The plural is wrong. Artist conception (singular). It accompanied the popular account by the "over enthusiastic English scientist" I referred to (Grafton Elliot Smith).
The scientists actually studying the tooth did NOT approve the "artist conception," however. Henry Fairfield Osborn, President of the American Museum of Natural History, and in charge of the effort, gave the following quote to the New York Times:
"such a drawing or 'reconstruction' would doubtless be only a figment of the imagination of no scientific value, and undoubtedly inaccurate."