Mandibulata

The clade Mandibulata constitutes one of the major subdivisions of the phylum Arthropoda, alongside Chelicerata. Mandibulates include the crustaceans, myriapods (centipedes and millipedes, among others), and all true insects. The name "Mandibulata" refers to the mandibles, a modified pair of limbs used in food processing, the presence of which are characteristic of most members of the group.

Mandibulata Temporal range: Cambrian Stage 3–Recent PreꞒ Ꞓ O S D C P T J K Pg N
The mandibles of a bull ant
Life restoration of Odaraia, an early mandibulate belonging to Hymenocarina with mandibles present near the mouth
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Clade:	Mandibulata de Clairville, 1798
Subdivisions
†Hymenocarina †Euthycarcinoidea Myriapoda †Marrellomorpha? Pancrustacea (including hexapods) †Phosphatocopina? incertae sedis †Acheronauta? †Aquilonifer †Bradoriida? †Cambropachycopidae? †Cambropodus? †Captopodus? †Cascolus? †Fuxianhuiida †Martinssonia? †Rhyniognatha? †Skaracarida? †Tanazios? †Thylacocephala? †Oelandocarididae? †Musacaris?

The mandibulates are divided between the extant groups Myriapoda (millipedes and centipedes, among others) and Pancrustacea (including crustaceans and hexapods, the latter group containing insects). Molecular phylogenetic studies suggest that the living arthropods are related as shown in the cladogram below. Crustaceans do not form a monophyletic group as insects and other hexapods have evolved from within them.^[1][2][3]

A number of extinct groups have also been placed in Mandibulata, including Hymenocarina,^[4] Euthycarcinoidea,^[5] and possibly Fuxianhuiida.^[6]

Cladogram after O’Flynn et al, 2023:^[7]

Total group Arthropoda

"Gilled lobopodians" (Pambdelurion, Kerygmachela) Opabinia Radiodonta (e.g Anomalocaris) Deuteropoda Kylinxia Fengzhengia Kiisortoqia Bushizheia Total group Chelicerata Megacheira Habeliida Mollisonia Chelicerata (horseshoe crabs, sea spiders, arachnids, etc) "Great appendage bivalved forms" (Occacaris, Forfexicaris) Isoxyida Artiopoda (including Trilobita) Mandibulata Fuxianhuiida Myriapoda (millipedes, centipedes, etc) Hymenocarina Pancrustacea (crustaceans, insects, etc)

Taxonomic history

The name "Mandibulata" was originally used for a subgroup of insects by Joseph Philippe de Clairville in 1798.^[8] In the 1930s, Robert Evans Snodgrass used the name to encompass myriapods, hexapods and crustaceans, which he considered to be united by a number of morphological similarities, including but not limited to the presence of mandibles.^[9] This proposal was contested by some other 20th century scholars, who considered mandibles the result of convergent evolution,^[10] though the existence of Mandibulata is now widely accepted based on genetic evidence.^[11]

See also

• Atelocerata
• Marrellomorpha
• Myriochelata
• Pancrustacea
• Crustaceomorpha
• Antennulata
• Arachnomorpha
• Uniramia