logo
Echidna Species Lived Watery Lifestyles Like Platypuses: Study

Echidna Species Lived Watery Lifestyles Like Platypuses: Study

NDTV29-04-2025
Sydney:
As the world's only surviving egg-laying mammals, Australasia's platypus and four echidna species are among the most extraordinary animals on Earth.
They are also very different from each other.
The platypus is well adapted for a semi-aquatic lifestyle, spending up to 20 hours a day swimming in Australian waterways to forage for freshwater invertebrates. Echidnas, on the other hand, live entirely on land. They are widely distributed across Australia and New Guinea, and adapted for feeding on termites, ants and earthworms.
How did these differences emerge? Some researchers think echidnas evolved from a swimming, platypus-like ancestor. This hypothesis is based on evidence from aspects of their genes and anatomy, and from hypotheses about their evolutionary history.
However, this idea is controversial because fossil evidence for such a profound evolutionary transformation has been lacking - until now.
A bone from 108 million years ago
In our study published today in PNAS, we gleaned new data from a 108-million-year-old mammal humerus (arm bone), found 30 years ago at Dinosaur Cove, Victoria, by a team from Museums Victoria.
This arm bone, from a species called Kryoryctes cadburyi, belongs to an ancestral monotreme - a semi-aquatic burrower like the platypus. Our findings support the hypothesis that land-living echidnas evolved from a swimming ancestor.
Kryoryctes lived during the Age of Dinosaurs (the Mesozoic), when monotremes and monotreme relatives were more common than they are today. Glimpses of this past diversity are found in the fossil record in southern Victoria and Lightning Ridge, New South Wales.
Nevertheless, Australian Mesozoic mammal fossils are exceedingly rare, and mostly consist of teeth and jaws. Kryoryctes is the only one known from a limb bone, which provides significant information about its identity, relationships and lifestyle.
Tiny clues inside bones
In order to test the evolutionary relationships of Kryoryctes, we added it to a broader data set of 70 fossil and modern mammals. From there, we calculated an evolutionary tree. This showed Kryoryctes is an ancestral monotreme.
We also compared the external shape of the Kryroryctes humerus bone to living monotremes. These analyses indicated the bone is more like those of echidnas, rather than platypuses.
But it was a different story on the inside. When we looked at the internal structure of the Kryoryctes humerus with several 3D scanning techniques, we uncovered microscopic features of this arm bone that were actually more like those of the platypus.
Such tiny features inside bones yield crucial clues about the lifestyle of an animal. Numerous previous studies link bone microstructure in mammals and other tetrapods (four-limbed animals) with their ecology.
Using the wealth of data available for living mammals, we compared characteristics of the Kryoryctes humerus microstructure to those in platypuses, echidnas and 74 other mammal species.
These analyses confirmed that the Kryoryctes humerus has internal bone features found in semi-aquatic burrowing mammals (such as the platypus, muskrat and Eurasian otter), rather than land-living burrowing mammals such as the echidna.
From water to land
This discovery suggests that a semi-aquatic lifestyle is ancestral for all living monotremes. It also suggests the amphibious lifestyle of the modern platypus had its origins at least 100 million years ago, during the Age of Dinosaurs.
In this scenario, the modern platypus lineage has retained the ancestral semi-aquatic burrowing lifestyle for more than 100 million years. Echidnas would have reverted to a land-based way of life more recently.
For echidnas, a return to land appears to have resulted in adaptations such as their long bones becoming lighter, as shown in our study.
They possibly also lost several other features more useful for spending time in the water rather than on land, including the loss of a long tail, reduction of webbing between fingers and toes, reduction of the duck-like bill to a narrow beak, and a reduced number of electroreceptors on that beak.
However, precisely when this evolutionary transformation occurred is not yet known. The answer must wait until early echidna fossils are found - so far, nothing definitive has turned up anywhere.
The modern habitats of monotremes are increasingly under threat from environmental degradation, interactions with humans and feral predators, and climate change. This is especially true for platypuses. To ensure the survival of this ancient lineage, we need to better understand how their unique features evolved and adapted.
(Author: Sue Hand, Professor Emeritus, Palaeontology, UNSW Sydney; Camilo López-Aguirre, Adjunct Professor, Department of Anthropology, University of Toronto; Laura A. B. Wilson, ARC Future Fellow, Head of Biological Anthropology, Australian National University, and Robin Beck, Lecturer in Biology, University of Salford)
Laura A. B. Wilson receives funding from the Australian Research Council
Robin Beck receives funding from the UK's National Environmental Research Council, and the Australian Research Council.
Camilo Lopez-Aguirre does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.)
Orange background

Try Our AI Features

Explore what Daily8 AI can do for you:

Comments

No comments yet...

