BURROWING IN LYSTROSAURUS: PREADAPTATION TO A POSTEXTINCTION ENVIRONMENT?
BURROWING IN LYSTROSAURUS: PREADAPTATION TO A POSTEXTINCTION ENVIRONMENT?
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DOI：
10.1080/02724634.2017.1365080
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发表时间：
2017-01-01
影响因子：
1.4
通讯作者：
Botha-Brink, Jennifer
中科院分区：
文献类型：
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作者：
Botha-Brink, Jennifer
水龙兽是在二叠纪-三叠纪大灭绝中幸存下来的标志性物种，并成为早三叠纪最丰富的陆生脊椎动物。先前的报告显示，三叠纪物种的骨骼遗骸被发现在洞穴中，暗示了它成功的可能原因，但缺乏明确的证据表明水龙龙个体是洞穴制造者。我在这里介绍的第一个关节状骨架的水龙兽在一个洞穴从下三叠统的南非卡鲁盆地，沿着埋藏证据表明，这个人是洞穴制造者。该种被鉴定为L. curvatus，唯一的水龙物种恢复从上方和下方推断二叠纪-三叠纪灭绝地平线。它提供了在二叠纪的一种水龙龙中穴居的第一个证据，表明这种行为比以前认为的更普遍。根据其大小，该标本被推断为幼年，表明水龙兽在幼年个体发育阶段就能够挖掘洞穴。在下三叠世地层中发现的大量水龙兽尸体化石和类似大小的洞穴表明，在灭绝后的恶劣、不可预测的条件下，洞穴在水龙兽的成功中发挥了关键作用。鉴于这些洞穴在整个下三叠统水龙兽组合区的丰度，水龙兽可能充当了生态系统工程师和其他物种的避难所提供者，这可能有助于解释卡鲁盆地最低三叠纪的高物种多样性。
Lystrosaurus is iconic for surviving the Permo-Triassic Mass Extinction and becoming the most abundant terrestrial vertebrate during the Early Triassic. Previous reports of skeletal remains of the Triassic species being found in fossilized burrows hint at a possible reason for its success, but unequivocal evidence showing that Lystrosaurus individuals were the burrow makers was lacking. I present here the first articulated skeleton of Lystrosaurus in a fossilized burrow from the Lower Triassic of the South African Karoo Basin, along with taphonomic evidence indicating that this individual was the burrow maker. The species is identified as L. curvatus, the only Lystrosaurus species recovered from above and below the inferred Permo-Triassic extinction horizon. It provides the first evidence of burrowing in a Permian species of Lystrosaurus, suggesting that this behavior was more prevalent than previously thought. Based on its size, the specimen is inferred to be a juvenile, showing that Lystrosaurus was capable of excavating burrows at young ontogenetic stages. The abundance of Lystrosaurus body fossils and similar-sized burrows from Lower Triassic strata suggests that burrowing played a pivotal role in the success of this genus in harsh, unpredictable postextinction conditions. Given the abundance of these burrows throughout the Lower Triassic Lystrosaurus Assemblage Zone, Lystrosaurus may have acted as an ecosystem engineer and refuge provider for other species, which may help to explain the high species diversity in the lowermost Triassic in the Karoo Basin.