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5 December 2013 11:26 am ,
Vol. 342 ,
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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ScienceShot: Roly-Poly Trilobites
24 September 2013 7:15 pm
What happens when you poke a trilobite? Since these ocean scuttlers went extinct 250 million years ago, no humans have been able to conduct this vital experiment. But the fossil record reveals that when trilobites were scared, they acted much like today’s pillbugs—tucking in their legs and antennae and rolling themselves into tight little balls. Finding fossils of rolled-up trilobites is usually no big deal for paleontologists, but most examples of this distinctive rolling, exoskeleton side out, come from after the Cambrian period, which ended about 485 million years ago. Now, scientists digging in the Rocky Mountains of western Canada have found much older enrolled trilobites that date back to the middle of the Cambrian, they report online today in Biology Letters. In fact, they represent the oldest known example of the defensive behavior in any kind of animal. These early practitioners of rolling-like-a-ball hadn’t fully mastered the technique: While their descendants could snap their trunks around to encapsulate their entire bodies, the best these older trilobites could do was to basically fold themselves in half, shown in the image above. What’s more, they had to keep their muscles engaged the whole time they wanted to hold the position. That means that when they died, their carcasses usually stretched out again—which explains why the Middle Cambrian fossil record isn’t full of folded-up trilobites. The rare specimens found by the researchers were likely quickly buried alive, preserving their positions for eternity.