English: Hatching asynchrony inferred from a partial clutch containing three oviraptorid embryos in ovo. (A) Oviraptorid eggs (SMNH-20140105) containing embryological material before preparation and separation into the individual eggs. This specimen is shown in a field-top view. The arrow points to the center of the original clutch, which can be identified based on the blunt ends of the eggs. (B–D) Oviraptorid egg containing scattered embryonic remains after preparation (B: Egg I, SMNH-20140105-1; C: Egg II, SMNH-20140105-2; D: Egg III, SMNH-20140105-3) in a field-top view. (E–G) Photomicrograph of sectioned eggshells from (E) Egg I, (F) Egg II, (G) Egg III. The undulating boundary between the CL and ML, as marked by white arrows, is a distinct feature of Macroolithus sp. (eggs of oviraptorids). The mammillae were a cone-like structure as shown by yellow dash lines. The significant erosion of the mammillary layer shown by the absence of mammillary tips indicates calcium absorption of the developing embryo. i, ilium; l.f., left femur; mt, metatarsal; p: pubis; r.f., right femur; t: tibia; v, vertebrae.