Abstract. Photosynthetically-active foraminifera are important carbonate producers contributing nearly 5 % of the reef and nearly 1 % of the total global calcium carbonate budgets. The abilities to be photosynthetically active, foraminifera realize by endosymbiosis with microalgae or by sequestering plastids (kleptoplasts) of digested algae. These ecological behaviors are a great advantage for the continued growth, survival of the hosts and enhance of foraminiferal calcification. Our data provide concurrent pieces of evidence for, as of now, the earliest (mid-Devonian) photosymbiosis in protists observed in the first true advanced multichambered calcareous foraminifera Semitextularia from the tropical shelf of the Laurussia paleocontinent. This adaptation might have had a significant impact on the evolutionary radiation of calcareous Foraminifera in the Devonian (“Givetian revolution”), which was one of the most important evolutionary events in foraminiferal history. The observed phenomenon coincided with the worldwide development of diverse calcifying marine communities inhabiting shelf environments linked with Devonian stromatoporoid-coral reefs.

中文翻译：

---

泥盆纪有孔虫的光合作用活动

摘要。光合作用活跃的有孔虫是重要的碳酸盐生产者，占珊瑚礁的近 5% 和全球碳酸钙总预算的近 1%。有孔虫通过与微藻的内共生或通过隔离消化藻类的质体（kleptoplasts）来实现光合活性的能力。这些生态行为对于宿主的持续生长、生存和促进有孔虫钙化具有很大的优势。我们的数据提供了目前在第一个真正的高级多室钙质有孔虫Semitextularia 中观察到的原生生物中最早（中泥盆世）光共生的同时证据来自劳鲁士古大陆的热带大陆架。这种适应可能对泥盆纪石灰质有孔虫的进化辐射产生了重大影响（“Givetian 革命”），这是有孔虫历史上最重要的进化事件之一。观察到的现象与世界范围内各种钙化海洋群落的发展相吻合，这些群落居住在与泥盆纪层孔珊瑚礁相关的大陆架环境中。