Parvoolithus

{{Short description|Oogenus of Mongolian fossil eggs}}

{{Oobox

| fossil_range = Campanian
~{{fossil range|84|70}}

| taxon = Parvoolithus

| authority = Mikhailov, 1996

| subdivision_ranks = Oospecies

| subdivision = P. tortuosus

}}

Parvoolithus is an oogenus of Mongolian fossil eggs from the Campanian Barun Goyot Formation. They are known from a single small, smooth egg, which cannot be assigned to any known oofamily.Mikhailov, K.E. (1997). Fossil and recent eggshell in amniotic vertebrates: Fine structure, comparative morphology and classification. Special Papers in Palaeontology 56. The Palaeontological Association. London. (page 58). It is very similar to the eggs of modern birds in many aspects; in fact, a cladistic analysis by Zelenitsky and Therrien found it to be a sister taxon to the guinea fowl (genus Numida), indicating that they represent the eggs of birds, rather than a non-avialan theropod.Zelenitsky, D.K. and Therrien, F. (2008). Phylogenetic analysis of reproductive traits of maniraptoran theropods and its implications for egg parataxonomy. Palaeontology, 51(4): 807–816