Fake News is Spreading Thanks to Information Overload

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 In the beginning, the internet was supposed to be the great equalizer, making knowledge accessible to everyone and giving all citizens a voice.


 Today, knowledge is more accessible, and more people have a voice, but it’s also increasingly hard to tell what’s real and what’s not.


 Blame social media. On networks like Facebook and Twitter, high- and low-quality information—read: accurate and inaccurate—have an equal chance of success, according to
 <a href="http://nature.com/articles/doi:10.1038/s41562-017-0132">
 a paper published today
 </a>
 by Diego F. M. Oliveira, Filippo Menczer, and a team of researchers.


 On social networks, they said, accuracy does not necessarily determine popularity. “Quality is not a necessary condition for virality,” Menczer said.


 Our ability to discriminate accurate information can be impeded by things like confirmation bias—where we are more likely to accept information if it matches our own beliefs—and popularity bias—where we view something as high quality because it is shared frequently.


 “Even when individual users can recognize and select quality information, the social media market rarely allows the best information to win the popularity contest,” Oliveira said.


 It’s a contest which is growing bigger by the day. According to a
 <a href="http://www.journalism.org/2016/05/26/news-use-across-social-media-platforms-2016/">
 2016 Pew Research Center report
 </a>
 , 62% of adults in the U.S. get news from social media sites, and 18% do so often. Nearly half the country uses Facebook as a news source in one form or another. People who use Facebook for news amount to 44% of the general population.

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 Despite the popularity of social media as a news source, not all popular content on these sites is high-quality, factual information. To see how low-quality information spread on these sites, Oliveira and Menczer’s paper,
 <a href="https://www.nature.com/articles/s41562-017-0132">
 published in Nature Human Behavior
 </a>
 , simulated a large social media system. The authors assumed that users were able to discern good quality information—an ideal scenario for social media usage, though perhaps a bit optimistic. They gave each post a quality rating that stood for factors such as accuracy, trustworthiness, reliability, and relevance. By varying how many pieces of information were produced in the system and how many posts a user could look at before sharing, the team examined conditions under which quality information went viral.


 When they modeled the hypothetical scenario—in which all users can tell good information from bad—the networks struck a balance between quality and diversity of information. In other words, many people’s voices were heard and the overall accuracy of posts on the site remained high.


 But when they introduced real-world data and conditions into the model, the volume of posts skyrocketed. The diversity of voices increased, but the quality of popular posts declined. The team discovered that eventually there is “so much information out there that we just can’t keep up,” Menczer said. “It underlines the limits of social media as a platform for news.”

<h2>
 Challenges of Diversity
</h2>

 “The implication is that the sheer diversity of information can actually have a downside,” John Wihbey, a professor of journalism and new media who studies virality and information literacy at Northeastern University, said of the study’s findings.


 “One of the critiques of the era of mainstream media is that we artificially gate-keep, not letting enough diverse voices into the conversation,” he said. “While the critique of high-quality news producers may still be valid, it’s a more complicated picture than maybe we’ve understood. When you have actors with bad intentions who want to do propaganda, misinformation, or just silly stuff…flooding environments with all kinds of clickbait, it doesn’t improve the ecosystem.”


 In the past year, fake news has become a global phenomenon. Only 24% of respondents in the
 <a href="http://www.digitalnewsreport.org/survey/2017/overview-key-findings-2017/">
 Reuters Institute Digital News Report
 </a>
 for 2017 that think social media is successful at separating fact from fiction, compared with 40% of respondents who think the same of the news media. The problem appears to be particularly acute in the U.S. Out of 36 countries, the U.S. emerged as the second most polarized. People reported trusting their favored news sources more than the news media in general by a 15% margin.


 But that hasn’t spelled the end of the news media. Online news subscriptions have risen from 9% to 16% this year, and news donations have tripled, according to the recent Reuters report. People under 35 contributed significantly to this increase, as the percentage of 18–24 year olds paying for news increased from 4% in 2016 to 18% in 2017.


