made publically available in digital form from the pharmacology database Zinc at the University of California, San Francisco.

Using SMU’s Maneframe high performance computer, Wise ran the compounds through a computer-generated model of the protein. The virtual model, designed and built by Wise, is the first computational microscope of its kind to simulate the actual behavior of P-glycoprotein in the human body, including interactions with drug-like compounds while taking on different shapes. The promising compounds were then tested in the lab.

“We have been quite successful and already have identified close to 20 novel compounds that block the pumps in our cell-based assays,” said Wise. “In these experiments we culture therapy-resistant prostate or ovarian or colon cancer cells in the lab and then show that we can kill these cancer cells using normal amounts of commonly available therapeutics in the presence of our novel compounds — even though in the absence of our novel compounds, the cancer cells would not be treatable.”

A pharmaceutical hit compound, like those discovered by Vogel and her co-authors, is a compound that is a promising candidate for chemical modification so it can eventually be delivered to patients as a therapeutic drug. In the case reported here, the compounds were commercially available for testing. The timeline from drug discovery to development to clinical trials and approval can take a decade or more.

SMU undergraduates and high school students experience world-class research
SMU undergraduate and high school students have been involved in different aspects of the research. Typically the beginning students work together with graduate or advanced undergraduate students to learn techniques used in the lab.

Some perform small research projects. Others have simply learned state-of-the-art techniques and “how science works” in the context of critical human health problems.

“High school student Robert Luo was interested in the computational side of our work, so he’s worked with senior SMU Ph.D. candidate James McCormick on trying to evaluate how strongly one of the therapy-sensitizing compounds we found potentially interacts with the pump protein at different proposed binding sites,” said Wise. “It is actually a significant project and will help with our research.”

The opportunities available for students to learn how science works using high performance computing, biochemistry and cell biology can be valuable even for those who won’t necessarily become practicing scientists, said Wise, citing as an example a recent SMU graduate who previously worked in the lab.

“Ketetha Olengue (SMU ’15) is a good example,” he said. “She is now in her second year at the Keck School of Medicine at the University of Southern California, where she is pursuing her M.D. degree in a novel program with USC Engineering.” — Margaret Allen, SMU

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Nearby massive star explosion 30 million years ago equaled brightness of 100 million suns

Analysis of exploding star’s light curve and color spectrum reveal spectacular demise of one of the closest supernova to Earth in recent years; its parent star was so big it’s radius was 200 times larger than our sun

A giant star that exploded 30 million years ago in a galaxy near Earth had a radius prior to going supernova that was 200 times larger than our sun, according to astrophysicists at Southern Methodist University, Dallas.

The sudden blast hurled material outward from the star at a speed of 10,000 kilometers a second. That’s equivalent to 36 million kilometers an hour or 22.4 million miles an hour, said SMU physicist Govinda Dhungana, lead author on the new analysis.

The comprehensive analysis of the exploding star’s light curve and color spectrum have revealed new information about the existence and sudden death of supernovae in general, many aspects of which have long baffled scientists.

“There are so many characteristics we can derive from the early data,” Dhungana said. “This was a big massive star, burning tremendous fuel. When it finally reached a point its core couldn’t support the gravitational pull inward, suddenly it collapsed and then exploded.”

The massive explosion was one of the closest to Earth in recent years, visible as a point of light in the night sky starting July 24, 2013, said Robert Kehoe, SMU physics professor, who leads SMU’s astrophysics team.

The explosion, termed by astronomers Supernova 2013ej, in a galaxy near our Milky Way was equal in energy output to the simultaneous brightness of 100 million of the Earth’s suns.

The star was one of billions in the spiral galaxy M74 in the constellation Pisces.

Considered close by supernova standards, SN 2013ej was in fact so far away that light from the explosion took 30 million years to reach Earth. At that distance, even such a large explosion was only visible by telescopes.

Dhungana and colleagues were able to explore SN 2013ej via a rare collection of extensive data from seven ground-based telescopes and NASA’s Swift satellite.

The data span a time period prior to appearance of the supernova in July 2013 until more than 450 days after.

