Abstract Ammonoids suffered a diversity bottleneck during the Permian-Triassic mass extinction (PTME) and experienced a rapid diversification in the Early Triassic. However, the kinds of ammonoids that were more likely to survive the PTME and that fueled subsequent diversification are still poorly known. We compiled a comprehensive morphological data set and used the nonmetric multidimensional scaling method to reveal the impact of the PTME on the morphological selectivity of ammonoids. Our results show that postextinction taxa occupied a quite different morphospace when compared with the pre-extinction assemblages. The survivors were mainly smooth and weakly ornamented forms, while the late Permian species were dominated by coarsely ornamented forms. Contrary to previously recognized nonselective patterns, these results suggest a morphological selectivity of the Permian-Triassic crisis. Newcomers in the Griesbachian were mainly compressed and smooth forms. This morphological shift from the coarsely ornamented ammonoids dominating the Changhsingian to the smooth ammonoids dominating the Griesbachian possibly suggests an ecological turnover of ammonoids during the PTME.

Xu Dai

Dieter Korn

Haijun Song

Geology

自 1973 年出版以来，《地质学》的特点是每月快速出版约 23 篇经过评审的短篇（四页）论文。文章涵盖所有地球科学学科，包括新的调查和挑衅性话题。地球科学专业的地质学家和大学水平的学生使用这本广泛阅读的期刊来跟上科学研究的趋势。在线论坛部分促进了作者与读者的对话。在超大尺寸松散插页上包括彩色插图和偶尔的大幅面插图。

Since its inception in 1973, Geology has featured approximately 23 peer-reviewed short papers (four pages each) published rapidly each month. The articles cover all disciplines of Earth sciences, including new investigations and provocative topics. Geologists and university-level students in the Earth sciences widely read this journal to keep up with trends in scientific research. The online forum section facilitates dialogue between authors and readers. Color illustrations and occasional large-format illustrations are included on oversized loose inserts.

《Geology》自1973年创刊以来，每月快速出版约23篇经过同行评审的短篇论文（四页）。这些文章涵盖了所有地球科学领域，包括新的研究调查和具有挑战性的话题。地球科学专业的地质学家和大学生广泛阅读这本期刊，以跟踪科学研究的最新趋势。期刊的在线论坛部分促进了作者与读者之间的交流。此外，期刊还在超大尺寸的松散插页上包含彩色插图和偶尔的大幅面插图。

Morphological selectivity of the Permian-Triassic ammonoid mass extinction

Figures S1 and S2, and Tables S1, S2 and S3 show the evolution of the number of patents awarded in the United States over the past 50 years.

Category	Quartile
地球科学	1
地球科学, 地质学	1

Morphological selectivity of the Permian-Triassic ammonoid mass extinction

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