How human faces can teach androids to smile

Research out of Osaka University examines the mechanical properties of human facial expressions to understand how androids can more effectively convey and recognize emotions

Peer-Reviewed Publication

OSAKA UNIVERSITY

 

IMAGE: 

VISUALIZED DISTRIBUTIONS OF THE STRAIN (LEFT) AND DISPLACEMENT (RIGHT) IN THE FACIAL ACTION FOR RAISING THE MOUTH CORNER

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CREDIT: HISASHI ISHIHARA

Osaka, Japan – Robots able to display human emotion have long been a mainstay of science fiction stories. Now, Japanese researchers have been studying the mechanical details of real human facial expressions to bring those stories closer to reality.

In a recent study published by the Mechanical Engineering Journal, a multi-institutional research team led by Osaka University have begun mapping out the intricacies of human facial movements. The researchers used 125 tracking markers attached to a person’s face to closely examine 44 different, singular facial actions, such as blinking or raising the corner of the mouth.

Every facial expression comes with a variety of local deformation as muscles stretch and compress the skin. Even the simplest motions can be surprisingly complex. Our faces contain a collection of different tissues below the skin, from muscle fibers to fatty adipose, all working in concert to convey how we’re feeling. This includes everything from a big smile to a slight raise of the corner of the mouth. This level of detail is what makes facial expressions so subtle and nuanced, in turn making them challenging to replicate artificially. Until now, this has relied on much simpler measurements, of the overall face shape and motion of points chosen on skin before and after movements.

“Our faces are so familiar to us that we don’t notice the fine details,” explains Hisashi Ishihara, main author of the study. “But from an engineering perspective, they are amazing information display devices. By looking at people's facial expressions, we can tell when a smile is hiding sadness, or whether someone’s feeling tired or nervous.”

Information gathered by this study can help researchers working with artificial faces, both created digitally on screens and, ultimately, the physical faces of android robots. Precise measurements of human faces, to understand all the tensions and compressions in facial structure, will allow these artificial expressions to appear both more accurate and natural.

“The facial structure beneath our skin is complex,” says Akihiro Nakatani, senior author. “The deformation analysis in this study could explain how sophisticated expressions, which comprise both stretched and compressed skin, can result from deceivingly simple facial actions.”

This work has applications beyond robotics as well, for example, improved facial recognition or medical diagnoses, the latter of which currently relies on doctor intuition to notice abnormalities in facial movement.

So far, this study has only examined the face of one person, but the researchers hope to use their work as a jumping off point to gain a fuller understanding of human facial motions. As well as helping robots to both recognize and convey emotion, this research could also help to improve facial movements in computer graphics, like those used in movies and video games, helping to avoid the dreaded ‘uncanny valley’ effect.

 

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The article, "Visualization and analysis of skin strain distribution in various human facial actions," has been published in the Mechanical Engineering Journal at DOI: https://doi.org/10.1299/mej.23-00189

Maximum stretches (left) and compressions (right), which each skin region experiences over 44 types of facial actions

CREDIT

Hisashi ISHIHARA

JOURNAL

Mechanical Engineering Journal

DOI

10.1299/mej.23-00189 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Visualization and analysis of skin strain distribution in various human facial actions

 

Forests with multiple tree species are 70% more effective as carbon sinks than monoculture forests

Above ground carbon stocks are at least 70% higher in mixed forests than in monocultures, with the highest carbon stocks relative to monocultures in forests comprised of four species

Peer-Reviewed Publication

FRONTIERS

To slow the effects of climate change, conserve biodiversity, and meet the sustainable development goals, replanting trees is vital. Restored forests store carbon within the forest’s soil, shrubs, and trees. Mixed forests are especially effective at carbon storage, as different species with complementary traits can increase overall carbon storage. Compared to single-species forests, mixed forests are also more resilient to pests, diseases, and climatic disturbances, which increases their long-term carbon storage potential. The delivery of other ecosystem services is also greater in mixed species forests, and they support higher levels of biodiversity.

