Kear Benjamin P, Lee Michael S Y
School of Earth and Environmental Sciences, University of Adelaide, Adelaide 5005, Australia.
Biol Lett. 2006 Mar 22;2(1):116-9. doi: 10.1098/rsbl.2005.0406.
Sea turtles (Chelonioidea) are a prominent group of modern marine reptiles whose early history is poorly understood. Analysis of exceptionally well preserved fossils of Bouliachelys suteri gen. et sp. nov. a large-bodied basal protostegid (primitive chelonioid) from the Early Cretaceous (Albian) of Australia, indicates that early sea turtles were both larger and more diverse than previously thought. The analysis implies at least five distinct sea turtle lineages existed around 100 million years ago. Currently, the postcranially primitive Ctenochelys and Toxochelys are interpreted as crown-group sea turtles closely related to living cheloniids (e.g. Chelonia); in contrast, the new phylogeny suggests that they are transitional (intermediate stem-taxa) between continental testudines and derived, pelagic chelonioids.
海龟(海龟总科)是现代海洋爬行动物中的一个重要类群,但其早期历史却鲜为人知。对来自澳大利亚早白垩世(阿尔比阶)的大型基干原盖龟科(原始海龟类)新属新种——萨特里布氏龟(Bouliachelys suteri)保存异常完好的化石进行分析表明,早期海龟比之前认为的体型更大、种类更多样。该分析表明,在约1亿年前至少存在五个不同的海龟谱系。目前,颅后结构原始的栉齿龟(Ctenochelys)和毒龟(Toxochelys)被解释为与现生海龟科(如绿海龟属(Chelonia))关系密切的冠群海龟;相比之下,新的系统发育分析表明,它们是陆栖龟类与特化的远洋海龟类之间的过渡类型(中间的干群分类单元)。