[N] 2006 Embryonic ornithischian from the Upper Cretaceous of Mongolia
Norell, M.A. (2006) Embryonic ornithischian from the Upper Cretaceous of Mongolia, Balanoff JVP 26(3) Abstracts pp.38-39
A small egg (~ 4cm) from the upper Cretaceous of Mongolia possible contains the embryonic remains of a Protoceratops. High-resolution X-ray computed tomography (HRCT) is used to visualize and describe the embryonic specimen contained within. The embryonic remains consists primarily of postcranial material, including the femur, tibia, fibula, humerus, ulna, and numerous vertebrae. The embryo is diagnosed to Ornithischia based on the placement of a fourth trochanter along the caudomedial diaphysis of the femur and is tentatively assigned as a protoceratopsian. This assignment is supported by the exclusive presence of protoceratopsians in surrounding sediments. If correctly allocated, this specimen provides another important stage in the life cycle for this clade.