 There are also other signs that internet users and companies are recognizing the problem of fake news. In a study this winter,
 <a href="http://www.niemanlab.org/2017/02/reddits-rworldnews-community-used-a-series-of-nudges-to-push-users-to-fact-check-suspicious-news/">
 J. Nathan Matias and other researchers at MIT
 </a>
 worked with Reddit to combat fake news by encouraging users fact-check potentially misleading stories, which doubled the number of comments with links on average, suggesting the users were backing up their comments with sources.
 <a href="https://www.journalism.cuny.edu/2017/04/announcing-the-new-integrity-initiative/">
 CUNY Graduate School of Journalism
 </a>
 recently joined Facebook and organizations like the Knight Foundation to announce the News Integrity Initiative to combat fake news. And on a more extreme level, last week Filipino senator Joel Villanueva proposed a bill that would jail or fine people and companies that spread fake news.

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 For now, Oliveira and Menczer recommend that social media sites reduce information load by restricting the posts from automated bots, which can manipulate sites by producing high volumes of low quality or inaccurate information. “We’re finding very strong quantitative evidence that social bots are very effective at getting fake news to go viral,” said Menczer.


 The group is currently working on studying and detecting automated bots to learn how to filter them out (much like spam filters for email).


 While the Menczer and Oliveira say that social media sites bear the brunt of the responsibility for dealing with this issue, they do recommend that individuals carefully check the sources of information and avoid sharing content without some critical examination. They also say people should not unfollow or unfriend people who hold different opinions. “That leads to echo chambers, which make us more vulnerable to misinformation,” Oliveira said.


 Wihbey agrees that bots are a significant problem. If platforms like Facebook and Twitter are better able to crack down on bots, he said, the high-quality information would have a better chance at spreading. By sharing their data sets, Facebook and other platforms could help researchers understand the relationship between virality and accuracy of information, he said, an increasingly important relationship in our democracy.


 While Wihbey admits that there are times in which low-quality information can be fun and amusing, social platforms and systems should take a harder look at how their algorithms treat credible content.


 “We have to acknowledge the limits of social media” Menczer said.


 Photo credit:
 <a href="https://www.flickr.com/photos/68532869@N08/17471462035/">
 Japanexperterna.se/Flickr (CC BY-SA)
 </a>

We’re being overwhelmed by social media posts—and our judgement is suffering as a result.

“Ape Who Went to College” Dies

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 Chantek, the beloved orangutan who was one of the first apes to learn sign language, has passed away at age 39.
 

 Chantek rose to fame after “attending university,” living with anthropologist Lyn Miles at the University of Tennessee for nine years. Miles and other caretakers taught him over 150 words in American Sign Language, as well as important human skills like cleaning his room, using the bathroom, and directing a car route.
 
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<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/chantek-1.width-990_2IV9LbC.jpg"/>
<figcaption>39-year-old Chantek was known for having an engaging personality.
 
 </figcaption>
</figure>

 His tenacity for learning made him the star of a 2014 PBS documentary “
 <a href="http://www.pbs.org/video/my-wild-affair-ape-who-went-college-1/">
 The Ape Who Went to College
 </a>
 .” In many ways, Chantek was raised much like a human. In fact, he sometimes referred to himself as an “orangutan person.”
 

 Chantek was among a special group of apes who knew ASL, including Koko, the gorilla, and Washoe, the chimpanzee.
 

 The BBC described the friendly ape:
 
<blockquote>

 Zoo Atlanta said that Chantek frequently used sign language to communicate with keepers but “he was shy about signing with individuals he did not know and often chose forms of communication which are more typical of orangutans, such as vocalisations and unique hand gestures”.
 

 “Chantek will be deeply missed by his family here at Zoo Atlanta,” said Hayley Murphy, vice president of the zoo’s animal divisions.
 

 “He had such a unique and engaging personality and special ways of relating to and communicating with those who knew him best. It has been our privilege to have had him with us for 20 years.”
 
</blockquote>

 Orangutans typically live about 35-45 years in the wild. Chantek was born at the Yerkes National Primate Research Center in Georgia. He returned to the Atlanta Zoo to live out his later years with other orangutans, including his friends 34-year-old female Madu and playful 10-year-old male Dumadi. While the cause of death has not been announced, he was being treated for heart disease, a leading cause of death among captive orangutans.
 

