Mysterious young sea stars, new research


Valvaster striatus sea stars

From the Smithsonian Tropical Research Institute in Panama, 13 October 2020:

Sea star’s ability to clone itself may empower this mystery globetrotter

October 13, 2020

Summary: The identity of wild cloning sea star larvae has been a mystery since they were first documented in the Caribbean. The most commonly collected cloning species was thought to belong to the Oreasteridae, on the basis of similarity with sequences from Oreaster reticulatus and Oreaster clavatus.

For decades, biologists have captured tiny sea star larvae in their nets that did not match the adults of any known species. A Smithsonian team recently discovered what these larvae grow up to be and how a special superpower may help them move around the world. Their results are published online in the Biological Bulletin.

“Thirty years ago, people noticed that these asteroid starfish larvae could clone themselves, and they wondered what the adult form was,” said staff scientist Rachel Collin at the Smithsonian Tropical Research Institute (STRI). “They assumed that because the larvae were in the Caribbean the adults must also be from the Caribbean.”

Scientists monitor larvae because the larvae can be more sensitive to physical conditions than the adults and larval dispersal has a large influence on the distribution of adult fishes and invertebrates. Collin’s team uses a technique called DNA barcoding to identify plankton. They determine the DNA sequence of an organism, then look for matches with a sequence from a known animal in a database.

“This mystery species was one of the most common in our samples from the Caribbean coast of Panama,” Collin said. “We knew from people’s studies that the DNA matched sequences from similar larvae across the Caribbean and it matched unidentified juvenile starfish caught in the Gulf of Mexico — but no one had found a match to any known adult organism in the Caribbean. So we decided to see if the DNA matched anything in the global ‘Barcode of Life’ data base.”

“That’s when we got a match with Valvaster striatus, a starfish that was thought to be found only in the Indo West Pacific,” Collin said. “The is the first-ever report of this species in the Atlantic Ocean. We could not have identifed it if Gustav Paulay from the University of Florida didn’t have DNA sequences from invertebrates on the other side of the world.”

But why are the larvae common in the Caribbean if adult Valvaster starfish have never been found here? Are the adult starfish hidden inside Caribbean reefs, or are the larvae arriving from the other side of the world?

V. striatus is widespread but rare in the western Pacific. The few reports from collectors and the confirmed photos on iNaturalist range from the Indian Ocean to Guam and Hawaii. These starfish live deep in the reef matrix, only coming out at night. So, it is possible that there are adults in the Caribbean that have never been seen. But the other possibility, that the ability to clone themselves may allow them to spread around the world, is also intriguing.

“It’s possible that the ability of the larvae to clone themselves is not just a clever way to stay forever young,” Collin said. “There’s a natural barrier that keeps organisms from the western Pacific and the Indian ocean from crossing the Atlantic to the Caribbean. After they make it around the tip of Africa, they are met by a cold current that presumably kills tropical species.”

“Just how cloning could help them get through the barrier is still not known, but it’s intriguing that another sea star species from the Indo West Pacific that was collected for the first time in the Caribbean in the 1980s also has cloning larvae,” Collin said.

New plant species evolved in Swiss Alps


This 2014 video says about itself:

Cardamine amara (Cardamine amère) (also Large bittercress) is a flowering plant in the family Brassicaceae.

From the University of Zurich in Switzerland:

Evolution in action: New Plant species in the Swiss Alps

October 6, 2020

A new plant species named Cardamine insueta appeared in the region of Urnerboden in the Swiss alps, after the land has changed from forest to grassland over the last 150 years. The inheritance of two key traits from its parent plants enabled the newly emerged species to grow in a distinct environmental niche, as researches from the University of Zurich now show.

The emergence of a new species is generally thought to occur over long periods of time. But — as the example of the plant Cardamine insueta shows — evolution can also happen quite quickly. C. insueta, a new bittercress species first described in 1972, has only recently emerged in Urnerboden, a small alpine village in central Switzerland. It evolved just within the past 150 years due to environmental changes in the surrounding valley: when the local people cleared the forest and turned it into pasture land.

