page_title: Nemegtomaia
section_title: Diet and feeding
hierarchical_section_title: Nemegtomaia / Palaeobiology / Diet and feeding
caption_attribution_description: Nemegtomaia barsboldi (GIN100/2112) lower jaw. Scale bar  = 1 cm.
context_page_description: Nemegtomaia is a genus of oviraptorid dinosaur from what is now Mongolia that lived in the Late Cretaceous Period, about 70 million years ago. The first specimen was found in 1996, and became the basis of the new genus and species N. barsboldi in 2004. The original genus name was Nemegtia, but this was changed to Nemegtomaia in 2005, as the former name was preoccupied. The first part of the generic name refers to the Nemegt Basin, where the animal was found, and the second part means "good mother", in reference to the fact that oviraptorids are known to have brooded their eggs. The specific name honours the palaeontologist Rinchen Barsbold. Two more specimens were found in 2007, one of which was found on top of a nest with eggs, but the dinosaur had received its genus name before it was found associated with eggs.
  Nemegtomaia is estimated to have been around 2 m in length, and to have weighed 40 kg. As an oviraptorosaur, it would have been feathered. It had a deep, narrow, and short skull, with an arched crest. It was toothless, had a short snout with a parrot-like beak, and a pair of tooth-like projections on its palate.
context_section_description: The diet of oviraptorids has been interpreted in various ways since the time Oviraptor was wrongly thought to have been a predator of eggs. It has been suggested that oviraptorosaurs as a whole were herbivores, which is supported by the gastroliths (stomach stones) found in Caudipteryx, and the wear facets in the teeth of Incisivosaurus. In 2010 Longrich and colleagues found that oviraptorid jaws had features similar to those seen in herbivorous tetrapods (four-limbed animals), especially those of dicynodonts, an extinct group of synapsid stem-mammals. Oviraptorids and dicynodonts share features such as short, deep, and toothless mandibles; elongated dentary symphyses; elongated mandibular fenestrae; and a downwards-projecting bar in the palate. Modern animals with jaws that resemble those of oviraptorids include parrots and tortoises; the latter group also has tooth-like projections on their premaxillae. Longrich and colleagues concluded that due to the similarities between oviraptorids and herbivorous animals, the bulk of their diet would most likely have been formed by plant matter. Oviraptorids are found at high frequencies in the formations they are known from, similar to the pattern seen in dinosaurs that are known to be herbivorous; these animals were more abundant than carnivorous dinosaurs, as more energy was available at their lower trophic level in the food chain. The jaws of oviraptorids may have been specialised for processing food, such as xerophytic vegetation (adapted for environments with little water), that would have grown in their environment, but this is not possible to demonstrate, as little is known about the flora of the area at the time. A 2013 study by Lü and colleagues found that oviraptorids appear to have retained their hind limb proportions throughout ontogeny (growth), which is also a pattern mainly seen in herbivorous animals. In 2017, the Canadian palaeontologist Gregory F. Funston and colleagues suggested that the parrot-like jaws of oviraptorids may indicate a frugivorous diet that incorporated nuts and seeds.
  In 1977 Barsbold suggested that oviraptorids fed on molluscs, but Longrich and colleagues rejected the idea that they practised shell-crushing altogether, since such animals tend to have teeth with broad crushing surfaces. Instead, the shape of the dentary bones in the lower jaws of oviraptorids suggests they had a sharp-edged beak used for shearing tough food, not for cracking hard food items such as bivalves or eggs. The symphyseal shelf at the front of the dentary may have given some ability for crushing, but as this was a relatively small area, it was probably not the main function of the jaws. The fact that most oviraptorids have been found in sediments that are interpreted as having been xeric and arid or semi-arid environments also argues against them having been specialised eaters of shellfish and eggs, as it is unlikely there would have been enough of these items under such conditions to support them.
  Longrich and colleagues pointed out that the robust forelimbs and enlargement of a single finger in heyuannine oviraptorids is similar to that seen in modern animals that eat ants and termites, such as anteaters and pangolins, but the morpholology of heyuannine jaws does not support them being insectivorous. The researchers found that the function of heyuannine forelimbs was unclear, but suggested that they could have been used for scratching, tearing, or digging, though not prey capture.
  In 2004 Lü and colleagues proposed that the articulation between the quadrate and quadratojugal bones in the skull of Nemegtomaia suggested that these bones were movable in relation to each other, which would have affected how the jaws functioned. In 2015 the Belgian palaeontologist Christophe Hendrickx and colleagues found it unlikely that Nemegtomaia and other oviraptords had bird-like kinesis in their skulls, due to the quadrate bone being immobile.
caption: Lower jaw of the holotype specimen, with beak on the right
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