o well-developed teeth substantially less flattened so that
they appear more nearly rounded in cross section Go to 15

15. a. Distinct elongated beak; pronounced bulge to forehead;
blowhole located in lateral crease behind bulge; body to 32 feet
(9.8 m); sometimes second pair of teeth behind first in lower
jaw.
Northern bottlenosed whale, p. 67

b. No distinct beak; forehead slightly concave in front of
blowhole, increasing in concavity with increasing size; body to
23 feet (7.0 m); united portion of lower jaw less than one-fourth
the length of the entire lower jaw; head of adult males all
white.
Goosebeaked whale, p. 70

16. a. A single pair of teeth in the united portion of the lower jaw,
at the suture of the mandible (about one-third of the way from
the tip of the snout to the gape); length to 22 feet (6.7 m);
flukes less than one-fifth the body length.
Antillean beaked whale, p. 78

b. A single pair of teeth back of united portion of lower jaw;
body less than 17 feet (5.2 m) Go to 17

17. a. Teeth not exceptionally large and located immediately back of
united portion of lower jaw, about half way from the tip of the
snout to the gape.
North Sea beaked whale, p. 82

b. Teeth exceptionally large, located on bony prominences near
the corner of the mouth, and oriented backwards; corners of
mouth, particularly in adult males, have high-arching contour;
flukes to one-sixth or one-fifth of the body length.
Dense-beaked whale, p. 80

18. a. Rostrum, if present, not sharply demarcated from forehead Go to 19

b. Head has a distinct, though sometimes short rostrum separated
from the forehead by a distinct crease angle Go to 30

19. a. Teeth spade-shaped, laterally compressed and relatively small;
body to only about 5 feet (1.5 m); 22-28 teeth in each upper and
lower jaw.
Harbor porpoise, p. 150

b. Teeth conical and sharply pointed (in cross section circular,
or slightly flattened anteroposteriorly) Go to 20

20. a. No distinct dorsal fin; back marked inste