Evolutionary changes in the structure of leaves have had far-reaching effects on the anatomy and physiology of vascular plants, resulting in morphological diversity and species expansion. People have long been interes...Evolutionary changes in the structure of leaves have had far-reaching effects on the anatomy and physiology of vascular plants, resulting in morphological diversity and species expansion. People have long been interested in the question of the nature of the morphology of early leaves and how they were attained. At least five lineages of euphyllophytes can be recognized among the Early Devonian fossil plants (Pragian age, ca. 410 Ma ago) of South China. Their different leaf precursors or "branch-leaf complexes" are believed to foreshadow true megaphylls with different venation patterns and configurations, indicating that multiple origins of megaphylls had occurred by the Early Devonian, much earlier than has previously been recognized. In addition to megaphylls in euphyllophytes, the laminate leaf-like appendages (sporophylls or bracts) occurred independently in several distantly related Early Devonian plant lineages, probably as a response to ecological factors such as high atmospheric CO 2 concentrations. This is a typical example of convergent evolution in early plants.展开更多
The Paleozoic flora of the state of Puebla is characterized by the presence of ancient and conservative lineages;we focus this study on the taxonomical Annularia, Bjuvia and the new morphotype. These groups are found ...The Paleozoic flora of the state of Puebla is characterized by the presence of ancient and conservative lineages;we focus this study on the taxonomical Annularia, Bjuvia and the new morphotype. These groups are found in carbonaceous lutite, where paleosoils, small roots and trunks in situ are abundant, and have been associated with swampy environments. In this paper, we discuss the presence of a new architectural form of megaphyll size that has not been registered in other Permian locations. These lutite imprints are the second most abundant in this location and their degree of preservation supports their autochthonous nature. The large size of its funnel-shaped blade and its extremely long petiole support the idea that its size was a response to a competition for biotic resources and to the hydric stress to which communities of this region were exposed, as consequence of the environmental conditions prevailing at the end of the Paleozoic era. It is proposed that they lived in environments with seasonal humidity and this hypothesis is supported by both the abundance of fossil groups and lithology.展开更多
基金supported by the National Natural Science Foundation of China(41272018 and 40830211)
文摘Evolutionary changes in the structure of leaves have had far-reaching effects on the anatomy and physiology of vascular plants, resulting in morphological diversity and species expansion. People have long been interested in the question of the nature of the morphology of early leaves and how they were attained. At least five lineages of euphyllophytes can be recognized among the Early Devonian fossil plants (Pragian age, ca. 410 Ma ago) of South China. Their different leaf precursors or "branch-leaf complexes" are believed to foreshadow true megaphylls with different venation patterns and configurations, indicating that multiple origins of megaphylls had occurred by the Early Devonian, much earlier than has previously been recognized. In addition to megaphylls in euphyllophytes, the laminate leaf-like appendages (sporophylls or bracts) occurred independently in several distantly related Early Devonian plant lineages, probably as a response to ecological factors such as high atmospheric CO 2 concentrations. This is a typical example of convergent evolution in early plants.
文摘The Paleozoic flora of the state of Puebla is characterized by the presence of ancient and conservative lineages;we focus this study on the taxonomical Annularia, Bjuvia and the new morphotype. These groups are found in carbonaceous lutite, where paleosoils, small roots and trunks in situ are abundant, and have been associated with swampy environments. In this paper, we discuss the presence of a new architectural form of megaphyll size that has not been registered in other Permian locations. These lutite imprints are the second most abundant in this location and their degree of preservation supports their autochthonous nature. The large size of its funnel-shaped blade and its extremely long petiole support the idea that its size was a response to a competition for biotic resources and to the hydric stress to which communities of this region were exposed, as consequence of the environmental conditions prevailing at the end of the Paleozoic era. It is proposed that they lived in environments with seasonal humidity and this hypothesis is supported by both the abundance of fossil groups and lithology.
