nandi's blog

Fukui Dinosaur Museum Renovation to Spark Roaring Trade

Monday, January 13, 2020

The Fukui Prefectural Dinosaur Museum

A dinosaur museum in Fukui Prefecture is set to receive a 9.4 billion yen ($86 million) facelift as the local government in the region known as Japan's fossil epicenter looks to boost visitor numbers by 50 percent.

Renovations at the Fukui Prefectural Dinosaur Museum are to be completed by 2023 with enlarged exhibition spaces set to make what is already Japan's largest dinosaur museum even larger.

The facility currently displays about 41,000 items in its 15,000-square-meter floor space, according to the prefecture.

More than 80 percent of dinosaur fossils discovered in Japan are dug up in the prefecture, the local government says.

Dinosaur Museum - FUKUI

With the floor space expanded by 5,700 sq meters, the renovated facility is planned to open in the summer of 2023 following the start of the Hokuriku Shinkansen bullet train serves to Fukui in the spring of that year.

The local government hopes that the annual number of dinosaur museum visitors will hit 1.4 million after the renovation is completed. The current record is 938,000 set in the year ended March 2019.

The museum in Katsuyama, which was established in 2000, will introduce a new section to offer interactive fossil excavation and replica-making lessons and a video room with 10-meter ceilings in which to display life-size dinosaurs.

Foreign language audio guide availability will also be improved.

Giants Roam Fukui at Prefectural Dinosaur Museum

Source: https://english.kyodonews.net/

Tyrannosaurus rex: The Teen Years

Monday, January 13, 2020

The fossilized skull of “Jane,” a juvenile T. rex at a museum in Rockford, Illinois. She is estimated to have been about 13 years old at the time of death. She was slender, with knife-like teeth not yet big enough to crush bone. Image via Scott A. Williams/ OSU.

Growing up Tyrannosaurus rex: A new study from Oklahoma State University provides details about what life was like for the famous dinosaurs during their juvenile teenage years.

When we think of dinosaurs, Tyrannosaurus rex – or T. rex – quickly comes to mind. This is hardly surprising, since T. rex is often called the king of dinosaurs and is probably the most famous dinosaur ever to have walked the Earth. An adult T. rex was a huge carnivorous predator with teeth that could crush the bones of any poor victim it caught. Scientists have learned a lot about this mighty and ferocious creature over the years. Now a new study is shedding more light on what T. rex teens were like.

The study was led by Holly Woodward of Oklahoma State University (OSU). It focuses on the bones of two mid-sized T. rex skeletons nicknamed Jane and Petey. The new peer-reviewed paper was published in the journal Science Advances on January 1, 2020.

Jane and Petey’s bones were first discovered and collected in the early 2000s in Carter County, Montana, by Burpee Museum of Natural History in Rockford, Illinois.

As with other dinosaur species, museums and scientists will often focus on the largest and most impressive fossils, including those of T. rex. That’s understandable, especially for public displays, but the OSU team wanted to study younger specimens of T.rex as well. As Woodward explained in a statement:

Historically, many museums would collect the biggest, most impressive fossils of a dinosaur species for display and ignore the others. The problem is that those smaller fossils may be from younger animals. So, for a long while we’ve had large gaps in our understanding of how dinosaurs grew up, and T. rex is no exception.

By examining the fossils of younger T. rexes, scientists can better understand how they changed as they got older, including their bones and proportions. They can also use paleohistology – the microscopic study of fossil bone structure – to learn about juvenile growth rates and ages. In the case of Jane and Petey, researchers removed thin slices of leg bones from fossils, and examined them under powerful microscopes.

The complete skeleton of Jane. Image via Burpee Museum of Natural History/ Smithsonian Magazine.

As Woodward pointed out, huge dinosaur bones are also fossilized on a microscopic scale, not just as large bones the way we see them:

To me, it’s always amazing to find that if you have something like a huge fossilized dinosaur bone, it’s fossilized on the microscopic level as well. And by comparing these fossilized microstructures to similar features found in modern bone, we know they provide clues to metabolism, growth rate, and age.

So what were T. rex teens – smaller but still ferocious predators – like?

Woodward and her colleagues found that they grew as fast as modern mammals and birds. It took the juvenile T. rexes about 20 years to mature into adults, these scientists said. They determined the ages of Jane and Petey by counting the number of annular rings in the bones, in much the same way that tree rings are counted. It turned out the two teen dinosaurs were about 13 and 15 years old, respectively – teenage T. rexes. According to Woodward:

The spacing between annual growth rings record how much an individual grows from one year to the next. The spacing between the rings within Jane, Petey, and even older individuals is inconsistent – some years the spacing is close together, and other years it’s spread apart.

