''Youngoolithus'' is an

oogenus Egg fossils are the fossilized remains of eggs laid by ancient animals. As evidence of the physiological processes of an animal, egg fossils are considered a type of trace fossil. Under rare circumstances a fossil egg may preserve the remains of t ...

dinosaur egg Dinosaur eggs are the organic vessels in which a dinosaur embryo develops. When the first scientifically documented remains of non-avian dinosaurs were being described in England during the 1820s, it was presumed that dinosaurs had laid eggs be ...

.Carpenter, K. 1999. Eggs, Nests, and Baby Dinosaurs: A Look at Dinosaur Reproduction (Life of the Past). Indiana University Press, Bloomington, Indiana. It is the sole member of the

oofamily Egg fossils are the fossilized remains of eggs laid by ancient animals. As evidence of the physiological processes of an animal, egg fossils are considered a type of trace fossil. Under rare circumstances a fossil egg may preserve the remains of t ...

Youngoolithidae, and consists of a single oospecies: ''Youngoolithus xiaguanensis''. It consists of a single fossil nest of 16 eggs with an associated dinosaur footprint that was first discovered in 1975 in the

Majiacun Formation The Majiacun Formation is a Santonian to Coniacian geologic formation in China. * '' Zhanghenglong, Zhanghenglong yangchengensis''Xing et al., 2014 * Baryonychinae indet.? (possibly an indeterminate theropod due to no shared synapomorphies prese ...

near Houzhuang Village,

Henan Province Henan (; or ; ; alternatively Honan) is a landlocked province of China, in the central part of the country. Henan is often referred to as Zhongyuan or Zhongzhou (), which literally means "central plain" or "midland", although the name is al ...

, in the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Xiaguan Basin. The eggs are smooth, olive-shaped, and arranged in five rows. It was originally described as being a Faveoloolithid egg, however the nest is arranged quite differently than other members of that family, so it has been moved to its own oofamily, Youngoolithidae.

References

Dinosaur reproduction Fossil parataxa described in 1979 {{eggshell-stub