[12][13] In the late 20th century, a flood of new fossil evidence mapped out in some detail the nature of the transition between the elpistostegalid fish and the early amphibians.

[14] Most herpetologists and paleontologists, therefore, no longer accept the view that amphibians have arisen twice, from two related but separate groups of fish.

Not all paleontologists today are convinced that Lissamphibia is indeed a natural group, as there are important characteristics shared with some non-lissamphibian Palaeozoic amphibians.

[16][17] Molecular studies of extant amphibians based on multiple-locus data favor one or the other of the monophyletic alternatives and indicate a Late Carboniferous date for the divergence of the lineage leading to caecilians from the one leading to frogs and salamanders, and an early Permian date for the separation of the frog and salamander groups.

[4][18][19] The stem-caecilian Funcusvermis, described in 2023, retained many dissorophoid temnospondyl features, supporting a monophyletic Lissamphibia within clade Temnospondyli.