Petalonam [1] ( lat. Petalonamae ) - a group of organisms of the Ediacar biota , which is usually given the rank of type, similar in shape and structure to modern sea feathers . They consisted of an organ of attachment of a pear-shaped or disk-shaped form, which turned into a leaf-shaped extension in the form of a feather, consisting of smaller feathers. Findings of two-, three- and four-lobed feathers are known. The organization of petalons combines radial-beam symmetry (central axis) and the symmetry of moving reflection characteristic of articules (feathers are arranged in alternating order) [2] .
| † Petalonamas | |||||||||||
 Charnia masoni | |||||||||||
| Scientific classification | |||||||||||
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| International scientific name | |||||||||||
Petalonamae Pflug , 1972 | |||||||||||
| Geochronology Ediacarius 635-541 Ma | |||||||||||
Petrified prints of petalones, similar to sea feathers and fern leaves, were first discovered in 1908 by German paleontologists in Precambrian sediments of Namibia (whence came the name of the group - Petalonames, “leaves from Namibia” proposed by G. Pflug). The found fingerprints were very different from previously known finds of the Cambrian fauna by the absence of mineralized skeletons and relatively large (up to several tens of centimeters) sizes. This difference made it possible to single out the finds into a special system, which was later called the Ediacar (Vendian) period [2] .
Petalamans were widespread in the Vendian seas. Fingerprints are rare, the usual find is a disk-shaped imprint of an attachment [2] . The most famous representatives of petalons: charnia , pteridinium , rangea , harniodisc , ventogirus , ernietta .
See also
- List of Ediacar clans
Notes
- ↑ Yeskov K. Yu . Dictionary of the names of living and fossil organisms // Amazing paleontology: the history of the Earth and life on it. - M .: ENAS, 2008 .-- 312 p. - ISBN 978-5-91921-129-7 .
- ↑ 1 2 3 Malakhovskaya Y. E., Ivantsov A. Yu. Vendian inhabitants of the Earth Archival copy of January 6, 2012 on the Wayback Machine . - Arkhangelsk: Publishing House of the Russian Academy of Sciences, 2003. - 48 p.