Juveniles were fast and had knife-like teeth. Adult T. rexes, though, were slower but had powerful jaws and teeth to crush bones. The researchers also found that if food was more scarce in a particular year for younger T. rexes, then they didn’t grow as much during that time period.

But if there was a lot of food, then they grew a lot.

An updated artist’s depiction of a fully-grown T. rex. More recent studies suggest the fearsome beasts had feathers on their heads, backs and tails. Image via Zhao Chuang/ PNSO/ Business Insider.

After Jane and Petey were first discovered, there was speculation that they might not be T. rexes at all, but rather belonged to a pygmy relative species called Nanotyrannus. Studies of the bones, however, confirmed they were juvenile T. rexes.

Our concepts of T. rex have changed over the years, with more recent findings suggesting that fully-grown T. rexes had feathers on the top of their heads, backs and tails. A fully-grown T. rex was fearsome, standing about 12 to 13 feet high at the hip, and about 40 to 43 feet long. Paleontologists have found most T. rex fossils in the northwestern U.S., in states such as Montana and South Dakota, as well as in Alberta, Canada. T. rex lived at the very end of the Late Cretaceous period, about 90 to 66 million years ago.

Bottom line: A new study from Oklahoma State University provides new details about what the famous Tyrannosaurus rex dinosaurs were like during their teenage years.

Source: Growing up Tyrannosaurus rex: Osteohistology refutes the pygmy “Nanotyrannus” and supports ontogenetic niche partitioning in juvenile Tyrannosaurus

Via OSU News and Information   /    https://earthsky.org/

Laura Dern Overjoyed that Her Jurassic Park Character is Feminist Icon

Sunday, January 12, 2020

Laura Dern is the Secret to JURASSIC PARK's Longevity

Laura Dern is overjoyed that her Jurassic Park character Dr. Ellie Sattler is a feminist icon for women.

The no-nonsense paleobotanist needs no leading man to save her in the 1993 movie, directed by Steven Spielberg, as she battles velociraptors to save the lives of Sam Neill and Jeff Goldblum at the ill-fated dinosaur park.

Since then, Laura revealed that she's been approached by women who love telling her how much they adore Ellie.
“I’ve had so many girls and women come up to me over the years talking about her being an icon for them, and that’s meant so much to me," she told Deadline.

And the 52-year-old is proud that she played such a strong character in Spielberg’s groundbreaking film.

RELATED: 10 Scariest Moments From The Jurassic Park Franchise

"I think the thing I love the most about playing Ellie Sattler, and this was the early ’90s, was that it was the first CGI movie ever," Laura explained. "We were going to do, it felt like, this wild thing that Steven wanted to attempt, which had never been done before.

"And he wanted to make sure that if all worked well, that the female in the centre of the story was as much of a bada*s and as fearless as anyone else. He took it seriously, and she was kind of a feminist.”

The Golden Globe-winning actress is excited to reprise her role for the upcoming Jurassic World 3, alongside her original Jurassic Park co-stars, ahead of a 2021 cinema release.

"It’s exciting to continue that journey and see what they come up with, and I’m excited to learn. Steven seems excited. Sam and Jeff seem excited, and I love that, so it’s really fun to think about," she gushed.

Source: www.film-news.co.uk/

Sexing a Fossil That’s Millions of Years Old

Saturday, January 11, 2020

Borealopelta by Julius T. Csotonyi

Borealopelta, an armoured dinosaur fossil featured in Dinosaur Cold Case, a documentary from The Nature of Things, had huge 51-centimetre-long shoulder spikes. Could that mean Borealopelta was a male, using its spikes for display and fighting, similar to animals today?

When it came to determining the sex of a fossil, scientists usually had to guess. That is, until paleontologist Mary Schweitzer found a definitive way of identifying the bones of a female dinosaur, after being dead for millions of years. She discovered medullary bone in the fossil fragments from a Tyrannosaurus rex.

Medullary bone is a special tissue that forms inside the bone cavities of modern birds, like chickens. The tissue is formed when a female is laying eggs and it acts as a calcium reservoir to form the eggshells. Schweitzer saw the same bone in a T.rex fossil and was able to determine that it was a female.

In the case of Borealopelta, the dinosaur’s body is so well preserved that researchers can’t see the skeleton, keeping the mystery of its sex a secret. For now.

