Articles tagged with Mandible
A 325-million-year-old shark fossil has provided new insights into the evolution of jaws in vertebrates, including humans. The study suggests that living sharks are more advanced than previously thought, with internal structures similar to those found in ancient bony fishes.
Scientists discover six new Dracula ants species in Madagascar that challenge the traditional ant caste system. The study reveals that minor workers become queens, revolutionizing our understanding of ant biology.
Male stag beetles have enlarged heads and muscles to compensate for their oversized mandibles, allowing them to generate powerful bites. Their male bites are six times stronger than females', with a recorded strength of 7N.
The extinct California porpoise, Semirostrum ceruttii, had a distinctive underbite with an extended lower jaw and innervated jaws, likely used for probing prey. The species' anatomy suggests adaptations to its environment, including poor eyesight and sensitive lower jaw used for echolocation and feeding.
A new species of ancient porpoise has been identified with an unprecedentedly long symphysis, a structure analogous to the human chin, measuring 85 cm. This unique feature suggests that the animal used its chin to probe the seabed for food, contradicting modern porpoises' feeding habits.
Fossilized jawbones and teeth from northern Egypt confirm the existence of a primitive lineage of bats, which eventually spread to South America. The discovery sheds light on the evolutionary history of sucker-footed bats, which roost head-up using wet adhesion.
Researchers at the Stowers Institute for Medical Research have developed the first genetic model of syngnathia, a rare congenital disorder characterized by fused upper and lower jaws. The study sheds light on the molecular mechanisms underlying the defect, which affects regions such as the head, heart, or gut.
A partial skeleton of Paranthropus boisei, a human ancestor characterized by its 'robust' jaw and skull bones, has been found in Tanzania. The find suggests that the species was more ruggedly built than previously thought and had strong forearms and powerful upper body.
A USC study has identified a cellular signaling pathway that converts healthy mesenchymal stem cells in the jaw into tumor cells, leading to benign but potentially harmful tumors. The researchers hope that this understanding can be used to develop target-specific treatments for these tumors.
Scientists studied Yangtze finless porpoise hearing using medical technology to understand impact of constant shipping and construction on their critical sense of hearing. The research revealed variations in hearing sensitivity among different species, with implications for effective management strategies.
The discovery of two new fossil jaws in Vellberg, Germany, provides evidence that the ancestors of lizards, snakes, and tuatara were alive during the Middle Triassic period. The findings suggest that lepidosaurs first appeared after the end-Permian mass extinction event, around 240 million years ago.
The Rim Fire remains active in multiple drainages and is expected to spread into Yosemite Wilderness areas. The fire is 80% contained over 255,000 acres affected, making it California's largest fire of the season.
Research reveals how ancient crocodiles evolved and survived alongside dinosaurs, with notable variations in jaw shapes and biomechanics. The study, published in Proceedings of the Royal Society B, provides new insights into the evolution and adaptation of ancient crocodiles during the Mesozoic Era.
Researchers report successful use of virtual surgical planning for complex maxillofacial reconstruction, achieving predictable outcomes and reduced operating times. The technology enables precise estimates of required bony components and enhances surgeons' ability to make accurate osteotomies.
Duke University researchers identified TRPV4 as a critical protein contributing to temporomandibular joint disorder (TMJD) pain. The study found that inhibiting TRPV4 reduced bite force and pain, suggesting it may be an attractive target for developing new treatments.
Entomologist Jack Longino identified 33 new species of predatory ants in Central America and the Caribbean. The ants were found in small patches of forest and have monster-like faces with sharp teeth and jaws. Their primitive eyes detect light, but not form images.
Ray-finned fish, including species like Fouldenia and Styracopterus, rapidly diversified in the aftermath of the Hangenberg extinction. They exploited ecological opportunities to fill vacant niches, using their crushing jaws to prey on hard-shelled animals.
A comprehensive family tree of the spiny-rayed fish group, including tuna and seahorses, has revealed surprising relationships and shed light on their evolution and diversity. The study found that some groups of fish have undergone rapid diversification followed by a slowdown in evolution.
Researchers used computer models to study the predatory behavior of Thylacosmilus atrox, a 3.5 million-year-old sabre-toothed super-predator. The results show that the animal relied on powerful forearms and precise neck muscles to kill its prey efficiently.
A new find in a 246-million-year-old sediment layer reveals the skull of a juvenile placodont, confirming its European origin and providing insight into the group's early evolution. The discovery highlights the significance of crushing dentition in placodonts, with pointed teeth appearing earlier than previously thought.
