Regarding the real diversity of Glyptodontidae (Mammalia, Xenarthra) in the late Pliocene (Chapadmalalan Age/Stage) of Argentina

A large diversity of Glyptodontidae has been proposed as characterizing the Chapadmalalan Age (Pliocene). Most of these taxa were recognized on the basis of partial dorsal carapaces and/or caudal tubes, whereas the main diagnostic characteristic is a particular morphology of the exposed surface of the osteoderms. From a biostratigraphic point of view some species are biostratigraphically important. The Upper Chapadmalalan is based on the Paraglyptodon chapadmalensis biozone. Both the re-evaluation of the type and referred materials and new significant findings from the Chapadmalal and El Polvorín Formations indicate that the diversity of Pliocene Glyptodontidae is more limited than previously supposed. The particular morphology of the exposed surface of the osteoderms that characterizes some of the species actually corresponds to a taphonomic alteration, which results in a non-real ornamentation pattern. Thus, the Glyptodontinae P. chapadmalensis must be replaced as a fossil guide because neither this species nor the species included in the genera Urotherium, Trachycalyptus and Lomaphorus are well characterized. Taking into account the diversity of Glyptodontidae for this lapse, the Glyptodontinae are very scarce (a situation that contrasts with its records in the Pleistocene), whereas Eosclerocalyptus, “Plohophorini” (Plohophorus) and Doedicurinae (cf. Eleutherocercus antiquus) are among the most recorded taxa.Facultad de Ciencias Naturales y MuseoCentro de Investigaciones Geológica

The glyptodont eleutherocercus solidus from the late neogene of north-western Argentina: Morphology, chronology, and phylogeny

Glyptodonts (Mammalia, Xenarthra, Glyptodontidae) represent a diversified radiation of large armored herbivores, mainly related to open biomes in South America, with an extensive fossil history since the late Eocene (ca. 33 Ma) until their extinction in the latest Pleistocene-earliest Holocene. During the Pliocene and Pleistocene, glyptodonts arrived in Central and North America as part of the Great American Biotic Interchange. Within glyptodont diversity, one of the most enigmatic groups (and also one of the least known) are the Doedicurinae, mainly recognized by the enormous Pleistocene Doedicurus, with some specimens reaching ca. two tons. Almost nothing is known about the Neogene evolutionary history of this lineage. Some very complete specimens of the previously scarcely known Eleutherocercus solidus, which in turn becomes the most complete Neogene Doedicurinae, are here described in detail and compared to related taxa. The materials come from the Andalhuala and Corral Quemado formations (north-western Argentina), specifically from stratigraphic levels correlated to the Messinian-Piacenzian interval (latest Miocene-Pliocene). The comparative study and the cladistic analysis support the hypothesis that Doedicurinae forms a well supported monophyletic group, located within a large and diversified clade mostly restricted to southern South America. Within Doedicurinae, the genus Eleutherocercus (E. antiquus + E. solidus) is the sister group of the Pleistocene Doedicurus. Unlike most of the late Neogene and Pleistocene lineages of glyptodonts, doedicurins show along its evolutionary history a latitudinal retraction since the Pleistocene, ending with the giant Doedicurus restricted to the Pampean region of Argentina, southernmost Brazil, and southern Uruguay. This hypothetic relationship between body mass and latitudinal distribution suggests that climate could have played an active role in the evolution of the subfamily.Fil: Núñez Blasco, Alizia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Miño Boilini, Ángel Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Bonini, Ricardo Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Cuadrelli, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Regarding the real diversity of Glyptodontidae (Mammalia, Xenarthra) in the late Pliocene (Chapadmalalan Age/Stage) of Argentina

A large diversity of Glyptodontidae has been proposed as characterizing the Chapadmalalan Age (Pliocene). Most of these taxa were recognized on the basis of partial dorsal carapaces and/or caudal tubes, whereas the main diagnostic characteristic is a particular morphology of the exposed surface of the osteoderms. From a biostratigraphic point of view some species are biostratigraphically important. The Upper Chapadmalalan is based on the Paraglyptodon chapadmalensis biozone. Both the re-evaluation of the type and referred materials and new significant findings from the Chapadmalal and El Polvorín Formations indicate that the diversity of Pliocene Glyptodontidae is more limited than previously supposed. The particular morphology of the exposed surface of the osteoderms that characterizes some of the species actually corresponds to a taphonomic alteration, which results in a non-real ornamentation pattern. Thus, the Glyptodontinae P. chapadmalensis must be replaced as a fossil guide because neither this species nor the species included in the genera Urotherium, Trachycalyptus and Lomaphorus are well characterized. Taking into account the diversity of Glyptodontidae for this lapse, the Glyptodontinae are very scarce (a situation that contrasts with its records in the Pleistocene), whereas Eosclerocalyptus, “Plohophorini” (Plohophorus) and Doedicurinae (cf. Eleutherocercus antiquus) are among the most recorded taxa.Facultad de Ciencias Naturales y MuseoCentro de Investigaciones Geológica

