State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China.
State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China; University of Chinese Academy of Sciences, Beijing, China.
Curr Biol. 2019 Nov 18;29(22):R1172-R1173. doi: 10.1016/j.cub.2019.10.005.
The twining habit is a climbing strategy that helps slender plants grow upward by using circumnutation around other plants. In geological history, climbing may have already been present in the first Middle Devonian forests, as indicated by possible climbers among aneurophytalean progymnosperms [1] and lycopsids [2]. By the late Carboniferous, climbing was both more common and diverse - preserved in swamp forests with modes of attachment ranging from aerial roots to appendages modified into hooks and tendrils on the leaves [3]. However, all of these diagnoses of a climbing habit are based upon either indirect morphological characteristics of the purported climber or on direct physical contact with a host plant, but without direct preservation of twining [3,4]. Permineralized epiphytes have been preserved in the Carboniferous [5], but the interpretation of scars purported to have been caused by twiners that have been found on trunk compressions of potential host-plants has been questioned [5] (see Supplemental Information). Direct preservation of a climber engaged in true twining around a host has only been documented in the Miocene Shanwang Formation of Eastern China, albeit with the identity of the twiner difficult to establish and likely to be a self-twiner [6]. Here, we report a climbing fern engaged in left-handed twining around a seed plant from the early Permian Wuda Tuff fossil Lagerstätte of Inner Mongolia, China [7]. Moreover, the host plant is likely to also be a climber based on its overall form. Such a climber-climbing-a-climber phenomenon signals the potential ecological complexity of late Paleozoic forests.
缠绕习性是一种攀爬策略，通过围绕其他植物进行回旋，帮助细长的植物向上生长。在地质历史上，攀爬可能已经存在于第一个中泥盆世森林中，这一点可以从有茎类原裸子植物[1]和石松类植物[2]中可能的攀爬者中得到证明。到了晚石炭世，攀爬变得更加普遍和多样化——在沼泽森林中被保存下来，其附着模式从气生根到叶片上修改成的钩和卷须都有[3]。然而，所有这些关于攀爬习性的诊断都是基于所谓攀爬者的间接形态特征，或者是与宿主植物的直接物理接触，但没有缠绕的直接保存[3,4]。在石炭纪已经保存了矿化的附生植物[5]，但对在潜在宿主植物的树干压缩物上发现的、据称是由缠绕植物造成的疤痕的解释一直存在质疑[5]（见补充信息）。只有在中国东部的中新世山旺组中，才记录到了真正缠绕在宿主植物上的攀爬植物的直接保存[6]，尽管缠绕植物的身份难以确定，而且很可能是一种自缠绕植物。在这里，我们报告了一种缠绕蕨类植物，它缠绕在一株来自中国内蒙古早二叠世五道砬子组的种子植物上，进行左旋缠绕[7]。此外，基于其整体形态，宿主植物也很可能是一种攀爬植物。这种攀爬植物-攀爬植物-攀爬植物的现象表明了晚古生代森林潜在的生态复杂性。
