The Jurassic rise of squamates as supported by lepidosaur disparity and evolutionary rates

The squamates (lizards, snakes, and relatives) today comprise more than 10,000 species, and yet their sister group, the Rhynchocephalia, is represented by a single species today, the tuatara. The explosion in squamate diversity has been tracked back to the Cretaceous Terrestrial Revolution, 100 million years ago (Ma), the time when flowering plants began their takeover of terrestrial ecosystems, associated with diversification of coevolving insects and insect-eating predators such as lizards, birds, and mammals. Squamates arose much earlier, but their long pre-Cretaceous history of some 150 million years (Myr) is documented by sparse fossils. Here, we provide evidence for an initial radiation of squamate morphology in the Middle and Late Jurassic (174–145 Ma), and show that they established their key ecological roles much earlier than had been assumed, and they have not changed them much since., Landmarking
Geometric morphometrics,

现今有鳞目（Squamata，包含蜥蜴、蛇类及其近缘类群）共计超过10000个物种，而其姊妹群喙头蜥目（Rhynchocephalia）目前仅存1个物种——喙头蜥（tuatara）。有鳞目物种多样性的爆发式扩张曾被追溯至1亿年前的白垩纪陆地革命（Cretaceous Terrestrial Revolution）：这一时期被子植物开始主导陆地生态系统，同时伴随协同演化昆虫以及蜥蜴、鸟类、哺乳类等食虫捕食者的辐射分化。有鳞目起源的时间远早于此，但其长达约1.5亿年的白垩纪前演化历史，目前仅能通过少量化石记录得以佐证。本研究提供证据表明，有鳞目在1.74亿至1.45亿年前的中侏罗世至晚侏罗世便发生了初始的形态辐射演化，并证实其关键生态位的建立时间远早于此前的学术推断，且此后其生态位未发生显著改变。
地标标记
几何形态测量学（Geometric morphometrics）