THE PRESENCE OF A NEOTROPICAL FAMILY (MALPIGHIACEAE) IN THE FAR SOUTH OF SOUTH AMERICA DURING THE EOCENE
THE PRESENCE OF A NEOTROPICAL FAMILY (MALPIGHIACEAE) IN THE FAR SOUTH OF SOUTH AMERICA DURING THE EOCENE
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DOI：
10.4072/rbp.2012.3.13
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发表时间：
2012-09-01
影响因子：
0.7
通讯作者：
Barreda, Viviana D.
中科院分区：
文献类型：
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作者：
Fernandez, Damian A.;Panti, Carolina;Barreda, Viviana D.
本文介绍了在圣克鲁斯省西南部的里奥图比奥组中发现的木兰科植物的花粉粒和叶印记，表明这个新热带家族的存在于始新世之前的南美洲最南端。Perisyncolporites pokornyi Germeraad，Hopping&Muller，直立用于对化石花粉进行分组，类似于马鞭草科，包括各种各样的花粉形式，具有复杂的气孔分布，与六边形的侧面或多或少一致。现存的与里奥图比奥组化石形式关系最密切的支系(四翅目和剑角类)今天分布在南美洲的热带和亚热带地区，一直延伸到南纬35度。唯一现存的物种分布在离研究地区更近的地方，而这反过来又代表着世界上最南端的渗透性家族(加拉多亚科，达到42岁的S)，在形态上与所研究的化石无关。叶面印记类似于以前在里约内格罗省里奥皮奇勒夫地区(Mascagnia sepiumoides Berry，TetRapteris precrebrifolia Berry)以及里约图比奥组(TetRapteris Precrebrifolia Berry)中发现的。目前的结果支持了早先的假设，即新热带血统在始新世期间主要渗透到最南纬地区，并可能经由南极洲迁移到澳大利亚，至少是那些与近沟孔虫相关的形式。
Presented here is the discovery of pollen grains and a foliar impression assigned to Malpighiaceae from the Rio Turbio Formation, SW Santa Cruz Province, indicating the presence of this Neotropical family in the southernmost tip of South America by the Eocene. Perisyncolporites pokornyi Germeraad, Hopping & Muller, erected to group fossil pollen similar to Malpighiaceae, includes a wide variety of pollen-forms with a complex aperture distribution, more or less concordant with the sides of a hexagon. The extant clades most closely related to the fossil forms of the Rio Turbio Formation (Tetrapteroids and Stigmaphylloids) are today distributed in tropical and subtropical regions of South America, reaching up to the 35 S. The only extant species distributed closer to the studied area, and that, in turn, represents the world's southernmost penetration of the family (Gallardoa fischeri Hicken, reaching the 42 S), is morphologically unrelated to the studied fossils. The foliar impression is similar to those recognized previously in the Rio Pichileufu locality, Rio Negro Province (Mascagnia sepiumoides Berry, Tetrapteris precrebrifolia Berry), and also in the Rio Turbio Formation (Tetrapteris precrebrifolia Berry). The present results support earlier hypotheses that suggest a major penetration of Neotropical lineages into the southernmost latitudes during the Eocene as well as a possible migration to Australia via Antarctica, at least of those perisyncolporate-related forms.