Heterodontus japonicus, de Miklouho Maclay & Macleay, 1884

3.1.3 | Heterodontus japonicus View in CoL

A large heterodontid egg case ( 142.5 – 144.1 mm ECL), lateral keels spiraling its length making 13 /4 rotations from anterior to posterior ends; surfaces smooth; anterior margin broad and weakly S-shaped when viewed from anterior plane; widest at anterior portion, gradually tapering posteriorly from rear third; keel base to keel apex space at midportion large (16.0% – 18.6% ECL); keels wide (9.7% – 10.4% ECL), straight, projecting strongly anteriorly (Figure 2c), flexible, ending abruptly (not tapering) at posterior end. Color brown with slight greenish hue when preserved (Figure 5), with deposited egg cases appearing grayish brown to brown.