Small things can have a effect on the prevention of biodiversity loss

UNIVERSITY OF HELSINKI

Research News

IMAGE: IN THE SPRING, GLANVILLE FRITILLARY LARVAE EAT THEIR HOST PLANT DOWN TO THE LAST BIT. view more 

CREDIT: SUSU RYTTERI

The population growth of an endangered butterfly species is greatest in habitats with microclimatic variability, demonstrates a study carried out collaboratively by the Faculty of Biological and Environmental Sciences and the Helsinki Institute of Life Science of the University of Helsinki as well as the Finnish Environment Institute.

Insects are often very restricted in their capacity for movement. In many species, specific stages of life are spent entirely immobile, making them dependent on the temperature and moisture conditions of their immediate surroundings. In the Åland Islands on the southwest coast of Finland, Glanville fritillary butterflies (Melitaea cinxia) spend roughly 10 months of the year in the larval stage. In the middle of summer, the newly hatched larvae eat, as a group, the host plant, on whose leaf the female happened to lay the eggs. Prior research has shown that plants can wither entirely in dry summers, with prolonged dry periods sealing the fate of butterfly larvae. In such cases, only those larvae survive whose eggs have been laid on a plant growing in an exceptionally moist spot.

"We investigated how varying microclimates affect larval growth and survival in the spring after the overwintering. We found that warm and sunny days in March woke up the larvae and made them look for food. However, very little food was to be found, since the few warm days in early spring were followed by a cool April, with the growing season of the larval host plants only beginning in earnest in May," says doctoral researcher Susu Rytteri from the University of Helsinki's Research Centre for Ecological Change. She defended her thesis at the end March 2021.

It was observed that, in sunny and warm microclimates, larvae grew faster but also perished in large numbers because of lack of food. In cooler and shadier microclimates, larval growth was slow, a boost to the sufficiency of food: food plants had the time to grow in sync with the nutritional requirements of the larvae. Comprehensive survey data from the Åland Islands also demonstrated that Glanville fritillary populations grew the most in meadows where their larvae inhabited varying microclimates.

"The growth of butterfly populations increased when larval groups were located in particularly warm spots on sunny southward slopes. At the same time, the larvae also benefited from cooler and shaded microclimates. Due to the unpredictability and variability of weather conditions, the optimal egg-laying strategy for insects would appear to be laying eggs in varying microclimates which have the capacity to protect their immobile offspring from unfavourable conditions. The problem is that habitats have declined in number and become increasingly uniform. Consequently, varying microclimates are not necessarily on offer," Rytteri says.

More microclimatic variability in yards and gardens

Promoting microclimatic variability in your backyard helps insects and other animals. The sunniest spot in the yard can be turned into an even warmer place for sunbathing by, for example, constructing a section of stone wall that stores heat and offers protective crevices for small creatures. An oasis in the shade can be built in the coolest location in the yard by planting lush plants that thrive away from the sun and by adding a water element that is not only pleasing to the human eye but also serves as a watering place for animals during dry spells.

"Butterflies benefit from diverse plants, and in butterfly gardens, the goal should be floral splendour stretching from early spring long into the autumn. Many garden plants are good melliferous plants, that is, plants rich in pollen and nectar, but wild meadow plants shouldn't be overlooked either. Trees, bushes, rocks and knolls form variable microclimates and offer protection from unfavourable weather conditions," Rytteri points out.

New guidelines for schools recommend against food bans

Staff should be trained on food allergies and have epinephrine available to treat anaphylaxis

MCMASTER UNIVERSITY

Research News

 

Hamilton, ON (May 5, 2021) - Schools and child care centres should train staff on food allergies and have epinephrine available to treat anaphylaxis, but new guidelines do not recommend food bans.

The recommendations come from an international team, led by McMaster University, which has developed practice guidelines for the prevention and management of allergic reactions to food at child care centres and schools. The guidelines were published today in the Journal of Allergy and Clinical Immunology.

"The management of food allergy is a sensitive topic," said Susan Waserman, chair of the guidelines panel, an allergist and professor of medicine at McMaster University.

"Our goal is to help the school community understand the risk of allergic reactions -- and offer evidence-informed guidance for managing it."

The guidelines recommend that child care and school personnel receive training on how to prevent, recognize, and respond to allergic reactions. The guidelines also suggest that unassigned epinephrine autoinjectors, which are sold under the brand names ALLERJECT, Emerade, and EpiPen, be stocked on site.

The guidelines recommend there be no site-wide food prohibitions, such as 'nut-free' schools, or allergen-restricted zones, such as 'milk-free' tables, except in limited special circumstances.

