Department of Geology, Center for Advanced Studies, University of Delhi, Delhi, 110007, India.
Higher Secondary School, Dhar District, Bakaner, Madhya Pradesh, India.
Sci Rep. 2022 Jun 7;12(1):9362. doi: 10.1038/s41598-022-13257-3.
Pathologic eggs have been documented in the amniote eggs of birds, turtles, and dinosaurs. These eggs occur either in the form of one egg within another egg, a condition known as ovum-in-ovo or multi-shelled eggs showing additional pathological eggshell layer/s besides the primary shell layer. Though multi-shelled eggs and eggshells were previously recorded only in reptiles and ovum-in-ovo eggs in birds, now it has been shown that multi-shelled egg pathology occurs in birds as well. However, no ovum-in-ovo egg has been reported in dinosaurs or for that matter in other reptiles. Here we describe an ovum-in-ovo pathological egg from a titanosaurid dinosaur nest from the Upper Cretaceous Lameta Formation of western Central India which makes it the first report of this pathology in dinosaurs. Birds possess a specialized uterus while other amniotes have a generalized uterus. However, alligators and crocodiles retain a specialized uterus like birds along with a reptilian mode of egg-laying. The discovery of ovum-in-ovo egg from a titanosaurid dinosaur nest suggests that their oviduct morphology was similar to that of birds opening up the possibility for sequential laying of eggs in this group of sauropod dinosaurs. This new find underscores that the ovum-in-ovo pathology is not unique to birds and sauropods share a reproductive behavior very similar to that of other archosaurs.
已在鸟类、海龟和恐龙的羊膜卵中记录到病理性卵。这些卵要么以一个卵在另一个卵中的形式出现，这种情况称为卵内卵，要么以多壳卵的形式出现，除了主壳层外还有额外的病理性蛋壳层/壳。尽管多壳卵和蛋壳以前仅在爬行动物和鸟类中记录到卵内卵，但现在已经表明，多壳卵病理学也发生在鸟类中。然而，恐龙或其他爬行动物都没有报告卵内卵。在这里，我们描述了一个来自印度中西部上白垩统拉梅塔组的泰坦巨龙恐龙巢中的卵内卵病理性卵，这是恐龙中首次报告这种病理学。鸟类拥有专门的子宫，而其他羊膜动物则拥有通用的子宫。然而，短吻鳄和鳄鱼与鸟类一样保留了专门的子宫，以及爬行动物的产卵方式。从泰坦巨龙恐龙巢中发现卵内卵表明，它们的输卵管形态与鸟类相似，这为这个蜥脚类恐龙群体中的卵序产卵提供了可能性。这一新发现强调了卵内卵病理学并非鸟类所特有，蜥脚类恐龙与其他主龙类动物具有非常相似的繁殖行为。
