Acta Palaeontologica Polonica

Upper Cretaceous amniotic eggs from Gobi Desert

Karol Sabath

Acta Palaeontologica Polonica 36 (2), 1991: 151-192

There are described several types of Upper Cretaceous fossil amniote eggs, clutches and eggshells, collected during the Polish-Mongolian Paleontological Expeditions (1963-1971) in several localities of the Gobi Desert. Isotopic ratios
of C and 0 are reported and discussed. The eggs may be attributed to saurischian and ornithischian dinosaurs, and palaeognathous birds. Four types of problematica are also described. Taphonomy and restoration of eggshells' diffusive
properties as compared with modern hard-shelled eggs suggest paleoecological interpretation of the nesting conditions as rather dry for smooth-shelled eggs, humid for ornamented eggs, and very humid for the thickestahelled eggs. Different nest types are postulated for ornamented and smooth egg, based on taphonomy and shell parameters.

Key words: Eggshells, Dinosauria, Aves, paleobiology, taphonomy, stable isotopes, Upper Cretaceous, Gobi.

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