New association of Eocene cingulates (Mammalia, Xenarthra) at Los Cardones National Park (Salta Province, Northwerstern Argentina)

FERNICOLA, JUAN CARLOS; ZIMICZ, ANA NATALIA; CHORNOGUBSKY L.; CRUZ L. E. ; BOND, MARIANO; ARNAL, MICHELLE; CARDENAS, M.; FERNÁNDEZ, MERCEDES

Encuentro; I Meeting of Systematics, Biogeography and Evolution (SBE); 2020

Fernicola et al sbe1. NEW ASSOCIATION OF EOCENE CINGULATES (MAMMALIA, XENARTHRA) AT LOS CARDONES NATIONAL PARK (SALTA PROVINCE, NORWESTERN ARGENTINA) 1 CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina) 2 Museo Argentino de Ciencias Naturales ?Bernardino Rivadavia?, Av. Ángel Gallardo 470, 1405 Ciudad Autónoma de Buenos Aires, Argentina, jctano@yahoo.com; lauracruz@macn.gov.ar; lchorno@macn.gov.ar; mechisfernandezpaleo@gmail.com; magicacar7@gmail.com 3 Departamento de Ciencias Básicas, Universidad Nacional de Luján (UNLu), Ruta 5 y Avenida Constitución (6700), Luján, Buenos Aires, Argentina, mechi_985@hotmail.com; 4 Instituto de Bio y Geociencias del Noroeste Argentino, Av. Bolivia 5550, 4400 Salta, Salta, Argentina, natalia.zimicz@gmail.com 5 División Paleontología Vertebrados, Museo de La Plata, Facultad de Ciencias Naturales y Museo de La Plata, UNLP, Paseo del Bosque s/n, B1900FWA La Plata, Argentina, constantino1453@yahoo.com.ar 6 División Paleontología Vertebrados, Unidades de Investigación Anexo Museo de La Plata, Facultad de Ciencias Naturales y Museo de La Plata, UNLP, Av. 122 y 60, B1900FWA La Plata, Argentina, michoarnal@fcnym.unlp.edu.ar JUAN C. FERNICOLA1,2,3,*, ANA N. ZIMICZ1,4, LAURA CHORNOGUBSKY1,2, LAURA E. CRUZ 1,2, MARIANO BOND1,6, MICHELLE ARNAL1,7, MAGALÍ CÁRDENAS2, AND MERCEDES FERNÁNDEZ 1,2,32. The Quebrada de los Colorados Formation (QLCF) outcrops at the Calchaquíes Valleys (Salta Province, Argentina). Its basal levels were dated in ca. 40 Ma. The specimens here presented were exhumed from QLCF levels at Quebrada Grande, in the area known as Camino de Los Colorados (Los Cardones National Park), below the dated levels and above the contact with the lower section of the Lumbrera Formation (LSLF). In the last revision of the Cingulata from the NWA, Ciancio et al. (2016) unequivocally recognized a single cingulate species, Pucatherium parvum, for these levels. In this work we present a new cingulate association for the QLCF and we analyze its relationship with other NWA associations. INTRODUCTION Localities of the studied area. From left to right: maps of South America, Argentina showing NW region, and detail of north- western Argentina showing the study area (star) in Salta Province. Detailed map of the study area, and stratigraphical column showing the basal part of the Quebrada de los Colorados Formation (QLCF)3. Terminology of the osteoderm features mentioned in the studio. 1, fixed osteoderm; 2, moveable osteoderm. MATERIALS & METHODS The specimens of cingulates studied here were collected between 2016 and 2019 by us, and are deposited at the Paleontology Collection of the Instituto de Bio y Geociencias del Noroeste Argentino (IBIGEO), Rosario de Lerma, Salta Province, Argentina. These specimens were identified through comparison with the type specimens and with more complete remains of specimens housed in the institutions MLP: Museo de La Plata; Buenos Aires Province, Argentina; MACN-PV: Colección Nacional Paleontología de Vertebrados Museo Argentino de Ciencias Naturales ?Bernardino Rivadavia?; MACN-A: Colección Nacional Ameghino Museo Argentino de Ciencias Naturales ?Bernardino Rivadavia?; PVL: Colección de Paleontología de Vertebrados Lillo, Tucumán, Argentina4. 1.- Pucatherium parvum Herrera et al., 2012, The following combination of osteoderm features allows us to assign these osteoderms to Pucatherium parvum. The external articular surface of the anterior part shows two or three well- developed longitudinal crests, separated by deep grooves. The external surface of the posterior part of the osteoderm is slightly wrinkled, with a principal central figure, surrounded by lateral grooves, roughly rectangular and with rounded corners. RESULTS The cingulates reported here correspond to three species of armadillos, one is new. The other two correspond to 2.- Parutaetus punaensis Ciancio et al., 2016. The following combination of fixed osteoderms features allows us to assign these osteoderms to Parutetus: 1.- External surface of the osteoderms is smooth and with convex figures, 2.- lateral contact surface between osteoderms is smooth, 3.- Piliferous system restricted to the posterior margin (two or six small foramina). 4.- Principal figure occupies the posterior two-thirds of the external surface of the osteoderm and it is surrounded by five or six peripheral figures delimited by narrow sulci. 5.- Principal figure is teardrop shaped, with its wider portion in the anterior portion of the osteoderm, and with its posterior narrower portion that does not reach the posterior edge of the osteoderm.. The specimens are assigned to Parutaetus punaensis based on the presence of a principal figure that gradually narrows towards the caudal part, while in Parutaetus chilensis and Parutaetus chicoensis the shape sharply changes. Scale bar 10 mm5. DISCUSSION & CONCLUSIONS Previous to this work, Pucatherium parvum and Parutaetus punaensis were recorded from the middle member of the Geste Formation (Catamarca, Argentina), while the first species was also registered from the same formation in Salta and Jujuy provinces and Upper section of the Lumbrera Fm. The middle section of the Geste Formation was dated between 37?35 Ma, while the top of the Upper section of the Lumbrera Fm. was dated in 39.9 Ma, giving a temporal extension for these taxa of ca. 3 Ma. The low number of species presented in this study (2 over 4) prevents us to formalize a new cingulate fauna for the middle Eocene of NWA. However, it should be noted that, at a regional level, the unequivocally assigned species of the Quebrada de Los Colorados and Geste formations, Pucatherium parvum and Parutaetus punaensis, have not yet been reported in any other formation. North-western Argentina Eocene?Oligocene biochronological successions (after Woodburne et al. (2014a, b) for the early?middle Eocene; Dunn et al. (2013) for the late Eocene?early Miocene). TAXON USLF QLCF GF New cingulate X Pucatherium parvum X X X Parutaetus punaensis X X Punatherium catamarcensis X Table 1. Comparative distribution of cingulates from Eocene age in Norwestern of Argentina. Upper section of the Lumbrera Formation (USLF), Quebrada de Los Colorados Formation (QLCF), and Geste Formation (GF).