A Review of Hadrosaurid Skin Impressions

Among dinosaurs, the fossil record of integument is most diversely represented in Hadrosauridae. A review of the literature, supplemented by additional undescribed specimens, identifies skin impressions from virtually all parts of the body, including rare examples from the face. In most cases, individual taxa are incompletely represented by only one or two specimens, and additional material is required to characterize the integumentary covering across the entire body of most taxa. Nevertheless, skin impressions on commonly represented areas, such as the tail, illustrate the diversity of scale architecture within Hadrosauridae. Where multiple individuals are available for a given species, consistency in scale characteristics and configurations supports the hypothesis that scale morphology and patterning is indeed species specific and does not vary significantly between individuals of the same species. Conversely, scale configuration is highly variable at both the inter- and intrageneric levels. Although these results are preliminary and more specimens are required before they can be fully incorporated into species diagnoses, closer attention should be paid to the standardized description of scale morphology, which should accompany osteological descriptions where possible.