For more, watch Dinosaur Cold Case on The Nature of Things.

Source: www.cbc.ca/

Royal Tyrrell Museum Palaeontologists Use 3D Printing to Replicate Fragile Fossils

Saturday, January 11, 2020

A 77.3 million-year-old daspletosaurus is now on display at the Royal Tyrrell Museum.

When a fossil is discovered it’s typically encased in rock.  

After surviving for millions of years, technicians at the Royal Tyrrell Museum of Paleontology painstakingly remove that rock with fine instruments.

Once the specimen is revealed it can become brittle, especially when it's only one or two millimetres thick.

Many of the fossils at the Royal Tyrrell are too fragile to be put on display, so for decades, they've sat protected on shelves in the museum.

But now those rare bones can be photographed and scanned to create 3D printed replicas.

Amy Kowalchuk is the preparation and 3D technician at the museum. She’s mastered the technique of photographing original fossils, inputting the data into a computer program and sending it off to be 3D printed.

Kowalchuk says there’s been a lot of learning over the last three years on how to take the right photos.

“If you don’t have the photography just right for photogrammetry, it can take hours and hours of editing to take out extraneous material because the program will try to recreate the whole room around your object," she said.

"So until you really nail down how to take the photographs efficiently, then it’s a lot more time consuming than it is now I think.”

Lorna O’Brien is the head technician at the museum and proudly shows off the "exploded skull" exhibit, featuring a 77.3 million-year-old Daspletosaurus.  O’Brien says the fossils remained in storage for 20 years because they were too delicate to display.

“It’s been sitting in our collection for quite a while and we were trying to figure out how do we put this beautiful specimen on display but not compromise the fossil material, and we were able to do that with 3D printing," she said.

Francois Therrien is the curator of dinosaur paleoecology at the museum and is focused on learning more about dinosaur brains.

His challenge is brain tissue doesn’t fossilize. So he’s left with an empty cavity.

Therrien says a medical CT scan is taken of a dinosaur skull to map the brain cavity. But now that data can be used to make a 3D model of a dinosaur brain.

"Having a 3D object in your hands, you can truly look at it in all its orientations and get a better sense of perspective to see what parts are bigger than others, what’s the shape of the brain," said Therrien.

“So having the luxury of holding a dinosaur brain in your hands rather than just staring at it on a monitor makes a lot of difference.”

Because 3D technology is ever-evolving, the museum uses an outside source to do its printing. 

Source: https://calgary.ctvnews.ca/

Fossil Reveals Earth’s Oldest Known Animal Guts

Saturday, January 11, 2020

Illustrated views of Cloudina, a worm that lived about 550 million years ago. © Stacy Turpin Cheavens, University of Missouri

“It was just really lucky,” said Dr. Smith, who works at Johns Hopkins University in Baltimore and is part of the team that reported the find in Nature Communications.

The guts are those of an extinct animal called Cloudina, which looked like a worm made of a stack of ice cream cones and lived about 550 million years ago, just after a period in Earth’s history when the entire planet was encased in ice.

Dr. Smith and a doctoral student in her lab wrapped the Cloudina fossils they found in toilet paper, put them in paint buckets and hauled them back to their field car, a Ford Ranger nicknamed Kitty. Later, Dr. Smith shipped the fossils to Tara Selly and James Schiffbauer, paleontologists at the University of Missouri, for further study.

Dr. Schiffbauer and Dr. Selly specialize in the group of fossils that Cloudina is a member of, the Ediacara biota. The group includes Earth’s oldest known animals, which means that if a researcher wants to figure out what the dawn of the animal kingdom looked like — and find out when animals developed intestines — studying animal fossils like Cloudina is a good place to start.

In their lab, the duo shined X-rays on Cloudina’s remains, building 3-D images of the fossils’ insides. “The first one we were looking at, we found a gut,” said Dr. Selly, who spotted the digestive system in the lab while Dr. Schiffbauer was in his office.

“She texted me and said, ‘Hey, found something really cool, you have to come look at this,’” Dr. Schiffbauer said. When he got to the lab and saw the X-ray images, he knew exactly what they had on their hands.

“This is a gut,” he recalled saying.

The tubular guts are only about as wide as a cocktail straw. They run through Cloudina’s entire length, meaning they passed all the way through from the front end to the back end. Not every animal has a digestive system that ends in a different place from where it begins. But that setup has been common in everything from humans to insects to dinosaurs. Cloudina’s guts, then, are the first known example of our particular kind of digestive tract in the history of animal life.

