{{Taxobox
|color = pink
|name = 幻龍
|status = fossil
|fossil_range = 三疊紀早期到晚期
|image = Nothosaurus_BW.jpg
|image_width = 250px
|image_caption = ''Nothosaurus sp.''
|regnum = 動物界 Animalia
|phylum = 脊索動物門 Chordata
|classis = 蜥形綱 Sauropsida
|ordo = 幻龍目 Nothosauria
|familia = 幻龍科 Nothosauridae
|genus = '''幻龍屬 ''Nothosaurus'''''
|genus_authority = Hunter, 1834
|subdivision_ranks = 種
|subdivision = 
*''N. mirabilis'' (模式種)
*''N. winterswijkensis''
*巨型幻龍 ''N. giganteus''
*''N. procerus''
}}

'''幻龍'''是鰭龍超目已滅絕的一屬，生存三疊紀，接近於2億3000萬年前。牠們身長約3公尺（10呎），是幻龍目中最著名的成員。

幻龍是半海生動物，牠們可能過者與現代海豹類似的生活。牠們可能用排列者針狀牙齒的長顎部，捕抓魚類與其他海中動物。牠們的身體在許多方面類似較晚的蛇頸龍類，但牠們沒達到蛇頸龍類般的高度適應水生環境。在柏林的自然歷史博物館可以看到一個''Nothosaurus raabi''的完整骨骸。

{{Taxobox
|name = ''Nothosaurus''
|fossil_range = Early to Late Triassic
|image = Nothosaurus_BW.jpg
|image_width = 250px
|image_caption = ''Nothosaurus sp.''
|regnum = Animalia
|phylum = Chordata
|classis = Sauropsida
|ordo = Nothosauria
|familia = Nothosauridae
|genus = '''''Nothosaurus'''''
|genus_authority = Hunter, 1834
|subdivision_ranks = Species
|subdivision = 
*''N. mirabilis'' (type)
*''N. winterswijkensis''
*''N. giganteus''
*''N. procerus''
*''N. raabi''
}}
'''''Nothosaurus''''' is an extinct genus of sauropterygian reptile from the Triassic period, approximately 240-210 million years ago, with fossils being distributed from North Africa and Europe to  China. It was about 4 m (13ft) long and is the best known member of the nothosaur order. Its name means ''False lizard.''

''Nothosaurus'' was a semi-seals. It had long, webbed toes and possibly a fin on its tail. When swimming, ''Nothosaurus'' would use its tail, legs, and webbed feet to propel and steer it through the water. The skull was broad and flat,with long jaws, lined with needle teeth, it probably caught fish and other marine creatures. ''Nothosaurus'' hunted by sneaking up slowly on prey, such as shoals of small fish, the putting on a last-minute burst of speed. Once caught, few animals would be able to shake themselves free from the mouth of ''Nothosaurus''.
thumb|left|''Nothosaurus'' skeleton in [[Berlin.]]
In many respects its body structure resembled that of the much later plesiosaurs, but it did not attain the plesiosaurs' high degree of adaptation to an aquatic environment. A complete skeleton of the species ''Nothosaurus raabi'' can be seen in the Natural History Museum in Berlin. It is though that one branch of the nothosaurs evolved into plesiosaurs such as ''Liopleurodon'' and the long-necked ''Cryptoclidus''.

== In Popular Culture ==

In the ''Fantasia'', ''Nothosaurus'' is briefly depicted; feeding its young and as the anachronistic prey of ''Dimetrodon''.

''Nothosaurus'' was featured in the 2003 BBC series ''Sea Monsters'', a spin-off of the successful ''Walking with Dinosaurs'' (1999). It was featured as a minor character that Nigel Marven kept at bay with an electric tazer.

== References ==