 Miles shared an example of his communication abilities
 <a href="http://www.bbc.com/news/av/uk-politics-40860444/he-asked-me-to-get-the-car-and-take-him-home">
 with the BBC
 </a>
 : “The last time I saw him not too long ago he asked me for meat cheese bread [a cheeseburger] and for me to get the car and take him home.”
 
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</div>
<div class="inline-caption">
 Watch the incredible story of Chantek, the orangutan raised as a human child on an American university campus during the '70s and '80s.
 </div>
</section>

 Photo credit:
 <a href="https://twitter.com/ZooATL/status/894681378834571266">
 Zoo Atlanta / Twitter
 </a>

Sperm counts in men from North America, Europe, Australia, and New Zealand have dropped by over 50 percent over the past 40 years.

Sperm Count is Decreasing in Rich Nations—and No One Knows Why

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 Over the past 40 years, sperm counts in men from North America, Europe, Australia, and New Zealand have dropped by over 50 percent, researchers announced on Tuesday.


 Researchers examined 7,500 studies conducted between 1973 and 2001. They selected 185 studies with consistent counting methods and performed analyses on data from almost 43,000 men.


 Their findings,
 <a href="http://dx.doi.org/10.1093/humupd/dmx022">
 released in
 
 Human Reproduction Update
 
</a>
 , showed that sperm concentration fell from 99 million per milliliter to 47.1 million per milliliter during the span of the study, indicating a 52.4% decline in sperm concentration and a 59.3% decline in total sperm count for men in these nations. What’s more, the scientists found that the decrease in sperm count is not slowing. As sperm counts have implications for morbidity and mortality, these results raise potential concerns for health and fertility.


 While previous studies on sperm count were criticized for not accounting for confounding variables like age, sexual activity, or infertility, this study used consistent sperm count methods and broad data sets from many locations to address these concerns.

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 The study did not directly address causes for the decline, though in interviews with
 <a href="https://www.newscientist.com/article/2141784-sperm-count-has-fallen-by-nearly-60-per-cent-in-richer-countries/#link_time=1501018098">
 New Scientist
 </a>
 , study author Shanna Swan of the Icahn School of Medicine at Mount Sinai indicated that since the decline occurred in these specific nations, there may be a causal relation with chemicals. The impact of chemicals, like phthalates that are often found in
 <a href="https://www.nytimes.com/2017/07/12/well/eat/the-chemicals-in-your-mac-and-cheese.html?_r=1">
 food packaging and make their way into nearly every brand of macaroni and cheese
 </a>
 , has been called into question lately by data that suggests they may interfere with testosterone production and endocrine systems.


 Here’s Kate Kelland,
 <a href="https://www.scientificamerican.com/article/sperm-count-dropping-in-western-world/">
 reporting
 </a>
 for Scientific American:

<blockquote>

 “This study is an urgent wake-up call for researchers and health authorities around the world to investigate the causes of the sharp ongoing drop in sperm count,” said Hagai Levine, who co-led the work at the Hebrew University-Hadassah Braun School of Public Health and Community Medicine in Jerusalem.


 The analysis did not explore reasons for the decline, but researchers said falling sperm counts have previously been linked to various factors such as exposure to certain chemicals and pesticides, smoking, stress and obesity.


 This suggests measures of sperm quality may reflect the impact of modern living on male health and act as a “canary in the coal mine” signaling broader health risks, they said.

</blockquote>

 But it’s not all bad news—47.1 million sperm per milliliter is still well above the 15 million sperm threshold that is considered low from a fertility standpoint. The study revealed no clear decline in sperm count for men in South America, Asia, or Africa, but the authors note that far fewer studies have been conducted in these regions.


 For now, the question of what is causing sperm count decline is still open, but the evidence of the trend is increasingly apparent.

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 Image credit:
 <a href="https://www.flickr.com/photos/82066314@N06/9233907080/">
 Iqbal Osman / (CC BY 2.0)
 </a>

An obvious decrease in sperm count amongst richer nations is showing no sign of slowing.

Scientists 'Teleport' Photons Into Space For the First Time

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 A
 <a href="https://arxiv.org/abs/1707.00934">
 team of researchers
 </a>
 set a record for quantum “teleportation” this week.
 

