Heterodontus portusjacksoni

3.1.7 | Heterodontus portusjacksoni View in CoL

A large heterodontid egg case (120.0 – 144.8 mm ECL), lateral keels making 2½ – 23 /4 rotations from anterior to posterior ends; surfaces mostly smooth; anterior margin broad and straight to weakly S-shaped when viewed from anterior plane; widest at anterior third, slightly and gradually tapering toward posterior end; keel base to keel apex space at midportion small to keel apex abutting the base of the adjacent keel (0.0% – 8.5% ECL); keels wide (16.0% – 18.6% ECL), straight, projecting strongly anteriorly (Figure 2f), flexible, ending abruptly (not tapering) at posterior margin. Color dark brown to black when preserved (Figure 9), with deposited egg cases brown to dark brown.