Related Articles

Not just humans, even ants follow caste. It defines their destiny
Not just humans, even ants follow caste. It defines their destiny

India Today

time11 hours ago

  • India Today

Not just humans, even ants follow caste. It defines their destiny

For ages, biologists have been fascinated by the world of ants, where destiny often depends on caste: queens grow large, sprout wings, and lay eggs, while their sisters remain small, wingless balance of genetics and environment in determining these roles has long been debated. Now, a study published in PNAS sheds new light on the intricate interplay between genes, body size, environment, and an ant's by Dr. Daniel Kronauer at The Rockefeller University, researchers set out to untangle whether environment or genetics is more important in shaping whether a developing ant becomes a queen or a worker. Using the clonal raider ant, Ooceraea biroi, which allows precise control of genetics and rearing conditions, the team found that size and caste are inextricably linked—but not by environment alone. The destiny is an interplay between genes, body size, environment. (Photo: Pixabay) Queens aren't just large workers; they possess wings, large ovaries, and special eyes, while workers lack these features. By manipulating food, temperature, and caregiver genotypes, the team found that these environmental factors influenced caste only by altering the ants' final body size, smaller ants remained workers, while those that grew big enough developed queen-like intriguing differences emerged when the team studied ants from different genetic lines under identical conditions. Some genetic lines produced ants that, even at small sizes, were more likely to develop queen-like traits."Genes don't just influence how big an ant grows," says Patrick Piekarski, co-author and postdoctoral researcher in Kronauer's lab, "they also set the body size threshold at which queen features appear."In other words, two ants of the same size but different genetics can have drastically different chances of becoming queens. Researchers set out to untangle whether environment or genetics is more important. (Photo: Getty) While environmental factors, like access to food, can increase or decrease overall size, only genetics determine how size translates to caste. The findings highlight that ant societies have evolved a robust, genetically controlled system for dividing roles, with genes both shaping growth and defining what that growth means to the the links between genes, size, and social roles isn't just about morphology, it's a window into the evolutionary logic behind insect societies and the roles individuals play within them.- EndsTrending Reel

What really causes obesity? Study says diet matters more than exercise
What really causes obesity? Study says diet matters more than exercise

Time of India

time3 days ago

  • Time of India

What really causes obesity? Study says diet matters more than exercise

Obesity is a complex medical condition marked by excessive body fat that increases the risk of serious health problems such as heart disease, diabetes, high blood pressure, and certain cancers. While it's often believed that lack of exercise is the primary cause of obesity, a groundbreaking study published in PNAS challenges this assumption. Researchers found that people in both industrialised and developing societies burn a similar number of calories daily, regardless of how active they are. This suggests that physical inactivity may not be the main driver of the obesity epidemic. Instead, the study points to diet, particularly the overconsumption of ultra-processed foods as the leading cause. What is obesity, and its causes Obesity is a complex health condition characterized by excessive body fat. It's not merely a cosmetic issue, it's a serious medical concern that significantly raises the risk of various diseases. Obesity doesn't have a single cause. It usually results from a combination of factors, including: Genetics: Family history can predispose individuals to obesity. Hormonal and metabolic factors: Hormonal imbalances and slowed metabolism play a role. Lifestyle habits: High-calorie diets, especially rich in ultra-processed foods, are a major contributor. Physical inactivity: Although not the sole cause, sedentary lifestyles can worsen weight gain. Environmental factors: Limited access to healthy foods, poor sleep, and stress can also contribute. Medications: Certain drugs (e.g., antidepressants, corticosteroids) can lead to weight gain. 'Constrained Total Energy Expenditure' model of the study Researchers measured total energy expenditure among over 4,200 individuals across 34 countries with lifestyles ranging from hunter-gatherers to city dwellers using the gold standard 'doubly labeled water' method. Surprisingly, when adjusted for body size, daily calorie burn was almost identical regardless of lifestyle, debunking the idea that less activity equals fewer calories burned This finding supports the constrained total energy expenditure model, which suggests our bodies regulate energy use within a fixed range, even with increased activity. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Many Irish Citizens Don't Know About This Read More Undo According to lead author Herman Pontzer, overeating, especially ultra-processed foods, is nearly ten times more responsible for obesity than decreased calorie burn. Is exercising still important to manage obesity? The study does not suggest abandoning exercise. While exercise may not significantly influence weight loss on its own, it plays a crucial role in: Maintaining weight after loss Improving cardiovascular and metabolic health Enhancing mood and mental clarity Building muscle and bone strength Increasing lifespan Exercise is essential for overall well-being, but controlling calorie intake is more effective for managing obesity. Health complications of obesity Unchecked obesity can lead to life-threatening complications, including: Insulin resistance and type 2 diabetes Heart attacks and strokes Liver damage and gallbladder disease Reproductive issues and infertility Increased risk of surgical and anesthetic complications Poor mental health: depression, anxiety, low self-esteem Certain types of cancer (Breast, Colon) Also read | What causes bloating: Discover the foods and tips that help reduce bloating

