Danise Silvia, Higgs Nicholas D
School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK Department of Geology, University of Georgia, 210 Field Street, 30602 Athens, GA, USA
Marine Institute, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
Biol Lett. 2015 Apr;11(4):20150072. doi: 10.1098/rsbl.2015.0072.
We report fossil traces of Osedax, a genus of siboglinid annelids that consume the skeletons of sunken vertebrates on the ocean floor, from early-Late Cretaceous (approx. 100 Myr) plesiosaur and sea turtle bones. Although plesiosaurs went extinct at the end-Cretaceous mass extinction (66 Myr), chelonioids survived the event and diversified, and thus provided sustenance for Osedax in the 20 Myr gap preceding the radiation of cetaceans, their main modern food source. This finding shows that marine reptile carcasses, before whales, played a key role in the evolution and dispersal of Osedax and confirms that its generalist ability of colonizing different vertebrate substrates, like fishes and marine birds, besides whale bones, is an ancestral trait. A Cretaceous age for unequivocal Osedax trace fossils also dates back to the Mesozoic the origin of the entire siboglinid family, which includes chemosynthetic tubeworms living at hydrothermal vents and seeps, contrary to phylogenetic estimations of a Late Mesozoic-Cenozoic origin (approx. 50-100 Myr).
我们报告了来自早白垩世晚期（约1亿年前）蛇颈龙和海龟骨骼的食骨蠕虫化石痕迹，食骨蠕虫是一种西伯加林科环节动物，以海底沉没的脊椎动物骨骼为食。尽管蛇颈龙在白垩纪末期大灭绝（6600万年前）时灭绝，但海龟在该事件中幸存并多样化，因此在鲸类动物辐射之前的2000万年间隔期为食骨蠕虫提供了食物来源，鲸类是它们现代的主要食物来源。这一发现表明，在鲸鱼出现之前，海洋爬行动物尸体在食骨蠕虫的进化和扩散中发挥了关键作用，并证实了它除了鲸骨之外，还能在不同脊椎动物尸体上定殖的通才能力是一种祖传特征。明确的食骨蠕虫痕迹化石的白垩纪时代也将整个西伯加林科的起源追溯到中生代，该科包括生活在热液喷口和冷泉的化学合成管虫，这与中生代晚期至新生代起源（约5000万至1亿年前）的系统发育估计相反。
