Cones, seeds, and foliage of Tetraclinis salicornioides (Cupressaceae) from the Oligocene and Miocene of western North America:: A geographic extension of the European Tertiary species
Cones, seeds, and foliage of Tetraclinis salicornioides (Cupressaceae) from the Oligocene and Miocene of western North America:: A geographic extension of the European Tertiary species
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DOI：
10.1086/314245
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发表时间：
2000-03-01
影响因子：
2.3
通讯作者：
Schorn, HE
中科院分区：
文献类型：
--
作者：
Kvacek, Z;Manchester, SR;Schorn, HE
在北美西部的渐新世和中新世，根据同时出现的球果、种子和叶枝，确定了柏科的Tetraclinis属。与两个先前公认的欧洲第三纪物种的形态和解剖学比较表明，北美标本在形态上与Tetraclinis salicornioides（Unger）Kvacek不可分割。北美分类群被视为一个新变种，T。柳角蕨praedecurrens（诺尔顿）comb，et stat.十一月，与欧洲代表T.柳角蕨salicornioides，通过轻微的解剖学差异在叶表皮。虽然化石物种的球果和种子与现存的Tetraclinis articulata非常相似，但叶子更“伸展”，由扁平的片段组成，具有融合的面部和侧叶，显然适应于更温和的气候。T.在北美西部发现的salicornioides（沿着），以及在东亚的化石和现代植物群中没有发现Tetraclinis，为该物种在第三纪早期或中期跨越北大西洋的交流提供了证据。
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) Kvacek. The North American taxon is treated as a new variety, T. salicornioides (Unger) Kvacek var. praedecurrens (Knowlton) comb, et stat. nov., and is distinguished from the European representatives, T. salicornioides (Unger) Kvacek 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.