article_snippet.sent: The fish ancestor roamed Earth's freshwater lakes during the Paleozoic Era, between 542 million and 251 million years ago.
article_snippet.sent: The creatures were some of the earliest known vertebrates to possess jaws, though The creatures had grinding plates rather than teeth.
article_snippet.sent: Pterichthyoides milleri (illustration pictured) roamed Earth's freshwater lakes during the Paleozoic Era, between 542 million and 251 million years ago .
article_snippet.sent: The  name 'Pterichthyodes' refers to The creatures odd wing-like appendages - 'pterichthys' coming from the Ancient Greek for 'wing-fish'.
article_snippet.sent: It is believed that the 'wings' led to the pectoral fins seen in modern fish.
article_snippet.sent: Pterichthyoides milleri lived at the bottom of freshwater lochs and had flippers to help Pterichthyoides milleri move around. '
article_snippet.sent: Pterichthyoides milleri head and back were covered in an armoured shell, showing that Pterichthyoides milleri was well-protected from predator attacks; ready for anything.'
highlights_snippet.sent: It is thought the fossil was found in Cromarty and would have once lived in a freshwater lake between 542 million years ago to 251 million years ago .
  