Preprismatoolithus

Preprismatoolithus is a Late Jurassic oogenus. The species P. coloradensis is described by John Foster as being "of the prismatic basic type," with subspherical eggs about 10 cm (4 inches) in diameter. This oospecies was first attributed to "hypsilophodontid" dinosaurs, although an initial lack of associated embryo material made confirming the egg-layer's identity impossible. After a finding in Portugal associated prismatic basic types with embryos, it now is known to be theropod.