Parasemionotiformes

Parasemionotiformes is an extinct order of neopterygian ray-finned fish that existed globally during the Triassic period. It comprises the families Parasemionotidae and Promecosominidae. Many of the included genera are monotypic and most species lived during the Early Triassic epoch.

Parasemionotiforms were normally small to medium-sized fishes. They were predominantly marine.

Evolutionary relationships
Parasemionotiformes are neopterygians, which is the clade that encompasses the vast majority of living ray-finned fishes (Actinopterygii) and about half of all living species of vertebrates. Neopterygii are divided into Teleostei and Holostei. The latter represents a depauperate group today but used to be a diverse clade especially during the Mesozoic Era. The only surviving members of the Holostei are the gars (Ginglymodi) and the bowfin (Halecomorphi).

Parasemionotiformes belong to Holostei and are one of the earliest clades of the Halecomorphi (bowfin and its extinct relatives). Parasemionotiformes are the sister group to all other halecomorphs according to cladistic analyses.

The following tree summarizes the evolutionary relationships of the Parasemionotiformes. Names accompanied by a dagger (†) represent extinct groups.

Classification

 * Order Parasemionotiformes Lehman, 1966
 * Family incertae sedis
 * Genus Peia Ji, 2009
 * Peia jurongensis Ji, 2009 (type species)
 * Family Parasemionotidae Stensiö, 1932 (= Ospiidae Stensiö, 1932 )
 * Genus Parasemionotus Piveteau, 1929
 * Parasemionotus labordei ( Priem, 1924 ) (type species)
 * Parasemionotus besairiei Lehman et al., 1959
 * Genus Ospia Stensiö, 1932
 * Ospia whitei Stensiö, 1932 (type species)
 * Genus Broughia Stensiö, 1932
 * Broughia perleididoides Stensiö, 1932 (type species)
 * Genus Watsonulus Brough, 1939 (= Watsonia Piveteau, 1934 )
 * Watsonulus eugnathoides ( Piveteau, 1934 ) (type species)
 * Genus Stensionotus Lehman, 1952
 * Stensionotus intercessus Lehman, 1952 (type species)
 * Stensionotus dongchangensis Liu et al., 2002
 * Genus Jacobulus Lehman, 1952
 * Jacobulus novus Lehman, 1952 (type species)
 * Genus Thomasinotus Lehman, 1952
 * Thomasinotus divisus Lehman, 1952 (type species)
 * Genus Albertonia Gardiner, 1966
 * Albertonia cupidinia ( Lambe, 1916 ) (type species)
 * Genus Lehmanotus Beltan, 1968
 * Lehmanotus markubai Beltan, 1968 (type species)
 * Genus Devillersia Beltan, 1968
 * Devillersia madagascariensis Beltan, 1968 (type species)
 * Genus Piveteaunotus Beltan, 1968
 * Piveteaunotus ifasiensis Beltan, 1968 (type species)
 * Genus Icarealcyon Beltan, 1980
 * Icarealcyon malagasium Beltan, 1980 (type species)
 * Genus Jurongia Liu et al., 2002
 * Jurongia fusiformis Liu et al., 2002 (type species)
 * Genus Qingshania Liu et al., 2002
 * Qingshania cercida Liu et al., 2002 (type species)
 * Genus Suius Liu et al., 2002
 * Suius brevis Liu et al., 2002 (type species)
 * Genus Candelarialepis Romano et al., 2019
 * Candelarialepis argentus Romano et al., 2019 (type species)
 * Family Promecosominidae Wade, 1940
 * Genus Promecosomina Wade, 1935
 * Promecosomina formosa  ( Woodward, 1890 ) (type species) (= P. beaconensis Wade, 1935 )