| Synonymous name | : | †Polyrhizodus amplus St. John & Worthen, 1875 | |
Ref: PBDB: 30 Apr 2013. |
| Synonymous name | : | †Polyrhizodus excavatus (Saint John & Worthen, 1866) | |
Ref: PBDB: 30 Apr 2013. |
| Synonymous name | : | †Polyrhizodus littoni Newberry & Worthen, 1870 | |
Ref: PBDB: 30 Apr 2013. |
| Synonymous name | : | †Polyrhizodus lobatus Newberry & Worthen, 1866 | |
Ref: PBDB: 30 Apr 2013. |
| Synonymous name | : | †Polyrhizodus princeps (Newberry & Worthen, 1866) | |
Ref: PBDB: 30 Apr 2013. |
| Synonymous name | : | †Polyrhizodus williamsi St. John & Worthen, 1875 | |
Ref: PBDB: 30 Apr 2013. |