Although the benefits of diverse forest systems are well known, many countries’ restoration commitments are focused on establishing monoculture plantations. Given this practice, an international team of scientists has compared carbon stocks in mixed planted forests to carbon stocks in commercial and best-performing monocultures, as well as the average of monocultures.

“Diverse planted forests store more carbon than monocultures – upwards of 70%,” said Dr Emily Warner, a postdoctoral researcher in ecology and biodiversity science at the Department of Biology, University of Oxford, and first author of the study published in Frontiers in Forests and Global Change. “We also found the greatest increase in carbon storage relative to monocultures in four-species mixtures.”

Species richness increases carbon storage potential

The researchers analyzed studies published since 1975 that directly compared carbon storage in mixed and single-species forests, and combined this with previously unpublished data from a global network of tree diversity experiments. “We wanted to pull together and assess the existing evidence to determine whether forest diversification provides carbon storage benefits,” Warner explained.

The mixed planted forests assessed in the study ranged in species richness from two to six species. In the dataset the scientists worked with, four-species mixtures were the most effective carbon sinks. One such mix was made up from different broadleaf trees which can be found across Europe. Mixes with two species also had greater aboveground carbon stocks than monocultures and stored up to 35% more carbon. Forests made up of six species, however, showed no clear advantage to monocultures.

Accordingly, the researchers were able to show that diversification of forests enhances carbon storage. Altogether, aboveground carbon stocks in mixed forests were 70% higher than in the average monoculture. The researchers also found that mixed forests had 77% higher carbon stocks than commercial monocultures, made up of species bred to be particularly high yielding.

Forests for the future

“As momentum for tree planting grows, our study highlights that mixed species plantations would increase carbon storage alongside other benefits of diversifying planted forests,” said Dr Susan Cook-Patton, a senior forest restoration scientist at The Nature Conservancy and collaborator on the study. The results are particularly relevant to forest managers, showing that there is a productivity incentive for diversifying new planted forests, the researchers pointed out.

While showing the increased potential of mixed forests to store more carbon, the researchers cautioned that their study is not without limitations, including the overall limited availability of studies addressing mixed vs monoculture forests, particularly studies from older forests and with higher levels of tree diversity.

“This study demonstrates the potential of diversification of planted forests, and also the need for long-term experimental data to explore the mechanisms behind our results,” Warner said. “There is an urgent need to explore further how the carbon storage benefits of diversification change depending on factors such as location, species used and forest age.”

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JOURNAL

Frontiers in Forests and Global Change

DOI

10.3389/ffgc.2023.1226514 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Young mixed planted forests store more carbon than monocultures – a meta-analysis

ARTICLE PUBLICATION DATE

9-Nov-2023

 

Video technology could transform how scientists monitor changes in species evolution and development

Peer-Reviewed Publication

UNIVERSITY OF PLYMOUTH

 

VIDEO: 

BY MEASURING TIMELAPSE VIDEOS OF EMBRYOS - SUCH AS THIS ONE OF A DEVELOPING SNAIL - SHOWING A NUMBER OF KEY DEVELOPMENTAL EVENTS, RESEARCHERS CAN CAPTURE COMPLEX DIFFERENCES IN HOW SPECIES GROW AND DEVELOP

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CREDIT: UNIVERSITY OF PLYMOUTH

Scientists have made a major breakthrough in the study of species evolution, and provided further evidence that state-of-the-art visual technology can be used to track the tiniest changes in different organisms’ development.

New research used a combination of robotic video microscopes and computer vision to measure all of the observable characteristics of embryos of three different species.

These measurements were recorded as spectra of energy and, through this, scientists were able to compare shifts between species alongside previously documented differences in the timing of discrete developmental events.

A detailed analysis of these so-called Energy Proxy Traits (EPTs) has provided researchers with the first evidence that traditionally measured timings of developmental events are associated with far broader changes to the full set of an embryo’s observable characteristics.

They also found huge changes in an embryo’s observable characteristics before and after the onset of each developmental event.

