Growth and Paleoecology of an Early Cretaceous Ornithopod Dinosaur

在德克萨斯州的普罗克特湖遗址， 年轻的和成年的恐龙，都是同一个物种，被发现在 超过一亿一千万年的岩石 成年人的良好骨骼 恐龙是罕见的，特别是在这个地质时期， 青少年更是罕见。 南方卫理公会的戴尔·温克勒博士 大学正在挖掘和研究这一组合， 深入了解行为、进食和运动的变化 在这些动物的成长过程中发生的变化。 这些 得克萨斯州的两足食草动物（鸟脚类）很小， 恐龙（大约3-4米长），但在 得克萨斯州和许多后来进化的州要大得多。 确定这些进化变化是如何以及为什么发生的， 对于理解不同群体之间的关系非常重要， 恐龙 最新的技术进步使标本的图像 通过摄像机输入计算机， 用于快速测量以及数据存储和交换。 这个新 将使用沿着方法和统计技术， 确定向更大规模发展的过程（超过 数百万年）遵循相同的途径， 个人在其一生中。 了解更多关于恐龙 行为和生活史，计算机方法也将用于 有助于展示男性和女性在形状上的细微差异， 女性骷髅 知道恐龙标本的性别 揭示了它们的筑巢习惯和社会结构。 恐龙和其他爬行动物一样， 他们的生活，所以有很多困难， 恐龙标本的年龄（刚孵化的，幼年的，成年的）。 由于体型通常在生长过程中发生变化， 同一物种的恐龙可能看起来不同， 被错误地称为不同的物种。 研究变化， 物种多样性随着时间的推移和其他进化的主题是 被这个问题所困扰。 为了帮助解决这个难题， 保存完好的普罗克特湖样本将用于绘制 在一个人的过程中可以预期的形状变化 恐龙的发展 同时，内部骨骼结构的变化 在生长过程中发生的变化可能与 身体形态 将这两种变化量化为 最大成人尺寸可以提供用于确定 其他恐龙标本的生长速度和年龄， 增长系列不可用。 这项研究成果 将提供工具来了解恐龙如何生活， 多样化，最终统治陆地动物超过150年 百万年。

At the Proctor Lake site in Texas, skeletons of hundreds of young and adult dinosaurs, all of the same species, are found in rocks over 110 million years old. Good skeletons of adult dinosaurs are rare, especially for this geological period, and juveniles are even rarer. Dr. Dale Winkler of Southern Methodist University is excavating and studying this assemblage to gain insight into the changes in behavior, feeding, and locomotion that occurred in these animals during their growth. These bipedal plant eaters (ornithopods) from Texas are small for dinosaurs (about 3-4 meters long), but related kinds found in Texas and many that evolved afterward are much larger. Determining how and why these evolutionary changes took place is important for understanding the relationships between groups of dinosaurs. Recent technical advances allow images of specimens to be entered into a computer by video camera for precise and rapid measurement and for storage and exchange of data. This new method along with statistical techniques will be used to determine if the process of evolving to larger size (over millions of years) follows the same pathway as the growth of an individual during its life. To learn more about dinosaur behavior and life history, computer methods will also be used to help demonstrate subtle differences in shape between male and female skeletons. Knowing the sex of the dinosaur specimens will reveal much about their nesting habits and social structure. Dinosaurs, like other reptiles, probably grew throughout their lives, so there have been many difficulties in recognizing the age of dinosaur specimens (hatchlings, juveniles, adults). Because body shape usually changes during growth, young and adult dinosaurs of the same species may look different and may mistakenly be called different species. Studies of changes in species diversity through time and other evolutionary topics are clouded by this problem. To help solve this dilemma, the excellently preserved Proctor Lake samples will be used to map the shape changes that can be expected during an individual dinosaur's development. Also, changes in internal bone structure that occur during growth can be correlated with the changes in body form. Quantifying both of these changes as a percent of the largest adult size may provide a system for determining the growth rate and age of other dinosaur specimens for which a growth series is not available. The results of this research will provide tools to understand how dinosaurs lived and diversified, ultimately dominating land faunas for over 150 million years.