TABLE 1. Comparison the specimen IGM 4550 and other Cretaceous-Paleocene incertae sedis perciformes, blue areas enclose the characters shared by IGM 4550 and other fossil taxa/specimens. Abbreviations: abd, abdominal vertebrae; cau, caudal vertebrae; cic, cicloid scale; cte, ctenoid scale; smx, supramaxila (based on Alaniz-Galvan, 2011, table 6).
| Dorsal fin formula | Anal fin formula | Vertebrae (abd+cau) | Vertebrea with parapophysis | Predorsal Formula | Scale Type | smx | |
| Percomorpha indet. (Arratia et al., 2004) | IX?+4? | ? | 14?(8?+6?) | 6? (3-8?) | ? | cte | ? |
| Nardoicthys | VI-VII+11-12 | 0+10 | 25(11+14) | 6 (6-11) | 0//0+0+1/1/1/ or 0/0/0+1/1/1 |
cic | 0 |
| Zornziperca | VI+11 | 0+10 | 25(11+14) | 6 (7-12) | 0/0/0+1/1/1/ | cic | 0 |
| Prolates | VIII-IX+10? | III+6? | 24-25(10-11+14) | ? | ? | cte | 1 |
| Proserranus | IX-X+10 | III+ ? | 24-25(10+14-15) | 2 (9-10) | ? | cte | ? |
| Eoserranus | ? | ? | ? | ? | ? | cic | ? |
| Bannikovperca | ? | III+9 | 17?(2?+15) | ? | ? | cic | 0 |
| Johnsonperca | IV?+? | - | 9?(9?+?) | 6? (4-9?) | /0+0/0+1/1/1/ | cic | 0 |
| Jimtylerius | X+9 | III+7? | 24(10+14) | 5 (6-10) | /0+0/0+2/1+1/ | cic | 0 |
| Saldenioicthys | VI?+? | III+? | 20?(6?+14) | - | ? | cte | 0 |
| Indiaicthys | VIII+8 | III+10 | 24(10+14) | 2 (9-10) | 0/0+0+2/1+1/ ? or 0+0/0+2/1+1/ ? or 0/0/0+2/1+1/ ? |
cte | 1 |
| Amphiperca | IX-XI+10-12 | III + 8-9 | 27-28(10-11+16-17) | 5? | 0/0/0+2/1+1/ | cte | ? |
| Palaeoperca | VIII + I, 8-9 | III + 6-8 | 23(10+ 13) | 7? | ? | cte | ? |
| Rhenanoperca | IX-XI+9-10 | III+7-9 | 24-25( 9-11?+14-15 | 7? | 0/0/0+2/1+1/ | cte | 1 |
| IGM 4550 | IX+10 | III+7 | 24(10+14) | 3 (8-10) | 0/0/0+2/1+1/ | cte | 1 |
