Stalicoolithidae Temporal range:
| |
---|---|
Egg fossil classification ![]() | |
Basic shell type: | †Dinosauroid-spherulitic |
Oofamily: | †Stalicoolithidae Wang, Wang, Zhao & Jiang, 2012 |
Oogenera | |
Stalicoolithidae is an oofamily of fossil eggs.[1]
Stalicoolithid eggs were first discovered in 1971, but they were described initially as Dendroolithids,[2] or as Spheroolithids, in the case of "Paraspheroolithus" shizuiwanensis and Shixingoolithus.[1]
Stalicoolithids are distinguished from other oofamilies by several characteristics. Most significantly, they have secondary eggshell units in the outer zone, and three distinct subzones of the columnar layer.[1][2] They have a unique mix of developmental characteristics, giving insight into the evolution of the amniotic eggshell.[1]
Stalicoolithidae contains at least three oogenera: Coralloidoolithus, Stalicoolithus, and Shixingoolithus. Shixingoolithus contains two oospecies: S. erbeni and S. qianshanensis.[1][3][4] Also, the enigmatic Parvoblongoolithus could potentially be a stalicoolithid.[2]