A new species of saber-toothed cat, Rhizosmilodon fiteae, has been discovered in Florida, with fossils dating back 5 million years. The discovery provides significant insight into the evolution and taxonomy of these iconic predators.
A multidisciplinary team of researchers investigated how whales got their teeth by analyzing the fossil record and embryonic development process. They found that whales evolved simpler teeth around 30 million years ago, which are shaped by proteins BMP4 and FGF8 during development.
A new study reveals that bite force is influenced by the size of both the eater and the eatee, peaking at an optimal level of muscle stretch. The research found that too much or too little stretch leads to reduced bite force, with some fish able to crush stronger tubes when their muscles are optimally stretched.
A 397,000-year-old fossil found in Serbia reveals that southeastern European human ancestors evolved differently than those in western Europe due to the absence of glaciers. The study confirms southeast Europe as a critical 'gate to the continent' where humans, plants, and animals sought refuge during glaciations.
A new fossil discovery in southern California challenges earlier claims of a 'killer walrus' existing. The ancient creature was found to have a diet rich in fish, contrary to initial estimates that it preyed on marine mammals.
A comprehensive snapshot of pupfish evolution reveals how natural selection drives specialization through the creation of adaptive landscapes. Research shows that species are often limited to generalist feeding styles due to stabilizing selection.
Researchers have discovered a potential new method for diagnosing Parkinson's disease by testing the saliva gland. The study found that abnormal proteins associated with the disease were consistently present in the submandibular salivary glands of patients, suggesting this non-invasive test could be used to diagnose living individuals.
A team of scientists discovered that the ancient piranha relative Megapiranha paranensis had a bite force that could crush bone and pierce through thick shells, rivaling even the mighty T. rex. The study, published in Scientific Reports, used computer simulations to estimate the bite forces of living and extinct piranhas.
Researchers at George Washington University studied piranhas to measure their biting forces, revealing that even smaller prey is not safe from their powerful attacks. The black piranha has the most powerful bite force among fish, with some specimens exerting over 30 times their body weight.
Researchers used non-invasive X-ray technology to study the jaws and teeth of a primitive jawed fish called Compagopiscis. The discovery provides solid evidence that teeth evolved along with or soon after the development of jaws in early vertebrates, shedding light on our evolutionary ancestry.
A new species of plant-eating dwarf dinosaur, Pegomastax africanus, has been discovered in southern Africa. The species had a unique combination of features, including a short parrot-shaped beak and stabbing canines that were likely used for self-defense and competitive sparring.
A novel surgical approach has successfully removed a rare facial tumor and rebuilt a patient's lower jaw and mouth. The procedure involved removing the tumor and oral tongue while creating a fully functional lower jaw using dual microvascular free flaps.
The discovery sheds light on early human evolution, providing a clearer picture of what our direct ancestral species looked like. The new fossils reveal that two species of Homo coexisted with Homo erectus between 1.78 and 1.95 million years ago.
A University of Notre Dame researcher has made significant discoveries about the evolution of jaws in mammals. The study found that animals consuming harder, tougher foods tend to have a lesser degree of jaw fusion, while those eating softer, smaller foods do not.
The tuatara's unique chewing technique, using its lower jaw to slice food apart, raises doubts about the link between chewing and high metabolism in mammals. This specialized mechanism allows the tuatara to eat a wide range of prey, including beetles, spiders, and small lizards.
A new sensory organ discovered in the chin of rorqual whales enables efficient lunge feeding by coordinating jaw position and throat expansion. This finding sheds light on how hyper-expandable throat pleats and other morphological specializations facilitate successful feeding in these ocean giants.
Researchers discovered a highly mineralized protective coating on freshwater crayfish teeth, made of calcium phosphate and amorphous calcium carbonate. This 'enamel' layer is remarkably similar to the enamel found in vertebrates, providing protection against wear and tear.
Researchers studied a giant pliosaur specimen from the Upper Jurassic and discovered signs of an arthritis-like disease that eroded its left jaw joint. The animal, believed to be an old female, lived with a crooked jaw for many years, still able to hunt despite its condition.
Researchers have discovered that a customized mouthpiece can decrease cortisol levels following exercise, indicating less stress and potentially leading to faster recovery times. The study suggests that this simple device may enhance exercise performance without the use of drugs or supplements.
Researchers at Tufts University have identified a self-correcting mechanism by which developing organisms recognize and repair head and facial abnormalities. This process allows craniofacial structures to move and remodel themselves to compensate for defects, restoring normal shape and position.
A new, pitch-black wasp species has been discovered in Sulawesi, Indonesia, belonging to the digger wasp family. The species differs from all known related digger wasps due to its unusual body size and long, sickle-shaped jaws.