The team measured the supernova’s evolving temperature, its mass, its radius, the abundance of a variety of chemical elements in its explosion and debris and its distance from Earth. They also estimated the time of the shock breakout, the bright flash from the shockwave of the explosion.

The star’s original mass was about 15 times that of our sun, Dhungana said. Its temperature was a hot 12,000 Kelvin (approximately 22,000 degrees Fahrenheit) on the tenth day after the explosion, steadily cooling until it reached 4,500 Kelvin after 50 days. The sun’s surface is 5,800 Kelvin, while the Earth’s core is estimated to be about 6,000 Kelvin.

The new measurements are published online here in the May 2016 issue of The Astrophysical Journal, “Extensive spectroscopy and photometry of the Type IIP Supernova 2013j.”

Shedding new light on supernovae, mysterious objects of our universe
Supernovae occur throughout the universe, but they are not fully understood. Scientists don’t directly observe the explosions but instead detect changes in emerging light as material is hurled from the exploding star in the seconds and days after the blast.

Telescopes such as SMU’s robotic ROTSE-IIIb telescope at McDonald Observatory in Texas, watch our sky and pick up the light as a point of brightening light. Others, such as the Hobby Eberly telescope, also at McDonald, observe a spectrum.

SN 2013ej is M74’s third supernova in just 10 years. That is quite frequent compared to our Milky Way, which has had a scant one supernova observed over the past 400 years. NASA estimates that the M74 galaxy consists of 100 billion stars.

M74 is one of only a few dozen galaxies first cataloged by the astronomer Charles Messier in the late 1700s. It has a spiral structure — also the Milky Way’s apparent shape — indicating it is still undergoing star formation, as opposed to being an elliptical galaxy in which new stars no longer form.

It’s possible that planets were orbiting SN 2013ej’s progenitor star prior to it going supernova, in which case those objects would have been obliterated by the blast, Kehoe said.

“If you were nearby, you wouldn’t know there was a problem beforehand, because at the surface you can’t see the core heating up and collapsing,” Kehoe said. “Then suddenly it explodes — and you’re toast.”

Distances to nearby galaxies help determine cosmic distance ladder
Scientists remain unsure whether supernovae leave behind a black hole or a neutron star like a giant atomic nucleus the size of a city.

“The core collapse and how it produces the explosion is particularly tricky,” Kehoe said. “Part of what makes SN 2013ej so interesting is that astronomers are able to compare a variety of models to better understand what is happening. Using some of this information, we are also able to calculate the distance to this object. This allows us a new type of object with which to study the larger universe, and maybe someday dark energy.”

Being 30 million light years away, SN 2013ej was a relatively nearby extragalactic event, according to Jozsef Vinko, astrophysicist at Konkoly Observatory and University of Szeged in Hungary.

“Distances to nearby galaxies play a significant role in establishing the so-called cosmic distance ladder, where each rung is a galaxy at a known distance.”

Vinko provided important data from telescopes at Konkoly Observatory and Hungary’s Baja Observatory and carried out distance measurement analysis on SN 2013ej.

“Nearby supernovae are especially important,” Vinko said. “Paradoxically, we know the distances to the nearest galaxies less certainly than to the more distant ones. In this particular case we were able to combine the extensive datasets of SN 2013ej with those of another supernova, SN 2002ap, both of which occurred in M74, to suppress the uncertainty of their common distance derived from those data.”

Supernova spectrum analysis is like taking a core sample
While stars appear to be static objects that exist indefinitely, in reality they are primarily a burning ball, fueled by the fusion of elements, including hydrogen and helium into heavier elements. As they exhaust lighter elements, they must contract in the core and heat up to burn heavier elements. Over time, they fuse the various chemical elements of the periodic table, proceeding from lightest to heaviest. Initially they fuse helium into carbon, nitrogen and oxygen. Those elements then fuel the fusion of progressively heavier elements such as sulfur, argon, chlorine and potassium.

