Key to the species of Anacanthobatidae in the Indian Ocean 1a Dorsal surface of disc with dermal papillae of distinct size; maximum size 29–43 cm TL............................ 2 1b Dorsal surface of disc with rudimentary or without dermal papillae; maximum size 56–68 cm TL...................... 4 2a Dorsal surface light reddish-brown with pattern of white spots and more or less symmetrically rosette-like arranged small ocelli; 28–35 tooth rows in upper jaw................................................. Anacanthobatis marmorata 2b Dorsal surface uniformly medium or dark grayish-brown; 18–26 tooth rows in upper jaw............................ 3 3a Dorsal and ventral surfaces dark grayish-brown; snout angle 85–106°; disc width 45–55% TL; tail longer than body; claspers short (length 14% TL) but very complex including external component pecten........................... Indobatis ori 3b Dorsal surface medium grayish-brown, ventral side lighter (largely beige with darker outer and posterior areas); snout angle 75°; disc width 64% TL; tail shorter than body; claspers longer (length 20% TL) and rather simple without pecten......................................................................................... Sinobatis sp. Broken Ridge 4a Ventral head length 38–42% TL; tail filamentous, not bulbous near tip............................................ 5 4b Ventral head length 23–36% TL; tail with flattened, bulbous tip...................................... S. bulbicauda 5a Dorsal surface pale grayish-brown, ventral side whitish anteriorly to pale grayish-brown with blotches posteriorly; disc very broad and long, width 71–73% TL, length 76% TL............................................ S. brevicauda n. sp. 5b Dark blue on both surfaces; disc narrower and shorter, width 57–63% TL, length 66–70% TL................. S. caerulea Comparative material ......continued on the next page Anacanthobatis (Schroederobatis) americana

Published as part of Weigmann, Simon & Stehmann, Matthias F. W., 2016, Sinobatis brevicauda n. sp., a new deep-water legskate (Rajiformes, Anacanthobatidae) and first generic record from the western Indian Ocean, pp. 478-500 in Zootaxa 4137 (4) on pages 495-497, DOI: 10.11646/zootaxa.4137.4.2, http://zenodo.org/record/268229