Present tense in first sentence reads clumsily, IMHO. I would suggest that "Archaeopteryx is the earliest and most primitive bird known to date" (the adverbial clause, to date qualifying the verb known) is somewhat preferable, but given that every other statement about the bird is in the past tense, I would suggest that "Archaeopteryx was the earliest and most primitive bird, according to present knowledge" reads better still. Kevin McE 13:36, 28 August 2007 (UTC)