Mecistocephalidae are a

monophyletic 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 gro ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

centipede Centipedes (from New Latin , "hundred", and Latin , " foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, an ...

s in the order

Geophilomorpha The centipedes or Chilopoda are divided into the following orders. Scutigeromorpha The Scutigeromorpha are anamorphic, reaching 15 leg-bearing segments in length. Also known as house centipedes, they are very fast creatures, and able to withstan ...

. It is the only family in the

suborder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

Placodesmata. Most species in this family live in tropical or subtropical regions, but some occur in temperate regions. This family is the third most diverse in the order Geophiliomorpha (after Geophilidae and

Schendylidae Schendylidae is a paraphyletic (with respect to Ballophilidae) family of soil centipedes in the order Geophilomorpha and superfamily Himantarioidea. There are at least 47 genera and 310 described species in Schendylidae. Compared to most ...

), with about 170 species, including about 130 species in the genus ''Mecistocephalus''. This family differs from all other geophilomorphs insofar as the number of segments in mecistocephalids is generally fixed within each species and the same for each sex. The family includes centipedes with odd numbers of leg-bearing segments ranging from as few as 41 to as many as 101. A majority of the species in the genus ''Mecistocephalus'' have 49 pairs of legs, a majority so large that most species in the family Mecistocephalidae have 49 leg pairs, even though only one mecistocephalid species (''Proterotaiwanella sculptulata'') outside the genus ''Mecistocephalus'' shares this number. The next most common numbers are 45 leg pairs, found in most species in the genus '' Tygarrup'' as well as in species distributed among five other genera, and 41 leg pairs, found in all species in the genera '' Agnostrup'', '' Anarrup'', ''

Arrup ''Arrup'' is a genus of centipede Centipedes (from New Latin , "hundred", and Latin , " foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcip ...

'', ''

Nannarrup ''Nannarrup hoffmani'', commonly known as Hoffman's dwarf centipede, is a species of centipede that was discovered in New York City's Central Park in 2002. It is 10 mm long, and has 82 legs. Researchers think that the species originated in ...

'', and ''Partygarrupius'' as well as in the species ''Dicellophilus anomalus'' and ''D. pulcher''; fewer mecistocephalid species have 47 leg pairs (e.g., ''Mecistocephalus angusticeps'' and ''M. tahitiensis'') or 51 leg pairs (e.g., ''M. sechellarum'' and ''M. lifuensis''), found only in the genus ''Mecistocephalus'', and the other remaining numbers are even more rare (e.g., 43 leg pairs, found in ''Dicellophilus carniolensis''). Variation in the number of leg-bearing segments within each sex and within species has been recorded among the mecistocephalid species with the greatest number of legs: ''Mecistocephalus diversisternus'', which has 57 or 59 leg pairs, ''M. japonicus'', which has 63 or 65 leg pairs, and ''M. microporus'', which has odd numbers of leg pairs ranging from 93 to 101. The mecistocephalid species ''Krateraspis sselivanovi'' has 53 leg pairs without intraspecific variation, which appears to be the maximum number thought to be fixed by species in the class

Chilopoda Centipedes (from New Latin , "hundred", and Latin , " foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, an ...

Genera

The family contains the following genera: *'' Agnostrup'' *'' Anarrup'' *''

'' *'' Dicellophilus'' *'' Krateraspis'' *'' Mecistocephalus'' *''

'' *'' Partygarrupius'' *'' Proterotaiwanella'' *'' Takashimaia'' *'' Tygarrup''

Description

Species of the suborder Placodesmata are characterized by an elongated head with lateral margins converging backwards; first maxillae with relatively elongate coxosternite, and coxal projections much wider than telopodites, both ending with a distinctly hyaline part; second maxillae with small simple claws; elongate forcipular coxosternite with pleurites projecting anteriorly into scapular points and displaced dorsally so that the coxopleural sutures run anteriorly on the dorsal side; metatergites of the posterior part of the trunk distinctly longer than those on the anterior part.

References

Centipede families Geophilomorpha {{Myriapoda-stub