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Blobrana


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Scientists discover fossil tumor in 255 million-year-old mammal forerunner

When paleontologists cut into the fossilized jaw of an ancient creature, they got more than they bargained for: a toothy tumor.
As the scientists report in a paper published today in the Journal of the American Medical Association Oncology, they discovered evidence that the specimen harbored a benign tumor made up of miniature, tooth-like structures. This type of tumor, known as a "compound odontoma," is common to mammals today. But this animal lived 255 million years ago -- before mammals existed.
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Blobrana


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Rooting the family tree of placental mammals

Placental mammals consist of three main groups that diverged rapidly, evolving in wildly different directions: Afrotheria (for example, elephants and tenrecs), Xenarthra (such as armadillos and sloths) and Boreoeutheria (all other placental mammals). The relationships between them have been a subject of fierce controversy with multiple studies coming to incompatible conclusions over the last decade leading some researchers to suggest that these relationships might be impossible to resolve.
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Blobrana


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Isle of Skye fossil makes three species one

During a fossil-hunting expedition in Scotland last year, a team of researchers from the University's Department of Earth Sciences discovered the fossilised remains of a mouse-sized mammal dating back around 170 million years to the Middle Jurassic period. The new find - a tiny lower jaw bearing 11 teeth - shows that that three species previously described on the basis of individual fossilised teeth actually belong to just one species.
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Blobrana


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Giant animal fossils found at building site in Lanzhou

Yu and Bai, two workers from Yuzhong county of Gansu province, were digging a ditch. When they reached 8 meters deep their shovels touched a gigantic animal cranium and they found several scattered bones and potteries. Policemen of Jiuzhou Police Station and officials in the culture center arrived at the building site after the local people called the police. About 40 pieces of animal bones were scattered on the ground, and the biggest cranium displayed among them drew the most attention.
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Blobrana


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Jurassic saw fastest mammal evolution

Mammals were evolving up to ten times faster in the middle of the Jurassic than they were at the end of the period, coinciding with an explosion of new adaptations, new research shows.
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Blobrana


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Earliest-known arboreal and subterranean ancestral mammals discovered

The fossils of two interrelated ancestral mammals, newly discovered in China, suggest that the wide-ranging ecological diversity of modern mammals had a precedent more than 160 million years ago.
With claws for climbing and teeth adapted for a tree sap diet, Agilodocodon scansorius is the earliest-known tree-dwelling mammaliaform - long-extinct relatives of modern mammals. The other fossil, Docofossor brachydactylus, is the earliest-known subterranean mammaliaform, possessing multiple adaptations similar to African golden moles, such as shovel-like paws. Docofossor also has distinct skeletal features that resemble patterns shaped by genes identified in living mammals, suggesting these genetic mechanisms operated long before the rise of modern mammals.
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Blobrana


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Earliest placental mammal ancestor pinpointed

The creature that gave rise to all the placental mammals - a huge group that includes whales, elephants, dogs, bats and us - has at last been pinpointed.
An international effort mapped out thousands of physical traits and genetic clues to trace the lineage.
Their results indicate that all placental mammals arose from a small, furry, insect-eating animal. 
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Blobrana


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Ernanodon antelios
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Fossil Skeleton of Strange, Ancient Digging Mammal Clears Up 30-Year Evolutionary Debate

Shortly after dinosaurs like Tyrannosaurus and Triceratops went extinct 65 million years ago, Earth's ancient landscapes were filled with unusual mammals only distantly related to those alive today. Until recently, one of these creatures, Ernanodon antelios, was only known from a single, highly distorted specimen that raised many questions about its habits and evolutionary relationships. In the most recent issue of the Journal of Vertebrate Palaeontology, scientists describe a second specimen of Ernanodon that sheds new light on this curious beast from the dawn of the "Age of Mammals."
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Cronopio dentiacutus
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An extraordinary looking, mouse-sized, fossil animal is shedding new light on the ancient history of mammals.
With a thin snout, beady eyes and long canines, the creature would have looked remarkably like that fictional sabre-toothed squirrel of Ice Age movie-fame.
But Cronopio dentiacutus is one of the very few mammal specimens to come out of South America from the era when dinosaurs ruled the Earth.
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Juramaia sinensis
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Until now, scientists believed that placental mammals first appeared some 125 million years ago. At that point, they branched off from the lineage that developed into modern marsupials, which nourish their young in their pouches instead of through placentas. Yet a recent fossil find backdates that divergence by about 35 million years, showing that mammals with placentas, known as eutherians, shared the earth with dinosaurs much longer than previously thought.
The fossil, described in August in the journal Nature, belongs to a tiny, shrewlike creature known as Juramaia sinensis that roamed China 160 million years ago. It appears to be the oldest known ancestor of placental mammals, according to a research group led by Zhe-Xi Luo, a paleontologist at the Carnegie Museum of Natural History.
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