It looks like a lizard. It walks like a lizard. It sunbathes and lounges and eats like a lizard, but the tuatara is not a lizard.

What the tuatara actually is goes as far back as the dawn of the dinosaurs. This mysterious creature (which is also one of the poster animals for New Zealand) belongs to a group of reptiles known as sphenodontians, which are thought to have spawned 230 million years ago, around the same time monsters that were somewhat related to it started roaming the Earth. A fossil of an extinct sphenodontian has revealed that the linage of the tuatara itself has now been found to reach almost that far back — 190 million years ago.

Sphenodontians were creeping around during the Mid to Late Triassic, and are thought to have possibly emerged even earlier than that, some 259 million years ago during the Late Permian, and held on for a while. Now only the tuatara is left. Paleontologist Tiago Simões was part of the team that identified the amazingly preserved fossil (above) and others as belonging to the new species, tuatara predecessor Navajosphenodon sani. He led a study recently published in Communications Biology. Why no other sphenodontians still exist remains unknown.

“We do not have the data yet to know how they managed to survive so long with such restricted diversity,” Simões told SYFY WIRE. "Without enough fossils, we cannot yet know where they were living and how they got to New Zealand at some point during the last 66 million years.”

Navajosphenodon sani is the oldest known direct ancestor of the tuatara. The nearly complete fossil that was unearthed is the holotype, or single specimen on which the identification of this species is based. More scattered fossils of Navajosphenodon teeth and bones were also found in the same formation, the Kayenta Formation in Coconino County, Arizona.... read more info news.yahoo.com/most-ancient-reptile-still-alive-220101964.html