Health emergency: Deadly Mpox strain Clade 1 hits Australia, only the 2nd case ever
Health emergency: Deadly Mpox strain Clade 1 hits Australia, only the 2nd case ever

Time of India

time4 days ago

  • Time of India

Health emergency: Deadly Mpox strain Clade 1 hits Australia, only the 2nd case ever

A rare and more dangerous strain of the Mpox virus, known as Clade 1, has been confirmed in Queensland, marking the first-ever case in the state and only the second known detection of this strain in Australia's history. Queensland Health officials say the individual had recently returned from overseas and was diagnosed while seeking care at Logan Hospital in the state's Metro South region. Contact tracing is currently underway, and public health teams are working to identify and notify anyone who may have been exposed. Explore courses from Top Institutes in Select a Course Category Data Analytics Leadership Others Design Thinking Cybersecurity healthcare others Product Management MCA Management Digital Marketing Degree MBA Operations Management Data Science Healthcare Artificial Intelligence Finance Public Policy Data Science Project Management CXO Technology PGDM Skills you'll gain: Data Analysis & Visualization Predictive Analytics & Machine Learning Business Intelligence & Data-Driven Decision Making Analytics Strategy & Implementation Duration: 12 Weeks Indian School of Business Applied Business Analytics Starts on Jun 13, 2024 Get Details 'Clade 1 is notorious for causing a more widespread rash, big blisters or pox-like lesions, typically all over the body,' said Dr. Paul Griffin, infectious diseases expert. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Unbelievable: Calculator Shows The Value Of Your House Instantly (Take a Look) Home Value Calculator Search Now Undo 'And because it is more severe, they can have other symptoms like high fevers.' The virus, previously known as monkeypox, spreads primarily through close, prolonged, or intimate contact, including skin-to-skin contact or exposure to bodily fluids, respiratory droplets, or contaminated materials like clothing or bedding. Live Events The patient is in isolation, and authorities say there is no current threat to the broader community. Rare but serious threat Mpox Clade 1 is far more severe than Clade 2, the milder strain that caused most of Australia's 2022 outbreak. Clade 1 has been associated with higher rates of complications, including secondary infections and in rare cases, death. The first Australian case of Clade 1 was reported in New South Wales in May 2025, also in a traveler returning from Africa. Clade 1 is more common in Central Africa and has been spreading more widely in the past year, prompting increased surveillance globally. FAQs What is MPox? Mpox is a viral infection similar to smallpox, but typically milder. It causes fever, body aches, swollen lymph nodes, and a characteristic blistering rash. What makes Clade 1 different? Clade 1 is a more dangerous strain. It causes larger, widespread blisters, more severe fever, and sometimes serious complications. It has a higher mortality rate than Clade 2, particularly in countries with limited healthcare access. How does Mpox spread? Mpox spreads through: Close or intimate contact (skin-to-skin, kissing, sex) Contact with lesions or scabs Respiratory droplets in close, prolonged face-to-face interaction Contaminated clothing, bedding, or surfaces Who is at risk? While anyone can contract Mpox, the risk is higher for: People with multiple intimate partners Travelers returning from endemic areas Close contacts of confirmed cases Healthcare and frontline workers Is there a vaccine? Yes. Australia offers free MPox vaccines to high-risk individuals. Two doses are recommended for full protection. Contact your local sexual health clinic or GP to book.

DOWNLOAD THE APP

Get Started Now: Download the App

Ready to dive into a world of global content with local flavor? Download Daily8 app today from your preferred app store and start exploring.
app-storeplay-store