Consider the Golden Mole

Iridescence turns up in many insects, some birds, the odd squid: but in only one mammal, the golden mole. There’s Grant’s golden mole (just 8 cm long, found only in the Namibian desert, known as the ‘dune shark’) and Marley’s golden mole (reddish-brown, found only on two small patches of land on the eastern slopes of the Lebombo Mountains), the robust golden mole (not robust at all: it’s dying out due to sweeping habitat loss in South Africa) and the largest species, the giant golden mole. This tiny jawbone, barely larger than a thumbnail clipping, did not match that of any other known mole, and so the Calcochloris tytonis – the Somali golden mole – was added to the species list.

Source: www.lrb.co.uk