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Categories: Paleontology: General, Physics: Acoustics and Ultrasound

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Aetosaurs had a small head and a crocodile-like body. The land dwellers were up to six meters long and widely distributed geographically. They died out about 204 million years ago, at the end of the Triassic. In Germany, an assemblage of 24 Aetosaurus ferratus individuals, only between 20 and 82 centimeters long, was discovered in 1877. Since then, scientists have been puzzling over whether they were juveniles or small adults. A team has now solved the mystery: Bone examination of two specimens shows that they are juveniles.

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There is currently less sea ice in the Antarctic than at any time in the forty years since the beginning of satellite observation: in early February 2023, only 2.20 million square kilometers of the Southern Ocean were covered with sea ice.

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About 250 million years ago, the Permian-Triassic mass extinction killed over 80 per cent of the planet's species. In the aftermath, scientists believe that life on earth was dominated by simple species for up to 10 million years before more complex ecosystems could evolve. Now this longstanding theory is being challenged by a team of international researchers.

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Along the shores of Africa's Lake Victoria in Kenya roughly 2.9 million years ago, early human ancestors used some of the oldest stone tools ever found to butcher hippos and pound plant material, according to new research. The study presents what are likely to be the oldest examples of a hugely important stone-age innovation known to scientists as the Oldowan toolkit, as well as the oldest evidence of hominins consuming very large animals. Excavations at the site, named Nyayanga and located on the Homa Peninsula in western Kenya, also produced a pair of massive molars belonging to the human species' close evolutionary relative Paranthropus. The teeth are the oldest fossilized Paranthropus remains yet found, and their presence at a site loaded with stone tools raises intriguing questions about which human ancestor made those tools.

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Scientists have compared the relationship among the strength of flight bones, body mass, and the way modern birds fly to better understand the evolution of flight in birds and extinct animals, such as the Pteranodon.

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The discovery of an 80-million-year-old fossil plant pushes back the known origins of lamiids to the Cretaceous, extending the record of nearly 40,000 species of flowering plants including modern-day staple crops like coffee, tomatoes, potatoes and mint.

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Researchers have pinpointed two intervals when ice and ocean conditions would have been favorable to support early human migration from Asia to North America late in the last ice age, a new paper shows.

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Scientists discovered the first-ever Dickinsonia fossil in India two years ago, changing our understanding of how the continent came to be. Now, new research shows the 'fossil' was just a beehive all along, changing our understanding for a second time, and the original scientists now support the new findings.

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The CT-scanned skull of a 319-million-year-old fossilized fish, pulled from a coal mine in England more than a century ago, has revealed the oldest example of a well-preserved vertebrate brain.

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New research found that using focused-ultrasound-mediated liquid biopsy in a mouse model released more tau proteins and another biomarker into the blood than without the intervention. This noninvasive method could facilitate diagnosis of neurodegenerative disorders, the researchers said.

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A new study has uncovered a new thalattosuchian -- an ancient 'sister' of modern-day crocodiles' ancestors.

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Scientists are working to understand the cause and how the events of the LPME unfolded by focusing on mercury from Siberian volcanoes that ended up in sediments in Australia and South Africa.

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Engineers and physicians have developed a wearable ultrasound device that can assess both the structure and function of the human heart. The portable device, which is roughly the size of a postage stamp, can be worn for up to 24 hours and works even during strenuous exercise.

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A team of paleontologists have discovered the first 'unmistakable' Triassic-era caecilian fossil -- the oldest-known caecilian fossils -- thus extending the record of this small, burrowing animal by roughly 35 million years. The find also fills a gap of at least 87 million years in the known historical fossil record of the amphibian-like creature.

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What drives crocodile evolution? Is climate a major factor or changes in sea levels? Determined to find answers to these questions, researchers discovered that while changing temperatures and rainfall had little impact on the crocodiles' gene flow over the past three million years, changes to sea levels during the Ice Age had a different effect.

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Shrunken seashells and unusually dark sediment cores have helped geoscientists better understand the chronology and character of events that led to Ocean Anoxic Event 2, nearly 100 million years ago.

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The discovery of more than 250 fossilized eggs reveals intimate details about the lives of titanosaurs in the Indian subcontinent, according to a new study.

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Until now, microscopic robotic systems have had to make do without arms. Now researchers have developed an ultrasonically actuated glass needle that can be attached to a robotic arm. This lets them pump and mix minuscule amounts of liquid and trap particles.

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A study is providing a glimpse into dinosaur and bird diversity in Patagonia during the Late Cretaceous, just before the non-avian dinosaurs went extinct. The fossils represent the first record of theropods -- a dinosaur group that includes both modern birds and their closest non-avian dinosaur relatives -- from the Chilean portion of Patagonia. The researchers' finds include giant megaraptors with large sickle-like claws and birds similar to todays ducks and geese.

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Hispaniola once had among the highest diversity of rodents in the Caribbean. Today, only one rodent species remains, and its prospects for survival are uncertain. New carbon dates place the blame squarely on humans.