Tag Archives: adapted

How Early Howler Monkeys Adapted to Leaf-Based Diets 13 Million Years Ago

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Discoveries of the Fossilized Jaw of an Ancient Monkey Species Stiltonia victoriae unveil insights from Colombia’s La Victoria Formation, indicating that early primates in South America adapted to leaf consumption, which enabled them to grow larger and explore new ecological niches. This remarkable find may also provide clues about the timeline of when this lineage developed the anatomical traits responsible for the powerful howls seen in today’s howler monkeys.

Howler monkey wearing a cloak (Alouatta palliata) in Panama. Image credit: Ariel Rodriguez-Vargas / CC BY 4.0.

The ancient primate Stiltonia victoriae thrived in what is now Colombia during the Miocene epoch, approximately 13 million years ago.

Dr. Siobhan Cook, a researcher from Johns Hopkins University, stated, “Prior to this discovery, there was no evidence indicating that South American primates consumed leaves.”

This research helps address crucial questions about ecological evolution in one of the Earth’s most biodiverse regions.

“What evolutionary changes occurred in the Amazon rainforest during the existence of these monkeys?”

In their recent study, Cook and colleagues investigated two fossilized mandibles of Stiltonia victoriae from Colombia’s La Victoria Formation in the Tatacoa Desert.

The findings indicate when this ancient monkey developed the ability to eat leaves, expanding its diet beyond fruit. This adaptation enabled it to grow larger and lessen food competition among howler monkeys and other primate species in ancient ecosystems.

“Millions of years ago, ancient monkeys traversed trees in what is now the Tatacoa Desert, once inhabited by wetland grasses, forests, and riverbanks,” said Dr. Cook.

These monkeys coexisted with long-extinct fauna in the Amazon basin, including giant sloths and armored armadillos.

“Before this, fossil findings were scarce. With Stiltonia victoriae, we could only glean knowledge from a few facial and cranial bone fragments,” Cook remarked.

“The latest discoveries not only shed light on their biodiversity and dietary habits but may also provide insight into when howler monkeys developed their distinctive ‘howl’, the loudest vocalization among land mammals.”

The structure of the jaws indicated a broad and deep mandibular body, which may have allowed the hyoid bone to protrude, similar to modern howler monkeys, potentially enabling their iconic calls.

“However, we are still uncertain about their exact behavior,” Dr. Cook added.

Paleontologists employed scans of the jaw fossils to create a 3D model for detailed analysis.

From the structure of the mandibular molars, researchers determined the dietary patterns, size, and distinguishing features of Stiltonia victoriae, comparing it against 3D models of other South American primate fossils, including Stiltonia tatakoensis, a known ancestor of howler monkeys.

They also closely examined the jaws of modern howler monkey ancestors and their relatives, such as spider monkeys and woolly gibbons residing in rainforests.

“Like modern howler monkeys, Stiltonia victoriae possessed relatively large molars with protrusions to act as ‘scissors’ for efficiently grinding carbohydrates, an adaptation common in leaf-eating primates,” said Dr. Cook.

Through their research, the body weight of Stiltonia victoriae was reconstructed, revealing these monkeys weighed between 17 and 22 pounds (8 to 10 kg).

Dr. Cook highlighted, “Previous South American monkeys in the fossil records were significantly smaller. This suggests that for the first time, these monkeys had access to abundant food sources, primarily leaves, enabling them to evolve into a heavier ecological niche.”

This discovery marks the emergence of a large and diverse group of primates in South America.

“We can now accurately trace the origins of various modern lineages.”

These findings will be published in the journal Paleoanthropology.

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Siobhan B. Cook et al. 2026. Mandibular specimen of Stiltonia victoriae from La Victoria Formation, La Venta, Colombia. Paleoanthropology 1: 148-170; doi: 10.48738/2026.iss1.3992

Source: www.sci.news

How Aardvarks are Adapted to Consume 50,000 Ants Each Night

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As the conversation around eating insects gains traction, we can learn from aardvarks (Orycteropus afer), gourmet consumers of African ants. This fascinating mammal can devour up to 50,000 crunchy ants in a single night.

