Opening a Bag of Worms — O. subserratus

Otodus subserratus (Fig. 1) is a species based on a single specimen, supposedly from the Early Eocene London Clay of Sheppey, UK. Unfortunately, the holotype, from its preservation and morphology is not from the London Clay of Sheppey, and not of this lineage. It is a tooth of Cosmopolitodus*, probably from the Belgian Miocene (see Woodward, 1889; Priem, 1912). Thus the name subserratus, at whatever rank, should not be used in the Otodus-Carcharocles lineage.

Fig. 1 Agassiz (1843) illustration and
photograph of specimen.

Woodward (1889: 411) regarded it as the senior synonym of Carcharodon escheri (AGASSIZ, 1843) — the transitional form between Cosmopolitodus hastalis and the great white shark Carcharodon carcharias.

Fig. 2 Agassiz (1843) illustration

The accompanying image of the subserratus holotype (Fig. 1) bears a greater resemblance to an upper anterior of a serrate Cosmopolitodus (Isurus) hastalis, i.e. C.escheri (fig. 2).

* By embracing Carcharocles, the authors also accept an evolutionary lineage for Carcharodon which is derived from Cosmopolitodus, the teeth traditionally termed the broad-toothed makos (Isurus).