Sauropod Food Ecology: Insights from plant-animal co-occurrence, paleobotany, and evolutionary history of the Jurassic conifer Araucaria

533研究单元第一和第二资助期对蜥脚类动物食物生态学的研究成果令人振奋，对蜥脚类动物特定栖息地的取食效率提出了新的问题，这可能导致了中中生代蜥脚类动物对某些植物类群的专门化，或导致了中中生代蜥脚类动物之间的栖息地划分。为了帮助回答这些问题，这里提出了额外的体外发酵实验，将重点放在木犀草和木犀草的消化率上——这两种植物都被认为是蜥脚类动物容易获得的、有效的、首选的食物来源——以及水生植物，这可能是沿海环境中蜥脚类动物重要的食物来源。基于蜥脚类动物一口食物的摄入量，生物量产量的经验测量将通过对中生代植物群最近的现存亲属进行种植试验来实现。利用这些数据，可以对特定生境（例如：木耳沼泽、蕨类“开放”草甸、荒木林、荒木林和其他针叶树混交林，以及蕨类、苏铁、银杏和针叶树的混合生态系统）的取食效率进行分析。在Howe-Stephens采石场的Morrison组中，对蜥脚类动物骨床（Howe-Stephens Quarry）的角质层和木材的持续研究将增加这个晚侏罗世蜥脚类生态系统中植物的物种多样性。

The exciting research results on sauropod food ecology generated in the first and second funding periods of Research Unit 533 have opened new questions on the feeding efficiency of specific habitats for the sauropods, which may have led to the specialization of sauropod taxa on certain plant groups by or to habitat partitioning among sauropods in the mid-Mesozoic. To help answer these questions, additional in-vitro fermentation experiments are proposed here that will focus on the digestibility of Araucaria and Equisetum— both of which are thought to have been accessible, efficient, and preferred sources of food for the sauropods—as well as that of water plants, which may have been important food sources for sauropods in coastal environments. Empirical measurements of biomass yield, based on the intake volume of a sauropod’s mouthful, will be made using cropping trials on the nearest living relatives of the Mesozoic flora. Using these data, the analysis of feeding efficiency in specific habitats (e.g., an Equisetum marsh, an “open” meadow of ferns, an Araucaria forest, a mixed forest of Araucaria and other conifers, and a mixed ecosystem of ferns, cycads, ginkgoes, and conifers) can be undertaken. The continued study of cuticle and wood from a sauropod bonebed (the Howe-Stephens Quarry) in the Morrison Formation at the Howe- Stephens Quarry will add to the species diversity of plants in this Late Jurassic sauropod ecosystem.