Seagrasses are marine angiosperms documented in shallow-marine, soft bottom settings across the Cenozoic. They proliferated globally after their divergence from other alismatid monocots in the late Cretaceous followed by an adaptation to the marine environment. Detailed evaluation of seagrasses in the geological archives is of utmost importance to understand their responses to climatic and environmental alterations in the deep time perspective. Here we examine the lower Miocene Quilon Limestone from the Kerala Basin (southwest India) that encompasses a Pseudotaberina-Halimeda floatstone signalling a robust photozoan foralgal skeletal assemblage. This is characterized by the dominant soritid foraminifer Pseudotaberina and the calcareous green alga Halimeda, in association with other foraminifera and representatives from various biotic groups that indicate a tropical seagrass paleoenvironment. Abundant soritids together with various bryopsidalean Halimeda species indicate light and temperature as the major ecological drivers regulating the Quilon Limestone seagrass paleocommunity during the early Miocene (Burdigalian). The spatio-temporal distribution patterns of Halimeda also indicate temperature as the most prominent ecological constraint determining its dispersal and evolution at multiple latitudes. A well illuminated substrate is envisaged to support the development and calcification of the Halimeda thalli. Abundance of K-strategist foraminifera with minor occurrence of suspension-feeding bryozoans and some gastropods, bivalves indicate a low-nutrient environment.

海草是新生代浅海软底环境中记录的海洋被子植物。它们在白垩纪晚期与其他泽泻单子叶植物分化并适应海洋环境后在全球范围内扩散。对地质档案中的海草进行详细评估对于从深层次的角度了解它们对气候和环境变化的反应至关重要。在这里，我们检查了来自喀拉拉邦盆地（印度西南部）的中新世下部 Quilon 石灰岩，其中包含Pseudotaberina-Halimeda浮石，表明存在强大的光虫藻类骨骼组合。其特征是优势的索里特有孔虫Pseudotaberina和钙质绿藻Halimeda，以及其他有孔虫和来自各种生物类群的代表，表明热带海草古环境。丰富的独角藻和各种苔藓纲的Halimeda物种表明，光和温度是中新世早期（布尔迪加利）调节奎隆石灰岩海草古群落的主要生态驱动因素。哈利梅达的时空分布格局也表明温度是决定其在多个纬度扩散和演化的最突出的生态约束因素。设想有一个照明良好的基质来支持Halimeda菌体的发育和钙化。K-策略有孔虫的丰富性以及悬浮进食的苔藓虫和一些腹足类、双壳类的少量出现表明了低营养环境。