stasis

Here’s Physorg on those recently found tintinnids from 635-715 million years ago. In “New fossils reveal oldest known ciliates” (November 16, 2011), Jennifer Chu reports, Anyone who has taken high school biology has likely come into contact with a ciliate. The much-studied paramecium is one of 7,000 species of ciliates, a vast group of microorganisms that share a common morphology: single-celled blobs covered in tiny hairs, or cilia. These cilia — Greek for “eyelash” — are used to propel a microbe through water and catch prey. Now, geologists at MIT and Harvard University have unearthed rare, flask-shaped microfossils dating back 635 to 715 million years, representing the oldest known ciliates in the fossil record. The remains are more than 100 Read More ›