Souza Juliane M, Iannuzzi Roberto
Depto de Paleontologia e Estratigrafia, Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
An Acad Bras Cienc. 2012 Mar;84(1):43-68. doi: 10.1590/s0001-37652012000100006.
The morphological analysis of seeds has been an important subject in modern ecological studies, once it provides evidence about the biology and adaptations of the parent plant. However, this kind of study has been restricted to the ecology of modern plants and is rarely used in interpretations of Paleozoic data. From the understanding of dispersal syndromes analysis as an important tool to paleoecological reconstruction, this study provides a first approach using this tool with seeds from the Lower Permian strata of southern Paraná Basin in Rio Grande do Sul. Based on previously classified seeds and using their biological and taphonomic data, the syndrome of dispersal was interpreted, and their placement in successional groups (pioneer, early-successional and later-successional) was suggested. Seven morphospecies were analyzed: Samaropsis gigas, representing a later-successional species living in water bodies with hydrochory as its dispersal syndrome; Samaropsis kurtzii, typical of early-successional species showing anemochory as its dispersal syndrome and living in distal areas in relation to water bodies; Samaropsis aff. S. millaniana, Cordaicarpus aff. C. brasilianus, Cordaicarpus cerronegrensis and Cordaicarpus truncata have typical characteristics of pioneer plants, exhibiting barochory as their primary dispersal syndrome with other syndromes associated.
种子的形态分析一直是现代生态学研究中的一个重要课题，因为它能提供有关亲本植物生物学和适应性的证据。然而，这类研究一直局限于现代植物生态学，很少用于解释古生代数据。基于将扩散综合征分析作为古生态重建的重要工具这一认识，本研究首次使用该工具对巴西南部南里奥格兰德州巴拉那盆地二叠纪下层的种子进行研究。根据先前对种子的分类，并利用其生物学和埋藏学数据，解读了扩散综合征，并建议将它们归入演替组（先锋、早期演替和晚期演替）。分析了七个形态种：巨型萨马罗普斯种子，代表一种晚期演替物种，生活在水体中，以水媒传播为其扩散综合征；库尔茨氏萨马罗普斯种子，是早期演替物种的典型代表，以风媒传播为其扩散综合征，生活在远离水体的区域；萨马罗普斯种子近似米兰萨马罗普斯种子、科代卡普斯种子近似巴西科代卡普斯种子、塞雷诺格伦西斯科代卡普斯种子和截顶科代卡普斯种子具有先锋植物的典型特征，以重力传播作为其主要扩散综合征，并伴有其他综合征。