Writing in Frontiers in Physiology, the study’s authors say that applying lessons from the research has the potential to advance how development and evolution is studied, by enabling greater depth in the assessment of biological development and the ability to combine data across a wide range of species.

This is something, they add, that is particularly crucial at a time when climate and other environmental changes are having a significant – and in many cases harmful – impact on many parts of the natural world.

The study was led by scientists from the University of Plymouth’s EmbryoPhenomics Research Group, in the School of Biological and Marine Sciences, and builds on its 15-plus years of groundbreaking research into ways of monitoring embryo development.

Dr Jamie McCoy, a postdoctoral researcher – funded by the Biotechnology and Biological Sciences Research Council – and the study’s lead author, said: “The advances highlighted in this paper are critical to addressing the fundamental question of how species differ in the way that they develop. Measuring differences in the timings of development is one of the main ways in which researchers investigate how changes in development may drive evolution. But the results from our study suggest that measuring the timings of developmental events is just the tip of the iceberg in terms of how we measure and analyse evolutionary changes. By assessing EPTs across three different species, we have seen how they could provide us with an alternative approach to understanding how development leads to evolutionary change.”

The EPT method uses timelapse video of animals during their earliest and most dynamic life stages.

Each video is composed of a series of individual pixels, whose brightness fluctuates from one frame to the next as objects – such as a beating heart, muscle contractions, or spinning of the whole embryo driven by tiny hairs – move.

Researchers can exploit these fluctuations in pixel values and convert them into frequency data, allowing them to track a huge breadth of different aspects of the biology of the animal as it develops.

The resulting visuals mean that rather than choosing individual parts of the animal to measure, scientists can capture all of its traits – such as changes in heart rate or movement – and interrogate the resulting frequency data to capture a greater breadth of its biological response.

Dr Oliver Tills, senior author on the study, has been pioneering studies into embryo phenomics since 2007 and was in 2020 awarded a UK Research and Innovation Future Leaders Fellowship to advance his work. He added: “Our current understanding of biology is limited by the technologies available to observe it, and we need a new technology-enabled approach to understanding the most complex period of an organism’s life history. This study has broad implications for advancing our understanding of the nexus between biological development and evolution, and marks a significant step forward in how we might monitor the development of lifeforms all over our planet.”

Two decades of expertise in developmental biology

The EPT method used in the current study builds on pioneering work started almost 20 years ago using manual measurements.

That work was led by Dr Jennifer Smirthwaite and colleagues at the University of Plymouth and the Technical University of Munich, and documented a number of heterochronies – changes in the timings of developmental events between species – in a number of species of freshwater snail.

EPTs were applied to three species of freshwater snail from that study, and aimed to understand whether these evolutionary changes in the timings of development were associated with more high-dimensional changes to the phenotype.

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JOURNAL

Frontiers in Physiology

DOI

10.3389/fphys.2023.1237022 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

parative phenomics: a new approach to study heterochrony

ARTICLE PUBLICATION DATE

6-Nov-2023

 

Health: Lack of friend or family visits is associated with increased risk of dying

Peer-Reviewed Publication

BMC (BIOMED CENTRAL)

Never being visited by friends or family is associated with an increased risk of dying, according to a study published in BMC Medicine. The authors suggest that their findings could be used to help identify patients at a higher risk of dying due to social factors, and to develop more effective interventions to combat the increased risk of death associated with social isolation.

Although previous research has identified associations between deaths due to any causes and both a ‘sense of loneliness’ and living alone, the combined impacts of different types of social interaction on mortality has been unclear.

Hamish Foster and colleagues used data from 458,146 adults recruited to UK Biobank to investigate the association between mortality and five types of social interaction. Participants were recruited between 2006 and 2010 and had a mean age of 56.5 years. The participants completed a questionnaire on recruitment during which they answered questions about five types of social interaction: how often they were able to confide in someone close to them and how often they felt lonely (subjective measures); and how often they were visited by friends and family, how often they participated in a weekly group activity, and whether they lived alone (objective measures). After a median 12.6 years follow-up, 33,135 of the participants had died based on linked death certificates.

