These oological records have helped in analyzing dinosaur reproductionВ and nesting behavior which fall between the other archosaurs, such as crocodiles and birds.

These cledoic eggs are notably observed in the oological records of theropods, sauropodomorphs, and ornithischians more or less from all over the globe 2, 3, 4, 5, along with the rare occurrences of embryos 6, 7, 8. Two traits that collectively characterize dinosaurs, birds, and other archosaurs are oviparous mode of reproduction and cledoic egg, the latter of which was instrumental in the rise of amniotes 1. 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. The discovery of ovum-in-ovo egg from a titanosaurid dinosaur nest suggests that their oviduct morphology was similar to that ofВ birds opening up the possibility for sequential laying of eggs in this group of sauropod dinosaurs. However, alligators and crocodiles retain a specialized uterus like birds along with a reptilian mode of egg-laying. Birds possess a specialized uterus while other amniotes have a generalized uterus. 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. However, no ovum-in-ovo egg has been reported in dinosaurs or for that matter inВ other reptiles. Though multi-shelled eggs and eggshells were previously recorded only in reptiles and ovum-in-ovo eggsВ in birds, now it has been shown that multi-shelled egg pathology occurs in birds as well. 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. Pathologic eggs have been documented in the amniote eggs of birds, turtles, and dinosaurs.

Outline synonym