Anderson, F. M. 1958. Upper Cretaceous of the Pacific Coast. The Geological Society of America, Memoir 71, 1-378. page(s): 109, pl. 1, fig. 5 [details] Available for editors
MolluscaBase eds. (2025). MolluscaBase. Trigonia packardi F. M. Anderson, 1958 †. Accessed through: Marine Species Traits editorial board (2025) Marine Species Traits at: https://marinespecies.org/traits/aphia.php?p=taxdetails&id=856759 on 2025-05-22
Marine Species Traits editorial board (2025). Marine Species Traits. Trigonia packardi F. M. Anderson, 1958 †. Accessed at: https://www.marinespecies.org/traits/aphia.php?p=taxdetails&id=856759 on 2025-05-22
original descriptionAnderson, F. M. 1958. Upper Cretaceous of the Pacific Coast. The Geological Society of America, Memoir 71, 1-378. page(s): 109, pl. 1, fig. 5 [details] Available for editors