Marine benthic dinoflagellates are interesting not only because some epiphytic genera can cause harmful algal blooms but also for understanding dinoflagellate evolution and diversification. Our understanding of their biodiversity is far from complete, and many thecate genera have unusual tabulation patterns that are difficult to relate to the diverse known phytoplankton taxa. A new sand‐dwelling genus, Pachena gen. nov., is described based on morphological and DNA sequence data. Three species were discovered in distant locations and are circumscribed, namely, P. leibnizii sp. nov. from Canada, P. abriliae sp. nov. from Spain, and P. meriddae sp. nov. from Italy. All species are tiny (about 9–23 μm long) and heterotrophic. Species are characterized by their tabulation (APC 4′ 3a 6′′ 5c 5s 5′′′ 2′′′′), an apical hook covering the apical pore, an ascending cingulum, and a sulcus with central list. The first anterior intercalary plate is uniquely “sandwiched” between two plates. The species share these features and differ in the relative sizes and arrangements of their plates, especially on the epitheca. The ornamentation of thecal plates is species‐specific. The new molecular phylogenies based on SSU and LSU rDNA sequences contribute to understanding the evolution of the planktonic relatives of Pachena, the Thoracosphaeraceae.

中文翻译：

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一个新的海洋，居住在沙地龙鞭藻属，Pachena（Dinophyceae）的形态和分子系统发育，并描述了三个新种。

海洋底栖的鞭毛藻不仅很有趣，因为某些附生属会引起有害的藻华，而且对理解鞭藻的进化和多样性也很重要。我们对它们的生物多样性的了解还远远不够，许多主题属具有不同的制表模式，很难与各种已知的浮游植物分类群联系起来。一种新的沙生属Pachena gen。nov。，是基于形态学和DNA序列数据进行描述的。在远处发现了三个物种，并对其进行了限制，即P. leibnizii sp.。十一月 来自加拿大，P。abriliae sp.。十一月 来自西班牙和P. meriddaesp。十一月 来自意大利。所有种类都很微小（约9-23μm长）且具有异养性。物种的特征在于它们的列表（APC 4'3a 6''5c 5s 5'''2''''），覆盖根尖孔的根尖钩，上升的扣带和带有中央列表的沟。第一前inter骨板独特地“夹在”两个板之间。该物种具有这些特征，并且其板的相对大小和排列方式有所不同，尤其是在上皮细胞上。垫板的装饰是特定于物种的。基于SSU和LSU rDNA序列的新分子系统学有助于理解Pachena的球形浮游近缘植物的进化。