NEW METHODS REVEAL OLDEST KNOWN FOSSIL EPIPHYLLOUS MOSS: BRYIIDITES UTAHENSIS GEN. ET SP NOV (BRYIDAE)
NEW METHODS REVEAL OLDEST KNOWN FOSSIL EPIPHYLLOUS MOSS: BRYIIDITES UTAHENSIS GEN. ET SP NOV (BRYIDAE)
复制标题
DOI：
10.3732/ajb.1300209
复制
发表时间：
2013-12-01
影响因子：
3
通讯作者：
Sageman, Bradley B.
中科院分区：
文献类型：
--
作者：
Barclay, Richard S.;McElwain, Jennifer C.;Sageman, Bradley B.
研究前提：叶生苔藓植物是许多湿润热带森林生态系统的一个高度特征。与寄主植物叶片的大量化石记录相比，叶生藓本身几乎不存在化石记录，尽管对苔藓的化石记录始于3.3亿年前的中石炭世。方法：利用荧光光学显微镜、扫描电子显微镜和原子力显微镜研究了新发现的叶生苔藓与白垩纪中期樟科植物宿主之间的密切联系。主要结果：我们描述了最古老的叶生苔藓化石标本，Bryi idites utahensis gen。ET sp.Nov.，从仅450亩长的个体标本中鉴定，位于大约1毫米见方的化石叶片碎片上。苔藓叶柄保存完好，为萌发孢子和短细胞原丝体，横向和斜面横壁与叶寄主表面现存的叶生苔藓十分吻合。结论：叶面记录可追溯到白垩纪中期，为9500万年前开花植物多样化过程中叶生苔藓的出现提供了化石证据。它还为白垩纪中期北美中部的热带海洋性气候提供了实质性证据。
Premise of the study: Epiphyllous bryophytes are a highly characteristic feature of many humid tropical forest ecosystems. In contrast to the extensive fossil record for the leaves of their host plants, the record is virtually nonexistent for the epiphylls themselves, despite a fossil record for mosses that begins in the Middle Carboniferous Period, 330 million years ago.Methods: Epifluorescence optical microscopy, scanning electron microscopy, and atomic force microscopy were employed to investigate an intimate association between a newly discovered epiphyllous moss and a Lauraceae plant host from the middle Cretaceous.Key results: We describe the oldest fossil specimen of an epiphyllous moss, Bryiidites utahensis gen. et sp. nov., identified from an individual specimen only 450 mu m long, situated on an approximately one millimeter square fossil leaf fragment. The moss epiphyll is exquisitely preserved as germinating spores and short-celled protonemata with transverse and oblique cross-walls closely matching those of extant epiphyllous mosses on the surface of the plant-leaf hosts.Conclusions: The extension of the epiphyll record back to the middle Cretaceous provides fossil evidence for the appearance of epiphyllous mosses during the diversification of flowering plants, at least 95 million years ago. It also provides substantive evidence for a tropical maritime climate in central North America during the middle Cretaceous.