Smith, A. B. & Wright, C. W. 2003. British Cretaceous echinoids. Part 7, Atelostomata, 1. Holasteroida. Monographs of the Palaeontographical Society 156 (619), 440-568. page(s): 476 [details]
Kroh, A.; Mooi, R. (2024). World Echinoidea Database. Protocardiaster Smith & Wright, 2003 †. Accessed at: https://marinespecies.org/echinoidea/aphia.php?p=taxdetails&id=512767 on 2024-04-26
original descriptionSmith, A. B. & Wright, C. W. 2003. British Cretaceous echinoids. Part 7, Atelostomata, 1. Holasteroida. Monographs of the Palaeontographical Society 156 (619), 440-568. page(s): 476 [details]