Research has found little evidence that food bans work. Child care centers and schools may use other common-sense strategies to reduce the risk of reaction, such as providing adult supervision during snack and meal times, avoiding allergens in curriculum and fieldtrip activities, and promoting handwashing.

From one to 10 per cent of infants and preschool children and one to 2.5 per cent of school children have food allergy. Most people who develop a severe allergic reaction known as anaphylaxis survive, although there can be fatalities, especially if the reaction is not treated.

"Given that children spend much of their time in child care centers and schools, it is not surprising that food allergy management has become a topic of concern in these settings," say the guidelines.

"Anxiety and fear about the risk of accidental exposure to food allergens, and the burden of managing that risk, may limit children's participation in day-to-day activities. Children with food allergy are also at risk of allergy-related bullying."

The international guideline panel included 22 health-care professionals, school administrators, and parents of children with and without food allergy, along with a team of six researchers with methodology expertise. A systematic literature review of practices for managing food allergy in schools found a lack of high-quality evidence, so the guideline recommendations are graded as conditional.

In many cases, current policies and practices at schools and child care centres may not be supported by the best available evidence.

"It's not possible to totally remove the risk of allergic reactions," said Waserman. "However, interventions based on evidence may help community members manage the risk and support allergic students."

"As more research becomes available, some of the recommendations might need to be updated," she said. "We hope to see more high-quality research conducted in the future."

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The guidelines are endorsed by the U.S. Allergy and Asthma Network; American Academy of Allergy, Asthma and Immunology; American College of Allergy, Asthma and Immunology; Canadian Society of Allergy and Clinical Immunology; and the World Allergy Organization.

The work was funded by the Allergy, Genes and Environment Network (AllerGen), a Canadian federally funded research network.

Note to editors:

The guidelines may be found post embargo at: https://www.jacionline.org/article/S0091-6749(21)00223-2/fulltext

Guideline panel members are available for comment including an RN who is also a parent of a child with food allergies.

Secondhand smoke linked to higher odds of heart failure

Findings call attention to need for more education and stringent smoke-free policies, especially for vulnerable populations

AMERICAN COLLEGE OF CARDIOLOGY

Research News

 

Breathing in secondhand cigarette smoke may leave you more vulnerable to heart failure, a condition where the heart isn't pumping as well as it should and has a hard time meeting the body's needs, according to a study being presented at the American College of Cardiology's 70th Annual Scientific Session.

The data showed that nonsmokers with recent exposure to secondhand smoke had a 35% increased odds of developing heart failure compared with those who hadn't been around tobacco. The association between tobacco exposure and heart failure remained, even after controlling for other factors known to heighten the risk for heart failure such as a history of other heart conditions, high cholesterol and diabetes.

While previous studies have demonstrated the impact of secondhand smoke exposure on people with existing heart failure--for example, on outcomes such as mortality, quality of life and exercise tolerance--this is the first to show an association between tobacco exposure and developing heart failure.

"It adds to overwhelming evidence that secondhand smoke is harmful," said Travis Skipina, MD, resident physician in the department of internal medicine at the Wake Forest School of Medicine and the study's lead author. "[Secondhand smoke] has been associated with stroke and heart attacks, but what really hadn't been reported before was its association with heart failure, which is a very debilitating and costly disease."

The analysis included 11,219 participants from the U.S. Third National Health and Nutrition Examination (NHANES) survey who reported being nonsmokers. Participants in this NHANES cohort were followed from 1988-1994. They were 48 years old on average, just over half were women (55.9%) and most (70.5%) were white. Nearly 1 out of 5 had evidence of secondhand smoke exposure.

The association of secondhand smoke and heart failure was stronger in men (compared with women) and among those who had reported a prior heart attack or stroke. The findings were similar across other subgroups, including different ethnic/racial groups and individuals with obesity and diabetes.

"For whatever reason, in males, the impact of secondhand smoke appears to be more likely to put them at risk of heart failure," Skipina said. "Males, in general, tend to get [cardiovascular] disease at a younger age and overall, they were younger, so that may be why they were predisposed."

Skipina and his colleagues defined secondhand smoke as having a serum cotinine level ?1ng/mL, the recommended cutoff for heavy exposure used by the Centers for Disease Control and Prevention. Serum cotinine is a metabolite of nicotine that is used to measure levels of smoke exposure and usually signifies that someone has been breathing in tobacco smoke in the environment within the last one to two days (half-life of 18-20 hours). To assess dose-response, cut-off points of serum cotinine ?3ng/mL and ?6ng/mL were also used. Whether someone had heart failure was defined as answering "yes" to the survey question, "Has a doctor ever told you that you have congestive heart failure?"

