''Xandarella'' is an extinct genus of xandarellid

artiopoda The Artiopoda is a grouping of extinct arthropods that includes trilobites and their close relatives. It was erected by Hou and Bergström in 1997 to encompass a wide diversity of arthropods that would traditionally have been assigned to the Trilo ...

n known from the

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

of China and Morocco, the type species ''Xandarella spectaculum'' was described in 1991 from the

Cambrian Stage 3 Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 and precedes Cambrian Stage 4, although neither its base nor top have been formally defined. The plan is for its lower boundary to correspond approxi ...

aged Chengjiang Biota in China. An additional species ''Xandarella mauretanica'' was described from the

Cambrian Stage 5 The Wuliuan stage is the fifth stage of the Cambrian, and the first stage of the Miaolingian Series of the Cambrian. It was formally defined by the ICS in 2018. Its base is defined by the first appearance of the trilobite species ''Oryctocephal ...

Tatelt Formation in Morocco in 2017, which preserved only the

ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

anatomy. Like other Xandarellids, the exoskeleton is unmineralised. The cephalon has pronounced eye slits, presumably derived from ancestral ventral stalked eyes.

References

Fossil taxa described in 1991 Artiopoda {{paleo-arthropod-stub