New plant species allows to observe ‘evolution in action’

“C. insueta proves to be an exceptional case to directly analyze the genetic traits and environmental responses of a new species. In other words: to observe ‘evolution in action’, a main topic of the university’s corresponding University Research Priority Program,” says Rie Shimizu-Inatsugi from the Department of Evolutionary Biology and Environmental Studies at the University of Zurich (UZH). The plant biologists were now able to unravel the genetic mechanisms underlying the plant’s evolution.

C. insueta developed from two parent species with specific ecological habitats: while C. amara grows in and beside water streams, C. rivularis inhabits slightly moist sites. The land-use conversion from forest to grassland induced the hybridization of the two progenitors generating the new species that is found in-between the parents’ habitats with temporal water level fluctuation. “It is the combination of genetic traits from its parents that enabled the new species to grow in a distinct environmental niche,” says Shimizu-Inatsugi. In fact, C. insueta inherited one set of chromosomes from C. amara and two sets of chromosomes from C. rivularis. It therefore contains three sets of chromosomes making it a so-called triploid plant.

Inheritance of two key parental traits enabled the survival

To characterize the responses to a fluctuating environment, the research team used high-throughput sequencing to analyze the time-course gene expression pattern of the three species in response to submergence. They found that the gene activity responsible for two parent traits were key for the survival of the new species in the novel habitat. First, C. insueta can clonally propagate through leaf vivipary, meaning it produces plantlets on the surface of leaves that can grow into new plants. It inherited the ability for asexual vegetative reproduction from C. rivularis. Since C. insueta is sexually sterile, it would not have been able to survive without this trait.

Second, C. insueta inherited the submergence tolerance from C. amara, since the genes responsible for this trait were active in both species. “The results show that C. insueta combined advantageous patterns of parental gene activity to contribute to its establishment in a new niche along a water-usage gradient. Depending on the environmental situation, the plant activates different set of genes it inherited from its two parent species.” says Rie Shimizu-Inatsugi.

Funding

This work is mainly funded by the University Research Priority Program “Evolution in Action: From Genomes to Ecosystems,” the Swiss National Science Foundation, Japan Science and Technology Agency, and the Human Frontier Science Program.

Woodpeckers’ drumming, new research


This 2016 video from the USA says about itself:

World’s Loudest Woodpecker Drumming and Pecking! Northern Flickers use real man-made steel drums – metal chimney caps – that makes them intelligent “tool-users” and likely among the loudest woodpecker drummers in the world. But loud doesn’t begin to describe what the 15-minute long drumming and calling sessions sound like inside the house whose chimney top is used as a drum. Enjoy this short documentary and imagine what this sounds like at the break of dawn as a male Northern Flicker defends his territory, mate and nest box!

From the University of Zurich in Switzerland:

Woodpeckers’ drumming: Conserved meaning despite different structure over the years

October 2, 2020

Summary: How do animals produce and perceive biological information in sounds? To what extent does the acoustic structure and its associated meaning change during evolution? An international team has reconstructed the evolutionary history of an animal communication system, focusing on drumming signals of woodpeckers.

Animal acoustic signals are amazingly diverse. Researchers from the University of Zurich and the University of Saint-Etienne, together with French, American and Dutch collaborators, explored the function and diversification of animal acoustic signals and the mechanisms underlying the evolution of animal communication systems.

To this end, they used Shannon & Weaver’s ‘Mathematical Theory of Communication’ originally applied to telecommunications in 1949, which has transformed the scientific understanding of animal communication. This theory allows the amount of information in a signal to be quantified. The researchers were the first to use this framework within an evolutionary perspective to explore the biological information encoded in an animal signal.

How drumming structure evolves over time

In deciding which biological model to choose, the researchers selected the woodpeckers’ drumming as their ideal candidate. This bird family is known for rapidly striking their beaks on tree trunks to communicate. The team combined acoustic analyses of drumming from 92 species of woodpeckers, together with theoretic calculations, evolutionary reconstructions, investigations at the level of ecological communities as well as playback experiments in the field.

