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