Because this is a cross sectional study, it only gives a snapshot in time and cannot establish cause and effect. It is also based on an older data set. Still, Skipina said the association of secondhand smoke exposure with prevalent heart failure persisted even in a contemporary comparison of 3,796 participants followed between 2003-2006, which comes after many public smoking efforts had taken effect.

"Even with the decrease in background secondhand smoke exposure, it was still found to have a positive association with heart failure," Skipina said. "Active and secondhand smoke induces a proinflammatory state, and higher levels of inflammation affects all body tissues, and it can lead to maladaptive changes in the heart structure and damage to the blood vessels."

More research is needed to unravel the link between secondhand smoke, especially with the advent of vaping, and heart failure. Still, Skipina said the findings are a reminder for people who have heart failure or are at high risk of developing it that "they should be aware that secondhand smoke exposure may play a role." He notes this is even more relevant for lower income communities and countries where rates of tobacco use are often much higher and stringent health policies are less likely to be in place and/or enforced.

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The study will be simultaneously published online in the journal, Nicotine & Tobacco Research.

Skipina will present the study, "Secondhand Smoke is Associated with Prevalent Heart Failure: The Third National Health and Nutrition Examination Survey," on Sunday, May 16, at 9:45 a.m. ET / 13:45 UTC.

ACC.21 will take place May 15-17 virtually, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC21 for the latest news from the meeting.

The American College of Cardiology envisions a world where innovation and knowledge optimize cardiovascular care and outcomes. As the professional home for the entire cardiovascular care team, the mission of the College and its 54,000 members is to transform cardiovascular care and to improve heart health. The ACC bestows credentials upon cardiovascular professionals who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. The College also provides professional medical education, disseminates cardiovascular research through its world-renowned JACC Journals, operates national registries to measure and improve care, and offers cardiovascular accreditation to hospitals and institutions. For more, visit ACC.org.

Repeat vape aerosol exposure causes minimal damage to lung tissue compared to cigarettes

How does vape aerosol affect lung cells over time? Scientific Digital Communications Editor Arran Frood details the latest research findings at Imperial Brands

IMPERIAL BRANDS

Research News

 

IMAGE: RESULTS SHOWED THAT VAPE AEROSOL HAD MINIMAL EFFECTS COMPARED TO CIGARETTE SMOKE. view more 

CREDIT: IMPERIAL BRANDS

5 May 2021, Bristol - In one of the most advanced applications of in-vitro 3D human lung models in vape research to date, a new peer-reviewed Imperial Brands study shows that, unlike combustible cigarette smoke, blu aerosol had little to no impact on numerous toxicological endpoints under the conditions of test using laboratory models.

Published in the journal Current Research in Toxicology, the experiments compared the toxicological responses of an in vitro 3D lung model (MucilAir™ from Epithelix) after repeated exposure to undiluted whole blu aerosol (1.6% tobacco flavour) or diluted whole cigarette smoke (3R4F Kentucky Reference) over a 28-day period.

After repeatedly exposing the model to smoke or aerosol from each product for four weeks, scientists assessed the biological activity of the 3D lung tissue model against five endpoints related to respiratory function:

• Cytotoxic response (general toxicity to cells or tissue)
• Barrier integrity (measuring the intactness of tissue structure )
• Immunohistochemistry (general assessment of tissue structure)
• Cilia beat frequency and active area (detecting abnormal lung cell function)
• Pro-inflammatory response (identifying lung tissue inflammation)

This is the first peer-reviewed vaping study evaluating repeated whole cigarette smoke and whole aerosol exposure to a 3D lung model (at the air liquid interface) for this extended 28-day time period.

The use of a 3D lung model and extending the exposure scenario produced a more clinically relevant setup than previous applications, because the model is a closer representation of how the human lung is exposed to aerosol or smoke.

The Toxicity Testing in the Twenty-First Century (TT21C) driven study reinforces Imperial Brands commitment to using advanced 3D tissue models and cellular assays to as part of a global movement to reduce industry reliance on in-vivo (animal) experiments. (Imperial does not test any products on animals, unless formally required to do so by governments or recognised regulatory authorities. See our Position here.)

Results consistent with previous findings

Correlating with Imperial's previous published applications of using a similar method, in the previous study an acute exposure to undiluted whole vape aerosol showed similar biological impact to the lung cell model as humidified air under the experimental conditions. However, diluted combustible cigarettes smoke elicited a significant dose-dependent response in all measured endpoints listed above.

As expected, in the present repeated exposure study, cigarette smoke produced a significant and dose-dependent biological response against all endpoints as the puff number was increased. "Cytotoxicity and inflammatory markers were all elevated in cigarette smoke," said Fan Yu, Pre-Clinical Toxicologist at Imperial Brands and corresponding author. "Likewise, diluted cigarette smoke disrupted normal cilia beat function, cell barrier integrity, as well as tissue structure."

