Harriotta raleighana, Goode & Bean, 1895

Smith, Moya, Manzanares, Esther, Underwood, Charlie, Healy, Chris, Clark, Brett & Johanson, Zerina, 2020, Holocephalan (Chondrichthyes) dental plates with hypermineralized dentine as a substitute for missing teeth through developmental plasticity, Journal of Fish Biology 97 (1), pp. 16-27 : 22

3.3 | Harriotta raleighana

In this juvenile specimen (Figure 6; Smith et al., 2019: figure 17a), with respect to whitlockin, the anterior dental plate has both rods and ovoids, while in the posterior plate, tritoral pads and ovoids are present (Figure 6c). In older individuals, these rods are replaced within the dental plate by ovoids and the tritoral pads are better developed ( Smith et al., 2019: figures 1D and 17). On the specimens examined, there is no indication of posterolingual rods on the posterior dental plate ( Smith et al., 2019: figure 17) and instead, in the youngest individual available (Figure 6C), two short series of ovoids are present. However, these do not transform into tritoral pads ( Smith et al., 2019: figure 17). One important difference between the Chimaeridae and Harriotta is the absence of lingual ridges on the anterior dental plates of Harriotta (Figure 6a,b,e). However, while these are not conspicuous on the lingual surface of the outer dentine, the distinct region of the plate associated with the ridges in the other taxa described here can be recognized and defined by the furrow and oral-aboral ridge (Figure 6e, arrows 1 and 2).