Science. 1989 Mar 31;243(4899):1711-3. doi: 10.1126/science.243.4899.1711.
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.
这里描述的上侏罗纪蛋是已知的第一个填补了下侏罗纪(南非)和下白垩纪早期(犹他州)之间 1 亿年化石记录空白的蛋。这个蛋是在与数千块恐龙骨骼混合在一起而不是在巢中发现的,蛋壳的病理性多层结构在现代和化石爬行动物中都有发现,而且蛋壳在埋藏时的柔韧性都表明蛋壳是在产卵管中被保留下来的。