Credit: Benjamin Bomfleur; (inset) Hans Kerp/Muenster University 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...
