1. "Eunotosaurus " was considered the ancestor of turtles up until the late 1940s. 2. "Eunotosaurus " was assigned to its own family, Eunotosauridae, in 1954. 3. The study identified several features that united " Eunotosaurus " with turtles in a true clade. 4. In 2000, " Eunotosaurus " was placed in the clade Parareptilia, separate from turtles and cotylosaurs. 5. "Eunotosaurus " was incorporated in a recent 2010 phylogenetic analysis that sought to determine the origin of turtles. 6. While the third phase is unique to " Eunotosaurus ", the second phase is also seen in modern turtles. 7. If " Eunotosaurus " is close to the ancestry of turtles, it may have had similar sets of muscles. 8. While relatively rare, " Eunotosaurus " is common enough in the Karoo to be used as a biostratigraphic marker. 9. However, more recent fossil finds have shown that " Eunotosaurus " is a parareptile unrelated to either turtles or captorhinids. 10. In each rib of " Eunotosaurus ", the posterior surface of the lower ridge has Sharpey's fibers embedded in it.
