Eoandromeda and the origin of Ctenophora.

• The Ediacaran fossil Eoandromeda octobrachiata had a high conical body with eight arms in helicospiral arrangement along the flanks. The arms carried transverse bands proposed to be homologous to ctenophore ctenes (comb plates). Eoandromeda is interpreted as an early stem-group ctenophore, characterized by the synapomorphies ctenes, comb rows, and octoradial symmetry but lacking crown-group synapomorphies such as tentacles, statoliths, polar fields, and biradial symmetry. It probably had a pelagic mode of life. The early appearance in the fossil record of octoradial ctenophores is most consistent with the Planulozoa hypothesis (Ctenophora is the sister group of Cnidaria + Bilateria) of metazoan phylogeny.

Ämnesord

NATURVETENSKAP  -- Biologi -- Zoologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Zoology (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geology (hsv//eng)

Nyckelord

Problematicum

Ctenophora

Development

Ediacaran

China

Ecosystems and species history

Ekosystem och arthistoria

Ecosystems and species history

Ekosystem och arthistoria

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)