• Researchers discover overlooked Jurassic

    From ScienceDaily@1:317/3 to All on Tue May 3 22:30:40 2022
    Researchers discover overlooked Jurassic Park of lizards

    Date:
    May 3, 2022
    Source:
    University of Bristol
    Summary:
    New research moves back the moment of the radiation of squamates
    -- the group of reptiles that includes lizards, snakes and worm
    lizards -- to the Jurassic, a long time before current estimates.



    FULL STORY ==========================================================================
    New research published today in eLife by researchers from the Institut
    Catala` de Paleontologia Miquel Crusafont (ICP) and the University of
    Bristol (UB) moves back the moment of the radiation of squamates --
    the group of reptiles that includes lizards, snakes and worm lizards --
    to the Jurassic, a long time before current estimates.


    ==========================================================================
    The Squamata is the largest order of reptiles, including lizards, snakes
    and worm lizards. Squamates are all cold-blooded, and their skins are
    covered by horny scales. They are key parts of modern terrestrial faunas, especially in warmer climates, with an astonishing diversity of more
    than 10,000 species.

    However, understanding the evolutionary paths that forged their success
    are still poorly understood.

    There is consensus that all the main squamate groups had arisen before
    the event that wiped out dinosaurs and other groups of reptiles at
    the end of the Mesozoic era. Before that global catastrophic event,
    through the Cretaceous, many terrestrial tetrapod groups like mammals,
    lizards and birds, apparently underwent a great diversification during
    the so-called Cretaceous Terrestrial Revolution, triggered by the rise
    of flowering plants. The scarcity of fossil remains of squamates through
    the Jurassic suggested that the main burst of squamate evolution happened
    in the Cretaceous (between 145 and 66 Myr.), when their fossil record dramatically improves.

    Now, a new paper published in eLife, led by Arnau Bolet, paleontologist
    at the Institut Catala` de Paleontologia Miquel Crusafont and the
    University of Bristol, however, challenges this view by suggesting
    a much earlier radiation of squamates. Along with colleagues from the University of Bristol Michael Benton, Tom Stubbs and Jorge Herrera-Flores, their research concludes that this group of reptiles probably achieved a diverse array of adaptations in the Jurassic (between 201 and 145 Myr.),
    long before previously thought. "Even though Jurassic squamates are rare, reconstructed evolutionary trees show that all the main specializations
    of squamates evolved then, and it's possible to distinguish adaptations
    of geckoes, iguanas, skinks, worm lizards, and snakes some 50 million
    years earlier than had been thought," explains Michael Benton, co-author
    of the research.

    But how could the scarce Jurassic fossils suggest an early burst in
    evolution? The key is in their anatomy. The few Jurassic squamates do not
    show primitive morphologies as would be expected, but they relate directly
    to the diverse modern groups. "Instead of finding a suite of generalized lizards on the stem of the squamate tree, what we found in the Jurassic
    were the first representatives of many modern groups, showing advanced morphological features," says Arnau Bolet, lead author of the article.

    The observed times of divergence, morphospace plots and evolutionary
    rates, all suggest that the Jurassic was a time of innovation in squamate evolution, during which the bases of the success of the group were
    established. According to these results, the apparent sudden increase
    in diversity observed in the Cretaceous could be related to an improved
    fossil record, capable of recording a larger number of species, or to
    a burst of origins of new species related to the new kinds of forests
    and insects.

    Establishing the timing and mode of radiation of squamates is key for not
    only understanding the dynamics of terrestrial ecosystems in the Mesozoic,
    but also for deciphering how the group achieved an astonishing diversity
    of more than 10,000 species, only rivalled by birds among tetrapods.


    ========================================================================== Story Source: Materials provided by University_of_Bristol. Note: Content
    may be edited for style and length.


    ========================================================================== Related Multimedia:
    * The_fossil_of_Jurassic_lizard_Eichstaettisaurus ========================================================================== Journal Reference:
    1. Arnau Bolet, Thomas L Stubbs, Jorge A Herrera-Flores, Michael
    J Benton.

    The Jurassic rise of squamates as supported by lepidosaur disparity
    and evolutionary rates. eLife, 2022; 11 DOI: 10.7554/eLife.66511 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/05/220503091754.htm

    --- up 9 weeks, 1 day, 10 hours, 50 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)