“We wanted to test whether drumming has evolved to enhance species-specific biological information, thereby promoting species recognition,” says lead author Maxime Garcia of the UZH Department of Evolutionary Biology and Environmental Studies.

Constant amount of information for 22 million years

Results demonstrate the emergence of new drumming types during woodpeckers evolution. Yet, despite these changes in drumming structure, the amount of biological information about species identity has remained relatively constant for 22 million years. Selection towards increased biological information thus does not seem to represent a major evolutionary driver in this animal communication system. How then can biological information be concretely maintained in nature? Analyses of existing communities around the globe show that ecological arrangements facilitate the efficiency of drumming signals: Communities are composed of only a few species, which distribute their drumming strategies to avoid acoustic overlap. “The responses to different drumming structures seen in our experimental approach show the ability of individuals to recognize their own species based on acoustic cues about species identity found in drumming signals,” says Garcia. This way, biological information about species identity can be maintained without necessarily inducing a strong evolutionary pressure on drumming signals.

The present study shows that random and unpredictable changes in the structure of communication signals over time can occur while maintaining the signals overall informative potential within and across species. This work leads the way to further investigate the evolution of meaning associated with communicating through multiple communication channels.

How blue whales sing and migrate


This video says about itself:

The following is my best Blue Whale footage from 2020! All of this was filmed off the coast of San Diego, California!

From Stanford University in the USA:

Blue whales switch to daytime singing before migrating

October 1, 2020

Summary: Through the use of two advanced audio recording technologies, researchers have found that blue whales switch from nighttime to daytime singing when they are starting to migrate.

The blue whale is the largest animal on Earth. It’s also among the loudest.

“Sound is a vital mode of communication in the ocean environment, especially over long distances,” said William Oestreich, a graduate student in biology at Stanford University’s Hopkins Marine Station. “Light, or any sort of visual cue, is often not as effective in the ocean as it is on land. So many marine organisms use sound for a variety of purposes, including communicating and targeting food through echolocation.”

Although whale songs have been studied for decades, researchers have had limited success in deciphering their meaning. Now, by recording both individual whales and their greater populations in the Northeast Pacific, researchers from Stanford and the Monterey Bay Aquarium Research Institute (MBARI) have identified patterns in the trills and bellows of blue whales that indicate when the animals are migrating from their feeding grounds off the North American coast to their breeding grounds off Central America. Their research was published Oct. 1 in Current Biology.

“We decided to compare daytime and nighttime song patterns from month to month, and there, in the divergence and convergence of two lines, was this beautiful signal that neither of us really expected,” said John Ryan, a biological oceanographer at MBARI and senior author of the paper. “As soon as that image popped up on the screen, Will and I were both like, ‘Hello, behavior'”.

Further analysis across the five years of hydrophone recordings could reveal new information about blue whale migration, a 4,000-mile journey that ranks among the longest in the world — and which the creatures repeat every year. Despite the immensity of blue whales and their travels, scientists know very little about their behaviors, such as how they are responding to changes in the ecosystem and food supply from year to year. Being able to predict the travel of whales along this important route could also help prevent ship strikes.

Supping and singing

To capture whales singing solo and in chorus, the researchers used two advanced recording technologies: an underwater microphone — or hydrophone — and tags that the researchers placed on individual whales.

In 2015, MBARI deposited a hydrophone 18 miles off the Monterey coast, 3,000 feet (900 meters) under sea level. The hydrophone is wired to their MARS undersea cabled observatory, which provides it with power and communications. This seafloor eavesdropper has recorded the deep ocean soundscape almost continuously for more than five years.

“The hydrophone fits in your hand,” said Ryan, who recommends listening to the hydrophone livestream in fall for optimal whale music (although only the humpback whale song can be heard through ordinary speakers). “It’s a little instrument that produces big data — about two terabytes per month.”

By focusing on the whale song wavelengths in the hydrophone data, the researchers noticed a distinct change over several months. Through the summers, the whale arias grew louder and were sung mostly at nighttime. Over the five years of data, the whale chorus was loudest around October and November, and singing happened more at nighttime. Following each annual peak in song activity, as the whales began to depart for warmer waters, singing became more of a daytime activity.

