Rhipidopsis in the upper Permian of the Dead Sea region, Jordan – Another clade of Mesozoic gymnosperms in the Permian?

近年来，死海地区(约旦)的上二叠统产生了丰富多样的植物群。这一植物群具有特殊的意义，因为：(1)它是为数不多的丰富多样的晚二叠世植物群之一，(2)它保存完好，具有出色的角质层，能够进行全植物重建，(3)它由来自不同植物区系省份(即欧亚、华夏和冈瓦那)的成分混合而成，以及(4)迄今仅从中生代已知的主要植物分支的早熟产状。需要资金用于在乌姆伊尔纳组两个新发现的、几乎未被开发的地区进行实地考察和研究这一材料。Rhiidopsis叶在这些地区特别常见，并发现与一种迄今未知的特殊类型的果实密切相关。Rhiidopsis通常被认为是早期的银杏。然而，第一次筛选表明，气孔与银杏的气孔非常不同，相关的果实看起来非常像卡伊托尼亚。Caytoniales是中生代的一小群种子蕨类植物，通常被认为是开花植物的祖先。这个小项目的目的是收集新的材料，以验证Rhiidopsis具有Caytonialean亲缘关系的假设。

In recent years, the upper Permian of the Dead Sea region (Jordan) has yielded a rich and varied flora. This flora is of special interest because: (1) it is one of the very few rich and diverse late Permian floras, (2) of its superb preservation with excellent cuticles which enable whole-plant reconstructions, (3) it consists of a mixture of elements from different floral provinces, i.e. Euramerica, Cathaysia and Gondwana, and (4) of the precocious occurrences of major plant clades so far only known from the Mesozoic. Funds are requested for fieldwork in two newly discovered, hardly exploited localities in the Umm Irna Formation and for studying this material. Rhipidopsis foliage is particularly common in these localities and found in close association with a peculiar type of fructification that is so far unknown. Rhipidopsis is commonly regarded as an early ginkgophyte. However, a first screening shows that the stomata are very different from those of ginkgophytes and that the associated fructification looks very Caytonia-like. The Caytoniales are a small Mesozoic group of seed-ferns that is often regarded as ancestral to the flowering plants. The aim of this small project is to collect new material in order to test the hypothesis that Rhipidopsis is of caytonialean affinity.