Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing, China.
School of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing, China.
Elife. 2024 Oct 8;13:RP92962. doi: 10.7554/eLife.92962.
The ovules or seeds (fertilized ovules) with wings are widespread and especially important for wind dispersal. However, the earliest ovules in the Famennian of the Late Devonian are rarely known about the dispersal syndrome and usually surrounded by a cupule. From Xinhang, Anhui, China, we now report a new taxon of Famennian ovules, gen. et sp. nov. Each ovule of this taxon possesses three integumentary wings evidently extending outwards, folding inwards along abaxial side and enclosing most part of nucellus. The ovule is borne terminally on smooth dichotomous branches and lacks a cupule. suggests that the integuments of the earliest ovules without a cupule evolved functions in probable photosynthetic nutrition and wind dispersal. It indicates that the seed wing originated earlier than other wind dispersal mechanisms such as seed plume and pappus, and that three- or four-winged seeds were followed by seeds with less wings. Mathematical analysis shows that three-winged seeds are more adapted to wind dispersal than seeds with one, two or four wings under the same condition.
具翅的胚珠或种子（受精胚珠）分布广泛，尤其是对风传播非常重要。然而，早泥盆世法门阶的最早胚珠很少了解其传播综合征，通常被杯状结构包围。来自中国安徽新杭的我们现在报告了一个新的法门阶胚珠分类群，gen. et sp. nov. 该分类群的每个胚珠都具有三个明显向外延伸的珠被翅，沿背侧向内折叠并包围珠心的大部分。胚珠末端着生于光滑二叉分枝上，没有杯状结构。 表明最早无杯状结构的胚珠的珠被在可能的光合作用营养和风力传播中进化出了功能。这表明种子翅的起源早于其他风传播机制，如种子羽和冠毛，并且具有三或四个翅的种子随后是具有较少翅的种子。数学分析表明，在相同条件下，三翅种子比具有一、二或四个翅的种子更适应风传播。