A tale of two clades: Comparative study of Glyptodon Owen and Glyptotherium Osborn (Xenarthra, Cingulata, Glyptodontidae)

Glyptodon and Glyptotherium represent the most conspicuous taxa of late Neogene and Pleistocene glyptodonts in South America and North America, respectively. The earliest records of Glyptodon in South America are 1.07 Ma (late early Pleistocene, Calabrian), although the possibility that “Paraglyptodon uquiensis” represents a Pliocene specimen of Glyptodon cannot be rejected. Glyptotherium originated from South American ancestry in northern South America or Central America about 3.9 Ma (early late Pliocene, Zanclean) or earlier. The diversity of South American Glyptodon is currently under study, but preliminary evidence would indicate that no more than three species (G. munizi, G. elongatus and G. reticulatus) are valid, plus a possible new Andean species. In turn, according to the updated taxonomy proposed herein, Glyptotherium includes two chronospecies. The earliest species, Gl. texanum, differs only slightly from the latest species, Gl. cylindricum. The relationship of Glyptodon and Glyptotherium has been problematical since the discovery of the North American lineage, at first identified as various species of Glyptodon and later considered a separate genus. Glyptodon is recognized as a natural group and recent taxonomic and phylogenetic revisions place all North American glyptodontines into Glyptotherium. In this paper, we propose a detailed morphological comparison between the southern South American species of Glyptodon and Glyptotherium in order to identify diagnostic differences and potential synapomorphies. Both genera can be distinguished mainly by differences in the skull, mandible, dentition, dorsal carapace, and caudal armor, Glyptodon being somewhat larger than Glyptotherium. Both clades show a highly conservative evolution, which could be interpreted as an anagenesis. The scarce records of glyptodonts in Central America show more morphological affinity with Glyptotherium than with Glyptodon.Fil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Gillette, David D.. Museum of Northern Arizona; Estados UnidosFil: Cuadrelli, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Carlini, Alfredo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Glyptotherium cylindricum (Cingulata, Glyptodontidae) from the Late Pleistocene of Guatemala: the most complete record of Glyptodontinae from Central America

Glyptodontinae stand out among the lineages of Glyptodontidae in having the greatest latitudinal distribution, including participation in the Great American Biotic Interchange, with significant speciation in new migration areas. The oldest records of Glyptodontinae occur in northern South America with Boreostemma from the middle Miocene–Pliocene. A later radiation incorporated the austral representatives ‘Glyptodontidium tuberifer’, ‘Paraglyptodon’ spp., Glyptodon munizi, Glyptodon reticulatus and Glyptodon jatunkhirkhi in the late Miocene–Late Pleistocene of southern South America, and the septentrional representatives Glyptotherium texanum and Glyptotherium cylindricum in the Pliocene–Late Pleistocene of North America, Central America and northeastern South America. Although knowledge of North and South American forms has increased in recent years, records from Central America are still scarce and fragmentary. Here we describe the most complete Central American glyptodontine fossils documented to date, which were recovered from the latest Pleistocene of Guatemala. The remains comprise: (1) an incomplete skull, the right and left hemimandibles, a fragmentary pelvis, cervical and caudal vertebrae, and articulated and isolated osteoderms; (2) a fragmentary pelvis, left hind limb (incomplete autopodium) and seven caudal vertebrae; (3) most of a dorsal carapace; (4) six incomplete caudal armature rings; and (5) a left hemimandible with complete dental series. Comparative assessment indicates that these remains are referrable to G. cylindricum. The presence of this species in northern Central America and northern South America during the latest Pleistocene spans more than 2200 km, suggesting a continuous distribution across this region, at least during the Last Glacial Maximum and the early Younger Dryas.Fil: Cuadrelli, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Escamilla González, Juan Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Gillette, David D.. No especifíca;Fil: Dávila, Lorena S.. Universidad de San Carlos de Guatemala (univ. de San C. de Guatemala)

Un peculiar ejemplar de Panochtus (Xenarthra, Glyptodontidae) de la cordillera Oriental, Bolivia

