Abstract:
Clam shrimps are a group of freshwater crustaceans who prospered during the Late Triassic. They were abundant in lacustrine sedimentary records of continental basins distributed throughout Pangea during this time. However, they show significant taxonomic differences between the clamp shrimp faunas from the rift basins of central Pangea and the southern Gondwanan basins. In this contribution, we show new fossil clam shrimp assemblages from the lacustrine sedimentary successions of the Eastern Cordillera of Colombia (the Bocas and Montebel formations), providing information on the Late Triassic species that inhabited the northwestern Gondwana basins. This study demonstrates that the basins of northwestern Gondwana shared Norian clamp shrimp species with rift basins of central Pangea and differed in their faunas with the basins of the southern portion of Gondwana. In addition, the Late Triassic clam shrimps paleobiogeographic distribution reflects the dispersal of this fauna throughout fluvial-lacustrine environments established in the rift valleys along the central Pangea. Therefore, the rift valleys produced during the early fragmentation of central Pangea could have acted as corridors for dispersion. Simultaneously, rift valleys also provided paleobiogeographic barriers that isolated the central Pangea clam shrimp faunas from southern Gondwana.
摘要:
蛤虾是一群在三叠纪晚期繁荣昌盛的淡水甲壳类动物。在此期间,它们在整个盘古分布的陆相盆地的湖相沉积记录中很丰富。然而,它们显示出来自中部Pangea裂谷盆地和南部Gondwanan盆地的钳夹虾动物区系之间的显着分类学差异。在这一贡献中,我们展示了来自哥伦比亚东部科迪勒拉山脉(Bocas和Montebel地层)的湖相沉积演替的新的蛤虾化石组合,提供有关居住在西北冈瓦纳盆地的晚三叠世物种的信息。这项研究表明,冈瓦纳西北部的盆地与中央盘古的裂谷盆地共享Norian夹虾物种,并且它们的动物区系与冈瓦纳南部的盆地不同。此外,晚三叠纪蛤虾的古生物地理分布反映了该动物区系在整个Pangea中部裂谷中建立的河流-湖泊环境中的分布。因此,在中央Pangea早期破碎期间产生的裂谷可以充当分散的走廊。同时,裂谷还提供了古生物地理屏障,将中央Pangeaclam虾类动物与冈瓦纳南部隔离开来。