Fossil of Gansufructus saligna gen. et sp. nov. showing branches, leaves as well as terminal fruits ... [+]
Science China PressIn his vast correspondence with other contemporary naturalists, Charles Darwin mentions the "abominable mystery” of the origin of angiosperms or plants with flowers. The fossil record shows that flowering plants appear relatively suddenly all around the world in the mid-Cretaceous (about 110 million years ago), in contrast with Darwin's belief of a gradual, slow evolution. Darwin explained the apparent sudden evolution using gaps in the fossil record.
Since Darwin many plant fossils have been found, but so far, we still have not completely solved the problem.
Recently, a new angiosperm was reported based on numerous exceptionally well-preserved fossils from the Lower Cretaceous of Jiuquan Basin, West Gansu Province, Northwest China. The new discovery is the earliest and unique record of early angiosperms in Northwest China. According to Science China Press, the study has been accepted for publication in the journal National Science Review and is currently available online.
The new angiosperm was named Gansufructus saligna, and all the fossil specimens were collected from the grayish green mudstone of the upper Zhonggou Formation, dating back to 112 million years ago. Remarkably, the plant fossils are almost completely preserved with branched axes, attached leaves and paniculate infructescences, providing valuable materials for the morphological studies of early angiosperms.
Gansufructus saligna is a small (just a few inches high) herbaceous plant with three to four branches and with alternating leaves. Leaves are simple and willow-shaped. The infructescences are loose grass-like panicles bearing fruits in different stages of maturity. Each fruit is formed from four fused carpels (the reproductive organs of a flowering plant) and contains three to five seeds.
Gansufructus saligna probably grew along the lakeshores, where the environment is low-lying and wet as the lake sediments, where the fossil is preserved, and the morphology of the leaves suggest.
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The fossil is the earliest known example of a core eudicot, a clade of angiosperms mainly characterized by having two seed leaves upon germination and comprising roughly 190,000 described species, or 75% of all known land plants. Numerous familiar plants are eudicots, including many common food plants, most leafy trees, and ornamentals.
Despite the discovery of many plant fossils in China, it is yet not clear if this area is also site of the evolutionary origin of flowering plants. Possible sites were placed in the Arctic region, Southeast or East Asia, South America and Africa - with China acting as a land-bridge connecting all those regions. In any case, after the Cretaceous radiation, flowering plants spread quickly from their site of origin. In just forty million years they colonized almost all terrestrial habitats, from wetlands to deserts, from prairies to the jungle, and from grassland to high mountains.
Gansufructus saligna is of great significance in exploring the origin, evolution, diversity and habitat preferences of early and modern flowering plants.
Tree saplings showing two seed leaves upon germination.
gettyMay 25, 2021 at 12:57AM
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Exceptionally Well-Preserved Herb-Like Fossil Sheds New Light On The Evolution Of Flowering Plants - Forbes
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