“Finding that we had a tubular structure inside this skeletal tube tells us that it had a distinct mouth and a distinct anus,” Dr. Schiffbauer said. In other animals like corals, the gut is a simple sac, and the only way into that sac is through the mouth, which also serves as the anus. But with the evolution of a through-going gut, animals no longer had to wait for their food to digest before regurgitating the waste so they could keep eating.

This made eating a lot more efficient, and it opened the door for other kinds of animals with through-going guts to evolve later on, said Lidya Tarhan, a paleontologist at Yale University who was not involved in the new research.

“I think this gets at the heart of some of the most outstanding questions about the evolution of complex life on our planet,” she said.

Source: www.msn.com/  -  https://www.nytimes.com/

New Study Sheds Light on Triceratops Behavior and Living Habits

Friday, January 10, 2020

An artist's reconstruction of "Larry" the Triceratops. "Larry's" uniquely kinked tail has given researchers clues into the animal's lifestyle in a new study published, Jan 7. Reconstruction by Andrey Atuchin.

A new study published by paleontologists Matthew M. Canoy Illies and Denver Fowler, examines the kinked tail of “Larry” the Triceratops, a fossilized dinosaur on display in a new exhibit at the Badlands Dinosaur Museum in Dickinson. The investigation sheds light on the animal’s behavior and answers crucial questions about its overall ecology and habits.

“Larry” the Triceratops was first unearthed in the 67 million year old Hell Creek Formation of the U.S. Forest Service lands in southwest North Dakota in 1988 by former museum curator, Larry League. With over 70% of the skeleton preserved, the unusually complete specimen was placed on public display at Dickinson’s dinosaur museum in 1993.

A little over two decades later, Fowler, while cleaning the skeleton with his staff, noticed a peculiar feature near the end of the dinosaur’s tail: an angled crimp showing evidence of an injury sustained while the animal was still alive.

“We were in there dusting everything and it just jumped out at me,” Fowler told The Press, detailing the experience of his discovery. “It was a really cool thing to see. We all have a bit of injury that we’re reminded of when bad weather occurs or we move wrong; The idea that dinosaurs were exactly the same is really cool.”

Fowler held on to the project until he was approached by Illies who also took an interest in the animal’s life as a living creature. Together, the pair set to analyzing the crooked vertebrae in the hopes of determining the injury’s possible cause.

“The study proposes a few different hypotheses that might explain how the injury occured,” a press release issued by the Dickinson Museum Center. “Perhaps the tail was clumsily struck against a tree or rock. Maybe the injury could have been caused during an attack, being bitten by a Tyrannosaurus rex.”

However, considering the fairly frequent appearance of these kinds of malformations in Triceratops, the likelihood of a T. rex attack seems quite low to Fowler. What seems more likely to the investigators is that the tail was accidentally stamped on by another of its kind in a herd-like setting.

The skeleton of "Larry" the Triceratops. "Larry's" uniquely kinked tail has given researchers clues into the animal's lifestyle in a new study published, Jan 7. Photo c/o the Badlands Dinosaur Museum

“It’s a real example of some sort of behavior — an event that happened in this animal’s life,” Fowler said as he described the dinosaur’s environment and behavior on the prehistoric Western Edge. “It was really flat and a bit swampy. Things like Triceratops are actually more common in these swampy environments; They seem to like it more swampy.”

Only within the last decade have researchers truly begun to understand the living habits of this supposedly social creature.

“We’ve started to find groups, preserved together, now, so we think they may have been in small groups,” Fowler said. “we’re not talking hundreds and hundreds like you might see in bison, but we are talking about small groups of maybe five to ten individuals.”

No matter the findings, Fowler and his staff are admittedly happy to breathe life into the area’s Cretaceous history with the new study and its accompanying exhibit.

“It gives character to something that’s been at the museum for quite some time, but it tells us a story about ‘Larry’ the Triceratops,” the researcher said. “It also shows the new direction for the museum: we’re looking at researching the specimens we’ve had here for a long time, finding out new things about them and also finding new specimens.”

Fowler had this to say of his institution’s overall objectives: “We had a nice picture done and hopefully it will show that Dickinson, as an institution, is growing — we’re starting to produce research and hopefully it will get noted. Rather than being dusty old bones, these were animals that had events happen in their lives.”

Source: www.thedickinsonpress.com/

What Did Dinosaurs Smell Like?

