Mammals
Blainville's Beaked Whale
Mesoplodon densirostris · also called Blainvilles beaked whale, dense-beaked whale
Surfacing briefly after an extended deep dive, a male Blainville’s beaked whale displays a pair of prominent teeth erupting through its upper jaw, a visible feature backed by bone so dense it ranks as the heaviest documented in any mammal on Earth.
Overview
Blainville’s beaked whale, Mesoplodon densirostris, is a deep-diving whale native to deep tropical and temperate ocean waters across a broad range spanning the Atlantic, Pacific, and Indian Oceans. Its record-breaking bone density, males’ visibly erupted competitive teeth, and unusually wide distribution among beaked whale species make it one of the more physically extreme and geographically far-reaching members of one of the ocean’s least understood whale families.
Bone dense enough to sink on its own
Few animals anywhere carry bone as dense as Blainville’s beaked whale, a physical trait so extreme that the skull alone struggles to float, hinting at adaptations for deep diving that researchers are still working to fully understand.
Status
Least Concern, widespread across suitable deep tropical and temperate ocean habitat throughout the Atlantic, Pacific, and Indian Oceans.
Blainville's Beaked Whale: common questions
Why does Blainville's beaked whale have such dense bone?
This species has the densest bone documented in any mammal, a characteristic so pronounced that its skull barely floats even when separated from the rest of the body, though the precise evolutionary reason behind this extreme density is still an active area of scientific research.
Why do male Blainville's beaked whales have visible teeth?
A male of this species develops a pair of large, forward-pointing teeth that erupt visibly through the upper jaw, unlike the mostly hidden teeth found in most other whale species, a feature likely used in visual displays and physical competition with rival males.
Why do many Blainville's beaked whales have scars?
Many individuals of this species, particularly males, carry visible scars believed to result from aggressive interactions with other males, likely related to the prominent erupted teeth used during these competitive encounters over territory or mating opportunities.
How widespread is Blainville's beaked whale?
This species has one of the broadest distributions of any beaked whale species, found across a wide range of deep tropical and temperate ocean waters spanning the Atlantic, Pacific, and Indian Oceans, making it one of the more geographically far-reaching members of its family.