Editing Dinosaur (section)

===Communication===
Modern birds [[Animal communication|communicate]] by visual and auditory signals, and the wide diversity of visual display structures among fossil dinosaur groups, such as horns, frills, crests, sails, and feathers, suggests that visual communication has always been important in dinosaur biology.<ref name=senter2008/> Reconstruction of the plumage color of ''Anchiornis'' suggest the importance of color in visual communication in non-avian dinosaurs.<ref name="Li2010"/> Vocalization in non-avian dinosaurs is less certain. In birds, the [[larynx]] plays no role in sound production. Instead, birds vocalize with a novel organ, the [[Syrinx (bird anatomy)|syrinx]], farther down the trachea.<ref name=":22"/> The earliest remains of a syrinx were found in a specimen of the duck-like ''[[Vegavis|Vegavis iaai]]'' dated 69 –66&nbsp;million years ago, and this organ is unlikely to have existed in non-avian dinosaurs.<ref name="Clarke2016"/> 
[[File:Lambeosaurus magnicristatus DB.jpg|thumb|Restoration of a striking and unusual visual display in a ''[[Lambeosaurus|Lambeosaurus magnicristatus]]''. The crest may also have acted as a resonating chamber for sounds.]]

On the basis that non-avian dinosaurs did not have syrinxes and that their next close living relatives, crocodilians, use the larynx, Phil Senter, a paleontologist, has suggested that the non-avians could not vocalize, because the common ancestor would have been mute. He states that they mostly on visual displays and possibly non-vocal sounds, such as hissing, jaw-grinding or -clapping, splashing, and wing-beating (possible in winged maniraptoran dinosaurs).<ref name=senter2008/> Other researchers have countered that vocalizations also exist in turtles, the closest relatives of archosaurs, suggesting that the trait is ancestral to their lineage. In addition, vocal communication in dinosaurs is indicated by the development of advanced hearing in nearly all major groups. Hence the syrinx may have supplemented and then replaced the larynx as a vocal organ, without a "silent period" in bird evolution.<ref name=":0" />

In 2023, a fossilized larynx was described, from a specimen of the ankylosaurid ''[[Pinacosaurus]]''. The structure was composed of [[cricoid cartilage|cricoid]] and [[arytenoid cartilage]]s, similar to those of non-avian reptiles; but the mobile cricoid–arytenoid joint and long arytenoid cartilages would have allowed air-flow control similar to that of birds, and thus could have made bird-like vocalizations. In addition, the cartilages were [[ossification|ossified]], implying that laryngeal ossification is a feature of some non-avian dinosaurs.<ref name=":1" /> A 2016 study concludes that some dinosaurs may have produced closed-mouth vocalizations, such as cooing, hooting, and booming. These occur in both reptiles and birds and involve inflating the esophagus or tracheal pouches. Such vocalizations evolved independently in extant archosaurs numerous times, following increases in body size.<ref name="Tobias2016"/> The crests of some hadrosaurids and the nasal chambers of ankylosaurids may have been [[acoustic resonance|resonators]].<ref name="Weishampel981"/><ref name="Witmer"/>