 In a first, scientists “teleported” information from Earth to space over a distance of over 300 miles. Previous experiments had done the same
 <a href="http://www.pbs.org/wgbh/nova/next/physics/scientists-generate-quantum-entanglement-in-space-for-the-first-time/">
 from space to Earth
 </a>
 and over shorter distances. Photon “teleportation” can enable long-range data encryption, and would be vital to a large-scale quantum computing network. But this doesn’t mean we’re ready to beam objects up to space.
 

 This transfer relies on the principle of entanglement, by which two particles are connected (regardless of distance) in that measuring one correlates to the state of the other. Using entanglement, the quantum state of a particle can be transferred to another, so it essentially assumes the identity of the other particle, much as we envision physical teleportation.
 
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/iss-40_thunderheads_near_borneo.width-990_yPo2CjP.jpg"/>
<figcaption>Scientists sent information between a high-altitude ground station in Tibet and a satellite in space.
 
 </figcaption>
</figure>

<a href="http://www.bbc.com/news/av/science-environment-40573621/first-object-teleported-to-earth-s-orbit">
 In an interview with the BBC
 </a>
 , Oxford professor Ian Walmsley explained that the team communicated information by harnessing the laws of quantum mechanics. They transferred information from a photon on Earth to a second photon up in a satellite, but did not physically send the first photon anywhere.
 

 Ryan Mandelbaum explains this phenomenon for
 <a href="https://gizmodo.com/scientists-teleport-a-particle-hundreds-of-miles-but-w-1796818859">
 Gizmodo
 </a>
 :
 
<blockquote>


 So, here’s a simplified version of quantum teleportation. Let’s say you take a red and a green ball, put each randomly into one of two bags, and hand one bag to a person on the ground, and another to a person at the satellite. But on the ground, there’s a second bag, containing another green ball that the folks on the ground want to “teleport” to the satellite, without anyone else knowing it was green. Quantum teleportation says that, with the entangled link already set up, the folks on the ground have only to open both of their bags, then call the satellite on the phone and say either “same” or “different.” If the ground observer opens both bags and sees both balls are green, she can just say “same” to the satellite. The satellite will then open his entangled bag, which has to have a red ball, which means the ground must have had the green ball in the entangled bag, and
 


 that
 


 means the secret ball had to be green.
 



 Thus, the state of the secret ball is “teleported” to the satellite.
 

</blockquote>

 In previous attempts, achieving great distances was challenging. Entanglement is fragile and easily disrupted as photons interact with matter over longer distances. Scientists have tested models of a quantum network by transmitting information through optical fibers, but the team from University of Science and Technology of China led by Chao-Yang Lu demonstrated much greater distances by using the vacuum of space, which has few particles with which the entangled photons might interact.
 

 Over the course of a month, the researchers sent millions of photons between the ground station and the Micius satellite, a sensitive photon receiver that reads information from photons on Earth. The ground station was placed at a high-altitude site in Tibet at over 13,000 feet above sea level to minimize disturbance from the atmosphere, which can disentangle photons. Over 900 of the transfers were successful. Based on satellite orbit, the photons were separated by between 310 and 870 miles.
 

 The “teleportation” process transfers qubits, or quantum bits of information. A quantum network would use entangled photons to share information. Measuring their state—the data encoded in the photon—would immediately disturb them. Thus, any attempts to read or interfere with messages outside of the receiver would instantly be detected.
 

 “This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” the team wrote in this week’s paper.
 
</section>

 Image credit: Expedition 40 crew member/NASA

Can Government Keep Up with Artificial Intelligence?

Artificial intelligence research is moving quickly. Can the government move quickly enough to effectively regulate it?

Anyone Can Be Trained to Hallucinate, and That’s Teaching Scientists About Perception

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 Hallucinations are often distressing—a suggestion that something is amiss in our brains. But new research suggests we’re all susceptible to hallucinations, and that may not be such a bad thing.


 In a paper released last week in
 <a href="http://science.sciencemag.org/content/357/6351/596">

 Science
 
</a>
 , a team from Yale University set out to understand how we interpret the world around us—in short, how we determine what’s real and what’s not. They suspected that people who regularly hallucinate perceive the world based on what they expect to happen, while others, who don’t hallucinate, would rely more what their senses are telling them is happening in the world.


