Sprigginidae is an extinct family of
cephalozoa
Cephalozoa are an extinct class of primitive segmented marine organisms within the Phylum Proarticulata from the Ediacaran period. They possessed bilateral symmetry and were characterized by a thin, rounded body.
Description
Unlike the other cl ...
ns characterized by having a greater number of
isomers
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers.
Iso ...
than its sister taxon,
Yorgiidae
Yorgiidae is an extinct family of cephalozoans, which lived 635 million years ago. They were filter fed.
Description
Like most proarticulates, they present semi-bilateral symmetry. They had a discoid appearance, with the body segmented by isome ...
. They lived approximately 635 million years ago, in the
Ediacaran period
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...
.
Distribution
Fossils are found within the
Ediacaran
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and th ...
sediments of
South Australia
South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...
.
Taxonomy
Sprigginidae presents 4 genera:
*†''
Spriggina
''Spriggina'' is a genus of early bilaterian animals whose relationship to living animals is unclear. Fossils of ''Spriggina'' are known from the late Ediacaran period in what is now South Australia. ''Spriggina floundersi'' is the official fossi ...
''
*†''
Marywadea
''Marywadea'' is a genus of Ediacaran biota shaped like an oval with a central ridge. It is a bilaterian organism as evidenced by its symmetry, vaguely resembling a very primitive trilobite. The fossil has an asymmetrical first chamber of the qui ...
''
*†''
Cyanorus
''Cyanorus singularis'' is a small proarticulatan, closely related to ''Spriggina'' and '' Marywadea''. Its two largest pairs of appendages are located on the anterior part of the body. The anterior part of the body was most likely not segmented. ...
''
*†''
Praecambridium
''Praecambridium sigillum'' is an extinct organism that superficially resembles a segmented trilobite-like arthropod. It was originally described as being a trilobite-like arthropod, though the majority of experts now place it within the Proartic ...
'',
sometimes included into Yorgiidae
Yorgiidae is an extinct family of cephalozoans, which lived 635 million years ago. They were filter fed.
Description
Like most proarticulates, they present semi-bilateral symmetry. They had a discoid appearance, with the body segmented by isome ...
.
Gallery
Spriggina_flounensi_C.jpg , ''Spriggina floundersi''
Cyanorus_singularis.jpg , ''Cyanorus singularis''
Praecambridium_sigillum.jpg , ''Praecambridium sigillum''
See also
*
Cephalozoa
Cephalozoa are an extinct class of primitive segmented marine organisms within the Phylum Proarticulata from the Ediacaran period. They possessed bilateral symmetry and were characterized by a thin, rounded body.
Description
Unlike the other cl ...
*
Yorgiidae
Yorgiidae is an extinct family of cephalozoans, which lived 635 million years ago. They were filter fed.
Description
Like most proarticulates, they present semi-bilateral symmetry. They had a discoid appearance, with the body segmented by isome ...
References
Ediacaran life
{{Ediacaran-stub