T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Whale (Strap-toothed whale) Mesoplodon layardii

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: Ziphiidae
Genus: Mesoplodon
Species: M. layardii
Binomial name: Mesoplodon layardii
Common names: Strap-toothed whale, Layard's beaked whale, long-toothed whale 

The strap-toothed whale (Mesoplodon layardii), is a large mesoplodont with some of the most bizarre teeth of any mammal. 
The strap-toothed whale is distributed in cool temperate waters of the Southern Hemisphere between 30°S and the Antarctic Convergence. 
Up to 1991, there were about 50 of this species stranded in New Zealand. 

The overall body shape of the strap-toothed whale is fairly typical for a mesoplodont, except for the large size. Male specimens have large and peculiar teeth even for the genus; the teeth emerge from the lower jaw and grow upward and back at a 45-degree angle to encircle the upper jaw and nearly close it. These teeth can sometimes grow to over 30 centimetres in length. The teeth have dorsally projecting denticles, and are apparently used for fighting. Barnacles are frequently found on the teeth, as well. Why the species would grow teeth that severely cut back on the size of prey it can consume is uncertain. The melon is somewhat bulbous and blends into the beak shortly before the strap teeth. The beak itself is fairly long, with a relatively straight mouthline.  
The colouration of this species is also unusual for a mesoplodont since it is rather bold; most of the body is black except for white areas on the front of the beak, the throat, behind the head in a shape reminiscent of a cape, and near the genitals. Scars and cookie cutter shark bites are also present. Males can reach around 5.9 metres whereas females reach 6.2 metres and likely weigh around 1,000–1,300 kilograms, indicating they are probably the largest species in the genus. 
Strap-toothed whales' diet consists primarily of squid, although research has suggested that a small portion of their diet may also consist of fish or crustaceans.

 A distinctive feature of the male of this species is two sharp canines that protrude above the upper jaw. in the male, become greatly elongated or strap-shaped. The females look like ordinary. An adult male can only open his mouth a few centimetres.
  

A graphic shows the size difference of Mesoplodon layardii and a human.

The blue areas show Mesoplodon layardii range


Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/