Late Miocene Dasypodidae Gray, 1821 (Xenarthra, Cingulata) from the Toro Negro Formation (Central Andes, Argentina): diversity and chronological and biogeographical implications Author Brandoni, Diego Laboratorio de Paleontología de Vertebrados, Centro de Investigación Científica y de Transferencia Tecnológica a la Producción - Consejo Nacional de Investigaciones Científicas y Técnicas (CICYTTP, CONICET-Prov. ER-UADER), España 149, E 3105 BWA Diamante (Argentina) dbrandoni @ cicyttp. org. ar (corresponding author) dbrandoni@cicyttp.org.ar Author Barasoain, Daniel Laboratorio de Evolución de Vertebrados y Ambientes Cenozoicos, Centro de Ecología Aplicada del Litoral - Universidad Nacional de Nordeste - Consejo Nacional de Investigaciones Científicas y Técnicas (CECOAL-UNNE-CONICET) y Cátedra de Paleontología, Facultad de Ciencias Exactas, Naturales y Agrimensura, Universidad Nacional del Nordeste, RP 5 3400 Corrientes (Argentina) danielbarasoain @ gmail. com danielbarasoain@gmail.com Author González Ruiz, Laureano R. Laboratorio de Investigaciones en Evolución y Biodiversidad (LIEB-FCNyCS sede Esquel, UNPSJB) y Centro de Investigaciones Esquel de Montaña y Estepa Patagónica (CIEMEP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Patagonia San Juan Bosco (UNPSJB), Roca 780, 9200, Esquel, Chubut (Argentina) lrgonzalezruiz @ comahue-conicet. gob. ar lrgonzalezruiz@comahue-conicet.gob.ar text Comptes Rendus Palevol 2023 2023-01-16 22 1 1 16 http://dx.doi.org/10.5852/cr-palevol2023v22a1 journal article 305481 10.5852/cr-palevol2023v22a1 09614d02-74d1-413d-9cd8-ae29a8cb089b 1777-571X 14204179 urn:lsid:zoobank.org:pub:896BCEBD-8547-4822-9F61-58E7BECC9469 Macrochorobates scalabrinii ( Moreno & Mercerat, 1891 ) ( Fig. 3M, N ; Table 1 ) Proeuphractus scalabrinii Moreno & Mercerat, 1891: 226 . MATERIAL REFERRED . CRILAR-Pv 120 , an association of one fixed osteoderm and one complete, plus one broken mobile osteoderm. GEOGRAPHIC AND STRATIGRAPHIC PROVENANCE . Quebrada de Las Torrecillas ( 28°36’37”S , 68°14’14”W ), La Rioja Province , Argentina ( Fig. 1 ). Upper levels of the lower member of the Toro Negro Formation (Messinian-Zanclean; Late Miocene-Early Pliocene). DESCRIPTION Fixed osteoderm. This osteoderm ( Fig. 3M ) is sub-rectangular in outline, longer than wide ( Table 1 ). Its entire dorsal surface is covered with small foramina. In lateral view, it maintains a constant width from the anterior to the posterior margin. The ornamentation pattern of the dorsal surface is composed by a large central figure surrounded both laterally and anteriorly by a set of 7 minor peripheral figures. The central figure is keeled in section and sub-elliptical. It is very extended posteriorly, extending beyond the posterior margin of the osteoderm. The central figure is much more elevated than the peripheral figures, and its height progressively increases towards the posterior margin. The central figure is delimited by a main sulcus in which there are several large dorsal foramina. The peripheral figures have a convex surface and develop very variable irregular contours from slightly oval to pentagonal. Their size is variable, as some figures are double the size of others. At each lateral of the central figure there are 3 peripheral figures, while one is placed anteriorly, between the central figure and the anterior margin of the osteoderm. All peripheral figures are delimited by shallow sulci, in which there are no dorsal foramina as also occurs in the main sulcus. At the posterior margin, there is a single row of 6 posteriorly oriented piliferous foramina of variable size. Additionally, there are several foramina along the entire length of the lateral margins. Among these, the 2 foramina placed in a posterior position are much larger than the others. Mobile osteoderm. This osteoderm ( Fig. 3N ) is broken posteriorly so that the posterior margin is absent. It is rectangular in outline, much longer than wider ( Table 1 ). The articular portion represents approximately one third of the osteoderm total length. The transitional area is short but develops a roughed surface. The ornamented portion includes a wide and elongated central figure, keeled in section, which extends straightly from the transitional area to the posterior margin, while maintaining a constant width. At either side, there is an elongated and undivided figure, which extends parallel to the central figure. The central figure is more elevated, and separated from the lateral figures by a wide but shallow sulcus. Along this sulcus there are a few small dorsal foramina which are randomly distributed, some of them cluster together. Along the entire length of the lateral margins there is a single row of several small foramina, which become larger towards the posterior margin. The posterior margin is not preserved. REMARKS Macrochorobates includes M. chapalmalensis ( Ameghino, 1908 ) and M. scalabrinii . The analyzed materials are assigned to M. scalabrinii for having piliferous foramina at the lateral margins of both fixed and mobile osteoderms, which are absent in M. chapalmalensis (see Contreras et al. 2013 ), and less convex peripheral figures of fixed osteoderms than M. chapalmalensis (see Scillato-Yané 1982 ).