b. Distinctive white head markings absent: mound or convexity in 

 front of blowhole absent; exposed tusks of males tilted forward, 

 with denticle positioned near front edge; tusks protrude rela- 

 tively far above gumline and often are worn along front edge; 

 maximum body length less than 6 m. Females and young require 

 museum preparation for positive identification. Subarctic dis- 

 tribution. [7] 



* Stejneger's Beaked Whale, Misoplodon sujncgtri (P) 



c. Uniformly dark beak; forehead of males lacking prominent 

 characteristic of (a J; single thin, mandibular tusk on either side 

 of mouth, barely breaking gumline; maximum body length 5 m. 

 Females and young require museum preparation for positive 

 identification. Tropical to subtropical distribution. 



* Ginkgo-toothed Beaked Whale, Utsoplodon gmkgoims (B) 



d. White markings on beak and forehead absent; lower jaw usually 

 light in color; teeth (tusks) exceptionally large, located on bony 

 prominences near corners of mouth, and oriented slightly for- 

 ward; corners of mouth, particularly in adult males, have high- 

 arching contour; lower jaw massive ("dense"); forehead marked 

 by depression or concavity in front of blowhole; maximum body 

 length 5m. Females and young require museum preparation for 

 positive identification. Cosmopolitan distribution. 



* BlamviUe's Beaked Whale, MesoploJon dcnsirostns (Bj 



17. a. Rostrum, if present, not sharply demarcated from forehead 



Go to 1 8 



b. Distinct, though sometimes short rostrum separated from the 

 forehead bv a distinct crease Go to ;o 



18. a. Teeth spade shaped, laterally compressed and relatively small 



Go to 19 



b. Teeth conical and sharply pointed (in cross section circular, or 

 slightly flattened anterposteriorly) Go to 22 



19. a. Body to 2.2 m, extremely robust with pronounced thickened 



keel; dorsal fin subtriangular, usually black and gray or white; 

 head very small relative to body size; striking black body with 

 large conspicuous white ov.iI patch on each side; upper rear 

 portion of flukes white Go to 20 



b. Body to 1 .8 m, though most individuals much smaller; dorsal fin 

 small, almost triangular and uniformly colored; head without 

 prominent forehead but moderately large relative to size; body 

 brownish on back with whitish belly and light gray zone on side 

 in front of dorsal fin Go to 21 



20. a. White coloration of side extends from back of chest to area of 



anus, does not extend forward ot flippers or aft of anus; 2J-28 

 teeth per jaw [8]. 



* Dall's Porpoise, Phccocndoidcs dalh (A) 



b. White coloration of body more extensive, extending well 

 forward onto chest, in front of flippers, higher onto sides, and 

 farther aft; 19-24 teeth per jaw [8]. 



* True's porpoise, Phococnoidis mm (P) 



[8] It is very important to remember that for species reported by a 

 small number of specimens tooth counts (ranges) may not fairly 

 represent the range for the entire species and shoiild therefore be used 

 cautiously. 



5^ 