At each puff dose, undiluted blu aerosol contained at least seven times more nicotine relative to cigarette smoke, but for all endpoints elicited no statistically significant difference with the negative control exposed only to humidified air. "Our results suggest nicotine is not the driver of the model's cytotoxic response to cigarette smoke," Yu explained. "More likely it is the many toxicants created through burning tobacco causing the responses that are absent, or substantially reduced, in vape aerosol."

The study is further evidence that vaping may have significant harm reduction potential compared to combustible cigarettes for adult smokers who would otherwise continue to smoke.

"For adult smokers who are uninterested or unwilling to stop smoking, this study adds to a growing body research demonstrating Next Generation Products such as vapes offer a potentially reduced harm alternative if adult smokers choose to transition to these products," said Dr Grant O'Connell, Head of Tobacco Harm Reduction Science.

He added: "To ensure adult smokers are fully informed of the scientific evidence base underpinning NGPs , we urge regulators, policy makers and media alike to recognise and communicate the scientific evidence, such as that presented here, as well as many other findings in the literature, and support a role for high quality, scientifically substantiated products in maximising tobacco harm reduction."

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See release on IMB Science website: https://imperialbrandsscience.com/timeline/repeated-exposure-to-vape-aerosol-causes-minimal-damage-in-human-lung-tissue-lab-model-compared-to-cigarette-smoke/

Read the full study here: https://www.sciencedirect.com/science/article/pii/S2666027X21000098?via%3Dihub

You are free to share this content with credit to Imperial Brands under a Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0) license: https://creativecommons.org/licenses/by-nd/4.0/

Light pollution at night affects the calls of migratory birds

WILEY

Research News

 

IMAGE: WHEN INVESTIGATORS IN THE UK RECORDED THE CALLS OF MIGRATORY BIRDS CALLED THRUSHES AT NIGHT, THEY FOUND THAT CALL RATES WERE UP TO FIVE TIMES HIGHER OVER THE BRIGHTEST URBAN... view more 

CREDIT: TIM JONES

When investigators in the UK recorded the calls of migratory birds called thrushes at night, they found that call rates were up to five times higher over the brightest urban areas compared with darker villages.

The findings, which are published in Ibis, provide support to previous and ongoing research indicating that artificial light at night affects migratory birds.

"We harnessed the respective strengths of citizen science, passive acoustic monitoring, and machine learning to gather evidence of the impact of artificial light at night on migratory birds," said corresponding author Simon Gillings, PhD, of The British Trust for Ornithology. "Finding that even modest urban areas without high-rise buildings can influence migration highlights the need for improved management of urban lighting."

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Legendary Sargasso sea may be sea turtles' destination during mysterious 'lost years'

A new study is helping solve the mystery of where sea turtles go during their 'lost years' and will inform conservation efforts to protect the threatened animals

UNIVERSITY OF CENTRAL FLORID

Research News

IMAGE: OCEANIC STAGE GREEN SEA TURTLE RELEASED WITH SOLAR-POWERED SATELLITE TAG IN SARGASSUM HABITAT. PERMIT NUMBER NMFS-19508. view more 

CREDIT: PHOTO CREDIT: GUSTAVO STAHELIN, UCF MTRG.

ORLANDO, May 5, 2021 - New research indicates that the legendary Sargasso Sea, which includes part of the Bermuda Triangle and has long featured in fiction as a place where ships go derelict, may actually be an important nursery habitat for young sea turtles.

In a study led by a University of Central Florida researcher and published today in the journal Proceedings of the Royal Society B, researchers presented evidence of baby green sea turtles arriving at the Sargasso Sea after entering the ocean off the east coast of Florida.

The study was the first time that green sea turtles have been tracked during their early "lost years," which is defined as the time between hatching from their nests along Florida's Atlantic coast and heading into the ocean and their "teenage years," when they return to coastal habitats after several years in the open ocean. Not much is known about where sea turtles go during these years, which is where the "lost years" description comes from. The new findings echo the team's previous research that showed baby loggerhead sea turtles arrive at the Sargasso Sea.

The results are helping to solve the mystery of where the turtles go and will also inform efforts to conserve the threatened animals, especially during their delicate first years at sea.

Florida's Atlantic coastline is a major nesting area for green and loggerhead sea turtles, which are iconic species in conservation efforts and important for their role in helping maintain ocean ecosystems, says UCF Biology Associate Professor Kate Mansfield, who led the study in collaboration with Jeanette Wyneken at Florida Atlantic University.

Scientists have long assumed that after hatching and going into the ocean, baby sea turtles would passively drift in sea currents, such as those circulating around the Atlantic Ocean, and ride those currents until their later juvenile years.