Thursday, January 9, 2020

School's in Session. BY  Herschel-Hoffmeyer

Smell was certainly an important part of dinosaur life. What do we know about it?

What did Triceratops smell like?

Bones have given us an osteological outline of what the famous “three-horned face” looked like. Skin impressions and colors of related animals have offered some possibilities about saurian fashion, too. But, if we were able to travel back 67 million years, what scent would waft away from the hefty herbivore? Would it smell like a barnyard? Like nothing at all? Would the dinosaur carry a whiff of… frill cheese?

We know more than ever about dinosaurs. New species, new insights, new hypotheses. It’s almost impossible to keep up with everything. But one aspect of dinosaur lives we know precious little about is how they would have smelled – to us or, more importantly, to each other.

I can think of a few reasons why discerning dino perfume hasn’t struck the cover of Nature or Science just yet. The first is a lack of direct evidence. Fossil bones can sometimes be smelly, but they don’t preserve the aromas of the living animals. Not to mention that finding evidence of scent glands or other relevant soft tissue evidence seems like a scant possibility (but we’ll get back to that in a moment).

There’s also the way we resurrect and envision dinosaurs. Our species relies greatly on sight and touch. More often that not, we try not to smell the entirety of the world around us. If you’ve taken your dog on a walk or watched your cat snuffle an intriguing spot on the couch, you know that we generally try to avoid developing a scentscape. Perhaps, to us, dinosaurs wouldn’t have carried much of a smell at all, their funk coming from fetid mud, rotted meat, excrement, or other odors daubed onto their skin. And given that so much of dinosaurian media is transmitted through art, skeletal reconstructions, and sometimes film, trying to suss out the essence of Tyrannosaurus just doesn’t come up.

And yet we know that smell was important to at least some dinosaurs. To go back to that all-too-dominant favorite, every dinosaur fan knows that Tyrannosaurus rex had a relatively large olfactory bulb compared to the rest of the brain. So did other predatory dinosaurs like Allosaurus, making these dinosaurs above average at detecting smells. The earliest birds – dinosaurs themselves – inherited these abilities. A good sniffer can be critical to finding food, regardless of what meat and veggie mix a particular species preferred. What I wonder about, though, is whether non-avian dinosaurs communicated through scent.

Here’s where we get into the distinction between what we’d be able to smell and how dinosaurs would perceive each other. In terms of modern reptiles, species kept as pets are often said to have no smell – unless you forget to clean their cage properly or frequently enough. Their scaly skins seem relatively stink free compared to a the fur of a companionable canid. And yet we know that smell is important for reptiles. Alligators and crocodiles, for example, have glands along their jaws that sometimes secrete an oily substance thought to be important in some form of communication. Garter snakes, too, can actually spray a compound into the air and tell competing mates to back off. And contrary to a long-held belief about birds, scent is important to communication among living dinosaurs, too.

We don’t know if any non-avian dinosaur advertised with scent in the same way. Our image of dinosaurs and their lives is principally molded by what they left behind, with our expectations of what can be found guiding what we look for. Personally, I think there’s an entire world of dinosaurian fragrances that we have yet to even catch the barest sniff of. We already have evidence that some dinosaurs were sensitive to smell thanks to endocasts of their brains, and, while circuitous nasal passages in groups like ankylosaurs have generally been hypothesized to be advantageous for cooling incoming air or making sounds, it’s possible some sensitive sniffing abilities were carried along.

There may be some aspects of Mesozoic lives that time has completely obscured. But I don’t think the scents of the dinosaurs’ world are impossible to detect. The fossil record is far more detailed than we ever knew. Shreds of degraded proteins and tatters of blood vessels can now be uncovered from fossils. Perhaps, somewhere out there, there’s a fossil that preserves some critical gland or organ that itself contains the biochemical remnants of what those tissues used to create. Something smelly. Until then, we can at least try to imagine the ancient odors. Close your eyes, picture your favorite dinosaur, and think about what you’d smell.

Source: https://blogs.scientificamerican.com/

Pu’an Dinosaur Geopark: China to Build Real-Life Jurassic Park in Megacity Ready for 2021

Wednesday, January 8, 2020

Plans for a real-life off screen Jurassic Park are under way in China (Image: Reuters)

Budding paleontologists will be able to discover more about dinosaurs at a real-life Jurassic Park adventure world in Chongqing, China called Pu’an Dinosaur Geopark.

Plans for a real-life off screen Jurassic Park are under way in China after megacity Chongqing approved a request for a dinosaur land.

