fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
ized remains of
egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...
s laid by
ancient
Ancient history is a time period from the History of writing, beginning of writing and recorded human history to as far as late antiquity. The span of recorded history is roughly 5,000 years, beginning with the Sumerian language, Sumerian c ...
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s. As evidence of the
physiological
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
processes of an animal, egg fossils are considered a type of
trace fossil
A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, ...
. Under rare circumstances a fossil egg may preserve the remains of the once- developing
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
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
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon.
The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838
by combining the Greek words ''palaiós'' (, "old") and ' ...
. Examples include
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s like
ammonoids
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
as well as
vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
s like
fishes
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
, possible
amphibian
Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...
s, and
reptile
Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...
s. The latter group includes the many
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 bec ...
s that have been recovered from
Mesozoic
The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceo ...
strata
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ei ...
. 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
Linnaean taxonomy can mean either of two related concepts:
# The particular form of biological classification (taxonomy) set up by Carl Linnaeus, as set forth in his '' Systema Naturae'' (1735) and subsequent works. In the taxonomy of Linnaeus ...
. This "
parataxonomy
Parataxonomy is a system of labor division for use in biodiversity research, in which the rough sorting tasks of specimen collection, field identification, documentation and preservation are conducted by primarily local, less specialized individu ...
" is called ''veterovata''.
History
The first named oospecies was '' Oolithes bathonicae'', a name given provisionally by Professor J. Buckman to a group of eggs which Buckman believed were laid by a
teleosaur
Teleosauridae is a family of extinct typically marine crocodylomorphs similar to the modern gharial that lived during the Jurassic period. Teleosaurids were thalattosuchians closely related to the fully aquatic metriorhynchoids, but were less a ...
. However, modern scientists no longer think it is possible to determine what kind of reptile laid these eggs. In 1859, the first scientifically documented dinosaur egg fossils were discovered in southern France by a Catholic
priest
A priest is a religious leader authorized to perform the sacred rituals of a religion, especially as a mediatory agent between humans and one or more deities. They also have the authority or power to administer religious rites; in particu ...
and amateur naturalist named Father
Jean-Jacques Poech Jean-Jacques is a French name, equivalent to "John James" in English. Since the second half of 18th century, Jean Jacques Rousseau was widely known as Jean Jacques. Notable people bearing this name include:
Given name
* Jean-Jacques Annaud (born 19 ...
, however he thought they were laid by giant birds.
The first scientifically ''recognized'' dinosaur egg fossils were discovered
serendipitously
Serendipity is an unplanned fortunate discovery. Serendipity is a common occurrence throughout the history of product invention and scientific discovery.
Etymology
The first noted use of "serendipity" was by Horace Walpole on 28 January 1754. I ...
in 1923 by an
American Museum of Natural History
The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...
crew while looking for evidence of
early humans
''Homo'' () is the genus that emerged in the (otherwise extinct) genus ''Australopithecus'' that encompasses the extant species ''Homo sapiens'' (modern humans), plus several extinct species classified as either ancestral to or closely related ...
in Mongolia. Egg discoveries continued to mount all over the world, leading to the development of multiple competing classification schemes. In 1975 Chinese paleontologist
Zhao Zi-Kui Zhao may refer to:
* Zhao (surname) (赵), a Chinese surname
** commonly spelled Chao in Taiwan or up until the early 20th century in other regions
** Chiu, from the Cantonese pronunciation
** Cho (Korean surname), represent the Hanja 趙 (Chinese ...
started a revolution in fossil egg classification by developing a system of "
parataxonomy
Parataxonomy is a system of labor division for use in biodiversity research, in which the rough sorting tasks of specimen collection, field identification, documentation and preservation are conducted by primarily local, less specialized individu ...