"That green turtles and loggerheads would continue in the currents, but that some might leave the currents and go into the Sargasso Sea was not ever considered or predicted by long-held hypotheses and the assumptions in the field," Mansfield says. "We found that the green turtles actively oriented to go into the Sargasso Sea and in even greater numbers than the loggerheads tracked in our earlier work. Granted, our sample sizes aren't huge, but enough turtles made this journey that it really throws into question our long-held beliefs about the early lives of sea turtles."

The Sargasso Sea, located off the east coast of the U.S. in the North Atlantic Ocean, has often been featured in popular culture, such as in Jules Verne's Twenty Thousand Leagues under the Sea, as a place where ships could become derelict when trying to travel through thick mats of the floating, brown, Sargassum algae for which it is named.

The researchers were able to track the turtles by attaching advanced, solar-powered tracking devices, about an inch in length, to their shells. This also required determining the optimum adhesive for applying the sensor, which was different for the green sea turtles than for loggerheads because of the greens' waxier-feeling shells. The tracking device is designed to fall off after a few months and does not hurt the turtles or inhibit the turtles' shell growth or behavior, Mansfield says.

In the current study, 21 green sea turtles less than a year old, had transmitters affixed and were released into the Gulf Stream ocean currents about 10 miles offshore from the beach where they were born. The turtle release dates were from 2012 to 2013, and the researchers were able to track the turtles for up to 152 days.

Of the 21 turtles, 14 departed the Gulf Stream and the North Atlantic gyre of circulating currents and entered the western or northern Sargasso Sea region in the western Atlantic Ocean, according to the study. This is compared to seven out of 17 loggerhead turtles that left the Gulf Stream and entered the Sargasso Sea in the previous study.

Wyneken, a professor of biological sciences and director of Florida Atlantic University's Marine Science Laboratory at Gumbo Limbo Environmental Complex, worked with Mansfield to collect, raise, tag and release the turtles.

She says the research is important because it sheds light on where the baby turtles go during a delicate period in their lives.

"These studies in which we learn where little sea turtles go to start growing up are fundamental to sound sea turtle conservation," Wyneken says. "If we don't know where they are and what parts of the ocean are important to them, we are doing conservation blindfolded."

Jiangang Luo, PhD, a scientist with the Tarpon Bonefish Research Center at the University of Miami's Rosenstiel School of Marine and Atmospheric Science and study co-author, has a background in mathematical biology, oceanography and advanced scientific data visualization. As part of the research team, he helped process and analyze the data and graphed and animated the results.

"It feels great to see how the little turtles are traveling and utilizing the ocean," Luo says. "The ocean is our future, and we must have the ocean to save the sea turtles."

The Sargasso Sea Commission, which works as a steward for the area with support from multiple governments and collaborating partners, will use data from the research as part of its upcoming ecosystem diagnostic project, says the commission's Programme Manager Teresa Mackey.

The project will quantify threats and their potential impact on the Sargasso Sea, including climate change, plastics pollution and commercial activities, as well as investigate ways to counter challenges the area faces and establish a baseline for ongoing monitoring and adaptive management.

"Dr. Mansfield's research into the critical habitat that this area provides for turtles early in their life cycle gives concrete evidence of the importance of the Sargasso Sea for endangered and critically endangered species and is one of the many reasons why conservation of this high-seas ecosystem is vitally important for marine biodiversity," Mackey says.

UCF's Marine Turtle Research Group, which Mansfield directs, has been one of the commission's collaborators since 2017.

Mansfield says next steps for the "lost years" research will include looking more closely at differences in orientation and swimming behavior between turtle species, understanding the role Sargassum plays in early sea turtle development, and testing newer, smaller, and more accurate tracking devices to learn more about the places the baby turtles go and how they interact with their environment.

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The research was funded largely through the Florida Sea Turtle Specialty License Plate grants program, Disney Conservation Fund and the Save Our Seas Foundation.

Mansfield received her doctorate in marine science from William & Mary University's Virginia Institute of Marine Science. She joined UCF's Department of Biology, part of UCF's College of Sciences, in 2013. In addition to directing UCF's Marine Turtle Research Group, Mansfield is a member of UCF's Sustainable Coastal Systems cluster and National Center for Integrated Coastal Research. For the latest updates and to learn more about UCF's Marine Turtle Research Group, follow them at @UCFTurtleLab on Twitter and Instagram.

A new pelomedusoid turtle from the Late Cretaceous of Madagascar discovered

A new pelomedusoid turtle from the Late Cretaceous of Madagascar provides evidence for convergent evolution of suction feeding among pleurodires.