While daytime versus nighttime differences in singing behavior had been noted in previous research, the whale-borne tags, developed by the lab of Stanford biologist Jeremy Goldbogen, helped explain what these 24-hour patterns and their inversion in late autumn could mean. Fifteen tags tracked the sounds of their carriers through accelerometer measurements — which monitor vibrations — and, in some cases, integrated hydrophones. In the summer, the whales spent much of the daytime feasting, bulking up for the long journey ahead and reserved their musical interludes for nighttime. When the time came, migration was again accompanied by daytime songs.

“In the hydrophone data, we saw really strong patterns over this enormous spatial domain. When we saw the exact same pattern on individual animals, we realized that what we’d been measuring over hundreds of kilometers is actually a real behavioral signal — and one that represents the behavior of many different whales,” said Oestreich. “As an ecologist, it’s very exciting to observe so many whales, simultaneously, using one instrument.”

Listening and learning

This research lays the groundwork for possibly predicting blue whale migration based on the transitions between the different song schedules — such forecasts could be used to warn shipping lanes further down the coast, like air traffic control but for the ocean. The researchers also hope that further analysis of the acoustic data will reveal more about whale behavior in response to environmental changes, such as warming waters and fickle food supplies.

“If, for example, we can detect differences in migration and foraging in response to changes in the environment, that is a really powerful and important way to keep an eye on this critically endangered species,” said Goldbogen, who is an assistant professor of biology in the School of Humanities and Sciences and also senior author of the paper. “That’s economically important, ecologically important and also culturally important.”

Already, Oestreich is pursuing a related question: If we can use this signal to determine whether whales are foraging or migrating, are whales using it that way too? It’s possible, said Oestreich, that a lone whale might listen around before giving up on feeding and heading south.

“Blue whales exist at incredibly low densities with enormous distances between them but, clearly, are sharing information in some way,” said Oestreich. “Trying to understand that information sharing is one motivation, but also potentially using that signaling as a means to study them is another exciting possibility.”

This research was funded by the National Science Foundation, Stanford University, the David and Lucile Packard Foundation, the Office of Naval Research, the Office of Naval Operations (Living Marine Resources program) and the California Ocean Alliance. This research was conducted under National Marine Fisheries Service permit 16111 and 21678.

Millipede evolution, new research


This 2016 video says about itself:

My friend Dani sent me two unidentified Millipedes. After a bit of research and investigation they turned out to be European White Legged Snake Millipedes (Tachypodoiulus niger ) so i thought i would show a size comparison to my adult female African Giant Millipede (Archispirostreptus gigas)

From PLOS:

Genomes of two millipede species shed light on their evolution, development and physiology

September 29, 2020

Millipedes, those many-legged denizens of the soil surface throughout the world, don’t always get the recognition they deserve. But a new study by Jerome Hui of Chinese University of Hong Kong and colleagues puts them in the spotlight, sequencing and analyzing complete genomes from two very different millipede species. The study, publishing on September 29th in the open-access journal PLOS Biology, provides important insights into arthropod evolution, and highlights the genetic underpinnings of unique features of millipede physiology.

Millipedes and centipedes together comprise the Myriapoda — arthropods with multi-segmented trunks and many legs. CentipedesHow centipedes walk and swim sport one pair of legs per segment, while millipedes bear two. Despite the apparent numeric implications of their names, different centipede species bear between 30 and 354 legs, and millipedes between 22 and 750. There are about 16,000 species of myriapods, including over 12,000 species of millipedes, but only two myriapod genomes have so far been characterized; a complete genome for the centipede Strigamia maritima, and a rough “draft” sequence of a millipede genome.

The authors of the new study fully sequenced the genomes of two millipede species, the orange rosary millipede Helicorthomorpha holstii, and the rusty millipede Trigoniulus corallinus, from two different orders, each distributed widely throughout the world. They also analyzed the gene transcripts (transcriptomes) at different stages of development, and the proteins (proteomes) of the toxin-producing “ozadene” glands.

