- News Home
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
- About Us
ScienceShot: Cocoon Preserves Microbe for the Ages
3 December 2012 3:00 pm
Cocoons don't just protect developing eggs and larvae; they can also preserve fossils for hundreds of millions of years. Scientists have discovered a 25-micrometer-long, teardrop-shaped protozoan (left) trapped in the wall of an egg case produced by a leech between 200 million and 215 million years ago. The Triassic-era relic's coiled stalk and large, horseshoe-shaped nucleus make it an ancient doppelgänger of the modern-day Vorticella (right), a group previously unknown in the fossil record, the researchers report online today in the Proceedings of the National Academy of Sciences. As soft-bodied organisms, protozoans aren't typically preserved as fossils. But egg cases—the walls of which quickly harden from a protein-and-sugar-rich mucus secreted by the invertebrates—of leeches and their kin are surprisingly common, the researchers explain. Like amber, which starts out sticky and then hardens, the tiny egg cases (one produced by Hirudo medicinalis, the medicinal leech, inset) can trap and then preserve soft-bodied organisms that would otherwise be quickly lost to decomposition. Although a few teams have previously described small fossils, such as spores and microorganisms entombed in such egg cases, the cocoons have largely been ignored by paleontologists and could therefore serve as an unrecognized yet bountiful source of microbial fossils.
See more ScienceShots.
*Correction, 4 December: This article has been updated to reflect that the fossil, as well as the modern-day microorganism Vorticella, is a protozoan and not a bacterium.