Aardvarks primarily feast on ants and termites, with the occasional “aardvark cucumber” adding some variety (more on that later).

Why focus on ants and termites? Their collective biomass outweighs all wild mammals by a factor of 10, making them an abundant food source.

Known as the African ant bear, the aardvark excels in locating these protein-packed snacks by invading ant nests and termite mounds.

Equipped with sturdy claws, aardvarks dig through resilient structures, using their strong leg bones to support the strain of excavation.

While ants may respond with aggression, swarming and biting, aardvarks have thick skin that withstands these defenses. Their long, pig-like snouts dive into nests, allowing them to sip their treats like a milkshake.

Aardvarks cleverly close their nostrils to prevent inhaling dust. Additionally, specialized salivary glands release a generous amount of sticky saliva, coating their 30-cm (12-inch) long tongues, making it easy to collect ants.

The ants cling to their tongues as if caught on flypaper. Once swallowed, the food moves to the gizzard-like stomach, where muscular walls crush it.

Chewing is minimal, but aardvarks possess unique teeth. Adults have approximately 20 nail-like teeth that grow continuously and wear down over time.

These teeth consist of hundreds of small hexagonal tubes made from a dentin-like material called vascular dentin.

Relatively soft due to the absence of enamel, these teeth are ill-suited for crushing but perfect for lightly mashing the aforementioned aardvark cucumber.

The aardvark cucumber is an edible fruit, growing from a low vine. Its life cycle relies on aardvarks for seed maturation and dispersal through feces. In return, aardvarks enjoy a juicy, hydrating snack.

Aardvarks can consume up to 50,000 ants in one night – Credit: Getty

It’s intriguing that ant-eating mammals, including aardvarks, anteaters, and pangolins, have independently evolved this trait at least 12 times since the dinosaurs went extinct 66 million years ago.

This phenomenon, known as convergent evolution, shows how different species can develop similar characteristics in response to the same challenges.

Faced with the question “How can I eat all these ants?”, they have all adapted with sticky tongues, strong forelimbs, and fewer teeth.

These ant-eating mammals are akin to a recurring trend, much like mullets, showcasing evolution’s penchant for clever adaptations.

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Source: www.sciencefocus.com

We’ve Adapted to Local Micronutrient Levels, but This Could Lead to Issues

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Numerous Mayan individuals reside in Acanceh, Mexico

Educational Images/Universal Image Groups via Getty Images

Historically, the quantity of zinc and other trace elements in human nutrition was largely influenced by the local soil conditions. Recent findings suggest that our ancestors adapted to varying levels of micronutrients as they dispersed globally.

This adaptation may have resulted in notable repercussions. For instance, the shorter statures observed in certain populations might be a consequence of adapting to low iodine availability. Additionally, these historical adjustments may lead to some individuals today experiencing deficiencies or excesses of specific micronutrients.

“For much of human history, the micronutrient profile of our diet has been determined by the soil beneath us,” stated Jasmine Reese from the University of Pennsylvania.

Reese and her team analyzed the genomes of nearly 900 individuals globally to uncover evidence of adaptation to local concentrations of 13 trace elements, including iron, manganese, and selenium. They investigated signs of positive selection in 270 genes related to the ingestion of these elements, highlighting benefits of genetic variations that became more common within certain populations.

The most compelling evidence was for iodine-related genes in the Maya populations of Central America. A similar pattern was observed in the Mbuti and Biaka peoples of Central Africa.

In 2009, it was suggested that the short stature of the Mbuti and Biaka peoples may be attributed to their adaptation to low iodine levels. This relates to iodine-binding genes that influence thyroid hormone function and subsequently growth. These groups are also notably more susceptible to thyroid enlargement due to dietary iodine deficiencies compared to nearby populations.

