''Mecodema antarcticum'' is a carnivorous

carabid Ground beetles are a large, cosmopolitan family of beetles, the Carabidae, with more than 40,000 species worldwide, around 2,000 of which are found in North America and 2,700 in Europe. As of 2015, it is one of the 10 most species-rich animal fa ...

beetle that burrows in sand above the high tide mark on

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

sandy beaches. First described by

Francis de Laporte de Castelnau Francis may refer to: People and characters *Pope Francis, head of the Catholic Church (2013–2025) *Francis (given name), including a list of people and fictional characters * Francis (surname) * Francis, a character played by YouTuber Boogie2 ...

in 1867 as ''Brullea antarctica'', it has since been reassigned to '' Mecodema.''

Description

''Mecodema antarcticum'' is large (up to 25 mm), glabrous reddish brown to black with a distinct "waist" or narrowing between thorax and abdomen (peduncle), like all '' Mecodema''. Indeed, recent DNA analysis places it within that genus, a sister group to '' Mecodema curvidens''; its distinctive differences in body shape may be adaptations to burrowing in sand. This species legs are well-adapted for digging in sand with greatly expanded coxa, femur and tibia: all tibia are greatly expanded at their

distal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

ends, and the middle and hind pairs are also strongly curved. Other features consistent with dwelling in and on sand are the short antennae, large curved mandibles, and a rather boxy shape in contrast to the longer and more elegant forest ''Mecodema'' species. The abdomen of ''M. antarcticum'' is covered in long setae to further protect it from abrasion. Its larval form was unknown for some time, and was first described in 1978.

Ecology

''Mecodema antarcticum'' is found in the

supralittoral The supralittoral zone, also known as the splash zone, spray zone or the supratidal zone, sometimes also referred to as the white zone, is the area above the spring high tide line, on coastlines and estuaries, that is regularly splashed, but not s ...

or splash zone of sandy beaches around the New Zealand coast, underneath logs or stones, hiding in the sand during the day and emerging at night to feed. It was described by

George Hudson George Hudson (probably 10 March 1800 – 14 December 1871) was an English railway financier and politician who, because he controlled a significant part of the Railway Mania, railway network in the 1840s, became known as "The Railway King"—a ...

as "usually rare", but is a secretive burrowing beetle, and occasionally is discovered in reasonable numbers. It was rediscovered by schoolchildren on the

Whanganui Whanganui, also spelt Wanganui, is a city in the Manawatū-Whanganui region of New Zealand. The city is located on the west coast of the North Island at the mouth of the Whanganui River, New Zealand's longest navigable waterway. Whanganui is ...

coast in 2006 after not being recorded for many years. ''Mecodema antarcticum'' has been recorded being heavily preyed on by katipō spiders, and it may be threatened by the introduced South African spider ''

Steatoda capensis Steatoda capensis is a spider originating from South Africa. Its common names include the ''black cobweb spider'', ''brown house spider'', ''cupboard spider'' and due to its similarities to the katipō spider it is commonly known as the ''false ...

,'' either as a predator or competitor.

References

{{Taxonbar, from=Q113377988 antarcticum Endemic beetles of New Zealand Taxa named by François-Louis Laporte, comte de Castelnau Beetles described in 1867