School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, UK.
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.
Science. 2014 Jun 27;344(6191):1504-6. doi: 10.1126/science.1253393.
Reef-building in metazoans represents an important ecological innovation whereby individuals collectively enhance feeding efficiency and gain protection from competitors and predation. The appearance of metazoan reefs in the fossil record therefore indicates an adaptive response to complex ecological pressures. In the Nama Group, Namibia, we found evidence of reef-building by the earliest known skeletal metazoan, the globally distributed Cloudina, ~548 million years ago. These Cloudina reefs formed open frameworks without a microbial component but with mutual attachment and cementation between individuals. Orientated growth implies a passive suspension-feeding habit into nutrient-rich currents. The characteristics of Cloudina support the view that metazoan reef-building was promoted by the rise of substrate competitors and predators.
后生动物的造礁作用代表了一种重要的生态创新，通过这种作用，个体可以共同提高摄食效率，并获得免受竞争者和捕食者侵害的保护。后生动物礁在化石记录中的出现因此表明了对复杂生态压力的适应性反应。在纳米比亚的 Nama 组，我们发现了最早的已知有骨骼的后生动物——在全球范围内分布的 Cloudina——大约在 5.48 亿年前进行造礁的证据。这些 Cloudina 礁形成了没有微生物成分的开放式框架，但个体之间相互附着和胶结。定向生长意味着它们具有被动悬浮摄食的习性，以便摄入富含营养的水流。Cloudina 的特征支持这样一种观点，即后生动物的造礁作用是由基质竞争者和捕食者的兴起所推动的。
