''Zoosphaerium darthvaderi'', also known as the Darth Vader giant pill millipede, is a species of

giant pill millipede Sphaerotheriida is an order of millipedes in the infraclass Pentazonia, sometimes known as giant pill millipedes. They inhabit Southern Africa, Madagascar, South and Southeast Asia, Australia and New Zealand. Like the Northern Hemisphere pill mil ...

endemic to the island state of

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. It is named after the ''

Star Wars ''Star Wars'' is an American epic film, epic space opera multimedia franchise created by George Lucas, which began with the Star Wars (film), eponymous 1977 film and quickly became a worldwide popular culture, pop-culture Cultural impact of S ...

'' character

Darth Vader Darth Vader is a fictional character in the ''Star Wars'' franchise. The character is the central antagonist of the original trilogy and, as Anakin Skywalker, is one of the main protagonists in the prequel trilogy. ''Star Wars'' creator George ...

. The millipede is restricted to the

Ambohitantely Reserve Ambohitantely Special Reserve is a wildlife reserve of Madagascar. Geography This reserve is situated in Analamanga region, north-west of the town of Antananarivo in the district of Ankazobe. It covers of primary rainforests and of grassland ...

and is considered an extremely endangered species.

History and classification

The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

and three immature male

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). Of ...

s of ''Zoosphaerium darthvaderi'' were collected via

pitfall trap A pitfall trap is a trapping pit for small animals, such as insects, amphibians and reptiles. Pitfall traps are a sampling technique, mainly used for ecology studies and ecologic pest control. Animals that enter a pitfall trap are unable to esca ...

s in an area of disturbed transitional mossy forest at an elevation of . The forested region is northeast of

Ankazobe Ankazobe is a municipality in Analamanga Region, in the Central Highlands (Madagascar), Central Highlands of Madagascar. It is the administrative capital of Ankazobe District and is situated at 75 km north of the capital Antananarivo. Infras ...

Antananarivo Province Antananarivo Province is a former province of Madagascar with an area of . It had a population of 5,370,900 in 2004. Its capital was Antananarivo, which is also the capital of the country. Established in 1965, it was the most important province of ...

, Madagascar, and the millipedes were collected in 1997 and subsequently accessioned into the

entomology Entomology () is the science, scientific study of insects, a branch of zoology. In the past the term "insect" was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such ...

collections of the

Field Museum of Natural History The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is popular for the size and quality of its educational ...

in Chicago. They were not fully examined and described until a team of entomologists from the Field Museum and

Mount Holyoke College Mount Holyoke College is a private liberal arts women's college in South Hadley, Massachusetts. It is the oldest member of the historic Seven Sisters colleges, a group of elite historically women's colleges in the Northeastern United States. ...

published the type description in 2010 along with the descriptions of four other species in the genus '' Zoosphaerium''. They coined the

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''darthvaderi'' after

, a character from the movie franchise ''

''. The name was attributed to the millipede's anal shield, which has a "pronounced bell shape" that the researchers considered to strongly resemble Vader's helmet in the films. ''Z. darthvaderi'' is of uncertain species-group placement within ''Zoosphaerium'', having

telopod Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derived from this feature. Each double-legged segment is a resu ...

s that include features seen in differing species groups. The frontal telopods are very similar to those in the ''neptunus'' species group, but the rear telopods are much closer in structure to the ''coquerelianum'' species group. This raises questions about the

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

of the described species groups and the need for more study of the genus. The species is considered an example of invertebrate

island gigantism Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general "i ...

Description

''Z. darthvaderi'' is a mostly smooth and small

pill millipede Pill millipedes are any members of two living (and one extinct) orders of millipedes, often grouped together into a single superorder, Oniscomorpha. The name Oniscomorpha refers to the millipedes' resemblance to certain woodlice (Oniscidea), also ...

with rear

tergites A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'mar ...

which are free from

setae In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. Th ...

. The

male is long and bears a wide by tall thoracic shield. The overall coloration of the body is of brown tones, although the color may have been altered somewhat during the preservation process in alcohol. Both the head and collum are a dark leafy green, while the antennae and legs are a lighter jade green. The legs are notably yellow-tipped. The body is a greenish brown, grading onto ochre along the edges of the tergites. Males also have a bell-shaped anal shield, with five or six teeth, that is a darker solid brown than the body. The collum is mostly smooth, with only scattered hairs along the edges. On the head, the eyes are composed of between 65 to 70

ocelli A simple eye (sometimes called a pigment pit) refers to a form of eye or an optical arrangement composed of a single lens and without an elaborate retina such as occurs in most vertebrates. In this sense "simple eye" is distinct from a multi-l ...

, and the antennae are six-segmented. Antennomeres 1 through 3 have hardened teeth along the sides while antennomere 6 has an apical disc hosting 20 sensory cones. Females of the species have not been found and described.

Threats

The species is restricted to the

, an area of

transitional forest Forest transition refers to a geographic theory describing a reversal or turnaround in land-use trends for a given territory from a period of net forest area loss (i.e., deforestation) to a period of net forest area gain. The term "landscape turn ...

in central Madagascar. ''Z. darthvaderi'' does not migrate, and is heavily threatened by rapid habitat loss through agriculture. Fragmented forest habitats, already endangered, are shrinking as a result of

slash-and-burn Slash-and-burn agriculture is a farming method that involves the cutting and burning of plants in a forest or woodland to create a field called a swidden. The method begins by cutting down the trees and woody plants in an area. The downed vegeta ...

agriculture and fire clearing for the creation of pasture land. The remaining forest fragments that are home to the millipede are separated by regions unfit for the species's adaptations, separating populations from one another. Consequently, the population of this millipede is likewise fragmented, and with no known individuals being bred in captivity the species's risk of extinction is extreme.

References

{{Taxonbar, from=Q81849356 Animals described in 2010 Endemic fauna of Madagascar Millipedes of Africa Arthropods of Madagascar