Juvenile-Only Clusters and Behaviour of the Early Cretaceous Dinosaur Psittacosaurus

  title={Juvenile-Only Clusters and Behaviour of the Early Cretaceous Dinosaur Psittacosaurus},
  author={Qi Zhao and Michael J. Benton and Xing Xu and P. Martin Sander},
It has hitherto been hard to prove that any association of juvenile dinosaurs represents original behaviour rather than sedimentary accumulation, and it has been hard also to determine the ages of such juveniles. A previously described specimen, which consists of an “adult” Psittacosaurus with 34 fully articulated juveniles, turns out to be a composite: the “adult” skull probably has been added, and in any case it is below breeding age. Other juvenile-only clusters have been reported, but the… 
The dominance of an extant gregarious taxon in an attritional accumulation: Taphonomy and palaeoecological implications
Abstract A recurrent aspect of the fossil record is the observation of a disproportionate number of specimens or individuals of a single taxon in some deposits, which is stated as dominance.
The osteology and taphonomy of a Psittacosaurus bonebed assemblage of the Yixian Formation (Lower Cretaceous), Liaoning, China
Abstract We present the first detailed description of the osteology and mineralogy of an assemblage of Psittacosaurus juveniles (DMNH D2156) associated with a larger specimen from the Lujiatun beds
The Chinese Pompeii? Death and destruction of dinosaurs in the Early Cretaceous of Lujiatun, NE China
The Lujiatun Unit (Yixian Formation) yields some of the most spectacular vertebrate fossils of the Jehol Group (Lower Cretaceous) of NE China. Specimens are preserved both articulated and
A New Mass Mortality of Juvenile Protoceratops and Size-Segregated Aggregation Behaviour in Juvenile Non-Avian Dinosaurs
Although the general hypothesis that many non-avian dinosaurs were gregarious and even social animals is supported, evidence for sociality has been overstated and a more conservative interpretation of some data of ‘sociality’ in dinosaurs is advocated.
Taphonomy and taxonomy of a juvenile lambeosaurine (Ornithischia: Hadrosauridae) bonebed from the late Campanian Wapiti Formation of northwestern Alberta, Canada
The overall size range and histology of the bones found at the Spring Creek Bonebed indicate that these animals were uniformly late juveniles, suggesting that age segregation was a life history strategy among hadrosaurids.
Testing for a dietary shift in the Early Cretaceous ceratopsian dinosaur Psittacosaurus lujiatunensis
2D mechanical analysis of the jaws of a hatchling and an adult to determine the differences between the two systems found some differences, but these were only modest; the adult was better suited to feeding on tough plant material than the hatchling, based on its higher values of absolute and relative bite forces.
Psittacosaurus amitabha, a New Species of Ceratopsian Dinosaur from the Ondai Sayr Locality, Central Mongolia
This taxon expands the knowledge of the already-speciose genus Psittacosaurus as well as the understanding of the Ondai Sayr fauna, which is poorly known in comparison to other Mongolian Early Cretaceous localities.
Research history, taphonomy, and age structure of a mass accumulation of the ornithopod dinosaur Dysalotosaurus lettowvorbecki from the Upper Jurassic of Tanzania
The region around Tendaguru Hill in southeastern Tanzania has provided a rich, Late Jurassic dinosaur fauna. Among them, thousands of bones of the basal iguanodontian ornithopod Dysalotosaurus
Bone Histology of the Non-Iguanodontian Ornithopod Jeholosaurus shangyuanensis and Its Implications for Dinosaur Skeletochronology and Development
It is estimated that Jeholosaurus reached sexual maturity at two to four years old, and the largest individual displays an apparently higher growth rate during the first two years, which is abruptly reduced in the following years, suggesting a distinct growth pattern that may be related to sexual dimorphism or variable environmental conditions.
A re-examination of Psittacosaurus lujiatunensis using modern techniques
This dissertation examines a small monospecific deposit that includes a large Psittacosaurus specimen and twenty-four juveniles, and describes it using osteological, histologic, and taphonomic methods to elucidate morphological and microstructural changes that occur during PsITTacosaurus ontogeny as well as determine the burial history of the deposit.


Mud-Trapped Herd Captures Evidence of Distinctive Dinosaur Sociality
A unique dinosaur assemblage from the Cretaceous beds of western Inner Mongolia preserves geologic and paleontologic data that clearly delineate both the timing and mechanism of death. Over twenty
Evidence for juvenile groups in the ornithopod dinosaur Tenontosaurus tilletti Ostrom
These recent discoveries have generated a number of hypotheses on the reproductive behavior of dinosaurs relating to the extent of parental care, fidelity in nesting sites, and the aggregation of juveniles into groups.
Taxonomy, Cranial Morphology, and Relationships of Parrot-Beaked Dinosaurs (Ceratopsia: Psittacosaurus)
in 1922, well-preserved fossils of the first parrotbeaked dinosaur were discovered in Early Cretaceous horizons in the Gobi Desert of Mongolia. Now referred to a single species, Psittacosaurus
Evidence for gregarious behavior and age segregation in sauropod dinosaurs
The differences between skeletal accumulations composed entirely of immature animals and mixed-age ichnological assemblages imply that herd composition was variable, and age segregation of herds also contraindicates extended parental care as typical of at least some sauropod taxa.
Nest of juveniles provides evidence of family structure among dinosaurs
The discovery of fifteen hadrosaurian (‘duck-billed’) skeletons together in a nest-like structure offers the first tangible evidence of the social behaviour of at least one group of dinosaurs.
Social behaviour and mass mortality in the basal ceratopsian dinosaur psittacosaurus (early Cretaceous, People's Republic of China)
An exceptionally preserved herd of the ceratop- sian dinosaur Psittacosaurus was recovered from the Lujiatun Beds of the Lower Cretaceous Yixian Formation, Liaoning Province, north-east China. This
Large Mesozoic mammals fed on young dinosaurs
Mesozoic mammals are commonly portrayed as shrewor ratsized animals that were mainly insectivorous, probably nocturnal and lived in the shadow of dinosaurs. The largest known Mesozoic mammal
Abstract Three newly discovered bonebeds from the Shishugou Formation of Xinjiang, China, are unusual in preserving vertically stacked and articulated to associated skeletons of at least 18 small,
In 1910, a collecting party from the American Museum of Natural History led by Barnum Brown floated down the Red Deer Riverof Alberta. In the Horseshoe Canyon Forma­ tion (Edmonton Group,
Hadrosaurid and lambeosaurid bone beds from the Upper Cretaceous Two Medicine Formation of Montana: taphonomic and biologic implications
Numerous dinosaur bone beds have been found in the Upper Cretaceous Two Medicine Formation. Taphonomy and size-frequency profiles for the most common skeletal elements of six predominantly