The authors found that all five types of social interaction were independently associated with mortality from any cause. Overall, increased mortality was more strongly associated with low levels of the objective measures of social interaction compared to low levels of the subjective measures. The strongest association was for individuals who were never visited by friends or family, who were at a 39% associated increased risk of death. Furthermore, the benefit of participating in weekly group activities was not observed in participants who never had friends or family visit — participants who never received visits but did join group activities had a comparable associated increased risk of death to those who had no visits and joined no activities (50% and 49% respectively). However, participants who received friend or family visits on at least a monthly basis had a significantly lower associated increased mortality risk, suggesting that there was potentially a protective effect from this social interaction.

The authors caution that although the overall strength of association is likely to be generalisable, the sample data from UK Biobank is not fully representative of the general UK population, and that the social interaction measures they assessed were self-reported and relatively simple. The authors suggest that further research could investigate the effects of other types of social interaction on mortality, or explore how much change in a type of interaction is needed to best benefit socially isolated people.

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JOURNAL

BMC Medicine

DOI

10.1186/s12916-023-03055-7 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Social connection and mortality in UK Biobank: a prospective cohort analysis

ARTICLE PUBLICATION DATE

10-Nov-2023

 

Any activity is better for your heart than sitting – even sleeping

Peer-Reviewed Publication

UNIVERSITY COLLEGE LONDON

The study, supported by the British Heart Foundation (BHF) and published in the European Heart Journal, is the first to assess how different movement patterns throughout the 24-hour day are linked to heart health. It is the first evidence to emerge from the international Prospective Physical Activity, Sitting and Sleep (ProPASS) consortium.

Cardiovascular disease, which refers to all diseases of the heart and circulation, is the number one cause of mortality globally. In 2021, it was responsible for one in three deaths (20.5m), with coronary heart disease alone the single biggest killer. Since 1997, the number of people living with cardiovascular disease across the world has doubled and is projected to rise further1.

In this study, researchers at UCL analysed data from six studies, encompassing 15,246 people from five countries, to see how movement behaviour across the day is associated with heart health, as measured by six common indicators2. Each participant used a wearable device on their thigh to measure their activity throughout the 24-hour day and had their heart health measured.

The researchers identified a hierarchy of behaviours that make up a typical 24-hour day, with time spent doing moderate-vigorous activity providing the most benefit to heart health, followed by light activity, standing and sleeping compared with the adverse impact of sedentary behaviour3.

The team modelled what would happen if an individual changed various amounts of one behaviour for another each day for a week, in order to estimate the effect on heart health for each scenario. When replacing sedentary behaviour, as little as five minutes of moderate-vigorous activity had a noticeable effect on heart health.

For a 54-year-old woman with an average BMI of 26.5, for example, a 30-minute change translated into a 0.64 decrease in BMI, which is a difference of 2.4%. Replacing 30 minutes of daily sitting or lying time with moderate or vigorous exercise could also translate into a 2.5 cm (2.7%) decrease in waist circumference or a 1.33 mmol/mol (3.6%) decrease in glycated haemoglobin4.

Dr Jo Blodgett, first author of the study from UCL Surgery & Interventional Science and the Institute of Sport, Exercise & Health, said: “The big takeaway from our research is that while small changes to how you move can have a positive effect on heart health, intensity of movement matters. The most beneficial change we observed was replacing sitting with moderate to vigorous activity – which could be a run, a brisk walk, or stair climbing – basically any activity that raises your heart rate and makes you breathe faster, even for a minute or two.”

The researchers pointed out that although time spent doing vigorous activity was the quickest way to improve heart health, there are ways to benefit for people of all abilities – it’s just that the lower the intensity of the activity, the longer the time is required to start having a tangible benefit. Using a standing desk for a few hours a day instead of a sitting desk, for example, is a change over a relatively large amount of time but is also one that could be integrated into a working routine fairly easily as it does not require any time commitment.

Those who are least active were also found to gain the greatest benefit from changing from sedentary behaviours to more active ones.

