I know we now know they went extinct 66 million years ago, and 64 millions is another date I’ve seen around, but how long how we known it was definitely way more than 40 millions ? I’m asking because it’s the date given in the the song “walk the dinosaurs” by Was (Not Was), and I wondered why such a number. Would it have seed credible at the time, or was it just arbitrary?
We’ve known that birds were descended from dinosaurs for a long time. Best I can tell, it was first proposed in the 1800’s, largely abandoned by the early 1900’s and then revived in the 1970’s. It was not new information about the lineage of birds that caused us to start saying ‘birds are dinosaurs’, but a different method of classification: Cladistics.