The dorsal fin spine of Edaphodon closely resembles that of the extinct genus Ischyodus Egerton 1843, but differs from the latter genus by displaying a weakly compressed subovate fin spine with a large subovate pulp cavity
, and an incomplete trabecular tissue layer confined to the anterior and posterior spine edge.
65 mm; anterior margin of crown bluntly rounded; crown narrower anteriorly than at midlength; crown posteriorly elongate, narrowing smoothly towards tip; crowns covered with very fine longitudinal ridges and grooves; all ridges on crown either distributed rostro-caudally over scale and converging on single posterior point, or median ridges running straight to posterior end of crown but with more lateral ridges curving from base upwards and posteriorly; each fine ridge may be formed from two parallel finer ridgelets; lower crown surface smooth; neck as very narrow furrow; base rounded, anteriorly placed; anterior spur-like projection short or absent; pulp cavity large, continuing as wide pulp canal posteriorly.
fins; single dorsal fin; hypocercal caudal fin, caudal fin "rays" absent; orbits on anterolateral corners of head surrounded by 2-3 rows of specialized, conical, high scales; scales of fin origin compact, relatively large; trunk scales with one median and up to eight posterior or posterolateral spines on crown; pulp cavity relatively large, shallow to deep; one median (= main) and up to eight lateral pulp canals corresponding to number of spines; dentine canals and tubules narrow, sinuous, branched.
m long); head and anterior part of trunk wide, dorsoventrally flattened, posterior part of trunk and caudal fin laterally compressed; paired pectoral fins, single dorsal and anal fin, and hypocercal caudal fin present; caudal fin strongly heterocercal in young individuals, becoming nearly symmetrical in adults; orbits on anterolateral corners of head; scale morphology variable depending on position on body; pulp cavity single, occasionally continuing as pulp canal posteriorly; dentine tubules long, narrow, straight.
1) "Gemination" may produce a tooth with a bifid crown and a single pulp cavity.
It seems less likely that the secondary tooth is the result of gemination because it has distinct roots and a relatively distinct crown, indicating that it has its own pulp cavity.