Coccocephalichthys enters the LRT

Today’s post is best understood in pictures
(Figs. 1–3) as a new transitional taxon is added between two previous sisters that were widely separated in time and had distinct morphologies (still, closer to one another than to any other of the 1565+ taxa).

Coccocephalichthys wildi (originally Coccocephalus wildi Watson 1925; Whitley 1940; Poplin and Véran 1996; Late Carboniferous; Fig. 2) was originally considered a palaeoniscid, like Cheirolepis.

In the large reptile tree (LRT, 1569 taxa) Coccocephalichthys nests between Strunius (Fig. 1) and Early Triassic  Saurichthys (Fig. 3) + Thunnus, the extant tuna. Note the genesis of the long rostrum alongwith the reduction of the squamosal here. Several bones are re-identified here.

Most of the time,
this is how the LRT grows, by adding new transitional taxon between two presently tested taxa. In this case, the transitional taxon neatly helps illustrate the evolution that occurred between the two extremes.

References
Poplin C and Véran M 1996. A revision of the actinopterygian fish Coccocephalus wildifrom the Upper Carboniferous of Lancashire. In Milner, A. R. (ed.) Studies on Carboniferous and Permian vertebrates. Special Papers in Palaeontology 52: 7-29.
Watson DMS 1925. The structure of certain palæoniscids and the relationships of that group with other bony fish. Proceedings of the Zoological Society of London, 54: 815–870.
Whitley GP 1940. The Nomenclator Zoologicus and some new fish names. Australian Naturalist, 10:241–243.

wiki/Strunius
wiki/Thunnus
wiki/Saurichthys
wiki/Cheirodus
wiki/Mimipiscis
wiki/Coccocephalichthys