Maya individuals also exhibit notably shorter statures, providing supporting evidence for the hypothesis that adaptations to low iodine levels influence height. Moreover, it is emphasized that the soils in the Mayan regions, particularly rainforests, are recognized as low in iodine.

“This is quite speculative,” she notes. “While I can’t definitively link short stature directly to iodine levels, we observe a striking correlation with the selection of iodine-related genes in these shorter populations.”

In the Uighur and Blahui populations of Central and South Asia, where soil magnesium concentrations are particularly elevated, there is strong selection impacting two genes involved in magnesium uptake. Some gene variants correlated with low magnesium levels suggest adaptive changes that minimize magnesium absorption to avoid toxicity from environmental excess.

These instances are merely a couple of examples. The research team has identified signs of positive selection related to at least one micronutrient across virtually all examined populations worldwide. “We truly observe a widespread signature of adaptation,” Reese states.

This research marks just the beginning, she emphasizes. Further investigations are crucial to elucidate the impacts of the numerous genetic variants discovered by the team. Given the global trade in food, individuals within certain populations may require increased or decreased intake of specific micronutrients. Reese compares this to populations in the UK, where individuals with darker skin may need vitamin D supplementation not just in winter but throughout the entire year.

“Understanding whether a specific population may require certain micronutrient supplements is essential,” notes Mark Stoneking at the Max Planck Institute for Evolutionary Anthropology in Germany.

“They’ve conducted groundbreaking work in identifying signatures of selection from genomic data,” he states. “However, further research is needed to confirm these findings as genuine cases of selection, as some may inevitably turn out to be false positives.”

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Source: www.newscientist.com

Fossilized Teeth Uncover How Extinct Carnivorous Mammals Adapted to Global Warming 56 Million Years Ago

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Around 56 million years ago, during a period of significant geological warming known as the Paleocene-Eocene Thermal Maximum (PETM), the mesonychid mammal Dissacus Praenuntius exhibited remarkable dietary changes—it began to consume more bones.

Dissacus Praenuntius. Image credit: DIBGD / CC by 4.0.

“I am a doctoral student at Rutgers University in New Brunswick,” stated Andrew Schwartz from the University of New Jersey.

“We are observing a similar trend: rising carbon dioxide levels, increasing temperatures, and the destruction of ecosystems.”

In their study, Schwartz and his team analyzed small pits and marks left on fossilized teeth using a method known as dental microwear texture analysis. The research focused on the extinct mammal Dissacus Praenuntius, part of the Mesonychidae family.

This ancient omnivore weighed between 12 and 20 kg, comparable in size to jackals and coyotes.

Common in the early Cenozoic forests, it likely had a diverse diet that included meat, fruits, and insects.

“They resembled wolves with large heads,” Schwartz remarked.

“Their teeth were similar to those of hyenas, though they lacked small hooves on their toes.”

“Before this phase of warming, Dissacus Praenuntius mainly consumed tough meat, akin to a modern cheetah’s diet.”

“However, during and after this ancient warming period, their teeth showed wear patterns consistent with crushing hard substances like bones.”

“Our findings indicate that their dental microwear is similar to that of lions and hyenas.”

“This suggests they were consuming more brittle food rather than their usual smaller prey, which became scarce.”

This shift in diet occurred alongside a slight decrease in body size, likely a result of food shortages.

“While earlier theories attributed body size reduction solely to rising temperatures, this latest research indicates that food scarcity was a significant factor,” Schwartz explained.

“The rapid global warming of this time lasted around 200,000 years, but the changes it caused were swift and dramatic.”

“Studying periods like this can offer valuable lessons for understanding current and future climatic changes.”

“Examining how animals have adapted and how ecosystems responded can reveal much about what might happen next.”

“The research underscores the importance of dietary flexibility; species that can consume a variety of foods are more likely to endure environmental pressures.”

“In the short term, excelling in a specific area can be beneficial,” Schwartz added.

“However, in the long run, generalists—animals that are adaptable across various niches—are more likely to survive environmental changes.”

This understanding can assist modern conservation biologists in identifying vulnerable species today.

