Koilops herma (Clack et al. 2016; NMS G. 2013.39/14) Tournasian, early Carboniferous ~375 mya) was traditionally considered a basal tetrapod, but it was a small fish with a flat skull and large orbits nesting at the base of the Elpistostege, Spathicephlaus and Tiktaalik clade, but was smaller and later than all three. It also nested between Tinirau and Panderichthys. In this small, neotonous taxon the nares were close to the rim of the short rorstrum. The pineal foramen was enormous. The teeth were relatively larger and sharp. The nasals were broader anteriorly.

Elpistostege watsoni (Westoll 1938, Schultze and Arsenault 1985, Cloutier et al. 2020; Late Devonian, 374mya; MHNM 06-2067) is another flathead fish transitional to tetrapods. Some tiny fingerbones are present in the finray fin. This fish is over a meter in length and the tiny fins are incapable of supporting weight. It is the last taxon in this line with an anal fin. The radius continues to be as long as the ulna + ulnare with the intermedium separating them distally.

Tiktaalik roseae (Daeschler, Shubin and Jenkins 2006; Late Devonian, 375mya; 2.5m in length) nests between Pandericthys and Tetrapoda in the large reptile tree.

Distinct from Pandericthys the opercular bones are absent, the orbits are further back and higher on the skull, ribs, a pelvis and large bones within the four limbs are present.

Spathicephalus mirus (Watson 1926; Late Carboniferous, 320 mya) was described, "unlike that of any other early tetrapod, with a flattened, square-shaped skull and jaws lined with hundreds of very small chisel-like teeth." The extended orbit shape traditionally allied Spathicephalus with Baphetes, but here it nests with the stem tetrapod, Tiktaalik.

The fossil does not show tooth replacement because every tooth is present without gaps. Distinct from derived temnospondyls, but like basal forms, the palate is closed on this bottom-feeder.

Milner et al. 2009 nested Spathicephalus close to Eucritta and Baphetes, but that relationship was not recovered in the LRT, despite sharing a closed palate. The elongate orbit without intrusions is convergent with that of Baphetes.