The southeastward extrusion of Indochina along the Ailao Shan–Red River shear zone (ARSZ) is one of two of the most prominent consequences of the India–Asia collision. This plate-scale extrusion has greatly changed Southeast Asian topography and drainage patterns and effected regional climate and biotic evolution. However, little is known about how Indochina was extruded toward the southeast over time. Here, we sampled 42 plant and animal clades (together encompassing 1,721 species) that are distributed across the ARSZ and are not expected to disperse across long distances. We first assess the possible role of climate on driving the phylogenetic separations observed across the ARSZ. We then investigate the temporal dynamics of the extrusion of Indochina through a multitaxon analysis. We show that the lineage divergences across the ARSZ were most likely associated with the Indochinese extrusion rather than climatic events. The lineage divergences began at ~53 Ma and increased sharply ~35 Ma, with two peaks at ~19 Ma and ~7 Ma, and one valley at ~13 Ma. Our results suggest a two-phase model for the extrusion of Indochina, and in each phase, the extrusion was subject to periods of acceleration and decrease, in agreement with the changes of the India–Asia convergence rate and angle from the early Eocene to the late Miocene. This study highlights that a multitaxon analysis can illuminate the timing of subtle historical events that may be difficult for geological data to pinpoint and can be used to explore other tectonic events.

中文翻译：

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系统发育证据阐明了印度支那的挤出历史


印度支那沿着哀牢山-红河剪切带（ARSZ）向东南挤压是印度-亚洲碰撞的两个最突出的后果之一。这种板块尺度的挤压极大地改变了东南亚的地形和排水格局，影响了区域气候和生物进化。然而，人们对印度支那如何随着时间的推移向东南方向挤压却知之甚少。在这里，我们对 42 个植物和动物进化枝（总共包含 1,721 个物种）进行了采样，这些进化枝分布在整个 ARSZ 中，预计不会长距离分散。我们首先评估气候对驱动 ARSZ 观察到的系统发育分离的可能作用。然后，我们通过多分类单元分析研究了印度支那挤压的时间动态。我们发现，整个 ARSZ 的谱系分歧很可能与印度支那的挤压有关，而不是与气候事件有关。谱系分歧开始于〜53 Ma，并在〜35 Ma急剧增加，在〜19 Ma和〜7 Ma有两个峰值，在〜13 Ma有一个谷。我们的研究结果提出了印度支那挤压的两阶段模型，在每个阶段，挤压都经历了加速和减少的时期，这与印度-亚洲辐合速率和角度从始新世早期到新世早期的变化一致。中新世晚期。这项研究强调，多分类单元分析可以阐明地质数据可能难以精确定位的微妙历史事件的时间，并可用于探索其他构造事件。