The cupressaceous genus Tetraclinis is recognized from the Oligocene and Miocene of western North America on the basis of co‐occurring seed cones, seeds, and foliage branches. Morphological and anatomical comparisons with the two previously recognized European Tertiary species indicate that the North American specimens are morphologically inseparable from Tetraclinis salicornioides (Unger) Kvaček. The North American taxon is treated as a new variety, T. salicornioides (Unger) Kvaček var. praedecurrens (Knowlton) comb. et stat. nov., and is distinguished from the European representatives, T. salicornioides (Unger) Kvaček var. salicornioides, by slight anatomical differences in the leaf epidermis. Although cones and seeds of the fossil species are closely similar to those of extant Tetraclinis articulata, the foliage is more “spreading,” composed of flattened segments with fused facial and lateral leaves that are apparently adaptive for a more mesic climate. The recognition of T. salicornioides in western North America along with the absence of Tetraclinis in the fossil and recent flora of eastern Asia provide evidence for communication of the species across the North Atlantic during the early or middle Tertiary.

中文翻译：

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来自北美西部渐新世和中新世的 Tetraclinis Salicornioides（柏科）的球果、种子和叶子：欧洲第三纪物种的地理延伸

根据共生的球果、种子和枝叶，从北美洲西部的渐新世和中新世确认了柏科属 Tetraclinis。与两个先前公认的欧洲第三纪物种的形态学和解剖学比较表明，北美标本在形态学上与 Tetraclinis salicornioides (Unger) Kvaček 密不可分。北美分类群被视为一个新品种，T. salicornioides (Unger) Kvaček var。praedecurrens (Knowlton) 梳子。等统计 11 月，并区别于欧洲代表 T. salicornioides (Unger) Kvaček var。salicornioides，通过叶表皮的细微解剖差异。尽管化石物种的锥体和种子与现存的 Tetraclinis articulata 的锥体和种子非常相似，但叶子更“散布，”由扁平段组成，融合了面部和侧叶，显然适应更温和的气候。在北美西部发现 T. salicornioides 以及在东亚的化石和近期植物群中没有 Tetraclinis，为该物种在第三纪早期或中期跨越北大西洋进行交流提供了证据。