Wednesday, October 31, 2012
Wonder
New flying fish fossils found in China provide the earliest evidence of vertebrate over-water gliding strategy.
Chinese researchers have tracked the "exceptionally well-preserved fossils" to the Middle Triassic of China (235-242 million years ago).
The Triassic period saw the re-establishment of ecosystems after the Permian mass extinction.
The fossils represent new evidence that marine ecosystems re-established more quickly than previously thought.
The Permian mass extinction had a bigger impact on the earth's ecological systems than any other mass extinction, wiping out 90-95% of marine species.
Previous studies have suggested that Triassic marine life developed more quickly than was once thought and that marine ecosystems were re-established more rapidly than terrestrial ecosystems.
The new research, published in Proceedings of the Royal Society B journal, was carried out by scientists from Peking University, the Chinese Academy of Sciences and the Zhejiang Museum of Natural History.
The study shows that the new flying fish, namedPotanichthys xingyiensis, was 153mm long and had the "unusual combination of morphological features" associated with gliding strategy in fishes.
The fossils show an asymmetrical, forked caudal (tail) fin and a "four-winged" body formation: a pair of enlarged pectoral fins forming "primary wings", and a smaller pair of pelvic fins acting as "auxiliary wings", according to the study.
The fossils were discovered in Guizhou Province in south-west China. They represent the first record of the extinct Thoracopteridae family of fishes to be found in Asia.
Previous Thoracopteridae fossils have been confined to the Upper Triassic of Austria and Italy, but the new discovery extends the group's geographical distribution from the western to the eastern rim of the Paleo-Tethys Ocean (an ocean that closed during the Jurassic period).
The Triassic Thoracopteridae family belongs in the same Neopterygii group of animals as today's flying fishes, of which there are around 50 species belonging to the Exocoetidae family.
Gliding has evolved many times in animals, such as in frogs, lizards and mammals but has "evolved only twice among fishes", according to the study: once in the Triassic Thoracopteridaefishes and again in the modern-day Exocoetidae family.
Scientists suggest both families of flying fishes evolved so that they could escape marine predators by "gliding" over-water to safety.
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