 To determine that, authors Phil Corlett and Al Powers began by conditioning participants to hear a tone when they were shown a checkerboard pattern. Then they slowly removed the actual sound and asked people when they heard it. Participants who regularly heard voices were five times more likely to say they heard a tone when there wasn’t one, and they were 25-30% more confident in their choice. But they weren’t alone in hearing things. In fact, all of the participants experienced some induced hallucinations during the experiment.


 “I did not expect that people who did not have a psychotic illness would perform so similarly to people who did hear voices,” Powers says. “They were very, very alike.”


 “Really healthy people that don’t hallucinate in their everyday lives—graduate students, and postdocs, and highly accomplished people—were very, very susceptible to this effect, even the ones who didn’t hear voices. They were more susceptible to it than I expected,” Corlett says. The study contributes to the idea that schizophrenia, much like autism, may exist as a spectrum, the authors say.

<h2>
 Hearing Things
</h2>

 Powers personally experienced the phenomenon when testing the software for the experiment. He was surprised to find that, despite his deep knowledge of the process and mechanisms, the effect still worked on him. “At the beginning, it was quite exciting,” he says, though he admitted that “it’s concerning, to be honest.”


 He and Corlett compared four groups: those with diagnosed psychoses who either did or did not hallucinate and those not diagnosed with psychoses who either did or did not hallucinate. Each of the groups contained 14-15 people. Most of these participants were relatively easy to recruit. But they needed to find people who experience hallucinations as part of daily life yet haven’t been diagnosed with a psychiatric disorder. So they turned to the Connecticut Psychics’ Association, specifically to psychics who regularly hear voices.

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<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/5323813967_ca7a703466_o.width-990_lcMBW3d.jpg"/>
<figcaption>Vincent van Gogh frequently suffered from psychotic episodes of hallucinations and delusions.
 
 </figcaption>
</figure>

 Many of the study participants who hallucinate but haven’t been diagnosed as psychotic tend to lead normal lives. The hallucinations don’t seem to interfere, like for a police officer in her 50s who heard daily narrations of her activities as she worked.


 Powers and Corlett wanted to know if people diagnosed with psychoses had brains that operated differently than the other subjects. To do that, they had to make people who don’t typically hallucinate…hallucinate. And that’s why they turned to a famous technique originally used on dogs—Pavlovian conditioning. The team conditioned participants to associate a checkerboard pattern with a 1-kHz tone, which sounds like the bleep over a swear on late-night TV. Initially, the scientists sprinkled in lots of 1-kHz tones that they were certain the participants could hear. Then, as the task went on, they changed their intensity and often removed them entirely. Like in a hearing test at the doctor, participants were asked to press a button when they heard the tone. In an added twist, participants could indicate how confident they were about their response. Meanwhile, their brains were examined using magnetic resonance imaging (MRI).

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 The researchers found the psychics’ descriptions of their hearings incredibly similar to the accounts of their psychotic hallucinating patients. That reinforced to Corlett and Powers that mental symptoms like hallucinations and delusions may exist on a continuum, from manageable occurrences to increasingly severe and disruptive clinical cases.


 Meanwhile, the group with known psychosis but no regular hallucinations responded differently. While most participants were unable to tell real tones from imagined ones, those in the psychotic, non-hallucinating group were more quickly and confidently able to determine the change.



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 Corlett thinks this is because most of the people in the psychotic non-hallucinators group experience delusions, a phenomenon separate from hallucinations where they have trouble connecting different clues from their environment. “They have a real problem picking up the contingency between the checkerboard and the tones,” he says. “The importance of including this group is to say that what we found isn’t simply attributable to psychosis, but particular to hallucinations.”


 Using MRI neuroimaging, the team was able to tie the underlying mechanism that causes auditory hallucinations to those used in normal perception. In other words, hallucinations prey on the same processes that allow us to see and hear. “We’re able to say that hallucinations are not just foreign, scary, unrelatable things, but are in fact a process or an alteration of a process that we ourselves undergo every day in deciding what surrounds us,” Powers says.

<h2>
 Role of Cultural Stigmas
</h2>

 Psychosis is typically defined as active hallucinations or delusions coupled with significant clinical distress, but there is still some debate over where the boundaries are. Up until now, schizophrenia has primarily been treated as a one condition, but Corlett and Powers think a symptom-by-symptom approach may serve patients better. Their work provides further evidence that there may not be one not one type of schizophrenia but many.


