A New Cloudinid Fossil Assemblage from the Terminal Ediacaran of Nevada, USA
A New Cloudinid Fossil Assemblage from the Terminal Ediacaran of Nevada, USA
复制标题
DOI：
10.1080/14772019.2019.1623333
复制
发表时间：
2019-07-20
影响因子：
2.6
通讯作者：
Cai, Yaoping
中科院分区：
文献类型：
--
作者：
Selly, Tara;Schiffbauer, James D.;Cai, Yaoping
由于它们在经典埃迪卡拉生物群衰退期间的时间位置和寒武纪时期更易识别的后生动物的出现，埃迪卡拉纪末期（类似于551-539 Ma）管状化石形式的组合有可能提高对埃迪卡拉纪末期附近生物周转的理解。Cloudinid分类群，包括埃迪卡拉纪末期的指标化石Cloudina，由于其全球古地理分布，是这些埃迪卡拉纪管状形式中研究最充分的。最近的报道揭示了美国内华达州大盆地地区的管栖生物生态系统，并将分类群分配给中国同时代沉积物中的Conotubus，Gaojiashania和Wutubus等属。然而，要了解这些生物体在后生动物进化史上可能发挥的作用，并认识到它们潜在的全球分布，需要仔细的分类学研究。在这里，我们详细的黄铁矿化石深泉和木材峡谷形成的埃斯梅拉达和奈县，内华达州，美国，分别。我们的调查集中在最丰富的管状分类群从内华达州网站，这是以前一般分配给芋螺。虽然在形态上与高家山分类群相似，但我们的研究确定，以前被认为是Conotubus的化石是两个不同的分类群。第一个代表了Saarina的一个新种- Saarina hagadorni sp. nov. -一个以前只知道来自东欧平台的属，第二个被建立为一个新的属和种，Costatubus bibendi gen. et sp. nov.。
Owing to their temporal position during the decline of the classic Ediacara biota and the appearance of the more recognizable metazoans of the Cambrian Period, the terminal Ediacaran (similar to 551-539 Ma) assemblages of tubular fossil forms hold potential to improve understanding of biotic turnover near the end of the Ediacaran Period. Cloudinid taxa, including the terminal Ediacaran index fossil Cloudina, are the most well studied of these Ediacaran tubular forms due to their global palaeogeographical distribution. Recent reports revealed ecosystems of tubicolous organisms from the Great Basin region, Nevada, USA, and assigned taxa to such genera as Conotubus, Gaojiashania and Wutubus, well known from contemporaneous Chinese deposits. Appreciating the role that these organisms may have played in the evolutionary history of metazoans and recognizing their potential global distribution, however, requires careful taxonomic study. Here, we detail pyritized fossils from the Deep Spring and Wood Canyon formations of Esmeralda and Nye counties, Nevada, USA, respectively. Our investigation focused on the most abundant tubular taxon from the Nevada sites, which was previously generically assigned to Conotubus. While outwardly similar in morphology to this Gaojiashan taxon, our investigation determines that those fossils previously figured as Conotubus are instead two distinct taxa. The first represents a new species of Saarina - Saarina hagadorni sp. nov. - a genus previously known only from the East European platform, and the second is established as a novel genus and species, Costatubus bibendi gen. et sp. nov.