We report the first Hettangian theropod tracksite (~200 Ma) yielding a rich accumulation of plant remains from the Bleymard Strait (southern France). It constitutes an excellent opportunity to reconstruct lowermost Jurassic ecosystems hosting dinosaurs and which are still poorly documented in this area. Two morphotypes of tridactyl tracks are distinguished. They share similarities with Grallator and Kayentapus. Plant-bearing beds yield abundant leafy axes (Pagiophyllum peregrinum), male cones (Classostrobus sp.), wood (Brachyoxylon sp.) and pollen of conifers (Classopollis classoides). Sedimentological, petrological and mineralogical analyses demonstrated that, in the Dolomitic Formation from Bleymard, the palaeoenvironment progressively evolved from (1) a shoreface to a foreshore domain; to (2) a shallow environment that is restricted or occasionally open to the sea; then to (3) an intertidal to supratidal zone. The Hettangian theropod ecosystem of the Bleymard Strait was composed of tidal flats that were periodically emerged and bordered paralic environments inhabited by a littoral conifer-dominated forest in which Cheirolepidiaceae were the main component. The paucity of the palaeobotanical assemblage, as well as the xerophytic characteristics of Pagiophyllum, show that flora from Bleymard was adapted to withstand intense sunlight and coastal environments exposed to desiccant conditions coupled with salty sea spray, and dry conditions. These features are those of a conifer-dominated flora under a tropical to subtropical climate. The flora as well as the clay mineral analyses suggest contrasting seasons (cyclically dry then humid). This study supports that theropods were abundant and particularly adapted to this type of littoral environment bordering Cheirolepidiaceae-dominated forests.

中文翻译：

---

来自布莱马尔海峡（法国南部）的侏罗纪最低恐龙生态系统：白云岩组的沉积学、矿物学、古植物学和古地质学

我们报告了第一个 Hettangian 兽脚亚目追踪点（~200 Ma），从 Bleymard 海峡（法国南部）产生了丰富的植物遗骸积累。它为重建侏罗纪最底层的恐龙生态系统提供了绝佳的机会，这些恐龙在该地区的记录仍然很少。区分了三趾轨道的两种形态类型。它们与磨碎机和凯恩塔普斯. 植物床产生丰富的叶轴（游隼), 公锥体 (类鸟sp.), 木头 (短枝sp.) 和针叶树的花粉 (类花粉）。沉积学、岩石学和矿物学分析表明，在 Bleymard 的白云岩组中，古环境逐渐从 (1) 滨海区域演变为前滨区域；(2) 受限制或偶尔向大海开放的浅水环境；然后到 (3) 潮间带至潮上带。Bleymard 海峡的 Hettangian 兽脚类生态系统由周期性出现的潮滩和毗邻以针叶树科为主要成分的沿海针叶树为主的森林所居住的 paralic 环境组成。古植物群落的匮乏，以及旱生植物的特征扇叶，表明来自 Bleymard 的植物群适应于承受强烈的阳光和暴露于干燥条件以及咸海喷雾和干燥条件的沿海环境。这些特征是热带至亚热带气候下以针叶树为主的植物群的特征。植物区系和粘土矿物分析表明不同的季节（周期性干燥然后潮湿）。这项研究支持兽脚类动物数量丰富，并且特别适应这种与 Cheirolepidiaceae 占主导地位的森林接壤的沿海环境。