Rajidae

M. A. Treloar, L. J. B. Laurenson & J. D. Stevens, 2006, Descriptions of rajid egg cases from southeastern Australian waters., Zootaxa 1231, pp. 53-68 : 57

[[ Family Rajidae ]]

Identification key for rajid egg cases collected from skates in southeastern Australian waters

1a Egg case small, ≤ 85 mm BL ........................................................................................ 2

1b Egg case medium to large, ≥ 90 mm BL ....................................................................... 5

2a Lateral keel absent; dorsal and/or ventral surfaces of egg case covered with dense fibroids .......................................................................................................................... 3

2b Lateral keel present; dorsal and ventral surfaces of egg case not covered with dense fibroids ....................................................................................... Dipturus sp. A (Fig. 3)

3a Posterior horns shorter than body width; egg case> 40 mm BL .................................. 4

3b Posterior horns at least 2.7 times maximum body width; egg case ≤ 40 mm BL ......... ................................................................................................. Pavoraja nitida (Fig. 10)

4a Ventral surface of egg case covered with dense fibroids; egg case narrow at posterior end; posterior apron 1.5 times length of anterior apron ............. Dipturus cerva (Fig. 6)

4b Ventral surface of egg case not covered with dense fibroids; posterior apron length almost 3 times the length of anterior apron .......................... Dipturus lemprieri (Fig. 8)

5a Dorsal and ventral surfaces of egg case covered with dense fibroids; posterior horns shorter than body width ................................................................................................. 6

5b Dorsal and ventral surfaces of egg case not covered with dense fibroids; posterior horns at least 1.4 times maximum body width ........... Amblyraja cf hyperborea (Fig. 2)

6a Lateral keel prominent,> 18% of maximum body width; aprons fringed ...................... ................................................................................................ Dipturus whitleyi (Fig. 9)

6b Lateral keel discrete, <14% of maximum body width; aprons not fringed .................. 7

7a Egg case large, ≥ 160 mm BL; posterior horns enclosed in apron .................................. ............................................................................................ Dipturus cf gudgeri (Fig. 7)

7b Egg case medium, ≤ 120 mm BL; posterior horns extending out of apron .................... ..................................................................................................... Dipturus sp. B (Fig. 4)

Note: Dipturus sp. L was not included in this key as only partially formed egg cases were examined.