A large and unusually thick-shelled turtle egg with embryonic remains from the Upper Cretaceous of China
| Autor: | Haishui Jiang, Fenglu Han, Darla K. Zelenitsky, Jinfeng Hu, Don Brinkman, Yuzheng Ke, Rui Wu, Shukang Zhang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
China
Fossil Record General Immunology and Microbiology Fossils Zoology General Medicine Biology Embryonic stem cell General Biochemistry Genetics and Molecular Biology Cretaceous Turtles law.invention Egg Shell Palaeobiology law Animals Turtle (robot) General Agricultural and Biological Sciences Ecosystem General Environmental Science |
| Zdroj: | Proc Biol Sci |
| ISSN: | 1471-2954 0962-8452 |
| DOI: | 10.1098/rspb.2021.1239 |
| Popis: | Turtle eggs containing embryos are exceedingly rare in the fossil record. Here, we provide the first description and taxonomic identification, to our knowledge, of a fossilized embryonic turtle preserved in an egg, a fossil recovered from the Upper Cretaceous Xiaguan Formation of Henan Province, China. The specimen is attributed to the Nanhsiungchelyidae (Pan-Trionychia), an extinct group of large terrestrial turtles (possibly the speciesYuchelys nanyangensis). The egg is rigid, spherical, and is one of the largest and thickest shelled Mesozoic turtle eggs known. Importantly, this specimen allowed identification of other nanhsiungchelyid egg clutches and comparison to those of Adocidae, as Nanhsiungchelyidae and Adocidae form the basal extinct clade Adocusia of the Pan-Trionychia (includes living soft-shelled turtles). Despite the differences in habitat adaptations, nanhsiungchelyids (terrestrial) and adocids (aquatic) shared several reproductive traits, including relatively thick eggshells, medium size clutches and relatively large eggs, which may be primitive for trionychoids (including Adocusia and Carrettochelyidae). The unusually thick calcareous eggshell of nanhsiungchelyids compared to those of all other turtles (including adocids) may be related to a nesting style adaptation to an extremely harsh environment. |
| Databáze: | OpenAIRE |
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