" based on the traditional Linnaean system to classify eggs based on their physical qualities rather than their hypothesized mothers. Zhao's new method of egg classification was hindered from adoption by Western scientists due to language barriers. However, in the early 1990s Russian paleontologist Konstantin Mikhailov brought attention to Zhao's work in the English language
scientific literature
: ''For a broader class of literature, see Academic publishing.''
Scientific literature comprises scholarly publications that report original empirical and theoretical work in the natural and social sciences. Within an academic field, scient ...
.
Diversity
Invertebrates
Eggs laid by invertebrate animals are known from the fossil record. Among these are eggs laid by ancient
cephalopods
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, an ...
. Eggs laid by
ammonoids
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
are the best known cephalopod egg fossils. The best preserved fossil ammonite eggs were preserved in the
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
Kimmeridge Clay
The Kimmeridge Clay is a sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea. This rock formation is the major source rock for North ...
of
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
. Nevertheless, the
fossil record
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
of cephalopod eggs is scant since their soft, gelatinous eggs decompose quickly and have little chance to fossilize. Another major group of Mesozoic cephalopods, the belemnoids, have no documented eggs in the fossil record whatsoever, although this may be because scientists have not properly searched for them rather than an actual absence from the fossil record.
Fishes and amphibians
Fossil fish eggs have an extensive record going at least as far back as the
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
and spanning into the
Cenozoic era
The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...
. The eggs of many different fish
taxa
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
have contributed to this record, including
lobe-finned fish
Sarcopterygii (; ) — sometimes considered synonymous with Crossopterygii () — is a taxon (traditionally a class or subclass) of the bony fishes known as the lobe-finned fishes. The group Tetrapoda, a mostly terrestrial superclass includ ...
,
placoderms
Placodermi (from Greek πλάξ 'plate' and δέρμα 'skin', literally 'plate-skinned') is a class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were ...
, and
sharks
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorp ...
. Occasionally eggs are preserved still within the mother's body, or associated with fossil
embryos
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sper ...
. Some fossil eggs possibly laid by fish cannot be confidently distinguished from those laid by
amphibians
Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbore ...
The fossil record of reptile eggs goes back at least as far as the
Early Permian 01 or '01 may refer to:
* The year 2001, or any year ending with 01
* The month of January
* 1 (number)
Music
* '01 (Richard Müller album), 01'' (Richard Müller album), 2001
* 01 (Son of Dave album), ''01'' (Son of Dave album), 2000
* 01 (Urban ...
. However, since the earliest reptile eggs probably had soft shells with little preservation potential, reptilian eggs may go back significantly farther than their fossil record. Many ancient reptile groups are known from egg fossils including
crocodilia
Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period ( Cenomanian stage) and are the closest living ...
ns,
dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...
s, and turtles. Some ancient reptiles, like ichthyosaursEllis, Richard, (2003) ''Sea Dragons - Predators of the Prehistoric Oceans''. University Press of Kansas. . and plesiosaurs are known to have given live birth and are therefore not anticipated to have left behind egg fossils. Dinosaur eggs are among the most well known kind of fossil reptile eggs.
Classification
Fossil eggs are classified according to the parataxonomic system called Veterovata. There are three broad categories in the scheme, on the pattern of organismal phylogenetic classification, called oofamilies, oogenera and oospecies (collectively known as ootaxa).Olga Amo, Gloria Cuenca–Bescós & José Ignacio Canudo (1999). José Ignacio Canudo & Gloria Cuenca-Bescós, ed. "Vertebrate eggshell fragments from the Lower Cretaceous (Lower Barremian) of Camino Canales (Galve Bassin, Province of Teruel, NE Spain)" (PDF). IV European Workshop on Vertebrate Palaeontology. Albarracín, Spain: Universidad de Zaragoza. The names of oogenera and oofamilies conventionally contain the root "oolithus" meaning "stone egg", but this rule is not always followed. They are divided up into several basic types: Testudoid, Geckoid, Crocodiloid, Dinosauroid-spherulitic, Dinosauroid-prismatic, and Ornithoid. Veterovata does not always mirror the taxonomy of the animals which laid the eggs.Carpenter, Kenneth (1999). ''Eggs, Nests, and Baby Dinosaurs: A Look at Dinosaur Reproduction (Life of the Past)'', Indiana University Press; .
