Little is known about the marine palynology of the neotropical oceans. Here, we present the first comprehensive study of organic-walled dinoflagellate cyst assemblages in 52 surface marine sediment samples from the southern Caribbean (SC) and the eastern tropical Pacific (ETP) and explain how these assemblages relate to sea-surface parameters. Multivariate analyses show that of the several environmental parameters considered, sea-surface salinity (SSS), phosphate concentrations, and nitrate concentrations best explain the relative abundances and the geographic distribution of dinoflagellate cysts in the studied area. Consistent with regional differences in marine productivity, dinoflagellate cyst concentrations were markedly different in the SC (1979 ± 1053 cysts/g) and the ETP (3105 ± 1956 cysts/g). Sediments of the SC are characterized by high relative abundances of the Spiniferites spp. group, cysts of Protoceratium reticulatum, and the presence of rare dinocyst taxa. The dinocyst assemblages from the ETP are characterized by higher relative and absolute abundances of Bitectatodinium spongium, Brigantedinium spp., and Echinidinium aculeatum. This pattern is explained by the more eutrophic nature of the ETP compared to the highly saline SC. Average values of the Shannon Index (H′) from the ETP are higher compared to the SC, demonstrating that dinocysts respond to the greater climatic variability that characterizes the ETP. Brigantedinium spp. abundances are negatively correlated to H′ diversity supporting its dominant character within the dinocyst community. This work fills a gap in our knowledge on modern dinocyst distribution in neotropical oceans and provides a modern reference for interpreting down core dinocyst variations and paleocenographical reconstructions in the region.

关于新热带海洋的海洋孢粉学知之甚少。在这里，我们提出了对来自南部加勒比海（SC）和东部热带太平洋地区（ETP）的52个表面海洋沉积物样本中的有机壁鞭毛藻囊肿组件的首次全面研究，并解释了这些组件如何与海面参数相关。多变量分析表明，在考虑的几个环境参数中，海表盐度（SSS），磷酸盐浓度和硝酸盐浓度最能解释研究区域中鞭毛藻囊肿的相对丰度和地理分布。与海洋生产力的区域差异一致，SC（1979±1053囊/ g）和ETP（3105±1956囊/ g）的鞭毛囊肿浓度明显不同。纺锤体属。组，网状原角藻的囊肿和稀有的狄诺氏囊类群的存在。来自ETP的藻类组合的特征是，Bitectatodinium海绵，Brigantedinium spp。和Echinidinium aculeatum的相对和绝对丰度更高。与高盐分的SC相比，ETP的富营养化性质解释了这种模式。与SC相比，ETP的Shannon指数（H）的平均值更高，表明恐龙囊对ETP的更大气候变异性有反应。Brigantedinium spp。丰度与H负相关'多样性支持其在藻囊群落中的主导特征。这项工作填补了我们对新热带海洋现代恐龙囊分布的认识的空白，并为解释该地区核心恐龙囊的变化和古地理重建提供了现代参考。