By meticulously comparing skull bone and soft tissue shapes, the findings illuminate a gradual emergence of distinctions ...

One of the main characteristics that may have helped snakes become so plentiful is their articulated skull. Some people refer to snake skulls as unhinged, Pyron says, but that isn't exactly accurate.

The wildlife service said X-ray scans had showed that the snake did not have two heads formed together. "Rather it appeared to be one skull with an additional eye socket and three functioning eyes ...