Parataxonomy
The oogenus level parataxonomy of Veterovata, following Lawver and Jackson (2014) for Testudoid, Hirsch (1996) for Geckonoid eggs, and Mikhailov et al. (1996) for the rest unless otherwise noted:
Testudoid
* ''Spheruflexibilis'' morphotype
** Oofamily Testudoflexoolithidae
*** '' Testudoflexoolithus''
* ''Spherurigidis'' morphotype
** Oofamily Testudoolithidae
*** '' Testudoolithus''
*** '' Emydoolithus''
*** '' Haininchelys''
*** '' Chelonoolithus''
Geckonoid
* Geckonoid morphotype
** Oofamily
Gekkoolithidae
''Gekkoolithus'' is an oogenus of fossil gecko egg. Unfortunately, gecko eggs have not been well-studied, and their fossils are very rare, making classification of them difficult. ''Gekkolithus'' eggs are very similar to those of the modern '' Ph ...
Mycomorphoolithus
''Mycomorphoolithus'' (meaning "fungus-shaped stone egg") is an oogenus of fossil eggs found in Spain and England. They possibly represent eggshells of non-eusuchian Crocodylomorpha, crocodylomorphs, and are similar to, but not part of, the Krokol ...
* Oofamily
Krokolithidae
Krokolithidae is an oofamily of fossil crocodylomorph eggs. The oogenus ''Mycomorphoolithus
''Mycomorphoolithus'' (meaning "fungus-shaped stone egg") is an oogenus of fossil eggs found in Spain and England. They possibly represent eggshells of ...
** ''
Bauruoolithus
''Bauruoolithus'' is an oogenus of fossilized eggs belonging to an extinct crocodyliform from the Late Cretaceous (late Campanian-early Maastrichtian) of Brazil. ''Bauruoolithus'' eggs were most likely laid by the notosuchian crocodyliform ''Baur ...
''
** ''
Krokolithes
''Krokolithes'' is an oogenus of Crocodiloid eggs. These eggs were laid by an extinct species of Crocodylian. It contains three oospecies: ''K. dinophilus'', ''K. wilsoni'' and ''K. helleri''.
1
Fossils of the oogenus have been found in the Oligo ...
Antarcticoolithus
''Antarcticoolithus'' is an oogenus of large fossil eggs from the Maastrichtian part of the Lopez de Bertodano Formation of Seymour Island, Antarctica. The genus contains the type species ''A. bradyi'', described by Legendre et al. in 2020. The ...
Spheroolithus
''Spheroolithus'' is an oogenus of dinosaur egg.Wang Q, Wang X L, Zhao Z K, and Jiang Y G. (2012).A new oofamily of dinosaur egg from the Upper Cretaceous of Tiantai Basin, Zhejiang Province, and its mechanism of eggshell formation Chinese Scienc ...
Ovaloolithus
''Ovaloolithus'' is an oogenus of dinosaur egg. Eggs of the genus have been found in China, Mongolia and Utah.
Species
Oospecies attributed to this genus include:Megaloolithidae
** '' Megaloolithus''
** '' Pseudomegaloolithus''
* Oofamily
Similifaveoloolithidae
''Similifaveoloolithus'' is an oogenus of fossil dinosaur egg from the Tiantai basin in Zhejiang Province, China. It is the sole known oospecies of the oofamily Similifaveoloolithidae.Wang Qiang, Zhao Zikui, Wang Xiaolin, Zhang Shukang, and Jian ...
** ''
Similifaveoloolithus
''Similifaveoloolithus'' is an oogenus of fossil dinosaur egg from the Tiantai basin in Zhejiang Province, China. It is the sole known oospecies of the oofamily Similifaveoloolithidae.Wang Qiang, Zhao Zikui, Wang Xiaolin, Zhang Shukang, and Jian ...
