Department of Mesozoic Faunas, Institut Català de Paleontologia "Miquel Crusafont", c/Escola Industrial 23, 08201, Sabadell, Spain.
Museu Conca Dellà, c/del Museu 4, 25650, Isona, Spain.
Sci Rep. 2017 Oct 23;7(1):13827. doi: 10.1038/s41598-017-14255-6.
The occurrence of dinosaur pathologic eggs in the Late Cretaceous of Europe is well known, but their origin remains unclear. Here we expose the results of a detailed sampling of the conspicuous fossil record of Late Cretaceous titanosaurian eggs (oogenus Megaloolithius) from several southwestern Europe basins. After examining more than 450 samples, we observed a remarkable and statistically supported occurrence of multiple pathologic eggs in a relatively short stratigraphic range at the end of the early Maastrichtian, circa 71-70 Ma. All pathologic specimens exhibit multi-layered eggshell condition, a characteristic related to dystocia, or egg retention within the female uterus for an abnormal prolonged period of time. After exploring various scenarios, the occurrence of pathologic eggs is strongly correlated with an intense dinosaur faunal replacement that occurred during the early Maastrichtian in the Ibero-Armorican Island. Given that inter-species competiveness is proved to produce major affects in ecological communities, our results suggest that pathologies in the eggs of European titanosaurians could be a consequence of an increase in reproductive stress triggered by direct ecological competition between different dinosaurs. Thus, the present study provides a new perspective of how dinosaurs might have been affected by ecological/environmental disturbance.
恐龙病理性蛋在欧洲晚白垩世的出现是众所周知的，但它们的起源仍然不清楚。在这里，我们展示了对来自欧洲西南部几个盆地的晚白垩世泰坦巨龙蛋（卵属 Megaloolithius）显著化石记录进行详细采样的结果。在检查了超过 450 个样本后，我们在早马斯特里赫特期末期（约 71-70 Ma）的相对较短的地层范围内观察到了一种显著的、具有统计学支持的多例病理性蛋的出现。所有病理性标本都表现出多层蛋壳状况，这一特征与难产或蛋在雌性子宫内异常长时间保留有关。在探讨了各种情况后，病理性蛋的出现与早马斯特里赫特时期伊比利亚-阿莫林岛发生的强烈恐龙动物群更替密切相关。鉴于物种间的竞争力被证明会对生态群落产生重大影响，我们的结果表明，欧洲泰坦巨龙蛋中的病理学可能是不同恐龙之间直接生态竞争引发的繁殖压力增加的结果。因此，本研究为恐龙如何受到生态/环境干扰的影响提供了一个新的视角。
