Chú thích Metaspriggina walcotti

  1. ↑ Conway Morris, Simon (2008). “A Redescription of a Rare Chordate, Metaspriggina Walcotti Simonetta and Insom, from the Burgess Shale (Middle Cambrian), British Columbia, Canada”. Journal of Paleontology. 82 (2): 424. doi:10.1666/06-130.1.