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 Forma...新墨西哥州湖谷组（Lake Valley Formation）的纳恩段（Nunn Member）形成于早奥塞吉期（Early Osagean），以产出丰富且多样的海百合（crinoids）而闻名。尽管海百合早在19世纪末就被首次报道，但目前尚无针对该类群的综合性研究，完整的海百合类群名录也尚未形成。湖谷组产出海百合的所有亚纲类群，但包壳海百合类（camerates）无疑是优势类群。研究团队对密歇根大学（University of Michigan）的Macurda藏品、新墨西哥大学（University of New Mexico）的Laudon藏品以及新采集的标本进行分析后，共整理出超过7000件标本，其中4500件可鉴定为包壳海百合类。纳恩段中已确认存在61种包壳海百合，包括5个新种：*Blairocrinus macurdai*、*Iotacrinus novamexicanus*、*Agaricocrinus alamogordoensis*、*Uperocrinus kuesi*及*Collicrinus laudoni*。该包壳海百合动物群与密西西比河谷下伯灵顿灰岩的动物群极为相似。关于湖谷组海百合类群的更新研究……