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Typically, each body segment carries one pair of appendages. An appendage which is modified to assist in feeding is known as a maxilliped or gnathopod. [citation needed] In annelids lateral protrusions from the body are called parapodia. In echinoderms an appendage called a pedicellaria is found. The end of the pedicellaria consists of valves ...
In the process of evolution, single-celled organisms have developed in a variety of directions, and thus their rich morphology results in a large spectrum of swimming modes. [8] [2] Many swimming protists actuate tail-like appendages called flagella or cilia in order to generate the required thrust. [9]
The head contained the brain and carried sensory and feeding appendages. The trunk bore the appendages responsible for locomotion and respiration (gills in aquatic species). In almost all modern arthropods, the trunk is further divided into a "thorax" and an "abdomen", with the thorax bearing the main locomotory appendages.
A pilus (Latin for 'hair') is a hair-like appendage found on the surface of many bacteria and archaea. [37] The terms pilus and fimbria (Latin for 'fringe') can be used interchangeably, although some researchers reserve the term pilus for the appendage required for bacterial conjugation. Dozens of these structures can exist on the bacterial and ...
The abdominal appendages of modern chelicerates are missing or heavily modified [12] – for example in spiders the remaining appendages form spinnerets that extrude silk, [16] while those of horseshoe crabs (Xiphosura) form gills. [17] [10]
Examples include the maggots of flies or grubs of weevils. In contrast, the larvae of other Coleoptera , such as the Scarabaeidae and Dytiscidae have thoracic legs, but no prolegs. Some insects that exhibit hypermetamorphosis begin their metamorphosis as planidia , specialised, active, legged larvae, but they end their larval stage as legless ...
An iconic example is the Devonian Rhyniognatha hirsti, dated at , its mandibles are thought to be a type found only in winged insects, which suggests that the earliest insects appeared in the Silurian period. [110] However later study shows that Rhyniognatha most likely represent a myriapod, not even a hexapod. [111]
A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word flagellate also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their means of motion. The term presently does not imply any specific relationship or classification of the ...