Professor Emmanuel Stamatakis, joint senior author of the study from the Charles Perkins Centre and Faculty of Medicine and Health at the University of Sydney, said: “A key novelty of the ProPASS consortium is the use of wearable devices that better differentiate between types of physical activity and posture, allowing us to estimate the health effects of even subtle variations with greater precision.”

Though the findings cannot infer causality between movement behaviours and cardiovascular outcomes, they contribute to a growing body of evidence linking moderate to vigorous physical activity over 24 hours with improved body fat metrics. Further long-term studies will be crucial to better understanding the associations between movement and cardiovascular outcomes.

Professor Mark Hamer, joint senior author of the study from UCL Surgery & Interventional Science and the Institute of Sport, Exercise & Health, said: “Though it may come as no surprise that becoming more active is beneficial for heart health, what’s new in this study is considering a range of behaviours across the whole 24-hour day. This approach will allow us to ultimately provide personalised recommendations to get people more active in ways that are appropriate for them.”

James Leiper, Associate Medical Director at the British Heart Foundation, said: “We already know that exercise can have real benefits for your cardiovascular health and this encouraging research shows that small adjustments to your daily routine could lower your chances of having a heart attack or stroke. This study shows that replacing even a few minutes of sitting with a few minutes of moderate activity can improve your BMI, cholesterol, waist size, and have many more physical benefits.

“Getting active isn’t always easy, and it’s important to make changes that you can stick to in the long-term and that you enjoy – anything that gets your heart rate up can help. Incorporating ‘activity snacks’ such as walking while taking phone calls, or setting an alarm to get up and do some star jumps every hour is a great way to start building activity into your day, to get you in the habit of living a healthy, active lifestyle.”

This research was funded by the British Heart Foundation.

1 More information on cardiovascular disease is available from the British Heart Foundation website.

2 The studies were part of the Prospective Physical Activity, Sitting and Sleep (ProPASS) consortium. Heart health was measured using six outcomes: body-mass index (BMI), waist circumference, HDL cholesterol, HDL-to-total cholesterol ratio, triglycerides and HbA1c.

3 The NHS website has guidance on the different levels of physical activity.

4 Glycated haemoglobin is a measure of average blood sugar levels over the last two-to-three months and is a key indicator in the management of diabetes.

Publication:

Blodgett JM and Ahmadi MH et al. ‘Device-measured physical activity and cardiometabolic health: the Prospective Physical Activity, Sitting, and Sleep (ProPASS) consortium’ is published in European Heart Journal and is strictly embargoed until Friday 10 November 2023 00:05 GMT.

DOI: https://doi.org/10.1093/eurheartj/ehad717

About UCL – London’s Global University

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Since 1826, we have championed independent thought by attracting and nurturing the world's best minds. Our community of more than 50,000 students from 150 countries and over 16,000 staff pursues academic excellence, breaks boundaries and makes a positive impact on real world problems.

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For almost 200 years, we are proud to have opened higher education to students from a wide range of backgrounds and to change the way we create and share knowledge.

We were the first in England to welcome women to university education and that courageous attitude and disruptive spirit is still alive today. We are UCL.

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JOURNAL

European Heart Journal

DOI

10.1093/eurheartj/ehad717 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Device-measured physical activity and cardiometabolic health: the Prospective Physical Activity, Sitting, and Sleep (ProPASS) consortium

ARTICLE PUBLICATION DATE

9-Nov-2023

 

Bullying victims who perceive they’re targeted due to social characteristics feel the effects worse, new research suggests

“Schools should do more to support children at risk of discriminatory bullying”

Peer-Reviewed Publication

TAYLOR & FRANCIS GROUP

Students who feel they have been victimized because of social characteristics such as their ethnicity or their sexuality are at additional risk of trauma, a new national US study has revealed. 

Published in the peer-reviewed Journal of School Violence, the research, of more than 2,200 young victims of bullying, found students reported that their physical health; self-esteem; social relationships, and schoolwork suffered more if they felt bias was behind the perpetrators’ actions.  

