福建中新世中期三宝木属(大戟科)一新种及其古气候与古生态学意义

本文描述了发现于福建省漳浦地区佛昙群的三宝木属(Trigonostemon)一新种:漳浦三宝木(Trigonostemon zhangpuensis sp. nov. J.L. Dong et B.N. Sun)。该化石叶片呈倒披针形,基部窄,顶端渐尖;中上部的叶缘具细齿,近叶基1/3的部位全缘;叶脉为羽状环曲脉,中脉粗壮,向上逐渐变细;气孔器为无规则型,气孔呈长椭圆形,分布稀疏,无规则排列;平周壁不光滑,具褶皱。化石种与现生种剑叶三宝木(Trigonostemon xyphophyllorides(Croiz.) L.K. Dai et T.L. Wu)在叶片形态特征方面最为相似。剑叶三宝木分布在我国的海南省,基于化石种与最近亲缘现生种的生态幅基本一致的假设,漳浦地区在中新世中期的气候特征可能类似于现今海南省。化石种叶片上共划分13种损伤类型,属于6类功能性取食组,包括孔洞取食(hole feeding)、边缘取食(margin feeding)、留脉式取食(skeletonization)、表面取食(surface feeding)、造瘿(galling)和刺吸式取食(pierci...

A new species of Trigonostemon Blume (Euphorbiaceae) from the middle Miocene of Fujian, Southeast China and its paleoclimatic and paleoecological significance

A new species of Trigonostemon Blume, namely Trigonostemon zhangpuensis sp. nov. J.L. Dong et B.N. Sun, is established based on well-preserved leaf fossils from the Fotan Group in Zhangpu County, Fujian, Southeast China. The new species is characterized by oblanceolate lamina with cuneate and narrow base, acuminate apex, serrate margin at the distal part and entire margin at the proximal 1/3 part of the lamina, pinnate brochidodromous venation with a stout primary vein thinning gradually toward the apex, anomocytic stomatal complex, sparsely distributed and randomly arranged stomata, and normal epidermal cells with striate periclinal walls. The morphological characters of the fossil leaves closely resemble those of extant Trigonostemon xyphophyllorides (Croiz.) L. K. Dai et T. L. Wu., which is endemic to Hainan Province. The ecological amplitude of the fossil species is similar to that of its nearest living relatives; the paleoclimate of the Zhangpu area during the middle Miocene might be similar to that of Hainan Province today. We recognize thirteen insect-mediated damage types belonging to six functional feeding groups on the leaves of T. zhangpuensis. The damage types include hole feeding, margin feeding, skeletonization, surface feeding, galling, and piercing and sucking. Moreover, our observation suggests that phytophagous insects feeding on leaves of T. zhangpuensis might be relatively diverse.