Is “modern” a technical term in biology/palaeontology, or is it just meant in the ordinary sense? Asking because I don’t actually know. In history, “modern” is a technical term - it refers to the period beginning in 1500 (approximately) - which is a bit different from the everyday meaning, the average person would probably not call the 1500s “modern”.

It depends. Half a second is a long time for code to respond to an API request. Half a million years is a short time to a geologist.