''
* Oofamily
Faveoloolithidae
Faveoloolithidae is an oofamily of dinosaur eggs. It contains '' Faveoloolithus'', '' Hemifaveoloolithus'', '' Parafaveoloolithus'', and probably '' Sphaerovum''. However, unlike the other Faveoloolthids, ''Sphaerovum'' has compactituberculate o ...
Parafaveoloolithus
''Parafaveoloolithus'' is an oogenus of Faveoloolithid fossil egg, known from the Cretaceous of China.Zhang, S.K. 2010A parataxonomic revision of the Cretaceous faveoloolithid eggs of China ''Vertebrata PalAsiatica'' 48(3):203-219
Description
...
Youngoolithus
''Youngoolithus'' is an oogenus of dinosaur egg.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 Youngoo ...
''
* Oofamily
Dendroolithidae
''Dendroolithus'' is an oogenus of Dendroolithidae, Dendroolithid dinosaur egg found in the Cenomanian, late Cenomanian Chichengshan Formation (Tiantai Group), in the Gong-An-Zhai Formation, Gong-An-Zhai and Santonian Majiacun Formations of China ...
Dictyoolithidae
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.
Distribution
All known dictyoolithids are known from the Cr ...
** ''
Dictyoolithus
''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.
Distribution
''Dictyoolithus'' is known fr ...
Polyclonoolithus
''Polyclonoolithus'' is an oogenus of fossil dinosaur egg. It is from the Early Cretaceous of Gansu, China. They have distinctive, branching eggshell units, which may represent the original form of spheroolithids.
Distribution
''Polyclonoolit ...
Arriagadoolithus
''Arriagadoolithus'' is the oogenus of fossil eggs which includes the eggs of the alvarezsaurid ''Bonapartenykus''. Fossils of the creature were found in Patagonia; it may have brooded on its eggs.
Description
''Arriagadoolithus patagoniensis'' i ...
Prismatoolithidae
Prismatoolithidae is an oofamily of fossil eggs. They may have been laid by ornithopods or theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on ea ...
** ''
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."Eggs," Foster (2007) page ...
''
** ''
Prismatoolithus
''Prismatoolithus'' is an oogenus of dinosaur egg from the Cretaceous (Hauterivian-Maastrichtian) and possibly also the earliest Paleocene. They likely belonged to troodontids
Troodontidae is a clade of bird-like theropod dinosaurs. During m ...
''
** ''
Protoceratopsidovum
''Protoceratopsidovum'' is an oogenus of dinosaur egg from Mongolia. Despite its name (which means "eggs of '' Protoceratops''"Zelenitsky, D., and Currie, P. (2004) "A Cladistic Analysis of Theropod Ootaxa." ''Journal of Vertebrate Paleontology. ...
''
** ''
Sankofa
(pronounced ''SAHN''-koh-fah) is a word in the Twi language of Ghana meaning “to retrieve" (literally "go back and get"; - to return; - to go; - to fetch, to seek and take) and also refers to the Bono Adinkra symbol represented either w ...
''
** '' Spheruprismatoolithus''E. S. Bray. 1999. Eggs and eggshell from the Upper Cretaceous North Horn Formation, central Utah. In D. D. Gillette (ed.), Vertebrate Paleontology in Utah, Utah Geological Survey Miscellaneous Publication 99-1:361-375
** ''
Trigonoolithus
''Trigonoolithus'' is an oogenus of dinosaur egg, representing a basal prismatoolithid. Its eggshell, like avian eggs, is composed of three structural layers, but cladistic analysis suggests that its parent was a non-avian theropod.
History
Foss ...
Ornitholithus
''Gastornis'' is an extinct genus of large flightless birds that lived during the mid Paleocene to mid Eocene epochs of the Paleogene period. Fossils have been found in Europe, Asia and North America, with the remains from North America origina ...
