Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada.
Department of Earth Sciences, University of Cambridge, Cambridge, Cambridgeshire CB2 3EQ, UK.
Integr Comp Biol. 2022 Aug 25;62(2):297-331. doi: 10.1093/icb/icac059.
The invasion of the land was a complex, protracted process, punctuated by mass extinctions, that involved multiple routes from marine environments. We integrate paleobiology, ichnology, sedimentology, and geomorphology to reconstruct Paleozoic terrestrialization. Cambrian landscapes were dominated by laterally mobile rivers with unstable banks in the absence of significant vegetation. Temporary incursions by arthropods and worm-like organisms into coastal environments apparently did not result in establishment of continental communities. Contemporaneous lacustrine faunas may have been inhibited by limited nutrient delivery and high sediment loads. The Ordovician appearance of early land plants triggered a shift in the primary locus of the global clay mineral factory, increasing the amount of mudrock on the continents. The Silurian-Devonian rise of vascular land plants, including the first forests and extensive root systems, was instrumental in further retaining fine sediment on alluvial plains. These innovations led to increased architectural complexity of braided and meandering rivers. Landscape changes were synchronous with establishment of freshwater and terrestrial arthropod faunas in overbank areas, abandoned fluvial channels, lake margins, ephemeral lakes, and inland deserts. Silurian-Devonian lakes experienced improved nutrient availability, due to increased phosphate weathering and terrestrial humic matter. All these changes favoured frequent invasions to permament establishment of jawless and jawed fishes in freshwater habitats and the subsequent tetrapod colonization of the land. The Carboniferous saw rapid diversification of tetrapods, mostly linked to aquatic reproduction, and land plants, including gymnosperms. Deeper root systems promoted further riverbank stabilization, contributing to the rise of anabranching rivers and braided systems with vegetated islands. New lineages of aquatic insects developed and expanded novel feeding modes, including herbivory. Late Paleozoic soils commonly contain pervasive root and millipede traces. Lacustrine animal communities diversified, accompanied by increased food-web complexity and improved food delivery which may have favored permanent colonization of offshore and deep-water lake environments. These trends continued in the Permian, but progressive aridification favored formation of hypersaline lakes, which were stressful for colonization. The Capitanian and end-Permian extinctions affected lacustrine and fluvial biotas, particularly the invertebrate infauna, although burrowing may have allowed some tetrapods to survive associated global warming and increased aridification.
陆地的入侵是一个复杂而漫长的过程，伴随着大规模灭绝，涉及从海洋环境到陆地的多种途径。我们整合古生物学、足迹学、沉积学和地貌学来重建古生代的陆地化过程。寒武纪的景观以横向移动的河流为主，河岸不稳定，植被稀少。节肢动物和类似蠕虫的生物暂时侵入沿海环境，显然并没有在大陆上建立群落。同期的湖泊动物群可能受到有限的养分供应和高沉积物负荷的抑制。奥陶纪早期陆地植物的出现引发了全球粘土矿物工厂主要位置的转移，增加了大陆上泥岩的数量。志留纪-泥盆纪维管陆地植物的兴起，包括第一批森林和广泛的根系，在进一步保留冲积平原上的细沉积物方面发挥了重要作用。这些创新导致了辫状河和曲流河的结构复杂性增加。景观变化与淡水和陆地节肢动物在漫滩、废弃河道、湖岸、短暂湖泊和内陆沙漠中的群落的建立同步发生。志留纪-泥盆纪的湖泊由于磷酸盐风化和陆地腐殖质的增加，养分供应得到改善。所有这些变化都有利于无颚和有颚鱼类频繁入侵淡水生境，并随后使四足动物在陆地上殖民。石炭纪见证了四足动物的快速多样化，这主要与水生繁殖有关，还有陆地植物，包括裸子植物。更深的根系促进了河岸的进一步稳定，有助于形成有植被岛屿的叉状河流和辫状水系。新型水生昆虫谱系的发展和新型摄食方式的扩展，包括草食性。晚古生代土壤通常含有广泛的根系和马陆痕迹。湖泊动物群落的多样性增加，伴随着食物网复杂性的提高和食物输送的改善，这可能有利于永久性地殖民近海和深水湖泊环境。这些趋势在二叠纪继续发展，但渐进的干旱化有利于形成高盐湖泊，这对殖民来说是一种压力。卡匹坦阶和二叠纪末期的灭绝影响了湖泊和河流生物群，特别是无脊椎动物的内部动物群，尽管挖掘可能允许一些四足动物在相关的全球变暖事件和增加的干旱化中幸存下来。
