Anais da Academia Brasileira de Ciências (2015) 87(1): 15-27 (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 http://dx.doi.org/10.1590/0001-3765201520140012 www.scielo.br/aabc On the fossil Remains of Panochthus Burmeister, 1866 (Xenarthra, Cingulata, Glyptodontidae) from the Pleistocene of southern Brazil JOSÉ D. FERREIRA1, MARTÍN ZAMORANO2 and ANA MARIA RIBEIRO3 1 Programa de Pós-Graduação em Geociências, Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Agronomia, 91501-970 Porto Alegre, RS, Brasil 2Consejo Nacional de Investigaciones Científicas y Técnicas/CONICET, División de Paleontología de Vertebrados, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Paseo del Bosque s/n, B1900FWA La Plata, Argentina 3Museu de Ciências Naturais, Fundação Zoobotânica do Rio Grande do Sul, Rua Dr. Salvador França, 1427, Jardim Botânico, 90690-000 Porto Alegre, RS, Brasil Manuscript received on January 23, 2014; accepted for publication on April 3, 2014 ABSTRACT The genus Panochthus represents the last lineage of “Panochthini” recorded in the Pleistocene. This genus has a wide latitudinal distribution in South America, and in Brazil it occurs in the southern and northeastern regions. In this paper we describe new material (isolated osteoderms and caudal tube fragments) assigned to Panochthus from the state of Rio Grande do Sul (southern Brazil) and discuss some taxonomic issues related to Panochthus tuberculatus and Panochthus greslebini based on this material . The occurrence of P. greslebini is the first for outside the Brazilian Intertropical Region. In addition, we describe new diagnostic features to differentiate the osteoderms of P. greslebini and P. tuberculatus. Unfortunately, it was not possible to identify some osteoderms at the species level. Interestingly, they showed four distinct morphotypes characterized by their external morphology, and thus were attributed to Panochthus sp. Lastly, we conclude that in addition to P.tuberculatus registered to southern Brazil, there is another species of the genus, assignable to P. cf. P. greslebini. Our analysis reinforce the reliability of caudal tube characters for the classification of species of Panochthus. Key words: Glyptodontidae, Panochthus, Pleistocene, southern Brazil, osteoderms. INTRODUCTION 1942, Hoffstetter 1958, Paula Couto 1979, McKenna The tribe “Panochthini” is a taxonomically diverse and Bell 1997, Zurita et al. 2011, Zamorano 2012); group of glyptodonts restricted to South America. however, in recent cladistic analyses they do not Its fossil record spans the late Miocene to the form a natural group (Zamorano and Brandoni 2013, late Pleistocene (Zamorano 2012). The genera see. Zamorano et al. 2013). Panochthus Burmeister, 1866, Nopachtus Ameghino, This genus has a wide latitudinal distribution 1888 and Propanochthus Castellanos, 1925 were in South America (Tonni and Scillato-Yané 1997), traditionally included within this tribe (Castellanos including both southern and northeastern regions (Fig. 1) (Porpino and Bergqvist 2002, Porpino et al. 2004, Correspondence to: José Darival Ferreira E-mail: [email protected] Ubilla et al. 2004, Zurita et al. 2009a, Zamorano 2012). An Acad Bras Cienc (2015) 87 (1) 16 JOSÉ D. FERREIRA, MARTÍN ZAMORANO AND ANA MARIA RIBEIRO coastal plain of the state of Rio Grande do Sul, Santa Vitória do Palmar Municipality. Subsequently, Panochthus was reported from deposits in northeast Brazil (tanks) by Branner (1915) and by several authors (e.g. Moreira 1971, Bergqvist 1993). The fossil content of these tanks was deposited during the late Pleistocene, with available electron spin resonance (ESR) ages dating it to between 63,000 to 10,000 years BP (e.g. Kinoshita et al. 2005, Oliveira et al. 2009, Silva 2009, Dantas et al. 2011). In the northeastern region of Brazil, P. greslebini and P. jaguaribensis are considered endemic species (e.g. Bergqvist 1993, Porpino and Bergqvist 2002, Zamorano 2012, but see Chimento and Agnolin 2011). P. tuberculatus has only been recorded in Rio Grande do Sul (e.g. Bombin 1976, Ribeiro and Scherer 2009). Another dubious record of Panochthus in the Amazon region is referred to by Paula Couto (1956); the material is a single isolated osteoderm collected in the Jurua River, in the state of Acre. In this paper, we describe new material of the Panochthus from the state of Rio Grande do Sul Figure 1 - Map of the geographic distribution of Panochthus (southern Brazil) and discuss some taxonomic in the Pleistocene. aspects of the species reported. MATERIALS AND METHODS The main characteristics of the genus Panochthus are the osteoderms of the carapace, The material studied here belongs to the which have a reticular pattern on the external paleontological collections of the Museu de surface, with small polygonal fi gures that are fl at Ciências Naturais da Fundação Zoobotânica and equivalent in size, and the caudal tube, which do Rio Grande do Sul (MCN/FZBRS), Museu has a similar ornamentation pattern to the carapace de Ciências Tancredo Filho Melo (MCTFM), (Castellanos 