This was particularly acute for those who felt they had more than one characteristic which put them at risk of discrimination. 

Schools’ anti-bullying and violence prevention programs should place more emphasis on these types of prejudicial victimization, the findings conclude, and staff should work to identify those whose characteristics might make them particularly vulnerable. 

“This study adds to the rising tide of evidence demonstrating that adolescent victimization motivated by bias is uniquely impactful. And I find that victimization involving multiple bias types appears to be especially influential,” states author Allison Kurpiel of the Pennsylvania State University. 

“Students who experienced biased victimization were also more likely than nonbiased victims to perceive negative effects on their schoolwork, implying that biased victimization might contribute to lower educational achievement for minoritized groups. This association between biased victimization and impacts on schoolwork was observed for students across the academic spectrum. 

“The findings demonstrate that schools should prioritize programming that targets the reduction of biased victimization. 

“Failing to do so could result in the exacerbation of existing inequalities through damage to students’ self-esteem, physical health, social relationships, and educational achievement.” 

Allison, who is a PhD Candidate in the Department of Sociology and Criminology at Pennsylvania, investigated data on under-18s who filled in a School Crime Supplement to the 2017 and 2019 National Crime Victimization Survey – a nationally representative household survey conducted every two years in the United States. 

Students were asked whether in the past year anyone had made fun of them, called them names, insulted them in a hurtful way, spread rumors about them or tried to make others dislike them, threatened them, pushed, shoved, tripped or spat on them, or tried to make them do things they did not want to do, such as giving away money. They were also asked if they had been excluded on purpose from activities or had their property destroyed in a non-accidental way. 

Those who said they had been victimized in one or more of these ways were asked if they had ever thought this was related to their race, religion, ethnic background, disability, gender, sexual orientation or physical appearance. They were then divided into two groups: those who said they had felt their experience was the result of these types of bias, and those who said they had not. 

The research then analyzed the impacts on the victims, asking whether those who felt they experienced more than one type of bias were more likely to suffer adverse effects than those who suffered just one. 

The study found around a quarter of all students had been victimized in the past year, and of those, around four out of 10 felt the actions were motivated by bias. The most commonly-reported bias – around three out of 10 of those who felt bias was a factor – related to physical appearance. 

The most common forms of victimization were being threatened or being subject to the spreading of rumors, and these were each experienced by around two-thirds of victims. Overall, students who reported bias against them felt they had suffered a greater range of types of victimization than those who did not.  

When it came to the perceived impacts, negative effects on self-esteem were the most common and were reported by more than a quarter of victims, while effects on physical health were the least common and were experienced by fewer than one in seven. 

Those who felt their victimization was linked to bias were three times more likely to suffer negative effects on their self-esteem, the research found, and also had increased odds of damage to their physical health, social relationships and schoolwork.  

Those who felt they suffered more than one type of bias had higher odds of experiencing all four of the negative effects which were measured. For example, each additional type of reported bias reported raised the odds of reporting negative effects on schoolwork by 70 per cent. Girls were more likely than boys to suffer all four negative effects, as were those who had lower grades.  

“Peer aggression which involves prejudice causes additional harm and can threaten schools’ abilities to create inclusive learning environments,” adds Ms Kurpiel. 

Her paper recommends schools should “work to raise awareness of these issues” and that prevention programs should aim, in particular, to identify students who are at risk because of multiple factors in their lives. 

“One potential intervention is to increase school organizations designed to promote inclusivity, such as Gay Straight Alliance clubs, which have been demonstrated as effective for reducing multiple types of bias-based bullying among female students who identify as LGBT,” she states.   

The results of the paper should be assessed while considering some limitations.  
 
For example, all possible types of victim impacts were not measured, so “biased victimization might not be associated with greater odds of impacts than nonbiased victimization for some unmeasured outcomes (e.g., risky behavior)”, the study declares.  

Factors related to the school climate that could be important for understanding the impacts of biased victimization (e.g., support groups) were not accounted for due to their lack of measurement in the data.  

