Pycnodontoidei

Belongs within: Pycnodontiformes.
Contains: Pycnodontidae.

The Pycnodontoidei are a clade of pycnodontiform fishes characterised by the loss of scales over much of the body (Poyato-Ariza & Wenz 2002).

Characters (from Poyato-Ariza & Wenz 2002): Opercular process of hyomandibular absent; ossifications in gular region absent; two branchiostegal rays, thin and separated; crenulations on vomerine and prearticular teeth occasional and weak if present; scales not covering the whole body; scales rows between bases of lepidotrichia of unpaired fins absent.

Pycnodontoidei
    |--Eomesodon Woodward 1918P-AW02
    |    |--*E. liassicus (Egerton 1855) [=Pycnodus liassicus]P-AW02
    |    |--E. barnesi (Woodward 1906)P-AW02
    |    |--E. depressus Woodward 1918P-AW02
    |    `--E. hoeferi (Gorjanovic-Kramberger 1905)P-AW02
    `--+--Apomesodon Poyato-Ariza & Wenz 2002P-AW02
       |    |--*A. gibbosus (Wagner 1851) [=Mesodon gibbosus, Gyrodus gibbosus Agassiz 1843 (n. n.)]P-AW02
       |    |--A. comosus (Thiollière 1858) [=Mesodon comosus, Macromesodon comosus]P-AW02
       |    `--A. surgens Poyato-Ariza & Wenz 2002P-AW02
       `--PycnodontoideaP-AW02
            |--PycnodontidaeP-AW02
            `--CoccodontidaeP-AW02
                 |--Trewavasia White & Moy-Thomas 1941P-AW02
                 |    `--*T. carinatus (Davis 1887) [=Xenopholis carinatus]P-AW02
                 `--+--Ichthyoceros Gayet 1984P-AW02
                    |    `--*I. spinosus Gayet 1984P-AW02
                    `--Coccodus Pictet 1850P-AW02
                         |--*C. armatus Pictet 1850P-AW02
                         `--C. lindstroemi Davis 1890 (n. d.)P-AW02

*Type species of generic name indicated

References

[P-AW02] Poyato-Ariza, F. J., & S. Wenz. 2002. A new insight into pycnodontiform fishes. Geodiversitas 24 (1): 139–248.