What’s the News: Researchers have now found a well-preserved fossil of the earliest known member of the animal group that encompasses today’s placental mammals, which includes humans. The shrew-like creature, named Juramaia sinensis, or “Jurassic mother from China,” dates back to 160 million years ago, 35 million years earlier than the oldest mammal fossil previously discovered. The Nature study gives some tangible support to genetic evidence suggesting that the two main types of mammals split well before the previous oldest mammal fossils.
At first glance, biologists slapping motion capture gear onto kangaroos sounds like a scientific foray into the 3-D-movie craze. But James Cameron can rest assured: The scientists are merely performing their day jobs, studying kangaroos—and using a nifty new camera to do it.
As kangaroos mosey along at low speeds, they walk, using their tail as a fifth limb. But as they speed up, they slip into their signature bounce. The mystery for scientists is why such large animals—some being over six feet tall—are so darn springy, and as Alexis Wiktorowicz-Conroy, a researcher at the Royal Veterinary College, told the BBC, “We can’t really explain … why their bones don’t break at high speeds.” Read More
What 15 million years ago was very bad for Australian marsupials is now very good for paleontologists: Researchers have uncovered a death trap, an underground limestone cave where hundreds of animals stumbled to their demise.
A paper published today in Journal of Vertebrate Paleontology details the resulting fossil menagerie, which includes an extinct wombat-like marsupial known as Nimbadon lavarackorum.
Karen Black of the University of New South Wales led the excavation and says in a press release that her team has already uncovered 26 Nimbadon skulls. The varying ages of the skulls detail the Nimbadon‘s whole life cycle from “suckling pouch” to “elderly adults.”
“This is a fantastic and incredibly rare site,” says Dr. Black [regarding the cave]. “The exceptional preservation of the fossils has allowed us to piece together the growth and development of Nimbadon from baby to adult.” [Society of Vertebrate Paleontology]
See a photo gallery of the excavation and fossil processing below the jump.
In 1935, Australia introduced the cane toad to its sugar cane fields to battle beetle infestations–and the ecosystem has never been the same. The toxic toads took a liking to Australia and began spreading through the northeast, killing the native predators like crocodiles, snakes, and lizards that dined on them. A small cat-like marsupial, the quoll, was no exception. In the decades after the toads’ introduction, quoll populations in northern Australia have dipped precipitously. This year, ahead of the toads’ march into the quolls’ last stronghold, the Kimberly region, scientists have found a clever way to save the endangered marsupial: training it to detest the taste of toad so it won’t get poisoned [Los Angeles Times]. And the success of the experiment has suggested a bizarre conservation campaign.
In their research, scientists from the University of Sydney found that other predators like crocodiles and snakes can learn to avoid trouble, because one experience of snacking on a sickening poison toad is usually enough to teach them a lesson. But because the smaller quoll will die from eating a single large toad, it never learns to make that association. So the researchers decided to train the marsupials to avoid the toads using a method known as conditioned taste aversion.