[5] A 2023 study concluded that both belonged to a single taxon: the Taiwanese form retained the species name, but was placed in Toyotamaphimeia, creating the new combination T.

[4] The holotype of Toyotamaphimeia is a nearly complete skeleton consisting of a skull, an entire cervical and dorsal series of vertebrae, various ribs, 33 osteoderms as well as almost half the bones of the limbs, hip region and pectoral girdle.

[4] Subsequent research papers in the 2020s estimated that both species of Toyotamaphimeia are roughly similar in size,[1] approximately between 6.3 and 7.3 metres (21 and 24 ft) based on vertebrae and skull length.

The fact that these injuries healed is evidence that the animal survived for a while after being injured and Katsura suggests that they may have been the result of intraspecific fights, furthermore hypothesizing that this could mean the Osaka University specimen may have been a male.

[2] The Ibaraki Formation, where the remains of Toyotamaphimeia have been found, is part of the Osaka Group, which consists of lacustrine and fluvial deposits of the Pliocene to Pleistocene.

Molluscs, pollen and plant fossils (species of lotus and water caltrop found in the Kasuri Tuff suggest a moderate climate.

[10] However, recent molecular studies using DNA sequencing have consistently indicated that the false gharial (Tomistoma) (and by inference other related extinct forms in Tomistominae) actually belong to Gavialoidea (and Gavialidae).

[11][12][13][14][15][16][17] Following this interpretation, Iijima et al. found Toyotamaphimeia to have been a basal member of Gavialinae, clading together with the Miocene Penghusuchus and the then newly named Hanyusuchus.

†Tomistoma cairense †Tomistoma coppensi †Maomingosuchus petrolica Tomistoma schlegelii, false gharial †Tomistoma lusitanicum †Gavialosuchus eggenburgensis †Melitosaurus champsoides †Tomistoma calaritanum †Tomistoma gaudense †Thecachampsa carolinensis †Thecachampsa antiqua †Paratomistoma courti †Penghusuchus pani †Toyotamaphimeia machikanensis †Hanyusuchus sinensis †Eosuchus lerichei †Eosuchus minor †Ocepesuchus eoafricanus †Eothoracosaurus mississippiensis †Thoracosaurus macrorhynchus †Thoracosaurus neocesariensis †Aktiogavialis puertoricensis †Eogavialis africanum †Argochampsa krebsi †Piscogavialis jugaliperforatus †Ikanogavialis gameroi †Siquisiquesuchus venezuelensis †Dadagavialis gunai †Gryposuchus neogaeus †Gryposuchus croizati †Aktiogavialis caribesi †Gryposuchus pachakamue †Gryposuchus colombianus †Rhamphosuchus crassidens †Myanmar gavialid †Gavialis lewisi †Gavialis bengawanicus Gavialis gangeticus, gharial †Siwalik Gavialis †Xaymacachampsa kugleri †Maroccosuchus zennaroi †Kentisuchus astrei †Kentisuchus spenceri †Megadontosuchus arduini †Dollosuchoides densmorei †Thecachampsa antiqua †Thecachampsa carolinensis †Penghusuchus pani †Toyotamaphimeia taiwanicus †Hanyusuchus sinensis

†Toyotamaphimeia machikanensis † Kishiwada Toyotamaphimeia † Yage tomistomine †Tomistoma cairense †Maomingosuchus petrolica †Paratomistoma courti †Tomistoma coppensi Tomistoma schlegelii, false gharial †Gunggamarandu maunale †Melitosaurus champsoides †Tomistoma lusitanicum †Gavialosuchus eggenburgensis †Tomistoma gaudense †Tomistoma calaritanum