“Studying the spectrum of a supernova over time is like taking a core sample,” Kehoe said. “The calcium in our bones, for example, was cooked in a star. A star’s nuclear fusion is always forging heavier and heavier elements. At the beginning of the universe there was only hydrogen and helium. The other elements were made in stars and in supernovae. The last product to get created is iron, which is an element that is so heavy it can’t be burned as fuel.”

Dhungana’s spectrum analysis of SN 2013ej revealed many elements, including hydrogen, helium, calcium, titanium, barium, sodium and iron.

“When we have as many spectra as we have for this supernova at different times,” Kehoe added, “we are able to look deeper and deeper into the original star, sort of like an X-ray or a CAT scan.”

SN 2013ej’s short-lived existence was just tens of millions of years
Analysis of SN 2013ej’s spectrum from ultraviolet through infrared indicates light from the explosion reached Earth July 23, 2013. It was discovered July 25, 2013 by the Katzman Automatic Imaging Telescope at California’s Lick Observatory. A look back at images captured by SMU’s ROTSE-IIIb showed that SMU’s robotic telescope detected the supernova several hours earlier, Dhungana said.

“These observations were able to show a rapidly brightening supernova that started just 20 hours beforehand,” he said. “The start of the supernova, termed ‘shock breakout,’ corresponds to the moment when the internal explosion crashes through the star’s outer layers.”

Like many others, SN 2013ej was a Type II supernova. That is a massive star still undergoing nuclear fusion. Once iron is fused, the fuel runs out, causing the core to collapse. Within a quarter second the star explodes.

Supernovae have death and birth written all over them
Massive stars typically have a shorter life span than smaller ones.

“SN 2013ej probably lived tens of millions of years,” Kehoe said. “In universe time, that’s the blink of an eye. It’s not very long-lived at all compared to our sun, which will live billions of years. Even though these stars are bigger and have a lot more fuel, they burn it really fast, so they just get hotter and hotter until they just gobble up the matter and burn it.”

For most of its brief life, SN 2013ej would probably have burned hydrogen, which then fused to helium, burning for a few hundred thousand years, then perhaps carbon and oxygen for a few hundred days, calcium for a few months and silicon for several days.

“Supernovae have death and birth written all over them,” Kehoe said. “Not only do they create the elements we are made of, but the shockwave that goes out from the explosion — that’s where our solar system comes from.”

Outflowing material slams into clouds of material in interstellar space, causing it to collapse and form a solar system.

“The heavy elements made in the supernova and its parent star are those which comprise the bulk of terrestrial planets, like Earth, and are necessary for life,” Kehoe said.

Besides physicists in the SMU Department of Physics, researchers on the project also included scientists from the University of Szeged, Szeged, Hungary; the University of Texas, Austin, Texas; Konkoly Observatory, Budapest, Hungary; and the University of California, Berkeley, Calif. — Margaret Allen

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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SMU Research Day 2016: Students present their research to the SMU and Dallas community

Day of presenting in Hughes-Trigg Student Center allows students to discuss their research, identify potential collaborators, discover other perspectives.

SMU graduate and undergraduate students presented their research to the SMU community at the University’s Research Day 2016 on Feb. 10.

Sponsored by the SMU Office of Research and Graduate Studies, the research spanned more than 20 different fields from schools across campus.

The annual Research Day event fosters communication between students in different disciplines, gives students the opportunity to present their work in a professional setting, and allows students to share with their peers and industry professionals from the greater Dallas community the outstanding research conducted at SMU.

A cash prize of $250 was awarded to the best poster from each department or judging group.

View the list of student winners whose research was awarded a cash prize.

View highlights of the presentations.

