Biology:Mandibulata

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

Characteristics

Mandibulates are characterized by a head tagma that has antennae and three feeding appendages that make up the mandible, including the mandible pair proper, the maxillae, as well as the maxillules. One pair of antennae typically makes up the first head appendage. In some living mandibulates such as myriapods and insects, the first pair of antennae is the only one present, a situation also found in fossil mandibulate groups.

Taxonomy

The name "Mandibulata" was originally used for a subgroup of insects by Joseph Philippe de Clairville in 1798. 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. This proposal was contested by some other 20th century scholars, who considered mandibles the result of convergent evolution, though the monophyly of Mandibulata is now widely accepted based on genetic evidence.

Phylogeny

Some studies suggest that Artiopoda, the broader group that contains trilobites and their extinct relatives, is more closely related to Mandibulata than to Chelicerata, and that artiopods and mandibulates are united by their shared presence of antennae, which these authors propose was a shared common ancestral trait. Consequently, the proposed clade containing both Artiopoda and Mandibulata is named Antennulata. This grouping may also contain other extinct arthropod groups like Marrellomorpha.

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.

Some extinct groups have been placed in Mandibulata, including Hymenocarina, Euthycarcinoidea, and Fuxianhuiida.

Cladogram after Liu et al, 2026:

Panarthropoda

† "Lobopodia" 80 px 90 px 50 px (paraphyletic, ancestral to tardigrades, onychophorans and arthropods)   Total group Euarthropoda   †Megadictyon 80 px         †Kerygmachela 80 px       †Pambdelurion 80 px       †Opabiniidae 70 px       † Radiodonta (e.g Anomalocaris) 70 px   Deuteropoda   †Erratus 70 px       †Sunella 70px       †Isoxyidae 70px + "Great appendage bivalved forms" 70px         †Fengzhengia 80 px     †Kylinxia 70px         †Megacheira 80px     Pan-Chelicerata 70px 70px         †Kiisortoqia 70px     †Bushizheia 70px   Antennulata   †Artiopoda (including Trilobita) 70px   Mandibulata   †Fuxianhuiida 70px       †Hymenocarina 70px       Myriapoda 70px     Pancrustacea 70px 70px

 

Cladogram of Mandibulata after Laville et al. (2025):

Mandibulata

†Aquilonifer 70px       †Tanazios 70px         †Acheronauta 70px     †Captopodus           †Nereocaris 50px       †Fuxianhuiida 50px     †Hymenocarina 50px             †Euthycarcinida 50px     Myriapoda (including centipedes and millipedes) 50px     Pancrustacea Allotriocarida   Branchiopoda (tadpole shrimp/Triops, fairy shrimp, clam shrimp, water fleas) 50px       Hexapoda (including springtails and insects) 50px   Xenocarida   Cephalocarida (horseshoe shrimp) 50px     Remipedia 30px           Oligostraca   Branchiura (fish lice) 50px       Ostracoda 50px     Mystacocaridida 30px       Multicrustacea   Copepoda 50px       Cirripedia (barnacles) 50px       †Cyclida (Americlidae) 50px       †Thylacocephala 50px       Malacostraca (shrimp, prawn, lobsters, mantis shrimp, crab, woodlice, etc) 50px

See also

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

References

Wikidata ☰ Q1633496 entry