Elongatoolithus is an oogenus of dinosaur eggs found in the Late Cretaceous formations of China and Mongolia. Like other elongatoolithids, they were laid by small theropods, and were cared for and incubated by their parents until hatching. They are often found in nests arranged in multiple layers of concentric rings. As its name suggests, Elongatoolithus was a highly elongated form of egg. It is historically significant for being among the first fossil eggs given a parataxonomic name.
Dendroolithus is an oogenus of Dendroolithid dinosaur egg found in the late Cenomanian Chichengshan Formation, in the Gong-An-Zhai and Santonian Majiacun Formations of China and the Maastrichtian Nemegt and Campanian Barun Goyot Formation of Mongolia. They can be up to 162 mm long and 130 mm wide. These eggs may have been laid by a Therizinosaur, Sauropod, or Ornithopod. The oospecies "D." shangtangensis was originally classified as Dendroolithus, however, it has since been moved to its own distinct oogenus, Similifaveoloolithus. This oogenus is related with embryos of the theropod Torvosaurus
Dictyoolithus is an oogenus of dinosaur egg from the Cretaceous of China. It is notable for having over five superimposed layers of eggshell units. Possibly, it was laid by megalosauroid dinosaurs.
Macroelongatoolithus is an oogenus of large theropod dinosaur eggs, representing the eggs of giant caenagnathid oviraptorosaurs. They are known from Asia and from North America. Historically, several oospecies have been assigned to Macroelongatoolithus, however they are all now considered to be a single oospecies: M. carlylensis.
Macroolithus is an oogenus of dinosaur egg belonging to the oofamily Elongatoolithidae. The type oospecies, M. rugustus, was originally described under the now-defunct oogenus name Oolithes. Three other oospecies are known: M. yaotunensis, M. mutabilis, and M. lashuyuanensis. They are relatively large, elongated eggs with a two-layered eggshell. Their nests consist of large, concentric rings of paired eggs. There is evidence of blue-green pigmentation in its shell, which may have helped camouflage the nests.
Phaceloolithus is an oogenus of dinosaur egg found in the Fenshui'ao Formation of the Dongting Basin of the Hunan Province of China. The eggs have a subspherical shape, measuring up to 168 mm on the long axis, and having a very thin shell.
Porituberoolithus is an oogenus of dinosaur egg found in the late Campanian Oldman Formation and Dinosaur Park Formation of Alberta, the Fossil Forest Member of the Fruitland Formation in New Mexico, the Upper Shale Member of the Aguja Formation in Texas and Cerro del Pueblo Formation of Mexico. It was originally described as distinct from the Elongatoolithids on the basis of its ornamentation, but it was listed as a member of that oofamily by Wang et al. 2010. It is very similar to Subtiliolithus, but has a thicker shell.
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 the once-developing embryo inside, in which case it also contains body fossils. A wide variety of different animal groups laid eggs that are now preserved in the fossil record beginning in the Paleozoic. Examples include invertebrates like ammonoids as well as vertebrates like fishes, possible amphibians, and reptiles. The latter group includes the many dinosaur eggs that have been recovered from Mesozoic strata. Since the organism responsible for laying any given egg fossil is frequently unknown, scientists classify eggs using a parallel system of taxonomy separate from but modeled after the Linnaean system. This "parataxonomy" is called veterovata.
Paraelongatoolithus is a late Cretaceous oogenus of Chinese fossil egg, classified in the oofamily Elongatoolithidae, which represents the eggs of oviraptorosaurs.
This timeline of egg fossils research is a chronologically ordered list of important discoveries, controversies of interpretation, taxonomic revisions, and cultural portrayals of egg fossils. Humans have encountered egg fossils for thousands of years. In Stone Age Mongolia, local peoples fashioned fossil dinosaur eggshell into jewelry. In the Americas, fossil eggs may have inspired Navajo creation myths about the human theft of a primordial water monster's egg. Nevertheless, the scientific study of fossil eggs began much later. As reptiles, dinosaurs were presumed to have laid eggs from the 1820s on, when their first scientifically documented remains were being described in England. In 1859, the first scientifically documented dinosaur egg fossils were discovered in southern France by a Catholic priest and amateur naturalist named Father Jean-Jacques Poech, however he thought they were laid by giant birds.
Coralloidoolithus is an oogenus of dinosaur egg from the Tiantai Basin in Zhejiang Province, containing a single known oospecies C. shizuiwanensis. Formerly, it was classified in the oogenus Paraspheroolithus; however, it was considered sufficiently different to be classified in its own genus. C. shizuiwanensis is similar to Stalicoolithus, leading to their classification in the same family, Stalicoolithidae.
Paradictyoolithus is an oogenus of dictyoolithid dinosaur egg from the Zhejiang Province, China. They are nearly spherical eggs, measuring up to 13.9 cm (5.5 in) in diameter, and have a thin eggshell. Their shells are made up of three or four superimposed layers of eggshell units. The two known oospecies are distinguished mainly by their pore structure.
Elongatoolithidae is an oofamily of fossil eggs, representing the eggs of oviraptorosaurs. They are known for their highly elongated shape. Elongatoolithids have been found in Europe, Asia, and both North and South America.
Guegoolithus is an oogenus of fossil egg from the early Cretaceous of Spain. It is classified in the oofamily Spheroolithidae, and was probably laid by an ornithopod dinosaur.
Undulatoolithus is an oogenus of Chinese fossil dinosaur egg belonging to Elongatoolithidae. It is very similar to Macroolithus, but has different ornamentation. Like other elongatoolithids, it was probably laid by oviraptorosaurs.
Dictyoolithidae is an oofamily of dinosaur eggs which have a distinctive reticulate organization of their eggshell units. They are so far known only from Cretaceous formations in China.
Tubercuoolithus is an oogenus of dinosaur egg from the early Campanian of Montana.
Triprismatoolithus is an oogenus of dinosaur egg native to Teton County, Montana. It is classified in the oofamily Arriagadoolithidae, the eggs of alvarezsaurs.
Pachycorioolithus is an oogenus of small, thin-shelled fossil egg from the early Cretaceous in China. It probably belongs to a bird, though there is a possibility the parent was a non-avian theropod. It was named in 2016, based on a single specimen found in Zhejiang.
Nanhsiungoolithus is an oogenus of dinosaur egg from the late Cretaceous of China. It belongs to the oofamily Elongatoolithidae, which means that it was probably laid by an oviraptorosaur, though so far no skeletal remains have been discovered in association with Nanhsiungoolithus. The oogenus contains only a single described oospecies, N. chuetienensis. It is fairly rare, only being know from two partially preserved nests and a few eggshell fragments.
