Blogs / Discoblog

If a creature was big, slow, and delicious, there’s a good chance that early humans hunters found it too good to pass up.

Researchers combing the Red Sea have identified a new species of clam, a giant one that could measure more than a foot in length and may have been one of our ancestors’ favorite meals. The oversized mollusk went undiscovered for so long because it accounts for only one percent of the current population of clams. However, checking the fossil record, the scientists found that the giant clam once made up 80 percent of the population, then dropped off precipitously around 125,000 years ago, a date that roughly coincides with early humans coming out of Africa.

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Perhaps Lonesome George should now be called Curious George.

The giant Galapagos tortoise earned his moniker by keeping to himself for most of his 36 years of captivity at the Charles Darwin Research Station. Now, all of the sudden, George appears to have broken out of his solitude and mated with one of the two females at the station that come from a similar species of Galapagos tortoise.

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Twenty thousand years ago, it was a lousy time to be a woolly mammoth. As the last ice age advanced, the grass they liked to eat became buried under layers of snow. But one plentiful source of nutrients was easily accessible to mammoths—their own dung.

The Telegraph reports that scientists studying a mammoth that was preserved in Siberia’s permafrost found a fungus in its stomach that grows only on dung that has been exposed to air.

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Tuatara are often called living fossils—the ancestors of these New Zealand creatures roamed the Earth 200 million ago and survived the extinction event that took down the dinosaurs. But according to a study released today in the Proceedings of the Royal Society, the lizard-like animal’s long run might come to a sudden end if the planet warms as rapidly as some fear.

The problem is that tuatara, like a lot of reptiles, show what’s called temperature dependent sex determination, meaning that the sex of a baby animal depends on the temperature during its development. For the tuatara, scientists say, the critical temperature is close to 71 degrees Fahrenheit. If the mercury reads higher than that during a baby tuatara’s development, it is much more likely to be born a male. So, the researchers say, a warmer world could throw off the male-female balance.

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If one Canadian researcher is right, the largest rodent ever found just lost about 1,300 pounds.

A biological brouhaha started this week over the fossils of the Josephoartigasia monesi, a giant rat that made its home a couple million years ago in what is now Uruguay. Unfortunately, only the fossilized skull survived — scientists never unearthed any of the remainder of the skeleton, so they had had to do a little guessing as to the rest of the creature’s proportions. Using the ratio of the size of a modern rat’s head to its body, the Uruguayan scientists who dug up the bones in January said the creature would have weighed a full ton — about 2,200 pounds, or 15 times heavier than the largest rodent roaming the earth today.

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At least one species of proboscidean, a prehistoric relative of the elephant, lived in an aquatic environment, according to a new study published in the Proceedings of the National Academy of Sciences. The extinct water-lover, which belonged to the genus Moeritherium and lived around 37 million years ago, appears to have munched on freshwater plants and spent most of its days in swamps or river systems, according to Alexander Liu, an earth sciences expert at the University of Oxford and the lead author of the study. (more…)