Reports

Upper Jurassic Dinosaur Egg from Utah

Science  31 Mar 1989:
Vol. 243, Issue 4899, pp. 1711-1713
DOI: 10.1126/science.243.4899.1711

Abstract

The Upper Jurassic egg described here is the first known egg from the 100-million-year gap in the fossil record between Lower Jurassic (South Africa) and upper Lower Cretaceous (Utah). The discovery of the egg, which was found mixed in with thousands of dinosaur bones rather than in a nest, the pathological multilayering of the eggshell as found in modern and fossil reptilians, and the pliable condition of the eggshell at the time of burial indicate an oviducal retention of the egg at the time of burial.