DENVER MUSEUM OF NATURE & SCIENCE

Research News

 

IMAGE: LIFE RECONSTRUCTION OF SAHONACHELYS MAILAKAVAVA, PREYING UPON TADPOLES OF THE GIANT MADAGASCAN FROG BEELZEBUFO AMPINGA USING SPECIALIZED SUCTION FEEDING. view more 

CREDIT: ARTWORK BY ANDREY ATUCHIN.

Joyce WG, Rollot Y, Evers SW, Lyson TR, Rahantarisoa LJ, Krause DW. 2021. A new pelomedusoid turtle, Sahonachelys mailakavava, from the Late Cretaceous of Madagascar provides evidence for convergent evolution of specialized suction feeding among pleurodires. Royal Society Open Science 8:210098. https://doi.org/10.1098/rsos.210098

First author: Prof. Dr. Walter Joyce (walter.joyce@unifr.ch), Professor of Paleontology, University of Fribourg, Switzerland

Co-authors:

- Yann Rollot (yann.rollot@unifr.ch), PhD student, University of Fribourg, Switzerland

- Serjsocha Evers (serjoscha.evers@unifr.ch; preferred: serjoscha.evers@googlemail.com), Postdoctoral Researcher, University of Fribourg, Switzerland

- Tyler Lyson (Tyler.Lyson@dmns.org), Associate Curator of Vertebrate Paleontology, Denver Museum of Nature and Science, USA

- Lydia Rahantarisoa (ralyhanta@yahoo.fr), Professor of Geology, Université d'Antananarivo, Madagascar

Senior author: David Krause (David.Krause@dmns.org), Senior Curator of Vertebrate Paleontology, Denver Museum of Nature & Science, USA

CAPTION

Fossil of Sahonachelys mailakavava, showing the preserved skull parts.

CREDIT

Prof. Dr. Walter Joyce

Figure details

Fig. 1 Life reconstruction of Sahonachelys mailakavava, preying upon tadpoles of the giant Madagascan frog Beelzebufo ampinga using specialized suction feeding. Artwork by Andrey Atuchin.

Fig. 2 Fossil of Sahonachelys mailakavava, showing the preserved skull parts.

Fig. 3 Fossil of Sahonachelys mailakavava, showing the preserved shell.

Content and importance

We here describe a new species of pelomedusoid turtle from a geological formation in Madagascar otherwise known for its exquisitely preserved fossil birds, dinosaurs, crocodilians, and mammals. The new turtle possesses an unusually flattened skull combined with a particularly gracile lower jaw and enlarged tongue bones (hyoids), which not only gave it a frog-like appearance, but also suggests that it was adapted to a specialized feeding mode called suction-feeding.

Suction feeders open their mouths rapidly to suck in prey items under water, which is in contrast to other subaquatic feeding modes in which animals shoot their heads forward to reach for prey. The new turtle has several modifications in its head skeleton that show that it was well suited for suction feeding: its skull is low but wide, and the jaws are strongly bowed and angled forward, which creates a strongly rounded mouth opening that is physically beneficial for creating large suction forces. The tongue bones are strongly developed, and this hints at large muscles that pulled the tongue skeleton backwards and opened the esophagus during the strike at prey - again creating more suction. As in all modern turtles, the new species lacks teeth, but in addition the surfaces at the upper and lower jaws that face toward each other are poorly developed, showing that this turtle did not use its jaws to process food, but instead swallowed prey whole, which is typical for suction feeders. We hypothesize that the turtle fed on small-bodied living prey, such as insect larvae, fish fry, and tadpoles using quick strikes. We, therefore, name the new species Sahonachelys mailakavava, which means "quick-mouthed frog turtle" using Malagasy and Greek words. Special about the turtle is also its preservation: it is known from a nearly complete skeleton, despite its small body size, barely more than a foot long.

Turtle fossils often come either as shells or skulls that have been separated from one another; for many extinct turtles, we only either one or the other, but not both. Having a complete skeleton helps us to understand the whole animal, and also makes it possible to compare it to other turtle fossils, regardless of how these are preserved. Based on such comparisons, we constructed a family tree of turtles that shows that Sahonachelys mailakvava was an early relative of podocnemidid turtles, which today are native to Madagascar and South America, but which were more widespread in the past.

The palaeontological fauna of Madagascar is known for animals that are very specialized, which is in part due to its long isolation from surrounding continents. Our turtle shows that the Madagascan fauna was already unique in the Late Cretaceous: Sahonachelys mailakavava is the only representative of its group to have evolved suction-feeding, which is otherwise only known in distant relatives, so-called snake-necked turtles.

CAPTION

Fossil of Sahonachelys mailakavava, showing the preserved shell.