Two new horned dinosaurs, Unescoceratops koppelhusae and Gryphoceratops morrisoni, have been named based on fossils found in Alberta, Canada. The discoveries fill gaps in the evolutionary history of small-bodied horned dinosaurs.
Researchers identified a genetic variation in the RBMS3 gene that increases the risk of osteonecrosis of the jaw (ONJ) in patients taking bisphosphonates. A genetic screening test could help determine safe treatment options, reducing the need for medication discontinuation or invasive dental procedures.
A new study from the University of Gothenburg found that dental X-rays can predict who is at risk of fractures. The research used data from a long-running Prospective Population Study of Women in Gothenburg and showed that people with sparse bone structure in their jaw are more likely to experience fractures, particularly as they age.
A comprehensive clinical assessment has been developed to identify individuals at risk of developing jaw pain disorders. The UB researchers found that people who develop jaw pain disorders exhibit specific characteristics, including more trauma to the jaw, limitations, and noises in the jaw, headaches, and generally worse medical status.
Researchers identified increased sensitivity to pain stimuli, altered heart rate responses, and genetic variations in patients with chronic TMJD. The study also found that socio-economic status does not correlate with TMJD incidence, contrasting with other chronic pain conditions.
A fossil fragment from Kent's Cavern in southern England establishes the presence of modern humans in western Europe by 40,000 years ago. The discovery joins a human skull and lower jaw from Romania, confirming modern humans at both ends of Europe by this date.
A preliminary study suggests that the SWIFT MRI technique can accurately detect mandibular invasion by squamous cell carcinoma, allowing for more precise planning and potentially preventing unnecessary removal of the jawbone. The researchers found a high degree of correlation between magnetic resonance images and histopathologic findings.
A new study published in the Journal of Zoology found that the Tasmanian tiger's weak jaws made it unlikely to catch large prey like sheep. The research suggests that its inability to kill large prey may have hastened its extinction, highlighting the vulnerability of large predators with specialized diets.
A team of researchers used advanced imaging techniques to study a 400 million-year-old fossilized jawless fish. They found evidence that the brain of early vertebrates was reorganized before the development of jaws, providing new insights into the evolutionary history of vertebrates.
Researchers at Johns Hopkins University discovered that the shape of jaw bones in human populations is influenced by both genetic and environmental factors. The study used archaeological jaw bones from two different regions to determine how much of the mandible's shape is plastic, a response to diet, and how much is genetic.
New study reveals that programmed cell death is involved in mandibular regression in termites. During termite development, body form and structure change, including the formation of defensive organs like the nasus and regressed mouth parts.
A new study suggests that vertebrate jaws evolved relatively early, around 420 million years ago, and that the diversity of feeding mechanisms in these early animals had little impact on jawless fishes. The researchers used physics and engineering concepts to analyze the potential feeding functions of early vertebrate jaw designs.
A new study reveals details of the first documented cookiecutter shark attack on a live human, highlighting concerns for swimmers entering warm summer waters. The sharks' unique feeding behavior leaves victims with crater-like wounds requiring plastic surgery, and their bioluminescent features may aid in tracking movement patterns.
A team of researchers analyzed new conodont fossils and developed a 3D model of their feeding mechanism, revealing that these ancient vertebrates used teeth on upper lips and tongue to grasp food. The findings confirm the primitive nature of conodonts and suggest a common ancestor with lampreys.
A previously unknown fossil primate, Mescalerolemur horneri, has been discovered in West Texas, dating back to the Eocene Epoch. The species is closely related to Eurasian and African adapiforms, challenging current understanding of North American primates.
A 120 million-year-old ichthyosaur fossil found in Australia shows healed bite wounds, suggesting the creature survived an attack from another member of its species. The discovery provides insights into the social behaviors of ancient sea creatures during the time of dinosaurs.
A new study found that Paranthropus boisei, a 1-million-year-old hominid, had a diet of 77% grasses and sedges, contradicting the long-held assumption of a nut-based diet. The analysis of carbon isotopes in fossil teeth revealed a preference for C4 grasses and sedges.
The discovery of Liaoconodon hui, a complete fossil mammal from China, provides clear evidence of the transitional middle ear evolution in mammals. The specimen shows cartilage supporting the detached middle ear bones, shedding light on the evolutionary shift from reptiles to mammals.
A new species of gigantic theropod dinosaur, Zhuchengtyrannus magnus, was identified from fossil skull and jaw bones discovered in China. The newly named dinosaur measured about 11 metres long, stood about 4 metres tall, and weighed close to 6 tonnes.