Britannica
Sources used in this answer
When did the earliest rhynchocephalians first appear in the fossil record?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
tuatara
The species is the sole living member of the reptile order Rhynchocephalia.
The earliest rhynchocephalians first appeared in the fossil record during the Middle Triassic Period.1