叶足动物（Lobopodia）是可以追溯至早期寒武纪时代的动物，对于当中绝大部分至今仍然所知不多。此门下的动物具体节，有足，同时却很难被分类到节肢动物的范畴。基本上这种动物就像「长着足的蠕虫」，外观上亦与其近亲很接近。当中大部分被认为与节肢动物及有爪动物有亲缘关系。叶足动物可能包括了奇虾、欧巴宾海蝎及一些似有爪动物的动物，如异虫Xenusion、微网虫、埃谢栉蚕、爪网虫、Paucipoda、心网虫、啰哩山虫及缓步动物。

由于一些微网虫有骨片的鳞，故有些学者将一些寒武纪早期有骨片的动物分类在此属中。

The lobopodians, members of the informal group Lobopodia Snodgrass 1938 (from the Greek, meaning "blunt feet") are worm-like taxa with stubby legs.

The scope of the Lobopodian concept varies from author to author. Its most limited sense refers to a suite of mainly Cambrian panarthropod taxa with flexible non-segmented limbs – for example Aysheaia, Hallucigenia and Xenusion. A broader definition of lobopodia would also incorporate the extant phyla Onychophora and Tardigrada. The broadest definition proposes the (monophyletic) Superphylum Lobopodia to encompass all three panarthropod phyla.