美国西伊利诺伊大学（Western Illinois University）的古生物学家M.Bonnan介绍说：“科学家们长期以来都认为大型蜥脚类恐龙（sauropod）在旱季时需要经过长距离跋涉才能寻找到食物来源。”明尼苏达州麦克莱斯特学院（Macalester College in Minnesota）的古生物教授K.Curry Rogers则说道：“此次新的发现也进一步证实了过去的推论。”
Rogers所说新的发现指的是科罗拉多大学（Colorado College）地质学家H.Fricke最近所研究的32颗蜥脚类恐龙牙齿化石，相关的研究成果已在著名的科学杂志《自然》上发表。
这32颗牙齿来自于美国恐龙化石资源丰富的怀俄明州（Wyoming）和犹他州（Utah），时代可追溯到距今1.5亿年前的晚侏罗世时期（late Jurassic）。蜥脚类恐龙是所有陆生脊椎动物中最巨大的，头小，颈部和尾部较长，四肢粗壮，四足行走，主要以植物为食。最大的蜥脚类恐龙体重可达100吨，体长120英尺（约36.5米），此次所研究的蜥脚类恐龙体型较小，体长约60英尺，体重约25吨。
通过比较分析恐龙牙齿珐琅质（牙冠表层的半透明白色硬组织，十分坚硬）和古沉积物中所保存的氧元素化学信息，科学家们可以了解这些史前巨兽的饮用水从何处获得。不一致的化学分析结果表明：这种史前巨兽必须要行走数百公里以上才能从平原地区来达高地地区找到珍贵的食物和水资源。
Fricke还说道：“蜥脚类恐龙的这种长途迁徙与季节变化有关，在夏季，它们要经历五个月的长途跋涉才能来到高海拔的高山地区，而在冬季又要再次返回——它就像一台完美的运动机器。”
而在气候湿润植物茂盛的时候，蜥脚类恐龙的食谱包括了当时的各类植物——蕨类、木贼类、松柏类和苔藓类植物，你可以想象它那庞大的身躯每顿的进食量也将会是十分惊人的。（生物谷 Bioon）
doi:10.1038/nature10570
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Lowland–upland migration of sauropod dinosaurs during the Late Jurassic epoch
Henry C. Fricke, Justin Hencecroth & Marie E. Hoerner
Sauropod dinosaurs were the largest vertebrates ever to walk the Earth, and as mega-herbivores they were important parts of terrestrial ecosystems. In the Late Jurassic-aged Morrison depositional basin of western North America, these animals occupied lowland river-floodplain settings characterized by a seasonally dry climate1, 2. Massive herbivores with high nutritional and water needs could periodically experience nutritional and water stress under these conditions, and thus the common occurrence of sauropods in this basin has remained a paradox. Energetic arguments and mammalian analogues have been used to suggest that migration allowed sauropods access to food and water resources over a wide region or during times of drought or both3, 4, but there has been no direct support for these hypotheses. Here we compare oxygen isotope ratios (δ18O) of tooth-enamel carbonate from the sauropod Camarasaurus with those of ancient soil, lake and wetland (that is, ‘authigenic’) carbonates that formed in lowland settings. We demonstrate that certain populations of these animals did in fact undertake seasonal migrations of several hundred kilometres from lowland to upland environments. This ability to describe patterns of sauropod movement will help to elucidate the role that migration played in the ecology and evolution of gigantism of these and associated dinosaurs.
