''Sinocallipus '' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of predominantly cave-dwelling millipedes in the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Callipodida. Five of the six known species are found in limestone caves on the

Indochinese Peninsula Mainland Southeast Asia, also known as the Indochinese Peninsula or Indochina, is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to the west an ...

from Vietnam to southern China, and it is the only callipodidan genus entirely confined to the

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

. Individuals range from long and possess 55 to 70 segments. ''Sinocallipus'' is the sole taxon of the callipodidan suborder Sinocallipodidea, and thought to be the most primitive and

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to all other callipodidans. In contrast to many other millipede groups, the gonopods (reproductive legs) of ''Sinocallipus'' show little variation between species, while other characters such as color, size, and other body parts differ more noticeably between species.

Species

All species except ''S. thai'' have been collected solely from caves, and show

troglomorphic Troglomorphism is the morphological adaptation of an animal to living in the constant darkness of caves, characterised by features such as loss of pigment, reduced eyesight or blindness, and frequently with attenuated bodies and/or appendages. The ...

(cave-adapted) traits such as pale coloration, long antennae, and long legs. ''S. jaegeri'' and ''S. simplipodicus'' show reduced eyes, consisting of only 10 to 16 colorless ocelli each, while the other species have 33 to 50 black ocelli. ''S. thai'' is unique for its dark coloration and terrestrial habitat, and correspondingly has the most ocelli and shortest antennae.

References

Millipede genera Cave millipedes Millipedes of Asia Callipodida {{myriapoda-stub

Species

See also

References