Timeline of egg fossil research

Last updated

Fossilized Dinosaur eggs displayed at Indroda Dinosaur and Fossil Park. Indroda eggs.JPG
Fossilized Dinosaur eggs displayed at Indroda Dinosaur and Fossil Park.

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. [1] 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.


The first scientifically recognized dinosaur egg fossils were discovered serendipitously in 1923 by an American Museum of Natural History crew while looking for evidence of early humans in Mongolia. These eggs were mistakenly attributed to the locally abundant herbivore Protoceratops , but are now known to be Oviraptor eggs. 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 started a revolution in fossil egg classification by developing a system of "parataxonomy" 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.


Late Paleolithic to early Neolithic

Precolumbian North America

19th-century paleontology

Hypselosaurus egg. Hypselosaurus egg 2.jpg
Hypselosaurus egg.



20th-century paleontology

Fossilized nest specimen AMNH FR 6508, recovered from Mongolia during the Central Asiatic Expedition of 1923. Oviraptor philoceratops nest AMNH FR 6508.jpg
Fossilized nest specimen AMNH FR 6508, recovered from Mongolia during the Central Asiatic Expedition of 1923.












They also found that the carbon in the eggshell is mostly the heavier Carbon 13 rather than the lighterCarbon 12. This means the dinosaur were primarily feeding on C3 plants which use 3 carbon atoms in their photosynthesis products rather than C4 plants that use four. [22]

Reconstruction of a Maiasaura nest with eggs Maiasaura Nest Model.001 - Natural History Museum of London.JPG
Reconstruction of a Maiasaura nest with eggs





Early to mid-1990s

21st-century paleontology

Pectinatites. Ammonoidea - Pectinatites pectinatus.jpg
Pectinatites .



See also


  1. Carpenter (1999); "First Discoveries", page 1.
  2. 1 2 3 Carpenter (1999); "First Discoveries", page 4.
  3. Mayor (2005); page 128.
  4. Mayor (2005); page 129.
  5. Mayor (2005); pages 129–130.
  6. 1 2 Carpenter (1999); "First Discoveries", page 5.
  7. 1 2 Carpenter (1999); "First Discoveries", page 6.
  8. Carpenter (1999); "Reason 3. Eggshell Too Thin, Eggshell Too Thick", page 253.
  9. Carpenter (1999); "First Discoveries", pages 6–7.
  10. 1 2 Carpenter (1999); "United States", pages 15–16.
  11. Carpenter (1999); "United States", page 16.
  12. Carpenter (1999); "First Discoveries", pages 1–2.
  13. Carpenter (1999); "First Discoveries", page 2.
  14. 1 2 3 Carpenter (1999); "Evolution of the Reptile Egg", page 43.
  15. Carpenter (1999); "India", page 27.
  16. Carpenter (1999); "India", page 28.
  17. Carpenter (1999); "Canada", page 19.
  18. 1 2 Etches, Clarke, and Callomon (2009); "Introduction", page 205.
  19. Carpenter (1999); "United States", pages 16–18.
  20. Carpenter (1999); "Tools of the Trade", page 125.
  21. Carpenter (1999); "Tools of the Trade", page 131.
  22. 1 2 3 Carpenter (1999); "Tools of the Trade", page 132.
  23. Carpenter (1999); "Growth of the Modern Classification System", pages 148-149.
  24. Horner (2001); "History of Dinosaur Collecting in Montana", page 56.
  25. Remnick, David J. "Whole Dinosaur Egg Unearthed, 1st in North America". The Washington Post. Retrieved 3 May 2023.
  26. Carpenter (1999); "How to Fossilize an Egg", page 112.
  27. Carpenter (1999); "Growth of the Modern Classification System", page 149.
  28. Etches, Clarke, and Callomon (2009); "Abstract", page 204.
  29. Koen Stein; Edina Prondvai; Timothy Huang; Jean-Marc Baele; P. Martin Sander; Robert Reisz (2019). "Structure and evolutionary implications of the earliest (Sinemurian, Early Jurassic) dinosaur eggs and eggshells". Scientific Reports. 9 (1): Article number 4424. Bibcode:2019NatSR...9.4424S. doi:10.1038/s41598-019-40604-8. PMC   6418122 . PMID   30872623.
  30. Shu-Kang Zhang; Jun-Fang Xie; Xing-Sheng Jin; Tian-Ming Du; Mei-Yan Huang (2019). "New type of dinosaur eggs from Yiwu, Zhejiang Province, China and a revision of Dongyangoolithus nanmaensis". Vertebrata PalAsiatica. in press. doi:10.19615/j.cnki.1000-3118.190107.
  31. Qing He; Shukang Zhang; Lida Xing; Qin Jiang; Yanfei An; Sen Yang (2019). "A new oogenus of Dendroolithidae from the Late Cretaceous in the Quyuangang area, Henan Province, China". Acta Geologica Sinica (English Edition). 93 (2): 477–478. doi:10.1111/1755-6724.13779. S2CID   135361965.
  32. Noe-Heon Kim; Seung Choi; Seongyeong Kim; Yuong-Nam Lee (2019). "A new faveoloolithid oogenus from the Wido Volcanics (Upper Cretaceous), South Korea and a new insight into the oofamily Faveoloolithidae". Cretaceous Research. 100: 145–163. Bibcode:2019CrRes.100..145K. doi:10.1016/j.cretres.2019.04.001. S2CID   146505811.

