Data from: Camerate crinoids from the Nunn Member (Osagean) of the Lower Mississippian Lake Valley Formation, New Mexico

The Nunn Member (Early Osagean) of the Lake Valley Formation of New Mexico is known for its abundance and diversity of crinoids. Although crinoids were first reported in the late 1800's, there has not been a comprehensive study of the crinoids, and a complete list of the crinoid taxa does not exist. All subclasses of crinoids occur in the Lake Valley, but the camerates are by far the dominant group. Study of the Macurda collection from the University of Michigan, the Laudon collection from the University of New Mexico, and new collections provided more than 7000 specimens, 4,500 of which were identifiable camerates. Sixty-one species of camerates are recognized in the Nunn Member, including five new species: Blairocrinus macurdai, Iotacrinus novamexicanus, Agaricocrinus alamogordoensis, Uperocrinus kuesi, and Collicrinus laudoni. This camerate fauna is very similar to that of the lower Burlington Limestone of the Mississippi Valley. An update of the crinoid taxa in the Lake Valley Formation allows for a better understanding of the temporal and geographic relationships of crinoid faunas across North American during the Early Mississippian when camerates were at their global diversity maximum. The majority of the camerates come from the western New Mexico outcrops where the Nunn is thicker and the marine shelf was shallower, but several also occur in association with the deep-water Waulsortian mounds.

美国新墨西哥州（New Mexico）湖谷组（Lake Valley Formation）的纳恩段（Nunn Member，奥塞阶早期（Early Osagean））以产出丰富多样的海百合（crinoid）化石而闻名。尽管海百合化石早在19世纪末便已有报道，但目前尚未开展针对该区域海百合的系统性研究，完整的海百合类群名录也尚未建立。海百合纲的所有亚类均在湖谷组有产出，其中闭壳海百合类（camerate）无疑是优势类群。通过对密歇根大学（University of Michigan）麦克尔达藏品、新墨西哥大学（University of New Mexico）劳登藏品以及新采集标本的研究，共获得超过7000件化石标本，其中4500件可鉴定为闭壳海百合类。纳恩段已确认61种闭壳海百合类，其中包含5个新种：Blairocrinus macurdai、Iotacrinus novamexicanus、Agaricocrinus alamogordoensis、Uperocrinus kuesi及Collicrinus laudoni。该闭壳海百合动物群与密西西比河谷（Mississippi Valley）下伯灵顿灰岩（Burlington Limestone）的动物群极为相似。对湖谷组海百合类群的修订，有助于我们更好地理解早密西西比世（Early Mississippian）——此时闭壳海百合类达到全球多样性峰值——北美各地海百合动物群的时空分布关系。绝大多数闭壳海百合类化石产自新墨西哥州西部的露头区，该区域纳恩段地层厚度更大，且当时的陆架水体更浅；但也有少量标本与深水沃尔索蒂安丘（Waulsortian mounds）伴生产出。