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JOURNAL

Journal of School Violence

DOI

10.1080/15388220.2023.2272133 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Biased and Nonbiased Victimization at School: Perceived Impacts among Victimized Youth in a National Sample

ARTICLE PUBLICATION DATE

10-Nov-2023

 

Palaeo-CSI: Mosasaurs were picky eaters

Signs of wear on teeth betray dietary preferences

Peer-Reviewed Publication

UNIVERSITEIT UTRECHT FACULTEIT GEOWETENSCHAPPEN

Joint press release Utrecht University and Natural History Museum Maastricht

The cradle of palaeontology – the study of fossil remains of animals and plants – lies in the Maastricht limestones, where the first Mosasaurus was discovered in 1766. The Dutch-Belgian border area around the Limburg capital is one of the best-explored areas in the world where Cretaceous rocks are concerned, the era that came to an abrupt end 66 million years ago. New data can now be added to all previous knowledge: the Maastricht mosasaurs turned out to be quite picky in their choice of diet. This is the conclusion of researchers from Utrecht University and the Natural History Museum Maastricht. In collaboration with English colleagues from the University of Leicester, they were the first in the world to study the wear marks on mosasaur teeth.

"We were curious whether different species of mosasaurs around Maastricht were really getting in each other's way in their choice of food, or whether this was not so much of a problem," explains Dr Femke Holwerda, palaeontologist at the Utrecht University Faculty of Geosciences. In the absence of data on stomach contents of the Maastricht monitor lizards, the researchers therefore looked at minute scratches on the teeth of these animals from southern Limburg (the Netherlands) and in the vicinity of Eben-Emael (province of Liège, Belgium).

Seafood banquet

"It seems that the various species of mosasaur reveal differences in diet. We noted these differences mainly between the smaller species - by mosasaur standards - of about three to seven metres in overall size, and the larger ones, eight to fifteen metres in length.” But there were also some differences between the larger species. “Prognathodon in particular, with its large cone-shaped teeth, appears to have had a surprising amount of shellfish in its diet, so it apparently loved its seafood buffet. Another species, Plioplatecarpus, with narrow pointed teeth, showed a striking number of signs of wear. Perhaps this species was also fond of fish with strongly scaled bodies.”

First

The researchers first made casts of the teeth in silicone rubber and put them in the 3D scanner. "This technique had already been used in dinosaurs, but we were the first to look at the teeth of mosasaurs in the same way," explains fellow palaeontologist Anne Schulp, also affiliated with Utrecht University.

Diversity

With this research, some missing pieces of the puzzle from the long-gone latest Cretaceous world are found. "We wish to understand diversity better," says Schulp. "And that is made easier for us because the animals studied all come from the same rocks, and therefore the same period. So instead of describing just one species, we look at the ecosystem as a whole."

Soft limestone

The limestone deposits around Maastricht are a goldmine for palaeontologists. Schulp: "Nowhere else in the world is the habitat of mosasaurus as well preserved as here. You can find them in very soft limestone, so wear and tear of the teeth from other causes may be ruled out."

Attraction

Of course, such an abundance of potential finds also exerts a great attraction on amateur palaeontologists. "There's nothing wrong with that," emphasises John Jagt, curator at the Natural History Museum Maastricht. "Amateur literally means 'enthusiast' and thanks to 250 years of intensive research by these enthusiasts, we have learnt a lot about mosasaurs and other extinct life forms. A museum like ours benefits greatly from this. What also helps is that this kind of amateur science is stimulated in the Netherlands: it is simply allowed by law. That's not the case everywhere."

Article

Femke M. Holwerda, Jordan Bestwick, Mark A. Purnell, John W.M. Jagt, Anne S. Schulp, ‘Three-dimensional dental microwear in type-Maastrichtian mosasaur teeth (Reptilia, Squamata)’, Scientific Reports, https://doi.org/10.1038/s41598-023-42369-7

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-023-42369-7 

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Three-dimensional dental microwear in type-Maastrichtian mosasaur teeth (Reptilia, Squamata)

ARTICLE PUBLICATION DATE

9-Nov-2023