CREDIT

Prof. Dr. Walter Joyce

Quotes by the authors:

"This is the best-preserved turtle of the entire Late Cretaceous of the southern continents and as such very significant in terms of reconstructing its way of life and relationships with other turtles" (Prof. Walter Joyce, first author of study)

"As palaeontologists, we try to understand the biology and evolution of past life. Fossils like this give a wealth of information that is not always present. The identification of suction feeding in a new turtle lineage is exciting and was unexpected. It shows how animals evolve similar traits for similar functions, even if they are only distantly related." (Serjoscha Evers, co-author of study)

"Sahonachelys is a stunning example of evolution in isolation. It represents a lineage that evolved on Madagascar for over 20 million years and joins a litany of other bizarre Late Cretaceous vertebrate animals that we've found on the island. This specimen is, by far, the best turtle fossil we discovered during the 28 years of conducting field research there." (David Krause, co-author of study)

 

Water flora in the lakes of the ancient Tethys Ocean islands

New biogeographical affinities in Cretaceous flora

UNIVERSITY OF BARCELONA

Research News

 

IMAGE: SCANNING ELECTRONIC MICROSCOPE IMAGES OF GYROGONITES OF THE NEW SPECIES MESOCHARA DOBROGEICA (ABOVE) AND THE UTRICLES OF THE NEW CLAVATOR AMPULLACEUS VAR. LATIBRACTEATUS VARIETY (BELOW) FOUND IN THE REGION OF... view more 

CREDIT: CRETACEOUS RESEARCH

A study published in Cretaceous Research expands the paleontological richness of continental fossils of the Lower Cretaceous with the discovery of a new water plant (charophytes), the species Mesochara dobrogeica. The study also identifies a new variety of carophytes from the Clavator genus (in particular, Clavator ampullaceus var. latibracteatus) and reveals a set of paleobiographical data from the Cretaceous much richer than other continental records such as dinosaurs'.

Among the authors of the study are Josep Sanjuan, Alba Vicente, Jordi Pérez-Cano and Carles Martín-Closas, members of the Faculty of Earth Sciences and the Biodiversity Research Institute (IRBio) of the University of Barcelona, in collaboration with the expert Marius Stoica, from the University of Bucharest (Romania).

Charophytes: a tool for biostratigraphy

Charophytes are pluricellular algae considered to be the ancestors of vascular plants. Since the Silurian period to date, they have occupied several lacustrine water environments (oligotrophic, alkaline and brackish waters). Nowadays, the anthropic action (exploitation of natural habitat, drainage of wet areas, pollution, etc.) is a threat to the conservation of charophyte pruderies.

For the scientific community, the fossil remains of charophytes -specially, their calcified fructifications- are abundant microfossils with a high biostratigraphy value in the dating of stratum at a local and regional scale. With a wide distribution and high rate of evolution and extinction, some species became excellent fossil indicators of the relative age of continental units.

Water flora in the lakes of the ancient Tethys Ocean islands

The study published in the journal Cretaceous Research focused on the analysis of the water paleoenvironments rich in charophytes in two continental formations -Z?voaia and Gherghina-, dominated by clay, silt and loam of lacustrine origins.

In the Lower Cretaceous, the charophytes flora of the paleo-islands of the large archipelago that built the area of current Europe and Maghreb revealed a defined biogeographical identity. In the islands of the archipelago of the ancient Tethys Ocean, the Clavatoraceae family stood out for its abundance and biodiversity.

The conclusions show a coincidence of 75% of taxons of the charophytes of the Iberia and Hateg (Romania) paleo-islands "that would differentiate these insular flowers from neighbouring continental flora, both Asiatic ones in the east and North-American ones in the western area", notes Josep Sanjuan, lecturer at the Department of Earth and Ocean Dynamics and first author of the article.

Despite the high affinity that existed between the charophyte flora of the islands that built the archipelago of the ancient Tethys Ocean, "there could also be island endemisms," says researcher Alba Vicente, who works at the National Autonomous University of Mexico. The dominant taxa on these islands from the past belong to the Clavatoraceae, an extinct family of charophytes. "Specifically, two subfamilies are represented (Clavatoroidae and Atopocharoidae), and one of the most prominent and common genera in all these islands was Globator, its evolution is a very useful tool for dating the continental successions of the Lower Cretaceous", note the experts Jordi Pérez-Cano and Carles Martín-Closas.

New findings in the charophyte paleontological records

The new species Mesochara dobrogeica is a gyrogonite -the fossilized oospore of charophytes- in the ovoid morphology with pointed apex and base. This small sized fossil fructification -which is about 385 microns high and 310 microns wide- presents apical pore shaped ornamentation. "This new species from the Mesochara genus would be the oldest ornamented piece of the current charophyte Charoidae family", notes Josep Sanjuan, who also collaborates with the American University of Beirut (Lebanon).

