Molecular clock calculations suggest a late Cambrian (~ 500 Ma) divergence of myriapod classes. Yet, the earliest myriapods only appear in the latest Silurian (~425 Ma). 75 million years later; though correlation with the standard marine-based geological time scale is difficult. We radiometrically dated (U/Pb method) zircons in sediments at 3 sites in the UK associated with the supposed earliest millipedes. Kerrera, with only extinct kampecarid myriapods from temporary playa lake deposits in a semi-arid intermontane basin is 425 Ma old. Ludlow, with kampecarid myriapods and the first trigonotarbid arachnids (with book lungs), from transported material in ripple troughs at the base of a semi-arid delta complex, is 420 Ma. Cowie, with the supposed earliest air-breathing millipede (with spiracles), from a temporary playa lake in an intermontane basin complex, is 414 Ma old. The more diverse land arthropod fauna of the Rhynie Chert hot spring deposit, also in an intermontane basin, is 407 Ma old. A rapid radiative evolution from simple intermontane lake margin communities through more evolved lowland communities took only about 20 Ma to reach complex forest grade communities by the Middle Devonian Givetian (about 385 million years).

分子时钟计算表明，晚寒武纪（〜500 Ma）的万足纲类的发散。然而，最早的无足动物仅出现在最新的志留纪（〜425 Ma）中。7500万年后；尽管很难与标准的海洋地质时标建立关联。我们对英国3个地点的沉积物中的锆石进行了放射性测年（U / Pb法），并与最早的千足虫有关。克雷拉（Kerrera）仅有425 Ma，是一个半干旱的山间盆地中临时普拉亚湖沉积物中已灭绝的坎帕克拉德万寿菊。来自半干旱三角洲复合体底部波纹沟中的已运输物质的卢德洛（Kampecarid myriapods）和第一个三角虫蛛形纲（有书肺）。考伊（Cowie），被认为是最早呼吸空气的千足虫（有气瓶），来自一座山际盆地综合体中的临时普拉亚湖，年龄414 Ma。Rhynie Chert温泉矿床的更多样化的陆生节肢动物区系，也位于一个山间盆地，年龄为407 Ma。从简单的山间湖边缘社区到更发达的低地社区的快速辐射演化，仅需20 Ma即可通过中泥盆纪纪天地（约3.85亿年）到达复杂的森林等级社区。