 The study’s findings also suggest that cultural or religious attitudes toward hallucinations may influence whether they are benign or disruptive, says anthropologist Tanya Luhrmann of Stanford, who studies unusual sensory experiences and their cultural implications. “It opens the possibility that if people with psychosis learn to expect to different things from their hallucinations, they might have different hallucinations,” she says. “The content [of hallucinations] has something to do with prognosis—the more mean and negative the voices, the worse the outcome.”


 In the U.S., we tend to assume that psychotic experiences are inherently negative, but in her work, Luhrmann has found that that’s not always the case in other cultures. Evidence by other scientists and anthropologists suggests that the more negatively one perceives their voices, the worse their outcome.

<div class="pullquote">

 “These hallucinations, either with neural feedback or with some kind of more spiritual training, might benefit these patients.”

</div>

 Luhrmann was intrigued by those who hallucinate frequently, but don’t show signs of psychosis, like the psychics. She, like Powers and Corlett, is curious about how their experiences differ from other hallucinators based on the stigma attached to their voices—or lack thereof. In some other cultures, like the people in Ghana that Luhrmann recently visited, those who hear voices undergo extensive training to take control of them. Globally, grassroots support groups for individuals who hear voices are becoming more common, empowering people to name their voices, share their experiences, and develop more positive relationships with the voices they hear. Intervoice, one such network based in the U.K., provides forums for people to share their stories without judgement and emphasizes auditory hallucinations as a meaningful human experience.


 By framing these experiences as significant and potentially benevolent, we can help hallucinators understand and take charge of their hallucinations. “This gives us more confidence that training these hallucinations, either with neural feedback or with some kind of more spiritual training, might benefit these patients,” Luhrmann says.


 Powers and Corlett hope they have also paved the way towards better diagnoses by pairing participant accounts of their experiences with computational modeling based on brain imaging. The individualized information could help psychiatrists determine the best way to treat patients based on where their symptoms and behaviors are on the psychosis spectrum.


 “We can use this objective measure to show somebody, ‘Yes, you’re having these odd experiences, they’re different from the people who don’t have a need for care in these ways,’” Corlett says. Understanding these differences could also help them identify who may develop a psychotic illness and who may not.


 The psychiatrists also want explore new therapies. Understanding the specific mechanisms that underlie hallucinations may help the team determine who would respond well to drugs, like those based on the cholinergic neurotransmitter system. Cholinergic neurotransmitters relate to our ability to reconsider prior expectations. These therapeutic drugs, which are based on the same active ingredient in belladonna or nightshade that can cause hallucinations, were initially rejected when they were administered broadly. But this could give researchers the means to determine who might respond well to the drugs.


 Ultimately the researchers have a better understanding of “what the neural mechanisms for hallucinations in the context for mental illness might be,” Corlett says. Knowing that these symptoms exist on a spectrum, and having the tools to recognize individual differences, “can be used to treat people more effectively in the future,” Powers says.


 Photo credits:
 <a href="https://www.flickr.com/photos/63002317@N08/8635598350/">
 eitsch723/Flickr (CC BY-NC-SA 2.0)
 </a>
<a href="https://flic.kr/p/97rWpZ">
 Estudio de Arquepoética y Visualística Prospectiva/Flickr (CC BY-NC-SA 2.0)
 </a>

We may all be susceptible to hallucinations—and they’re not that different from how our brain interprets actual events.

Hybrid Dinosaur May Change How We Understand Dinosaur Evolution

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 The mysterious
 
 Chilesaurus
 
 —the dino with the seemingly mismatched features—finally has a home on the family tree.
 

 The dinosaur confused paleontologists at first. Its bird-like hips and flat teeth are reminiscent of
 
 Stegasaurus
 
 , but its head, arms, and legs are more similar to
 
 Velociraptor
 
 . Paleontologists originally put the kangaroo-sized creature in the same suborder as
 
 Velociraptor
 
 . But now, paleontologists are recognizing it as a link between dinosaurs like the
 
 T. rex
 
 and others like
 
 Triceratops
 
 . The findings, released this week in the Royal Society journal
 <a href="http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2017.0220">
 Biology Letters
 </a>
 , may change our understanding of dinosaur evolution.
 
