It's from the Royal Ontario Museum in Toronto. Wikipedia on Crurotarsans (spelling?) says nothing of it.
The Arms of an Ammonite
2 hours ago in Catalogue of Organisms
Pleiotropy comes from the Greek πλείων pleion, meaning "more", and τρέπειν trepein, meaning "to turn, to convert". It designates the occurrence of a single gene affecting multiple traits, and is a hugely important concept in evolutionary biology.Reference: