Qvarnström Martin, Vikberg Wernström Joel, Wawrzyniak Zuzanna, Barbacka Maria, Pacyna Grzegorz, Górecki Artur, Ziaja Jadwiga, Jarzynka Agata, Owocki Krzysztof, Sulej Tomasz, Marynowski Leszek, Pieńkowski Grzegorz, Ahlberg Per E, Niedźwiedzki Grzegorz
Department of Organismal Biology, Uppsala University, Uppsala, Sweden.
The Arctic University Museum of Norway, UiT The Arctic University of Norway, Tromsø, Norway.
Nature. 2024 Dec;636(8042):397-403. doi: 10.1038/s41586-024-08265-4. Epub 2024 Nov 27.
The early radiation of dinosaurs remains a complex and poorly understood evolutionary event. Here we use hundreds of fossils with direct evidence of feeding to compare trophic dynamics across five vertebrate assemblages that record this event in the Triassic-Jurassic succession of the Polish Basin (central Europe). Bromalites, fossil digestive products, increase in size and diversity across the interval, indicating the emergence of larger dinosaur faunas with new feeding patterns. Well-preserved food residues and bromalite-taxon associations enable broad inferences of trophic interactions. Our results, integrated with climate and plant data, indicate a stepwise increase of dinosaur diversity and ecospace occupancy in the area. This involved (1) a replacement of non-dinosaur guild members by opportunistic and omnivorous dinosaur precursors, followed by (2) the emergence of insect and fish-eating theropods and small omnivorous dinosaurs. Climate change in the latest Triassic resulted in substantial vegetation changes that paved the way for ((3) and (4)) an expansion of herbivore ecospace and the replacement of pseudosuchian and therapsid herbivores by large sauropodomorphs and early ornithischians that ingested food of a broader range, even including burnt plants. Finally, (5) theropods rapidly evolved and developed enormous sizes in response to the appearance of the new herbivore guild. We suggest that the processes shown by the Polish data may explain global patterns, shedding new light on the environmentally governed emergence of dinosaur dominance and gigantism that endured until the end-Cretaceous mass extinction.
恐龙的早期辐射仍然是一个复杂且鲜为人知的进化事件。在此，我们使用数百个具有进食直接证据的化石，来比较五个脊椎动物组合中的营养动态，这些组合记录了中欧波兰盆地三叠纪 - 侏罗纪演替过程中的这一事件。粪化石（化石消化产物）在这一时期大小和多样性均有所增加，表明出现了具有新进食模式的更大恐龙动物群。保存完好的食物残渣以及粪化石 - 分类群关联使得对营养相互作用能够进行广泛推断。我们的结果与气候和植物数据相结合，表明该地区恐龙多样性和生态空间占有率呈逐步增加趋势。这一过程包括：（1）机会主义和杂食性恐龙先驱取代了非恐龙类群成员，随后（2）出现了食虫和食鱼的兽脚亚目恐龙以及小型杂食性恐龙。三叠纪晚期的气候变化导致植被发生重大变化，为（（3）和（4））食草动物生态空间的扩大以及大型蜥脚形亚目恐龙和早期鸟臀目恐龙取代伪鳄类和兽孔目食草动物铺平了道路，这些恐龙摄入范围更广的食物，甚至包括烧焦的植物。最后，（5）兽脚亚目恐龙迅速进化并体型变得巨大，以应对新的食草动物类群的出现。我们认为波兰数据所显示的过程可能解释全球模式，为直到白垩纪末大灭绝一直存在的恐龙主导地位和巨型化的环境驱动出现提供新的线索。