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/chilesaurus_nt_small-1.width-990_bVqZgOx.jpg"/>
<figcaption>Artistic rendering of the puzzling Chilesaurus.
 
 </figcaption>
</figure>

 Here’s Pallab Ghosh, interviewing Barron for
 <a href="http://www.bbc.com/news/science-environment-40890714">
 the BBC
 </a>
 :
 
<blockquote>

 “We had absolutely no idea how the ornithischian body plan started to develop because they look so different to all the other dinosaurs. They have so many unusual features,” the Cambridge scientist said.
 

 “In the 130 years since the ornithischian group was first recognised, we have never had any concept of how the first ones could have looked until now.”
 
</blockquote>

 Ornithischians, like
 
 Triceratops
 
 and
 
 Stegasaurus
 
 , were long considered a monolithic branch on the dinosaur family tree, while saurischians were thought to include two branches, theropods—like
 
 T. rex
 
 and
 
 Velociraptor
 
 —and sauropods—like
 
 Brachiosaurus
 
 .
 

 But in March, Matthew Baron of Cambridge University and his colleagues published findings in
 <a href="http://www.nature.com/nature/journal/v543/n7646/full/nature21700.html?foxtrotcallback=true">
 Nature
 </a>
 that challenged long-standing assumptions. By examining the features of
 
 Chilesaurus
 
 that overlapped with members of both the theropod and ornithician dinos, the researchers realized that the newly discovered species bridged the carnivorous and herbivorous saurichians. Their analysis resulted in moving theropods from Saurischia and into a class of bird-limbed dinosaurs now known as Ornithoscelida (which formerly contained ornithischians like
 
 Triceratops
 
 ).
 
<figure class="richtext-image full-width">
<img alt="" class="richtext-image full-width" src="https://www.pbs.org/wgbh/nova/media/images/dinos.width-990_74ikOMr.jpg"/>
<figcaption>Chilesaurus gave the scientists evidence to rethink dinosaur classification, providing a link between theropods and ornithischians.
 
 </figcaption>
</figure>


 Chilesaurus
 
 lived during the late Jurassic period, around 150 million years ago, in what is now Chile. It stood at about seven to ten feet tall. The specimen was
 <a href="http://www.smithsonianmag.com/science-nature/meet-chilesaurus-new-raptor-dinosaur-vegetarian-diet-180955101/">
 discovered in 2004
 </a>
 by seven-year-old Diego Suarez on a hike with his parents (who happened to be geologists), leading to its moniker of
 
 Chilesaurus diegosuarezi
 
 .
 

 Baron and his team analyzed over 450 characteristics of dinosaurs and compared existing species to the perplexing hodgepodge
 
 Chilesaurus
 
 fossil. By noting feature-by-feature similarities, they reevaluated the family tree and concluded that the new dinosaur may bridge the
 
 Triceratops
 
 branch with the
 
 T. rex
 
 branch.
 

 Understanding where
 
 Chilesaurus
 
 sits in dinosaur lineage has apparently taught Baron and his colleagues a lot about dinosaur evolution. The species may be one of the first to consume plants for sustenance, for example. Scientists have long wondered how this transition occurred, and whether herbivorous dinosaurs first developed the beaks used to graze on plants or the
 <a href="http://www.latimes.com/science/sciencenow/la-sci-sn-dinosaur-missing-link-20170815-story.html">
 stomachs needed to digest them
 </a>
 . The
 
 Chilesaurus
 
 ‘s bird-like hips indicates that the gut led the way.
 

 By reorganizing the dinosaur tree, paleontologists have also added further evidence that birds are indeed dino descendants: previously, the theropods we view as birds’ ancestors were not considered relatives of the bird-limbed group, but with the new evidence—and reorganization—they’re all on the same part of the family tree.
 
</section>

 Image credits:
 <a href="https://commons.wikimedia.org/wiki/File:Chilesaurus_NT_small.jpg">
 Nobu Tamura/Wikimedia Commons (Public Domain)
 </a>
 ,
 <a href="https://commons.wikimedia.org/wiki/User:LadyofHats/gallery1">
 LadyofHats/Wikimedia Commons (Public Domain)
 </a>

Bianca Datta

Articles