The Clavator ampullaceus var. latibracteatus is a new variety of charophyte fossil that shows a type of fruiting, the utricle, large in size (about 769 microns high and 802 microns wide) with bilateral symmetry. It consists of a phylloid - a leaf-like structure close to the main axis, two internal lateral bract cells and a bract cell in abaxial position. The two internal bract cells appear near the apical pore and have a complex structure that characterizes this new variety.

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Ancient DNA reveals origin of first Bronze Age civilizations in Europe

Finding shed light on role of migration in Neolithic to Bronze Age transition and emergence of Indo-European languages

CENTER FOR GENOMIC REGULATION

Research News

 

IMAGE: SKELETON OF ONE OF THE TWO INDIVIDUALS WHO LIVED IN THE MIDDLE OF THE BRONZE AGE AND WHOSE COMPLETE GENOME WAS RECONSTRUCTED AND SEQUENCED BY THE LAUSANNE TEAM. IT COMES... view more 

CREDIT: EPHORATE OF ANTIQUITIES OF KOZANI, HELLENIC MINISTRY OF CULTURE, GREECE. COURTESY OF DR GEORGIA KARAMITROU-MENTESSIDI.

The first civilisations to build monumental palaces and urban centres in Europe are more genetically homogenous than expected, according to the first study to sequence whole genomes gathered from ancient archaeological sites around the Aegean Sea. The study has been published in the journal Cell.

Despite marked differences in burial customs, architecture, and art, the Minoan civilization in Crete, the Helladic civilization in mainland Greece and the Cycladic civilization in the Cycladic islands in the middle of the Aegean Sea, were genetically similar during the Early Bronze age (5000 years ago).

The findings are important because it suggests that critical innovations such as the development of urban centres, metal use and intensive trade made during the transition from the Neolithic to the Bronze Age were not just due to mass immigration from east of the Aegean as previously thought, but also from the cultural continuity of local Neolithic groups.

The study also finds that by the Middle Bronze Age (4000-4,600 years ago), individuals from the northern Aegean were considerably different compared to those in the Early Bronze Age. These individuals shared half their ancestry with people from the Pontic-Caspian steppe, a large geographic region stretching between the Danube and the Ural rivers and north of the Black Sea, and were highly similar to present-day Greeks.

The findings suggest that migration waves from herders from the Pontic-Caspian steppe, or populations north of the Aegean that bear Pontic-Caspian Steppe like ancestry, shaped present-day Greece. These potential migration waves all predate the appearance of the earliest documented form of Greek, supporting theories explaining the emergence of Proto-Greek and the evolution of Indo-European languages in either Anatolia or the Pontic-Caspian Steppe region.

The team took samples from well-preserved skeletal remains at archaeological sites. They sequenced six whole genomes, four from all three cultures during the Early Bronze Age and two from a Helladic culture during the Middle Bronze Age.

The researchers also sequenced the mitochondrial genomes from eleven other individuals from the Early Bronze Age. Sequencing whole genomes provided the researchers with enough data to perform demographic and statistical analyses on population histories.

Sequencing ancient genomes is a huge challenge, particularly due to the degradation of the biological material and human contamination. A research team at the CNAG-CRG, played an important role in overcoming this challenge through using machine learning.

According to Oscar Lao, Head of the Population Genomics Group at the CNAG-CRG, "Taking an advantage that the number of samples and DNA quality we found is huge for this type of study, we have developed sophisticated machine learning tools to overcome challenges such as low depth of coverage, damage, and modern human contamination, opening the door for the application of artificial intelligence to palaeogenomics data."

"Implementation of deep learning in demographic inference based on ancient samples allowed us to reconstruct ancestral relationships between ancient populations and reliably infer the amount and timing of massive migration events that marked the cultural transition from Neolithic to Bronze Age in Aegean," says Olga Dolgova, postdoctoral researcher in the Population Genomics Group at the CNAG-CRG.

The Bronze Age in Eurasia was marked by pivotal changes on the social, political, and economic levels, visible in the appearance of the first large urban centres and monumental palaces. The increasing economic and cultural exchange that developed during this time laid the groundwork for modern economic systems--including capitalism, long-distance political treaties, and a world trade economy.

Despite their importance for understanding the rise of European civilisations and the spread of Indo-European languages, the genetic origins of the peoples behind the Neolithic to Bronze Age transition and their contribution to the present-day Greek population remain controversial.

Future studies could investigate whole genomes between the Mesolithic and Bronze Age in the Armenian and Caucasus to help further pinpoint the origins of migration into the Aegean, and to better integrate the genomic data with the existing archaeological and linguistic evidence.

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