| 翻訳と辞書 |
Treptichnus pedum
''Treptichnus pedum'' (formerly ''Phycodes pedum'', ''Manykodes pedum'' by J. Dzik, or most of the time named ''Trichophycus pedum'') is regarded as the earliest widespread complex trace fossil. Its earliest appearance, which was contemporaneous with the last of the Ediacaran biota, is used to define the dividing line between the Ediacaran and Cambrian Periods.〔(Subcommission on Neoproterozoic Stratigraphy ) - URL retrieved June 22, 2009〕〔International Commission on Stratigraphy, International Chronostratigraphic Chart, 2012, http://www.stratigraphy.org/column.php?id=Chart/Time%20Scale〕
''Treptichnus pedum'' has a fairly complicated and distinctive burrow pattern: along a central, sometimes sinuous or looping burrow it made successive probes upward through the sediment in search of nutrients, generating a trace pattern reminiscent of a fan or twisted rope. The organism that left such traces is considered more complex than earlier Ediacaran fauna; and these trace fossils, which occur worldwide, are usually found in strata above those.〔(【引用サイトリンク】 Life in the Cambrian )〕
Since only its burrows have been found, it is presumed that the ''Treptichnus'' animal lacked any hard anatomical features, such as shells or bones. Its morphology and relationship to modern animals is therefore unknown, and some dispute even its inclusion within the animal kingdom. Despite this lack of fossil evidence, surface trails produced by modern priapulid worms exhibit the same probing morphology as ''Treptichnus'', suggesting a close anatomical relationship between the trace-maker and modern priapulids.
The name ''Treptichnus pedum'' means "turned-trail (Greek) of feet (Latin)".
==References==
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Treptichnus pedum」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|