1942). According to a recent review of Laboratório de Geologia e Paleontologia da Panochthus by Zamorano (2012), six species were Universidade Federal de Rio Grande (LGP/ recognized: P. subintermedius Castellanos, 1937, FURG) and Museu Nacional do Rio de Janeiro P. intermedius Lydekker, 1895, P. tuberculatus (MNRJ), Brazil. The anatomical nomenclature (Owen, 1845), P. frenzelianus Ameghino, 1889, follows Porpino and Bergqvist (2002), while the P. jaguaribensis (Moreira, 1965) and P. greslebini scheme for the different regions of the carapace Castellanos, 1942. is based on; systematics follow Zamorano et al. The fi rst record ofPanochthus , for the territory (2013) (see. Zamorano and Brandoni 2013). of Brazil was mentioned by Ihering (1891), in The description and terminology for osteoderms correspondence to Florentino Ameghino, from the follows Hill (2006). An Acad Bras Cienc (2015) 87 (1) Panochthus FROM SOUTHERN BRAZIL 17 GEOGRAPHIC AND STRATIGRAPHIC III located between coastal barrier II (westwards) PROVENANCE OF MATERIALS and barrier III (eastwards). The age of the fossils The material was found in the municipalities of of Chuí Creek was estimated to be at least 120,000 Uruguaiana (Touro Passo Creek), Santa Vitória years BP based on their location within the barrier- do Palmar (Balneário Hermenegildo, coastal plain lagoon system III (Lopes et al. 2005). However, and Chui Creek) and Rosário do Sul (Rincão dos subsequently it was demonstrated that these fossils Fialho) (Fig. 2). are more recent (Lopes et al. 2010). A sample from Touro Passo Creek (29°40′S, 56°51′W) is 13 the bank of Chuí Creek dated by ESR suggests an km the north of Uruguaiana Municipality (Da-Rosa age between 42,000 and 33,000 years BP (Lopes 2003). Despite this, the biogeographic correlation et al. 2010). The mammal fossils collected are is discussed since it shares faunal elements with assigned to the Lujanian age (Oliveira et al. 2005). the Sopas Formation (Uruguay), which are not Rincão dos Fialho is located in Rosário do Sul recorded in Buenos Aires province, Argentina (see Municipality (30°12′S; 55°16′W). It is situated in the Ubilla 1985, Oliveira 1996, Ubilla and Perea 1999). southwestern state of Rio Grande do Sul. The material According to Milder (2000), the age obtained by was collected near the Fialho farmhouse, in a stream thermoluminescence dating, encompasses a time span that cuts through layers of sandy sediments of variable from 42,600 to 6,400 years BP (Kerber et al. 2011). thickness, of Pleistocenic age, that are directly in Balneário Hermenegildo (53°15′S, 33°42′W) contact with the Triassic (Ferigolo et al. 1997). comprises the southern portion of the coastal plain SYSTEMATIC of Rio Grande do Sul, 20 km from Santa Vitória do Palmar. Over time, it has suffered modifications Superorder Xenarthra Cope, 1889 to its landscape related to sea level fluctuations Order Cingulata Illiger, 1811 (transgressive-regressive events), which developed Suborder Glyptodontia Ameghino, 1889 four lagoon-barrier systems (Villwock and Superfamily Glyptodontoidea Gray, 1869 Tomazelli 1995). The fossil remains of the coastal Family Glyptodontidae Gray, 1869 plain are associated with deposits of lagoon-barrier Genus Panochthus Burmeister, 1866 system III, with an estimated age of 120,000 years BP (Villwock and Tomazelli 1995). The dates Panochthus tuberculatus (Owen, 1845) obtained for the coastal plain of Rio Grande do Sul (Fig. 3A; Fig 4C-D) show a wide variation from younger than 18,000 REFERRED MATERIAL to 650,000 years BP (Lopes et al. 2008, 2010). According to Lopes et al. (2010), the mixture of Caudal tube, right distal portion, LGP P0212. fossils from the middle and late Pleistocene is Isolated osteoderms, MCN-PV 3948; MCN-PV 3953. probably the result of reworking of several fossil GEOGRAPHIC PROVENANCE beds by successive Quaternary transgressive events. Chuí Creek (33°35′S; 53°20′W) is located in Balneário Hermenegildo, coastal plain of Rio southernmost part of Rio Grande do Sul, in Santa Grande do Sul. Vitória do Palmar Municipality. The material was DESCRIPTION found in situ exposed along the banks of Chuí Creek. The plain through which the creek flows and The caudal tube is a right distal tip belonging where the fossil remains of Chuí Creek occur are to Panochthus tuberculatus. The distal portion associated with deposits of lagoon-barrier system is rounded, such as in some specimens of P. An Acad Bras Cienc (2015) 87 (1) 18 JOSÉ D. FERREIRA, MARTÍN ZAMORANO AND ANA MARIA RIBEIRO Figure 2 - Location map of fossiliferous localities. A. Panoramic view of banks exposing the TouroPasso Formation and stratigraphic sequences (modifi ed from Bombin 1976); B. BalneárioHermenegildo and transect of the coastal plain of Rio Grande do Sul, showing its main depositional systems (modifi ed from Tomazelli and Villwock 2005); C. Panoramic view of banks exposed at Chui Creek and stratigraphic sequences (modifi ed from Lopes 2013); D. Rincão dos Fialho, where the material of Panochthus sp was collected.