The researchers found that two species have genomes of vastly different sizes — the orange rosary’s genome is 182 million base pairs (Mb), while the rusty’s is 449 Mb — which the authors showed was due mainly to the rusty millipede’s genome containing larger non-coding regions (introns) within genes and larger numbers of repetitive “junk” DNA sequences.

Homeobox genes play central roles in body plan formation and segmentation during animal development, and the authors found lineage-specific duplications of common homeobox genes in their two species, which differed as well from those found in the previously published millipede genome. None of the three, however, displayed the massive duplications seen in the homeobox genes in the centipede genome. They made further discoveries about the organization and regulation of the homeobox genes as well.

Many millipedes bear characteristic glands on each segment, called ozadene glands, which synthesize, store, and secrete a variety of toxic and noxious defensive chemicals. The authors identified multiple genes involved in production of these chemicals, including genes for synthesizing cyanide, as well as antibacterial, antifungal, and antiviral compounds, supporting the hypothesis that ozadene gland secretions protect against microbes as well as predators.

The results of this study provide new insights into evolution of the myriapods, and arthropods in general. “The genomic resources we have developed expand the known gene repertoire of myriapods and provide a genetic toolkit for further understanding of their unique adaptations and evolutionary pathways,” Hui said.

Did dinosaur age pterosaurs have feathers?


This December 2018 video says about itself:

Feathers might have originated tens of millions of years before we’d thought, and a 3D rendering of ankylosaur nasal passages lends new insight into how they stayed cool.

From the University of Portsmouth in England:

Evidence that prehistoric flying reptiles probably had feathers refuted

September 28, 2020

Summary: Experts have examined the evidence that prehistoric flying reptiles called pterosaurs had feathers and believe they were, in fact, bald.

The debate about when dinosaurs developed feathers has taken a new turn with a paper refuting earlier claims that feathers were also found on dinosaurs’ relatives, the flying reptiles called pterosaurs.

Pterosaur expert Dr David Unwin from the University of Leicester’s Centre for Palaeobiology Research, and Professor Dave Martill, of the University of Portsmouth have examined the evidence that these creatures had feathers and believe they were in fact bald.

They have responded to a suggestion by a group of his colleagues led by Zixiao Yang that some pterosaur fossils show evidence of feather-like branching filaments, ‘protofeathers’, on the animal’s skin.

Dr Yang, from Nanjing University, and colleagues presented their argument in a 2018 paper in the journal Nature Ecology and Evolution. Now Unwin and Martill, have offered an alternative, non-feather explanation for the fossil evidence in the same journal.

While this may seem like academic minutiae, it actually has huge palaeontological implications. Feathered pterosaurs would mean that the very earliest feathers first appeared on an ancestor shared by both pterosaurs and dinosaurs, since it is unlikely that something so complex developed separately in two different groups of animals.

This would mean that the very first feather-like elements evolved at least 80 million years earlier than currently thought. It would also suggest that all dinosaurs started out with feathers, or protofeathers but some groups, such as sauropods, subsequently lost them again — the complete opposite of currently accepted theory.

The evidence rests on tiny, hair-like filaments, less than one-tenth of a millimetre in diameter, which have been identified in about 30 pterosaur fossils. Among these, Yang and colleagues were only able to find just three specimens on which these filaments seem to exhibit a ‘branching structure’ typical of protofeathers.

Unwin and Martill propose that these are not protofeathers at all but tough fibres which form part of the internal structure of the pterosaur’s wing membrane, and that the ‘branching’ effect may simply be the result of these fibres decaying and unravelling.

Dr Unwin said: “The idea of feathered pterosaurs goes back to the nineteenth century but the fossil evidence was then, and still is, very weak. Exceptional claims require exceptional evidence — we have the former, but not the latter.”

Professor Martill noted that either way, palaeontologists will have to carefully reappraise ideas about the ecology of these ancient flying reptiles. He said, “If they really did have feathers, how did that make them look, and did they exhibit the same fantastic variety of colours exhibited by birds. And if they didn’t have feathers, then how did they keep warm at night, what limits did this have on their geographic range, did they stay away from colder northern climes as most reptiles do today. And how did they thermoregulate? The clues are so cryptic, that we are still a long way from working out just how these amazing animals worked.”

