Percomorpha are the most
diverse group of teleost fish today. Teleosts, and percomorphs in particular, thrived during the
Cenozoicera. Fossil evidence shows that there was a major increase in size and abundance of teleosts immediately after the
mass extinction event at the
Cretaceous-Paleogene boundary ca. 66
Ma ago.[7] The oldest known percomorph fossils are of the early
tetraodontiformsProtriacanthus and
Cretatriacanthidae from the
Santonian to
Campanian of
Italy and
Slovenia.[8] A higher diversity of early percomorphs is also known from the
Campanian of
Nardò,
Italy, and these also show some level of diversification into modern orders, with representatives of the
Syngnathiformes and Tetraodontiformes known.[9] Possibly the oldest percomorph is Plectocretacicus from the
Cenomanian of
Lebanon, which may be a stem-tetraodontiform; however, some morphological analyses indicate that it shows similarities with non-percomorph groups.[8][10]
Phylogeny
External relationships
The two
cladograms below are based on Betancur-R et al., 2017.[5] Percomorphs are a
clade of
teleost fishes. The first cladogram shows the interrelationships of percomorphs with other living groups of teleosts.
^Laurin, M.; Reisz, R.R. (1995). "A reevaluation of early amniote phylogeny". Zoological Journal of the Linnean Society. 113 (2): 165–223.
doi:
10.1111/j.1096-3642.1995.tb00932.x.