主题:动物/精选条目/9

禽龙属（学名：Iguanodon，意为“鬣蜥的牙齿”），属于蜥形纲鸟臀目鸟脚下目的禽龙类，是大型草食性动物，身长约10米，高3到4米，前手拇指有一尖爪，可能用来抵抗掠食动物，或是协助进食。

禽龙的化石多数发现于欧洲的比利时、英国、德国。牠们主要生存于白垩纪早期的巴列姆阶到早阿普第阶，约1亿2600万年前到1亿2500万年前。禽龙的演化位置大约位于行动敏捷的棱齿龙类首次出现，演化至鸟脚下目中最繁盛的鸭嘴龙类，这段演化过程的中间位置。禽龙与年代更晚的鸭嘴龙类，共同属于禽龙类演化支。

禽龙的化石在1822年首次发现，并在1825年由英国地理学家吉迪恩·曼特尔进行描述与命名。在过去的研究历史中，有许多化石被归类于禽龙，年代横跨侏罗纪启莫里阶到白垩纪森诺曼阶，范围广达欧洲、北美洲、亚洲内蒙古、以及北非。但根据近年研究，这些化石多被归类于其他属，或是建立为新属。目前的唯一有效种是贝尼萨尔禽龙（I. bernissartensis）。

禽龙是继斑龙之后，世界上第二种正式命名的恐龙。斑龙、禽龙、以及林龙是最初用来定义恐龙总目的三个属。古生物学界对于禽龙的了解，因为新发现的化石而随着时间不断改变。禽龙的大量标本，包括从两个著名尸骨层发现的接近完整骨骸，使得研究人员可提出许多禽龙生活方面的假设，包括进食、移动方式、以及社会行为。禽龙的重建图也随着标本的新发现而改变。

Iguanodon (/ɪˈɡwɑːnədɒn/ i-GWAH-nə-don; meaning "iguana-tooth") is a genus of ornithopod dinosaur that existed roughly halfway between the first of the swift bipedal hypsilophodontids of the mid-Jurassic and the duck-billed dinosaurs of the late Cretaceous. While many species have been classified in the genus Iguanodon, dating from the late Jurassic Period to the early Cretaceous Period of Asia, Europe, and North America, research in the first decade of the 21st century suggests that there is only one well-substantiated species: I. bernissartensis, which lived from the late Barremian to the earliest Aptian ages (Early Cretaceous) in Belgium, Spain, and possibly elsewhere in Europe, between about 126 and 125 million years ago. Iguanodon were large, bulky herbivores. Distinctive features include large thumb spikes, which were possibly used for defense against predators, combined with long prehensile fifth fingers able to forage for food.

The genus was named in 1825 by English geologist Gideon Mantell, based on fossil specimens that are now assigned to Therosaurus and Mantellodon. Iguanodon was the second type of dinosaur formally named based on fossil specimens, after Megalosaurus. Together with Megalosaurus and Hylaeosaurus, it was one of the three genera originally used to define Dinosauria. The genus Iguanodon belongs to the larger group Iguanodontia, along with the duck-billed hadrosaurs. The taxonomy of this genus continues to be a topic of study as new species are named or long-standing ones reassigned to other genera.

Scientific understanding of Iguanodon has evolved over time as new information has been obtained from fossils. The numerous specimens of this genus, including nearly complete skeletons from two well-known bonebeds, have allowed researchers to make informed hypotheses regarding many aspects of the living animal, including feeding, movement, and social behaviour. As one of the first scientifically well-known dinosaurs, Iguanodon has occupied a small but notable place in the public's perception of dinosaurs, its artistic representation changing significantly in response to new interpretations of its remains.