Dickinsonia is a genus of extinct organism, most likely an animal, that lived during the late Ediacaran period in what is now Australia, China, Russia, and Ukraine.

[2][11] The body is divided into two by a midline ridge or groove,[2][11][12] except for a single unpaired segment at one end, dubbed the "anterior most unit" suggested to represent the front of the organism.

[17] Dickinsonia is suggested to have been a mobile marine organism that lived on the seafloor and fed by consuming microbial mats growing on the seabed using structures present on its underside.

Dickinsonia-shaped trace fossils, presumed to represent feeding impressions, sometimes found in chains demonstrating this behaviour have been observed.

[13][19][20] A 2022 study suggested that Dickinsonia temporarily adhered itself to the seafloor by the use of mucus, which may have been an adaptation to living in very shallow water environments.

[21] The first species and specimens of this fossil organism were first discovered in the Ediacara Member of the Rawnsley Quartzite, Flinders Ranges in South Australia.

[28] As a rule, Dickinsonia fossils are preserved as negative impressions ("death masks") on the bases of sandstone beds.

Since 1947, a total of nine species have been described, of which three are currently considered valid:[39] A claimed specimen of Dickinsonia from India was later determined to be the remains of a beehive.

[14] Proarticulata includes a number of morphologically similar organisms, such Spriggina, Yorgia, Andiva and Cephalonega, which share the same segmented articulation.

[9] Within Animalia, a number of affinities have been proposed, including as stem-eumetazoans forming a clade with rangeomorphs,[52] to Placozoa,[53] and to Cnidaria.