Fossil gets a leg up on snake family tree
A newly described fossil snake with legs may have climbed higher into the snake family tree than previously thought.
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The 95-million-year-old fossil snake, dubbed Haasiophis terrasanctus, is a relative of another legged fossil snake—Pachyrhachis problematicus—that some scientists think may be the earliest link between snakes and extinct marine lizards, like mosasaurs (SN: 4/19/97, p. 238).
However, the new fossil suggests that the two-limbed snakes are advanced big-mouthed snakes, like pythons and boas, rather than primitive serpentine ancestors, says paleontologist Olivier Rieppel of the Field Museum of Natural History in Chicago.