''
** '' Reticuloolithus''D. K. Zelenitsky and W. J. Sloboda. 2005. Eggshells. In P. J. Currie and E. B. Koppelhus (eds.), Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Indiana University Press, Bloomington 398-404
** '' Struthiolithus''
** '' Tristraguloolithus''
** '' Tubercuoolithus''
** Oofamily
Elongatoolithidae
Elongatoolithidae is an oofamily of fossil eggs, representing the eggs of oviraptorosaurs (with the exception of the avian '' Ornitholithus''). They are known for their highly elongated shape. Elongatoolithids have been found in Europe, Asia, and ...
Elongatoolithus
''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 (probably oviraptorosaurs), and were cared for and incubated by thei ...
''
*** ''
Heishanoolithus
''Heishanoolithus'' is an oogenus of Elongatoolithid fossil egg from the Shahai Formation in Liaoning. It is known only from seven eggshell fragments. It is most notable for having a very thin eggshell (1.2-1.3 mm thick), the dense covering of ...
''
*** ''
Macroelongatoolithus
''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 ''Macroelo ...
''
*** ''
Macroolithus
''Macroolithus'' is an oogenus (fossil-egg genus) 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 ...
''
*** ''
Nanhsiungoolithus
''Nanhsiungoolithus'' is an oogenus (fossil-egg genus) 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 ...
''
*** ''
Paraelongatoolithus
''Paraelongatoolithus'' is a late Cretaceous oogenus of Chinese fossil egg, classified in the oofamily Elongatoolithidae, which represents the eggs of oviraptorosaurs.
Distribution
''Paraelongatoolithus'' is known solely from Chengguan, Tiantai ...
''
*** ''
Porituberoolithus
''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 Fo ...
''
*** ''
Rodolphoolithus
''Rodolphoolithus'' is an oogenus of elongatoolithid egg native to Morocco. It is known only from a single partial egg and several eggshell fragments, but it probably had a highly elongated shape like other Elongatoolithids. They have an eggshell ...
Undulatoolithus
''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.Q. Wan ...
Subtiliolithus
''Subtiliolithus'' is an oogenus of fossil egg from the Nemegt Formation of Mongolia and the Ohyamashimo Formation of Japan. The eggs are notable for a very thin eggshell. It contains three oospecies: ''S. hyogoensis'', ''S. kachchhensis'' and ' ...
''
*** ''
Tipoolithus
''Tipoolithus'' is an oogenus of fossil egg native to the Irbzer Formation in Morocco. Its classification is uncertain, but it most closely resembles Laevisoolithids, and like members of that oofamily, it was laid by an enantiornithine bird or ...
Gobioolithus
''Gobioolithus'' is an oogenus of fossil bird egg native to Mongolia. They are small, smooth-shelled, and elongated eggs that were first discovered in the 1960s and early 70s during a series of fossil-hunting expeditions in the Gobi desert. Two ...
''
''
Incertae sedis
' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...
/Unclassified''
* ''
Oolithes
''Oolithes'' is an oogenus with uncertain affinities. It has historical significance because it was the earliest named oogenus. James Buckman described the first named species as ''Oolithes bathonicae'' in a communication to the 4 May 1859 meet ...
Mycomorphoolithus
''Mycomorphoolithus'' (meaning "fungus-shaped stone egg") is an oogenus of fossil eggs found in Spain and England. They possibly represent eggshells of non-eusuchian Crocodylomorpha, crocodylomorphs, and are similar to, but not part of, the Krokol ...
Fossil footprint
A fossil track or ichnite (Greek "''ιχνιον''" (''ichnion'') – a track, trace or footstep) is a fossilized footprint. This is a type of trace fossil. A fossil trackway is a sequence of fossil tracks left by a single organism. Over the year ...
*
Coprolite
A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is de ...