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Categories: Offbeat: Earth and Climate, Paleontology: Early Mammals and Birds

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1 in 5 adult female white-necked jacobin hummingbirds look like males. New research shows that this is a rare case of 'deceptive mimicry' within a species: Females with male-like plumage are trying to pass themselves off as males, and as a result receive a benefit in the form of reduced aggression from males.

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Did the first ancestors of whales pick up where the mosasaurs left off 66 million years ago, after the extinction of all the large predatory marine reptiles? A study has looked into the possible convergences in morphology and behavior that may exist between these two groups of large marine predatory animals.

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Approximately 13.5 million years ago, north-west Queensland was home to an unusual and particularly tiny species of crocodile and now scientists are unlocking its secrets.

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To investigate whether paleoclimatic temperature shifts are correlated with body size changes, biologists decided to test this hypothesis using tetraodontiform fishes as a model group.

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A new study shows that 87 genes have been affected by deletions or short insertions during the course of the mammoth's evolution. The researchers note that their findings have implications for international efforts to resurrect extinct species, including the woolly mammoth.

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Researchers successfully captured CT images of an entire woolly mammoth tusk. Researchers were able to do a full scan of the tusk in its entirety -- or in toto -- using a newer clinical CT scanner. The new technology allows for large-scale imaging without having to do multiple partial scans.

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Whether by the spear or the plow, humans have been homogenizing the mammal communities of North America for 10,000-plus years, says a new analysis of 8,831 fossils representing 365 species.

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Which group of mammals has the more 'primitive' reproductive strategy -- marsupials, with their short gestation periods, or humans and other placental mammals, which have long gestation periods? For decades, biologists viewed marsupial reproduction as 'more primitive.' But scientists have discovered that a third group of mammals, the long-extinct multituberculates, had a long gestation period like placental mammals. Since multituberculates split off from the rest of the mammalian lineage before placentals and marsupials had even evolved, these findings question the view that marsupials were 'less advanced' than their placental cousins.

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Warm-bloodedness is a key mammal trait, but it's been a mystery when our ancestors evolved it. A new study points to an unlikely source for telling a fossil animal's body temperature: the size of tiny structures in their inner ears. The fluid in our ears becomes runnier at higher temperatures, so animals with warm bodies don't need as big of canals for it to flow through. Turns out, mammal ancestors became warm-blooded nearly 20 million years later than previously thought.

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Australia's first fossil vulture has been confirmed more than 100 years after it was first described as an eagle. The discovery highlights the diversity of Australian megafauna and other animals many thousands of years ago in the Pleistocene period.

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According to a new study, the first louse to take up residence on a mammalian host likely started out as a parasite of birds. That host-jumping event tens of millions of years ago began the long association between mammals and lice, setting the stage for their coevolution and offering more opportunities for the lice to spread to other mammals.

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The fossil record tells us about ancient life through the preserved remains of body parts like bones, teeth and turtle shells. But how to study the history of soft tissues and organs, which can decay quickly, leaving little evidence behind? In a new study, scientists use gene expression patterns, called transcriptomics, to investigate the ancient origins of one organ: the placenta, which is vital to pregnancy.

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Australian palaeontologists have described a new genus of giant fossil kangaroo from the mountains of central Papua New Guinea. The new description of the fossil kangaroo has found that, rather than being closely related to Australian kangaroos, it most likely belongs to a unique genus of more primitive kangaroo found only in PNG.

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Using radio transmitters, scientists have gained new insights into the behavior of medium ground finches in the Galapagos Islands. A study reveals daily movement patterns covering an area equivalent to the size of 30 soccer fields.

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New research suggests that determining evolutionary trees of organisms by comparing anatomy rather than gene sequences is misleading. The study shows that we often need to overturn centuries of scholarly work that classified living things according to how they look.

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Paleontologists have debated whether dinosaurs were warm-blooded, like modern mammals and birds, or cold-blooded, like modern reptiles. In a new paper, scientists are unveiling a new method for studying dinosaurs' metabolic rates, using clues in their bones.

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Scientists settle debate surrounding species that laid eggs exploited by early Australian people around 50,000 years ago. Shell proteins point to Genyornis, which was among the 'mega-fauna' to go extinct a few thousand years after humans arrived on the continent.

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Researchers shed light on the way Quetzalcoatlus would have flown, finding that the dinosaur's flying dynamics were actually very different to how it has been depicted in popular culture.

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Jars of tiny platypus and echidna specimens, collected in the late 1800s by the scientist William Caldwell, have been discovered in the stores of Cambridge's University Museum of Zoology.

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Researchers have examined the mass extinction of large animals over the past tens of thousands of years and found that extinct species had, on average, much smaller brains than species that survived.