Subprionocyclus neptuni (Geinitz, 1850)
| 2005. | Subprionocyclus neptuni (Geinitz, 1850) Harada, K. & Tanabe, K. 2005 p. 49, fig. 6A |
| 1993. | Subprionocyclus neptuni (Geinitz) Tanabe, K. 1993 p. 348 |
| Condition: | Present |
| Material: | juvenile |
| Taxonomy: | Mollusca: Cephalopoda: |
| Geologic Time: | Mesozoic: |
| Harada, K. and Tanabe, K., 2005: Paedomorphosis in the Turonian (Late Cretaceous) collignoniceratine ammonite lineage from the north Pacific region. Lethaia, vol. 38, no. 1, pp. 47–57. (Reference No. 0798) |
| Tanabe, K., 1993: Variability and mode of evolution of the middle Cretaceous ammonite Subprionocyclus (Ammonitina: Collignoniceratidae) from Japan. Geobios, no. 15, pp. 347–357, pl. 1. (Reference No. 0695) |
| Ito, Y. et al., 2009, no. 80, p. 9. |
| Ichikawa, T., 1995, no. 33, p. 52. |
