Descriptions of three new diatom species in the genus Eunotia (Eunotiaceae, Bacillariophyta) from the Eocene Arctic
Descriptions of three new diatom species in the genus Eunotia (Eunotiaceae, Bacillariophyta) from the Eocene Arctic
复制标题
来自始新世北极的 Eunotia 属（Eunotiaceae，Bacillariophyta）中的三种新硅藻物种的描述
DOI：
10.11646/phytotaxa.567.1.2
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发表时间：
2022
期刊：
影响因子：
1.1
通讯作者：
LOTT, ANNE M.
中科院分区：
文献类型：
--
作者：
SIVER, PETER A.;ODDSUND, ERIK;LOTT, ANNE M.
Eunotia是Eunotiaceae家族中最大和最多样化的属，是一种主要的淡水硅藻群，通常在稀，酸性和腐殖土污染的环境中发现。该属物种的特征是沿沿着其顶轴不对称，关于经顶轴对称，并且具有简单且减少的缝系统，其大部分位于外套膜上并限于瓣膜的顶端。此外，Eunotia taxa每个裂孔有一个或多个裂孔，通常靠近顶端。由于其减少的中缝系统，再加上rimoportulae的存在，Eunotia及其亲属通常被视为最古老的中缝硅藻谱系。迄今为止，最古老的Eunotia物种的遗骸已被报道从早到中始新世，包括长颈鹿管道地点，一个古老的始新世化石遗址位于加拿大北部靠近北极圈的北方。从这个网站的岩石包含一个大的和不同的组合Eunotia类群。本研究的目的是开始描述这一组合的三个新种，长颈鹿Eunotia giraffensis sp. nov.，E. petasum sp. nov.和E.新物种，代表在长颈鹿管地方发现的最长的标本，每个具有共同的特征Eunotia使他们很容易分配到本属。由于Eunotia谱系在始新世早期就已确立，因此它可能要古老得多。
Eunotia is the largest and most diverse genus within the family Eunotiaceae, a primarily freshwater group of diatoms often found in dilute, acidic and humic-stained environments. Species in this genus are characterized by being asymmetric along their apical axis, symmetric about the transapical axis, and with a simple and reduced raphe system situated largely on the mantle and restricted to the apical ends of the valve. In addition, Eunotia taxa have one or more rimoportula per valve, usually close to the apex. Because of their reduced raphe system, coupled with the presence of rimoportulae, Eunotia and its relatives are often viewed as the oldest lineage of raphe-bearing diatoms. To date, the oldest remains of Eunotia species have been reported from the early to middle Eocene, including from the Giraffe Pipe locality, an ancient Eocene fossil site located in northern Canada near the Arctic Circle. Rocks from this site contain a large and diverse assemblage of Eunotia taxa. The purpose of this study is to begin to characterize this assemblage with descriptions of three new species, Eunotia giraffensis sp. nov., E. petasum sp. nov. and E. pseudonaegelii sp. nov. The new species, representing the longest specimens found at the Giraffe Pipe locality, each possess characteristics common to Eunotia making them easily assigned to this genus. Because the Eunotia lineage was well established by the early part of the Eocene, it is likely to be significantly older.