燕辽生物群脊椎动物的多样性及与其他生物群的对比分析*

燕辽生物群已发现脊椎动物54属58种, 包括鱼类、两栖类、爬行类、哺乳类等, 但其脊椎动物多样性及其成因机制还未有详细研究。本文对该生物群脊椎动物进行统计分析, 并与同时代的其他生物群脊椎动物类型进行对比, 这为认识燕辽生物群脊椎动物的多样性及其成因提供了重要的证据。早期代表道虎沟生物群与晚期代表玲珑塔生物群虽存在时代上的传承关系, 但生物组合特征明显不同。对比燕辽生物群与相近时代的新疆五彩湾动物群和四川大山铺恐龙动物群, 脊椎动物组合特征差异显著。燕辽生物群恐龙类群主要以小型兽脚类恐龙为主, 还包括一些小型鸟臀类恐龙。另外还具有非常丰富的翼龙和哺乳动物。脊椎动物生态多样性高, 适应飞行、树栖、水生、穴居等多种生活方式, 但是脊椎动物的类型与同时代的相近地区明显不同。翼龙、恐龙和哺乳动物等类群都展现出独特的生物组合特征。有证据表明该时期东亚地区与其他地区可能存在一定程度的地理隔离, 结合陆生脊椎动物组合特征推测燕辽生物群脊椎动物与外界可能存在一定的交流障碍。

Vertebrate diversity of the Yanliao Biota and comparison with other biotas

A total of 54 genera and 58 species of vertebrates, including fishes, amphibians, reptiles and mammals, have been reported previously from the Yanliao Biota. However, the diversity of the vertebrates and the formation mechanism of the Yanliao Biota have not been well-studied in detail based on biological analysis. Here, we present a statistical analysis of the vertebrates in the Yanliao Biota and a detailed comparison with other biotas of similar age, which provide significant information on the diversity of vertebrates and the formation of the Yanliao Biota. Although the early Daohugou Biota and the late Linglongta Biota are successive, they show different characteristics of biological combination of vertebrates. The Yanliao Biota, which includes a large number of invertebrate, vertebrate and plant fossils, is significantly different from other biotas of similar age, such as the Wucaiwan Fauna from Xinjiang and the Dashanpu Dinosaur Fauna from the Sichuan Basin. Dinosaurs from the Yanliao Biota contain only small theropods and some early ornithischians. But the Yanliao Biota is very rich in pterosaurs and mammals. Vertebrates from the Yanliao Biota have high ecological diversity and a unique combination of taxa groups. Some evidence indicates that geographic isolation may exist between East Asia and other regions during this period. Combined with the characteristics of terrestrial vertebrate assemblages, it can be inferred that there may have been some obstacles to the interchange of vertebrates between the Yanliao Biota and the outside world.