Baby Yingliang (YLSNHM01266) is a remarkably preserved

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

embryo An embryo ( ) is the initial stage of development for 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 sp ...

discovered in

Ganzhou Ganzhou (), alternately romanized as Kanchow, is a prefecture-level city in the south of Jiangxi province, China, bordering Fujian to the east, Guangdong to the south, and Hunan to the west. Its administrative seat is at Zhanggong District. His ...

, southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. It was discovered in rock layers of the Hekou Formation, which dates to the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

. The embryo belongs to an

oviraptorid Oviraptoridae is a group of bird-like, herbivorous and omnivorous maniraptoran dinosaurs. Oviraptorids are characterized by their toothless, parrot-like beaks and, in some cases, elaborate crests. They were generally small, measuring between one ...

theropod dinosaur, and the egg is classified as

elongatoolithid Elongatoolithidae is an oofamily of fossil eggs, representing the eggs of oviraptorosaurs (with the exception of the Bird, avian ''Ornitholithus''). They are known for their highly elongated shape. Elongatoolithids have been found in Europe, Asia ...

. The specimen has been described as one of the best dinosaur embryos ever found. The specimen represents a late-stage embryonic individual preserved in a position similar to

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

birds, and is the first example of this to be found in a non-avian dinosaur. In birds, this behavior is known as "tucking", and is controlled by the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

. This positions the head below the body with the feet on either side of the head and the back curled. The position aids in successful hatching. However, this interpretation of the specimen has been challenged, with some scientists suggesting that it cannot be directly compared to extant birds. Nesting Nemegtomaia

Discovery and description

The egg was discovered in 2000 by the stone mining company Yingliang Group. The head to tail size of Baby Yingliang measures 10.6in (27cm) that rests inside a 6.7 inch-long egg at the Yingliang Stone Nature History Museum in China.

References

Oviraptoridae Dinosaur fossils Hekou Formation {{Dinosaur-stub