Some highlights of the research:

  • Faris Altamimi, a student of Dr. Sevinc Sengor in Lyle School‘s Civil and Environmental Engineering Department, presented a study investigating experimental and modeling approaches for enhanced methane generation from municipal solid waste, while providing science-based solutions for cleaner, renewable sources of energy for the future.
  • Yongqiang Li and Xiaogai Li, students of Dr. Xin-Lin Gao in Lyle School’s Mechanical Engineering Department, are addressing the serious blunt trauma injury that soldiers on the battlefield suffer from ballistics impact to their helmets. The study simulated the ballistic performance of the Advanced Combat Helmet.
  • Audrey Reeves, Sara Merrikhihaghi and Kevin Bruemmer, students of Dr. Alexander Lippert, in the Chemistry Department of Dedman College, presented research on cell-permeable fluorescent probes in the imaging of enzymatic pathways in living cells, specifically the gaseous signaling molecule nitroxyl. Their research better understands nitroxyl’s role as an inhibitor of an enzyme that is key in the conversion of acetaldehyde to acetic acid.
  • Rose Ashraf, a student of Dr. George Holden in the Psychology Department of Dedman College, presented her research on harsh verbal discipline in the home and its prediction of child compliance. It was found permissive parents are least likely to elicit prolonged compliance.
  • Nicole Vu and Caitlin Rancher, students of Dr. Ernest N. Jouriles and Dr. Renee McDonald in the Psychology Department of Dedman College, presented research on children’s threat appraisals of interparental conflict and it’s relationship to child anxiety.

See the full catalog of participants and their abstracts.

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New fossils intensify mystery of short-lived, toothy mammals unique to ancient North Pacific

Oddball creature, Desmostylia, from waters where “Deadliest Catch” TV show is filmed, ate like a vacuum cleaner and is new genus and species of the only order of marine mammals ever to go extinct — surviving a mere 23 million years

Identification of a new species of the marine mammal Desmostylia has intensified the rare animal’s brief mysterious journey through prehistoric time, finds a new study.

Desmostylians were a big, hippo-sized animal with a long snout and tusks. The new species is 23 million years old and has a unique tooth and jaw structure, said vertebrate paleontologist and study co-author Louis L. Jacobs, Southern Methodist University, Dallas.

Those features indicate it was not only a vegetarian, but literally sucked vegetation from shorelines like a vacuum cleaner, Jacobs said.

But unlike other marine mammals alive today — such as whales, seals and sea cows — desmostylians went totally extinct. Desmostylians, every single species combined, lived in an interval between 33 million and 10 million years ago.

Its strange columnar teeth and odd style of eating don’t occur in any other animal, Jacobs said.

The new specimens — from at least four individuals — were recovered from Unalaska, an Aleutian island in the North Pacific.

While alive, the creatures lived in what is now Unalaska’s Dutch Harbor, where fishing boats depart on Discovery channel’s “Deadliest Catch” reality TV show.

“The new animal — when compared to one of a different species from Japan — made us realize that desmos do not chew like any other animal,” said Jacobs, a professor in SMU’s Roy M. Huffington Department of Earth Sciences. “They clench their teeth, root up plants and suck them in.”

To eat, the animals buttressed their lower jaw with their teeth against the upper jaw, and used the powerful muscles that attached there, along with the shape of the roof of their mouth, to suction-feed vegetation from coastal bottoms. Big muscles in the neck would help to power their tusks, and big muscles in the throat would help with suction.

“No other mammal eats like that,” Jacobs said. “The enamel rings on the teeth show wear and polish, but they don’t reveal consistent patterns related to habitual chewing motions.”

The new specimens also represent a new genus — meaning desmostylians in the same family diverged from one another in key physical characteristics, particularly the tooth and jaw structure, said Jacobs, who is one of 10 scientists collaborating on the research.

Discovery of a new genus and species indicates the desmostylian group was larger and more diverse than previously known, said paleontologist and co-author Anthony Fiorillo, vice president of research and collections and chief curator at the Perot Museum of Nature and Science, Dallas, and an adjunct research professor at SMU.

“Our new study shows that though this group of strange and extinct mammals was short-lived, it was a successful group with greater biodiversity than had been previously realized,” said Fiorillo.

Unique from other marine mammals in their diet, eating, lifespan
A large, stocky-limbed mammal, desmos’ modern relatives remain a mystery. They’ve been linked previously to manatees, horses and elephants.

Compared to other mammals, desmos were latecomers and didn’t appear on earth until fairly recently — 33 million years ago. Also unusual for mammals, they survived a mere 23 million years, dying out 10 million years ago.

