This beaked whale is known from temperate waters of the Southern Hemisphere. Genomic and specimen comparisons led to its description as distinct from True’s beaked whale, but its appearance does not reliably distinguish it from the close relative M. mirus.
Reported animals are gray, with a dark patch around the eye and a body that tapers from the rounded forehead toward the rostrum and tail. These features are also found in M. mirus and are not a reliable way to identify M. eueu by sight alone.
The records discussed in the paper come from temperate Southern Hemisphere waters, including specimens and strandings. The sources reviewed here do not establish this species’ own diet or behavior at sea.
An extinction-risk assessment has not been added yet.