The paper “No protofeathers on pterosaurs” is published this week in Nature Ecology and Evolution.

Why tarantula spiders are blue or green


This video is called Greenbottle Blue and Sazimai’s Blue Tarantula Comparison.

By Yale-NUS College in the USA:

Scientists discover why tarantulas come in vivid blues and greens

September 24, 2020

Summary: Researchers find support for new hypotheses: that tarantulas‘ vibrant blue colors may be used to communicate between potential mates, while green coloration confers the ability to conceal among foliage. Their research also suggests that tarantulas are not as color-blind as previously believed, and that these arachnids may be able to perceive the bright blue tones on their bodies.

Why are some tarantulas so vividly coloured? Scientists have puzzled over why these large, hairy spiders, active primarily during the evening and at night-time, would sport such vibrant blue and green colouration — especially as they were long thought to be unable to differentiate between colours, let alone possess true colour vision.

In a recent study, researchers from Yale-NUS College and Carnegie Mellon University (CMU) find support for new hypotheses: that these vibrant blue colours may be used to communicate between potential mates, while green colouration confers the ability to conceal among foliage. Their research also suggests that tarantulas are not as colour-blind as previously believed, and that these arachnids may be able to perceive the bright blue tones on their bodies. The study was published in Proceedings of the Royal Society B on 23 September, and is featured on the front cover of the current (30 September 2020) issue.

The research was jointly led by Dr Saoirse Foley from CMU, and Dr Vinod Kumar Saranathan, in collaboration with Dr William Piel, both from the Division of Science at Yale-NUS College. To understand the evolutionary basis of tarantula colouration, they surveyed the bodily expression of various opsins (light-sensitive proteins usually found in animal eyes) in tarantulas. They found, contrary to current assumptions, that most tarantulas have nearly an entire complement of opsins that are normally expressed in day-active spiders with good colour vision, such as the Peacock Spider.

These findings suggest that tarantulas, long thought to be colour-blind, can perceive the bright blue colours of other tarantulas. Using comparative phylogenetic analyses, the team reconstructed the colours of 110 million-year-old tarantula ancestors and found that they were most likely blue. They further found that blue colouration does not correlate with the ability to urticate or stridulate — both common defence mechanisms — suggesting that it did not evolve as a means of deterring predators, but might instead be a means of attracting potential mates.

The team also found that the evolution of green colouration appears to depend on whether the species in question is arboreal (tree-dwelling), suggesting that this colour likely functions in camouflage.

“While the precise function of blueness remains unclear, our results suggest that tarantulas may be able to see these blue displays, so mate choice is a likely potential explanation. We have set an impetus for future projects to include a behavioural element to fully explore these hypotheses, and it is very exciting to consider how further studies will build upon our results,” said Dr Foley.

The team’s survey of the presence of blue and green colouration across tarantulas turned up more interesting results. They found that the blue colouration has been lost more frequently than it is gained across tarantulas. The losses are mainly in species living in the Americas and Oceania, while many of the gains are in the Old World (European, Asian, and African) species. They also found that green colouration has evolved only a few times, but never lost.

“Our finding that blueness was lost multiple times in the New World, while regained in the Old, is very intriguing. This leaves several fascinating avenues for future research, when considering how the ecological pressures in the New and the Old Worlds vary,” said Dr Saranathan. “For instance, one hypothesis would be differences in the light environments of the habitats between the New and the Old World, which can affect how these colours might be perceived, if indeed they can be, as our results suggest.”

New mosasaur genus discovered


A skeletal mount of the mosasaur Gnathomortis stadtmani at BYU’s Eyring Science Center. Image credit: BYU

From Utah State University in the USA:

Jaws of death: Paleontologist renames giant, prehistoric marine lizard

September 23, 2020

Summary: Paleontologists describe a new genus of mosasaur, Gnathomortis stadtmani, a marine lizard that roamed the oceans of North America toward the end of the Age of Dinosaurs.