Unlike whales and seals, but like manatees, desmos were vegetarians. They rooted around coastlines, ripping up vegetation, such as marine algae, sea grass and other near-shore plants.

They probably swam like polar bears, using their strong front limbs to power along, Jacobs said. They walked on land a bit, lumbering like a sloth.

Adult desmostylians were large enough to be relatively safe from predators.

The authors report their discoveries in a special volume of the international paleobiology journal, Historical Biology. The article published online Oct.1 at http://bit.ly/1PQAHZJ.

The research was funded by the Perot Museum of Nature and Science, U.S. National Park Service — Alaska Region Office, and SMU’s Institute for the Study of Earth and Man.

Home was the North Pacific, on wave-battered “Deadliest Catch” island
The newest desmo made its home on Unalaska Island, the farthest north of any occurrence of the group, which only lived along the shores of the North Pacific.

“That’s the only place they’re known in the world — from Baja, California, up along the west coast of North America, around the Alaska Peninsula, the storm-battered Aleutian Islands, to Russia’s Kamchatka Peninsula and Sakhalin Island, to the Japanese islands,” Jacobs said.

The Unalaska fossils represent at least four individuals, and one is a baby.

“The baby tells us they had a breeding population up there,” Jacobs said. “They must have stayed in sheltered areas to protect the young from surf and currents.”

In addition, “the baby also tells us that this area along the Alaska coast was biologically productive enough to make it a good place for raising a family,” said Fiorillo.

Just as cattle assemble in a herd, and a group of fish is a school, multiple desmostylians constitute a “troll” — a designation selected by Jacobs to honor Alaskan Ray Troll, the artist who has depicted desmos most.

To make the Unalaska and Japanese specimens readily available to scientists anywhere in the world, each fossil was modeled as a 3-D image to reconstruct the skull and provide interactive animations of the fossils, said Michael J. Polcyn, research associate and director of SMU’s Digital Earth Sciences Laboratory.

Also, 3-D renders of the digital models are available to download without restriction at http://bit.ly/1JWbLLy, including instructions for downloading. The renderings are in QuickTime Virtual Reality format, QTVR, and are large files that take time to download. Once downloaded, each fossil can be virtually examined and manipulated.

Journey from the land to the ocean to a quarry
The first Unalaska fossils were discovered in the 1950s in a rock quarry during U.S. Geological Survey mapping.

Others found more recently were on display at the Ounalashka Corporation headquarters. Those specimens were offered to Fiorillo and Jacobs for study after Fiorillo gave a public presentation to the community on his work in Alaska.

“The fruits of that lecture were that it started the networking with the community, which in turn led us to a small, but very important collection of fossils that had been unearthed in the town when they built a school a few years earlier,” Fiorillo said. “The fossils were shipped to the Perot Museum of Nature and Science for preparation in our lab and those fossils are the basis for our work now.”

From there, the researchers discovered that the fossils were a new genus and species.

The researchers named the new mammal Ounalashkastylus tomidai. “Ounalashka,” means “near the peninsula” in the Aleut language of the indigenous people of the Aleutian Islands.

“Stylus” is from the Latin for “column” and refers to the shape of cusps in the teeth.

“Tomida” honors distinguished Japanese vertebrate paleontologist Yukimitsu Tomida.

The article appears in a special volume of Historical Biology to honor the career accomplishments of Tomida upon his retirement from the Department of Geology and Paleontology in Tokyo’s National Museum of Nature and Science.

In addition to Jacobs, Fiorillo and Polcyn, other authors were Yosuke Nishida, SMU; Yuri Kimura, Smithsonian Institution and the Tokyo Museum; Kentaro Chiba, University of Toronto; Yoshitsugu Kobayashi, Hokkaido University Museum, Naoki Kohno, National Museum of Nature and Science; and Kohei Tanaka, University of Calgary.

The Historical Biology article is titled “A new desmostylian mammal from Unalaska (USA) and the robust Sanjussen jaw from Hokkaido (Japan), with comments on feeding in derived desmostylids.” It appears in the special issue “Contributions to vertebrate palaeontology in honour of Yukimitsu Tomida.” — Margaret Allen