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Paleoproterozoic
2012-11-18 19:08:04

The Paleoproterozoic is the first of three subdivisions of the Proterozoic Eon (occurring from 2.5 billion to 1.6 billion years ago (Ga). This period is marked by the first stabilization of the continents, and also when cyanobacteria--a type of bacteria that uses biochemical processes of photosynthesis to produce oxygen--evolved. Experts have found paleontological evidence that during at...

Word of the Day
sudarium
  • A handkerchief.
  • Specifically— The legendary sweat-cloth; the handkerchief of St. Veronica, according to tradition miraculously impressed with the mask of Christ; also, the napkin about Christ's head (Johu xx. 7).
  • In general, any miraculous portrait of Christ.
The word 'sudarium' comes from a Latin word meaning 'a handkerchief'.