Name(s) in cluster
| †Ptychaspis ceto | urn:lsid:organismnames.com:name:3674435 |
| †Ptychaspis ceto Walcott | urn:lsid:organismnames.com:name:2341391 |
| †Ptychaspis ceto Walcott 1905 | urn:lsid:organismnames.com:name:680265 |
...
| †Ptychaspis ceto | urn:lsid:organismnames.com:name:3674435 |
| †Ptychaspis ceto Walcott | urn:lsid:organismnames.com:name:2341391 |
| †Ptychaspis ceto Walcott 1905 | urn:lsid:organismnames.com:name:680265 |