Species with specialized diets, like pandas, may struggle as their habitats diminish, while more adaptable species, such as jackals and raccoons, might thrive.

“We’re already starting to see these trends,” Schwartz noted.

“Previous research has shown that African jackals have begun to consume more bones and insects over time, likely due to habitat loss and climate stress.”

The study also indicated that rapid climate change, reminiscent of historical events, could lead to significant shifts in ecosystems, influencing prey availability and predator behaviors.

This suggests that contemporary climate change could similarly disrupt food webs, pushing species to adapt and face extinction risks.

“Nonetheless, Dissacus Praenuntius was a robust and adaptable species that thrived for about 15 million years before eventually going extinct,” Schwartz said.

Scientists believe this extinction was driven by environmental changes and competition with other species.

The study was published in June 2025 in the journal Paleogeography, Paleoclimatology, Paleoecology.

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Andrew Schwartz et al. 2025. Dietary Changes in Mesonychids During the Eocene Heat Maximum: The Case of Dissacus Praenuntius. Paleogeography, Paleoclimatology, Paleoecology 675:113089; doi:10.1016/j.palaeo.2025.113089

Source: www.sci.news

New Fossil Discovery Shows Baleen Whales Adapted to Large Bodies in Cold Southern Waters for the First Time

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Baleen whales (mysterious animals) are the largest animals on Earth. How they achieved such enormous sizes is still debated, and research to date has focused primarily on when they grew, rather than where they grew. was. Paleontologists now report on the remains of a toothless baleen whale (chaeomysticete) from South Australia. At an estimated length of 9 meters, it is the largest baleen whale from the early Miocene. Analysis of body size over time shows that ancient baleen whales in the Southern Hemisphere were larger than those in the Northern Hemisphere.

Mysterious gigantism from the early Miocene. Image credit: Ruairidh Duncan

It was previously thought that the onset of the Ice Age in the Northern Hemisphere about 3 million years ago triggered the evolution of truly gigantic baleen whales.

The new study, led by Dr James Rule of Monash University and the Natural History Museum in London, reveals that this evolutionary size jump did, in fact, occur as early as 20 million years ago, and in the exact opposite direction in the southern hemisphere. I made it.

The major discovery came from a study of 16- to 21-million-year-old fossils held in Museum Victoria’s collection.

This specimen, the anterior end of the lower jaw of a large edentulous baleen whale, was discovered in 1921 on a cliff face on the banks of the Murray River in South Australia, but was largely unrecognized in collections.

In their study, Dr. Ruhl and colleagues explain how whales evolved to be larger in the southern hemisphere rather than the northern hemisphere, and that whales have been larger in the southern hemisphere throughout their evolutionary history (about 20 million to 30 million years). It was shown that

The discovery highlights the vital importance of the Australian and wider Southern Hemisphere fossil record in putting together a global picture of whale evolution.

The Murray River whale fossil confounds that theory, although previous leading theories were based primarily on fossils found in the northern hemisphere.

“The Southern Hemisphere, and Australia in particular, has always been overlooked as a frontier for fossil whale discovery,” says Dr Eric Fitzgerald, a palaeontologist at Museums Victoria Research Institute.

“Like the Murray River whale, the fossil whale discoveries in the south have shaken up whale evolution, giving us a more accurate, truly global picture of what was happening in the oceans in ancient times. .”

Researchers have discovered that the tip of a baleen whale’s jaw can expand depending on its body size.

They estimated the baleen whale to be about 9 meters long.

“The largest whales alive today, such as the blue whale, reach the length of a basketball court,” Dr. Ruhl said.

“About 19 million years ago, Murray River whales were nine meters long, already a third of this length. So baleen whales were well on their way to becoming ocean giants.”

of result will appear in Proceedings of the Royal Society B.

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James P. Rule other. 2023. A huge baleen whale emerges from its cold cradle in the south. Procedure R. Soc. B 290 (2013): 20232177; doi: 10.1098/rspb.2023.2177

Source: www.sci.news