Related Research Articles

<i>Hypselosaurus</i> Extinct genus of reptiles

Hypselosaurus is a dubious genus of titanosaurian sauropod that lived in southern France during the Late Cretaceous, approximately 70 million years ago in the early Maastrichtian. Hypselosaurus was first described in 1846, but was not formally named until 1869, when Phillip Matheron named it under the binomial Hypselosaurus priscus. The holotype specimen includes a partial hindlimb and a pair of caudal vertebrae, and two eggshell fragments were found alongside these bones. Because of the proximity of these eggshells to the fossil remains, many later authors, including Matheron and Paul Gervais, have assigned several eggs from the same region of France all to Hypselosaurus, although the variation and differences between these eggs suggest that they do not all belong to the same taxon. Hypselosaurus has been found in the same formation as the dromaeosaurids Variraptor and Pyroraptor, the ornithopod Rhabdodon, and the ankylosaurian Rhodanosaurus, as well as indeterminate bones from other groups.

<span class="mw-page-title-main">Dinosaur egg</span> Vessel for dinosaur embryo development

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 because they were reptiles. In 1859, the first scientifically documented dinosaur egg fossils were discovered in France by Jean-Jacques Poech, although they were mistaken for giant bird eggs.

<i>Elongatoolithus</i> Fossil dinosaur eggs

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.

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.

<i>Cairanoolithus</i> Oogenus of dinosaur egg

Cairanoolithus is an oogenus of dinosaur egg which is found in Southwestern Europe. The eggs are large and spherical. Their outer surface is either smooth, or covered with a subdued pattern of ridges interspersed with pits and grooves. Multiple fossil egg clutches are known but the nest structure is unclear.

Sphaerovum is an oogenus of dinosaur egg that has only been discovered in South America.

Protoceratopsidovum is an oogenus of dinosaur egg from Mongolia. Despite its name, it does not represent the eggs of a protoceratopsid, but rather the eggs of maniraptoran theropods.

<i>Macroolithus</i> Dinosaur egg

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.

<span class="mw-page-title-main">Egg fossil</span> Fossilized remains of eggs laid by ancient animals

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.

<span class="mw-page-title-main">Egg paleopathology</span>

Egg paleopathology is the study of evidence for illness, injury, and deformity in fossilized eggs. A variety of pathological conditions afflicting eggs have been documented in the fossil record. Examples include eggshell of abnormal thickness and fossil eggs with multiple layers of eggshell. The identification of egg paleopathologies is complicated by the fact that even healthy eggs can be modified during or after fossilization. Paleontologists can use techniques like cathodoluminescence or thin sectioning to identify true paleopathologies in fossil eggs. Despite the diversity of paleopathologies known from fossil eggs, the vast majority of conditions known to afflict modern eggs have not yet been seen among fossils.

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.

<span class="mw-page-title-main">Elongatoolithidae</span>

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.

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.

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.

<i>Gobioolithus</i> Fossil bird egg native to Mongolia

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 oospecies have been described: Gobioolithus minor and G. major. The eggs were probably laid in colonial nesting sites on the banks of rivers and lakes.

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.