The small forehead is defined posteriorly by the indentation at blowhole. The melon merges seamlessly to the narrow, moderate length rostrum. The mouthline is relatively straight.

Adult males are dark gray dorsally and medium gray ventrally with pectoral fins uniformly dark gray above and below. Scarring is often readily visible and appears to be more prevalent in adult males and can occur in round, oval or linear patterns. Oval scars may result from cookie cutter sharks and linear lines from conspecifics given the placement of mandibular teeth. Female pigmentation is similar to adult males, some adult females display a patch of white about 15 cm in diameter that extends from just anterior to the genital slit to a point just posterior to the anus. This patch has not been observed in males. Juveniles have a white belly.

Adult body length ranges between 4.5 to 4.9 m. Recorded maximum body length for adult males and females is 4.8 m and 4.9, respectively. Length at birth is approximately 2.1 m.

Mesoplodon bidens
Mesoplodon mirus
Ziphius cavirostris