Mecodema haunoho is the only ground beetle (Carabidae) species that is endemic to Little Barrier Island (Hauturu).

[1][2][3] It is sister species of the Great Barrier Island (Aotea) species M. aoteanoho and both are closely related to M. manaia, a species found in Bream Head, Northland, New Zealand.

[1] Distinguished from other North Island Mecodema species by having: Length 20.5–24.1 mm, pronotal width 5.1–5.9 mm, elytral width 6.3–6.8 mm.

Colour of the entire body is matte to glossy black.

[1][2] Found throughout the island, but more commonly encountered in the broadleaf forests of the southern and southwestern areas of Hauturu.