The wetzelielloid dinocyst genera Wetzeliella and Apectodinium are crucial for dating and correlation of Lower Eocene Sparnacian facies in NW Europe. Previous ill-documented reports of Wetzeliella in one of these facies, the Epernay Formation, Paris Basin, are corroborated by a study of new samples. The findings support current age-interpretations of the Epernay Formation as early-mid Ypresian.

Apectodinium was a thermophilic genus, but it may have been more sensitive to other ecologic conditions than warmth. Three examples show that even extreme acmes of Apectodinium developed locally in lagoonal/coastal environments at times when no warming took place and when Apectodinium was absent or rare in adjacent, offshore areas. The best known Apectodinium acme, the quasi-global acme developed within the Paleocene-Eocene Thermal Maximum (PETM), may not be directly attributable to the increased warmth, but caused by a secondary climatic effect, elevated nutrients in the neritic waters.

Wetzeliella和Apectodinium湿zel角藻类囊藻属对于欧洲西北部下始新世Sparnacian相的年代和相关性至关重要。对新样品的研究证实了以前在这些相之一的埃兹佩尼组（Wespereellaella）在巴黎盆地埃佩尔内组中的不良文献报道。这些发现支持了埃佩尔奈组的当前年龄解释，即伊普尔早中期。

pect是嗜热属，但它对其他生态条件的敏感性可能比对温度更高。三个例子证明的，即使是极端Acme的Apectodinium在泻湖/沿海环境有时本地开发时没有变暖发生，当Apectodinium在相邻，近海地区不存在或罕见。在古新世-始新世热最大值（PETM）内发展起来的最著名的pect地球突可能不是全球变暖的直接原因，而是由次生气候效应引起的。