Lõualuipurusteid

Lõualuipurusteid, known scientifically as Mandibulata, is a major subphylum of arthropods that includes insects, arachnids, and myriapods. The defining characteristic of this group is the presence of mandibles, which are paired, jaw-like appendages used for grasping, tearing, or chewing food. These mandibles are derived from the first pair of pre-oral appendages and are a key evolutionary innovation that allowed for a diverse range of feeding strategies.

Mandibulata is one of the two major clades within Arthropoda, the other being the Chelicerata, which includes spiders, scorpions, and horseshoe crabs. Chelicerates possess chelicerae instead of mandibles. The evolutionary relationship between Mandibulata and Chelicerata is a fundamental topic in arthropod phylogeny.

Within Mandibulata, there are three extant classes. The Insecta, or insects, are characterized by a body divided into three distinct segments: head, thorax, and abdomen, and typically possess three pairs of legs attached to the thorax. The Myriapoda, including centipedes and millipedes, have elongated bodies with numerous segments, each bearing one or two pairs of legs. The Arachnida, or arachnids, such as spiders, scorpions, ticks, and mites, have a body divided into two main parts, the cephalothorax and abdomen, and usually possess four pairs of legs.

The evolution of mandibles in Mandibulata played a crucial role in their ecological success, enabling them to exploit a wide variety of food sources and inhabit diverse environments. This innovation is considered a significant factor in the vast species diversity observed within this subphylum.