| 翻訳と辞書 |
| Phylloceratidae ： ウィキペディア英語版 |
Phylloceratidae
Phylloceratidae is the predominant family of the Phylloceratina with some 15 or more genera found in rocks ranging from the Lower Jurassic to the Upper Cretaceous. Members of the Phylloceratidae are characterized by smooth, involute shells with very thin walls. Many are covered with fine growth lines but are usually without ribbing. Sutures are complex with the major and minor branches of the saddles with phylloid or spatulate endings.〔Treatise on Invertebrate Paleontology Part L Mollusca 4, Ammonoidea, 1957〕
==Evolution and phylogeny==
The Phylloceratidae are probably derived from the Late Triassic Discophyllitidae by increasing the sutural complexity and evolving involute coiling. The Discophyllitidae in tern have their origin in the Ussuritidae, also known as the Monophyllitidae.〔
The Phylloceratidae gave rise at or near the beginning of the Jurassic to the ancestral Lytoceratina, the early Lower Jurassic Peluroacanthitidae and Ectocentridae. The Phyloceratidae also gave rise at or near the beginning of the Jurassic to the Psilocerataceae which unites families of the Early Jurassic Ammonitina. Other Jurassic Ammonitina are derived from the Lytoceratina. Later, phylloceratids are said to have given rise to Cretaceous Ammonitina included in the Desmocerataceae, Hoplitaceae, and Acanthocerataceae.〔
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「Phylloceratidae」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.
|
|