Publication Date: 2017.
Author affiliation: Ponce, Denis A. Universidad Nacional de Río Negro; Argentina
Author affiliation: Ponce, Denis A. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Author affiliation: Cerda, Ignacio A. Universidad Nacional de Río Negro; Argentina
Author affiliation: Desojo, Julia B. División Paleontología Vertebrados, Museo de La Plata, Universidad Nacional de La Plata; Argentina
Author affiliation: Cerda, Ignacio A. Instituto de Investigación en Paleobiología y Geología; Argentina
Author affiliation: Nesbitt, Sterling J. Department of Geosciences, Virginia Tech; Estados Unidos
Osteoderms are common in most archosauriform lineages, including basal forms, such as doswelliids and proterochampsids. In this survey, osteoderms of the doswelliids Doswellia kaltenbachi and Vancleavea campi, and proterochampsid Chanaresuchus bonapartei are examined to infer their palaeobiology, such as histogenesis, age estimation at death, development of external sculpturing, and palaeoecology. Doswelliid osteoderms have a trilaminar structure: two cortices of compact bone (external and basal) that enclose an internal core of cancellous bone. In contrast, Chanaresuchus bonapartei osteoderms are composed of entirely compact bone. The external ornamentation of Doswellia kaltenbachi is primarily formed and maintained by preferential bone growth. Conversely, a complex pattern of resorption and redeposition process is inferred in Archeopelta arborensis and Tarjadia ruthae. Vancleavea campi exhibits the highest degree of variation among doswelliids in its histogenesis (metaplasia), density and arrangement of vascularization and lack of sculpturing. The relatively high degree of compactness in the osteoderms of all the examined taxa is congruent with an aquatic or semi-aquatic lifestyle. In general, the osteoderm histology of doswelliids more closely resembles that of phytosaurs and pseudosuchians than that of proterochampsids.
Repository: RID-UNRN (UNRN). Universidad Nacional de Río Negro