Dinosaur eggs with embryos of the Dendroolithidae type from the Nanchao Formation were identified as belonging to therizinosaurs based on anatomical features, and described by paleontologist Martin Kundrát and colleagues in 2007.
The development of the embryos (their bones were extensiely ossified) and the fact that no adults were found in association with the nests indicate that theirzinosaur hatchlings were precocial, capabale of locomotion from birth, and able to leave their nests to feed alone, independently of their parents.
The development of the teeth of the hatchlings was consistent with an omnivorous diet.
Subterraneously constructed nests are also indicative of a lack of parental care during the incubation period.

In a 2013 conference abstract, paleontologist Yoshitsugu Kobayashi and colleagues reported a nesting ground of theropod dinosaurs at the Javkhlant Formation, which contained at least 17 egg clutches from the same layer within an area of 22 m by 52 m. Each clutch contained 8 spherical eggs with rough surfaces which were in contact with each other and arranged in a circular structure without a central opening.
Based on microscopical features in the eggshells, the researchers identified the eggs as the type Dendroolithidae, which had previously been attributed to therizinosaurs.
Though therizinosaurs are not known from the Javkhlant Formation, it overlies the Bayan Shireh Formation, where Segnosaurus, Erlikosaurus, and Enigmosaurus were found.
The multiple clutches indicate that some therizinosaurs were colonial nesters, like hadrosaurs, prosauropods, titanosaurs, and birds, and the fact that they were found in a single stratigraphic layer suggests the dinosaurs nested at the site on a single occasion, and therefore did not exhibit site fidelity.
The discovery was the first record of colonially nesting non-avian theropods from Asia, as well as the largest known non-avian theropod colony.
Dinosaur eggs with embryos of the Dendroolithidae type from the Nanchao Formation were identified as belonging to therizinosaurs based on anatomical features, and described by paleontologist Martin Kundrát and colleagues in 2007. The development of the embryos (their bones were extensiely ossified) and the fact that no adults were found in association with the nests indicate that theirzinosaur hatchlings were precocial, capabale of locomotion from birth, and able to leave their nests to feed alone, independently of their parents. The development of the teeth of the hatchlings was consistent with an omnivorous diet. Subterraneously constructed nests are also indicative of a lack of parental care during the incubation period.
In a 2013 conference abstract, paleontologist Yoshitsugu Kobayashi and colleagues reported a nesting ground of theropod dinosaurs at the Javkhlant Formation, which contained at least 17 egg clutches from the same layer within an area of 22 m by 52 m. Each clutch contained 8 spherical eggs with rough surfaces which were in contact with each other and arranged in a circular structure without a central opening. Based on microscopical features in the eggshells, the researchers identified the eggs as the type Dendroolithidae, which had previously been attributed to therizinosaurs. Though therizinosaurs are not known from the Javkhlant Formation, it overlies the Bayan Shireh Formation, where Segnosaurus, Erlikosaurus, and Enigmosaurus were found. The multiple clutches indicate that some therizinosaurs were colonial nesters, like hadrosaurs, prosauropods, titanosaurs, and birds, and the fact that they were found in a single stratigraphic layer suggests the dinosaurs nested at the site on a single occasion, and therefore did not exhibit site fidelity. The discovery was the first record of colonially nesting non-avian theropods from Asia, as well as the largest known non-avian theropod colony.
Therizinosauria