A Cretaceous troodontid laid her pairs of eggs vertically and arranged spirally in a nest
Unlike other dinosaurs,the troodontids laid their eggs standing up in loose sands or muddy soil.The clutch of fossil tro-odontid eggs in the Upper Cretaceous Chichengshan Formation from Tiantai Basin,Zhejiang Province,China indicated that these crea-tures produced a pair of eggs every time in open nests and covered them with sands or muddy soil and laid their eggs starting at the cen-ter of the nest,then screwed in turn outward laying more than 20 eggs per nest.It suggests that a female troodontid had a pair of func-tional oviducts as that of oviraptorosaurs,and laid her eggs again and again in a single nest and perhaps looked after these eggs fre-quently.The troodontid eggshell,furthermore,was rigid as that of some modern bird eggs and strong enough to resist pressure while the eggs were forced into sands and muddy soil when they were laid.Some of the other dinosaur eggshells,in contrast,were stretchable as those of some modern reptiles.
NETL
NSTL
万方数据
维普