Some 92 to 66 million years ago, as the Age of Dinosaurs waned, giant marine lizards called mosasaurs roamed an ocean that covered North America from Utah to Missouri and Texas to the Yukon. The air-breathing predators were streamlined swimmers that devoured almost everything in their path, including fish, turtles, clams and even smaller mosasaurs.

Coloradoan Gary Thompson discovered mosasaur bones near the Delta County town of Cedaredge in 1975, which the teen reported to his high school science teacher. The specimens made their way to Utah’s Brigham Young University, where, in 1999, the creature that left the fossils was named Prognathodon stadtmani.

“I first learned of this discovery while doing background research for my Ph.D.,” says newly arrived Utah State University Eastern paleontologist Joshua Lively, who recently took the reins as curator of the Price campus’ Prehistoric Museum. “Ultimately, parts of this fossil, which were prepared since the original description in 1999, were important enough to become a chapter in my 2019 doctoral dissertation.”

Upon detailed research of the mosasaur’s skeleton and a phylogenetic analysis, Lively determined the BYU specimen is not closely related to other species of the genus Prognathodon and needed to be renamed. He reclassified the mosasaur as Gnathomortis stadtmani and reports his findings in the most recent issue of the Journal of Vertebrate Paleontology.

His research was funded by the Geological Society of America, the Evolving Earth Foundation, the Texas Academy of Science and the Jackson School of Geosciences at The University of Texas at Austin.

“The new name is derived from Greek and Latin words for ‘jaws of death,'” Lively says. “It was inspired by the incredibly large jaws of this specimen, which measure four feet (1.2 meters) in length.”

An interesting feature of Gnathomortis’ mandibles, he says, is a large depression on their outer surface, similar to that seen in modern lizards, such as the Collared Lizard. The feature is indicative of large jaw muscles that equipped the marine reptile with a formidable biteforce.

“What sets this animal apart from other mosasaurs are features of the quadrate — a bone in the jaw joint that also forms a portion of the ear canal,” says Lively, who returned to the fossil’s Colorado discovery site and determined the age interval of rock, in which the specimen was preserved.

“In Gnathomortis, this bone exhibits a suite of characteristics that are transitional from earlier mosasaurs, like Clidastes, and later mosasaurs, like Prognathodon. We now know Gnathomortis swam in the seas of Colorado between 79 and 81 million years ago, or at least 3.5 million years before any species of Prognathodon.”

He says fossil enthusiasts can view Gnathomortis’ big bite at the BYU Museum of Paleontology in Provo, Utah, and see a cast of the skull at the Pioneer Town Museum in Cedaredge, Colorado. Reconstructions of the full skeleton are on display at the John Wesley Powell River History Museum in Green River, Utah, and in BYU’s Eyring Science Center.

“I’m excited to share this story, which represents years of effort by many citizen scientists and scholars, as I kick off my new position at USU Eastern’s Prehistoric Museum,” Lively says. “It’s a reminder of the power of curiosity and exploration by people of all ages and backgrounds.”

Young tortoises are attracted to faces


This video says about itself:

Differentiating Mediterranean Tortoises

Featuring the Marginated tortoise (Testudo marginata), the Greek tortoise (Testudo graeca) and the Hermann’s tortoises (Testudo hermanni). Chris Leone shows how to properly tell one from the other.

From Queen Mary University of London in England:

Tortoise hatchlings are attracted to faces from birth

September 16, 2020

Tortoises are born with a natural preference for faces, according to new research from scientists at Queen Mary University of London, the University of Trento and the Fondazione Museo Civico Rovereto.

The study provides the first evidence of the tendency for solitary animals to approach face-like shapes at the beginning of life, a preference only previously observed in social species such as human babies, chicks and monkeys.

The researchers tested the reactions of hatchlings from five different species of tortoise to different patterned stimuli, made up of a series of blobs. They found that the tortoises consistently moved to areas with the ‘face-like’ configuration — containing three blobs arranged in an upside-down triangle shape.

The findings suggest that this early behaviour likely evolved in the common ancestors of mammals, reptiles and birds more than 300 million years ago.