Budding explorers will be able to discover more about their favourite reptile giants and even dig through a fossil site in the excavation area.

The attraction will also feature a dinosaur fossil museum and research base which will study the movement of dinosaurs from the late Jurassic era to the early middle Jurassic era.

For Jurassic Park fans truly living on the wild side of life, the park will also feature rollercoasters and large scale rides.

It is not yet clear when the building for the park will be complete but developers have dubbed it Pu’an Dinosaur Geopark.

Construction is expected to begin early spring and the adventure park is set for completion by the end of 2020 - ready for a 2021 opening.

The Jurassic Dinosaur Park will become the second large geo-park for Chongqing with Longgang National Geopark a much-loved tourist attraction in the city.

According to the Chongqing Municipal Planning and Natural Resources Bureau the application for the exotic park was approved early on Monday.

News of the attraction will delight Jurassic Park fans who have developed a cult following for the dinosaur franchise.

It began in 1990 when Universal Pictures acquired the rights to the novel by Michael Crichton and developed it under the guidance of Steven Spielberg in 1993.

The original film is centred on a disastrous attempt to create a theme park of cloned dinosaurs which would be open to the public.

Steven Spielberg also directed the second Jurassic Park film The Lost World in 1997 and there have since been five films in total with a sixth scheduled for 2021.

Source: www.dailystar.co.uk/

Ghost Worms Mostly Unchanged Since the Age of Dinosaurs

Wednesday, January 8, 2020

Upper specimen: Stygocapitella josemariobrancoi from a beach close to Plymouth, UK: Lower specimen: Stygocapitella furcata from the 4th of July beach on San Juan island, WA, USA Credit: José Cerca, Christian Meyer, Günter Purschke, Torsten H. Struck

It is well known that the size, shape and structure of organisms can evolve at different speeds, ranging from fast-evolving adaptive radiations to living fossils such as cichlids or coelacanths, respectively.

A team led by biologists at the Natural History Museum (University of Oslo) has uncovered a group of species in which change in appearance seems to have been brought to a complete halt. The tiny annelid worms belonging to the genus Stygocapitella live in sandy beaches around the world. In their 275-million-year history, the worms have evolved 10 distinct species.

But what makes the group stand out is the presence of only four morphotypes. Such absence of morphological change has lately proven to be a common feature of many so-called cryptic species complexes, for example, in mammals, snails, crustaceans and jellyfish.

"Cryptic species are species which have already been distinct species for a substantial amount of time, but have accumulated very little or no morphological differences. Such species can help us understand how evolution proceeds in the absence of morphological evolution, and which factors might be important in these cases," explains Professor Torsten Struck at the Natural History Museum (University of Oslo)

Two of the Stygocapitella species that were investigated split apart at the time when Stegosaurus and Brachiosaurus lived. But despite 140 million years of evolution, these ghost worms today look almost exactly the same. However, looks may be deceiving. Molecular investigations reveal that they are highly genetically distinct, and considered reproductively isolated species.

In comparison to other cryptic species complexes separated by a maximum of a couple million years, the time span in this complex is 10 times longer, which makes the lack of change in ghost worms extreme.

"These species can also be studied to understand how species respond to extreme ecological changes in the long run. Some of these morphotypes have experienced the much warmer conditions of the Cretaceous as well as the changing intervals of the ice ages," says Struck.

What makes the case of Stygocapitella particularly puzzling is that closely related taxa seem to be evolving morphotypes significantly faster. The findings therefore highlight that evolutionary change in appearance should be viewed as a continuum, ranging from accelerated to decelerated, and where the investigated worms stand out as one of the more extreme cases of the latter. The study also points out that species formation is not necessarily accompanied by morphological changes.

The researchers suggest that lack of morphological change may be linked to the worms having adapted to an environment that has changed little over time.

"Beaches have always been around and had the same composition then as now. We suspect these worms have remained in the same environment for millions and millions of years and they are well adapted. We suspect they have become good in moving around, but not having changed much," explains first author of the study Ph.D. Fellow José Cerca. "Alternatively, it has been suggested that populations regularly crash to only a few surviving individuals, and newly evolved characters get eliminated in the course of these events. Finally, besides or instead of the environment, their development may constrain their evolution."

However, the reasons for the slow rate of morphological change are still inconclusive in the current study, and remain to be explored by the group in the future.

More information: José Cerca et al, Deceleration of morphological evolution in a cryptic species complex and its link to paleontological stasis, Evolution (2019). DOI: 10.1111/evo.13884

Source: https://phys.org/

Pages