Dr Elisabetta Versace, lead author of the study from Queen Mary University of London, said: “Researchers have previously observed this spontaneous attraction to faces in social animals such as humans, monkeys and chicks. Because all these species require parental care, it was thought this early adaptation was important for helping young animals respond to their parents or other members of the same species. However, now we have shown that this behaviour is also found in solitary tortoise hatchlings, suggesting it may have evolved for another reason.”

Tortoises were hatched and kept away from any animal or human faces from birth until the start of the test. Each animal was then placed in the middle of a rectangular space divided into four areas containing either a face-like or control stimuli. The researchers analysed the preference of hatchlings for face-like stimuli by recording the first area the animal entered during the experimental period.

Unlike birds and mammals, tortoises are solitary species — they have no post-hatching parental care and do not form social groups as adults. Previous research has even shown that tortoise hatchlings ignore or avoid members of the same species in early life.

Silvia Damini from the University of Trento, said: “It is possible that this preference for face-like stimuli enhances learning from living animals in both social and solitary species from the early stages of life. In fact, other animals can provide information on important environmental factors, such as the availability of resources.”

Gionata Stancher, Head of the Tortoise Sanctuary Sperimentarea (Fondazione Museo Civico Rovereto, Italy) where the experiments were conducted, said: “Being able to recognise and respond to cues associated with other living animals could help young animals acquire information vital for their survival.”

New spider species discovered in Colombia


This 21 September 2020 video is called New species of spider discovered – Ocrepeira klamt.

From the Universität Bayreuth in Germany:

A new species of spider

September 16, 2020

During a research stay in the highlands of Colombia conducted as part of her doctorate, Charlotte Hopfe, PhD student under the supervision of Prof. Dr. Thomas Scheibel at the Biomaterials research group at the University of Bayreuth, has discovered and zoologically described a new species of spider. The previously unknown arachnids are native to the central cordillera, not far from the Pacific coast, at an altitude of over 3,500 meters above sea-level. In the magazine PLOS ONE, the scientist from Bayreuth presents the spider she has called Ocrepeira klamt.

“I chose the zoological name Ocrepeira klamt in honour of Ulrike Klamt, my German teacher at high school. The enthusiasm with which she pursues her profession and the interest she shows in her students and in literature are an inspiration to me,” says Charlotte Hopfe.

The cordillera in Colombia is famous for its unusually large variety of species. The habitats of these species are distributed at altitudes with very different climatic conditions, vegetation, and ecosystems. The Bayreuth researcher has collected and zoologically determined specimens of more than 100 species of spider in these habitats. In doing so, she was mainly in a region that has only been accessible to researchers since the end of civil war in Colombia in 2016. She discovered the new spider, which differs from related species in the striking structure of its reproductive organs, at altitudes of over 3,500 meters above sea-level. In the identification of this and many other spider specimens, Hopfe received valuable support from researchers at Universidad del Valle in Cali, Colombia, with which the University of Bayreuth has a research cooperation. Colombia has been identified as a priority country in the internationalization strategy of the University of Bayreuth, which is why it maintains close connections with several Colombian universities.

The study of spiders from regions of such various huge climatic and ecological variety may also offer a chance to find answers to two as yet unexplored questions. It is not yet known whether temperatures, precipitation, or other climatic factors influence the evolution of spiders, or the properties of their silk. For example, is the proportion of species with extremely elastic silk in the lowland rainforest higher than in the semi-desert? And it is also still unclear whether the properties of the silk produced by a species of spider are modified by climatic factors. Would a spider living in the high mountains, such as Ocrepeira klamt, produce the same silk if it were native to a much lower region of the cordillera? The answer to these questions could provide important clues as to the conditions under which unusual spider silks develop.

Along similar lines, it would also be interesting to explore whether there are spider silk proteins which, due to their properties, are even more suitable for certain applications in biomedicine and biotechnology than silk proteins currently known. “The greater the variety of spider silks whose structures and properties we know, the greater the potential to optimize existing biomaterials and to develop new types of biomaterials on the basis of silk proteins,” Hopfe explains.

Charlotte Hopfe’s research was funded by the German Academic Exchange Service and the German Academic Scholarship Foundation.