Panochthus Burmeister es uno de los gliptodontes más diversificados y ampliamente distribuidos en el Pleistoceno de Sudamérica, incluyendo zonas situadas a gran altura (>4.000 m s.n.m.). Dentro del género, se reconocen actualmente ocho especies (P. intermedius Lydekker, P. subintermedius Castellanos, P. tuberculatus (Owen), P. frenzelianus Ameghino, P. greslebini Castellanos, P. jaguaribensis Moreira, P. hipsilis Zurita, Zamorano, Scillato-Yané, Fidel, Iriondo y Gillette, y P. florensis Brambilla, López y Parent). Aquí reportamos una coraza dorsal (UATF-V n/n) procedente del Pleistoceno de los alrededores de Potosí, Bolivia, que muestra algunas particularidades morfológicas respecto a las corazas de P. intermedius, P. frenzelianus, P. subintermedius y P. tuberculatus, incluyendo: a) máximo diámetro dorso-ventral situado a la altura de la mitad anterior, mientras que en otras especies se encuentra a la altura del punto medio (e.g., Propalaehoplophorus) o de la mitad posterior (e.g., Glyptodon); b) el perfil dorsal es diferente en comparación con las restantes especies de gliptodontes (e.g., Glyptodon, Glyptotherium, Neosclerocalyptus, Propalalehoplophorus); c) el patrón de ornamentación de los osteodermos muestra una figura central rodeada de pequeñas figuras periféricas poligonales a lo largo de la mayor parte de la superficie expuesta de la coraza (excepto en la región medio dorsal que muestra un patrón de ornamentación reticular), el cual es diferente al de las especies restantes, en las que las figuras centrales se limitan a las regiones caudal, cefálica y más lateral de la coraza. En resumen, la combinación de caracteres sugiere que podría pertenecer a una nueva especie o, alternativamente, a P. floriensis o P. jaguaribensis en las que aún no se conoce la coraza dorsal. El análisis filogenético confirma su posición basal dentro del género Panochthus, lo que evidencia la importancia de estas zonas de gran altitud en los Andes de América del Sur para comprender la compleja historia evolutiva de los gliptodontes.Panochthus Burmeister is one of the most diversified and widely distributed glyptodonts in the Pleistocene of South America, which includes areas located at high altitudes (>4,000 m a.s.l.). Within the genus, eight species (P. intermedius Lydekker, P. subintermedius Castellanos, P. tuberculatus (Owen), P. frenzelianus Ameghino, P. greslebini Castellanos, P. jaguaribensis Moreira, P. hipsilis Zurita, Zamorano, Scillato-Yané, Fidel, Iriondo and Gillette, and P. f lorensis Brambilla, López and Parent) are currently recognized. Here, we report a dorsal carapace (UATF-V n/n) from the Pleistocene of the surroundings of Potosí, Bolivia, that shows some morphological particularities when compared to the carapace of P. intermedius, P. frenzelianus, P. subintermedius and P. tuberculatus, including: a) its maximum dorso-ventral diameter is at the anterior half, meanwhile in other species is at mid-point (e.g., Propalaehoplophorus) or at posterior half (e.g., Glyptodon); b) the dorsal profile is different in comparison to other glyptodonts (e.g., Glyptodon, Glyptotherium, Neosclerocalyptus, Propalaehoplophorus); c) the ornamentation pattern of the osteoderms shows a central figure surrounded by small polygonal figures along the most exposed surface of the carapace (except for the mid-dorsal region that shows reticular ornamentation pattern), being different from that of the remaining species: of Panochthus, in which central figures are limited to the caudal/cephalic and most lateral regions of the carapace. In summary, the combination of characters suggests that it could belong to a new species or, alternatively, to P. f loriensis or P. jaguaribensis in which the dorsal carapace is not yet known. The phylogenetic analysis confirms its basal position among Panochthus and highlights the importance of these high elevation areas of the Andes in South America in order to understand the complex evolutionary history of glyptodonts.Fil: Cuadrelli, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Zamorano, Martín. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barasoain Goñi, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Anaya, Federico. Universidad Autónoma Tomás Frías; BoliviaFil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin

Regarding the real diversity of Glyptodontidae (Mammalia, Xenarthra) in the late Pliocene (Chapadmalalan Age/Stage) of Argentina

ABSTRACT A large diversity of Glyptodontidae has been proposed as characterizing the Chapadmalalan Age (Pliocene). Most of these taxa were recognized on the basis of partial dorsal carapaces and/or caudal tubes, whereas the main diagnostic characteristic is a particular morphology of the exposed surface of the osteoderms. From a biostratigraphic point of view some species are biostratigraphically important. The Upper Chapadmalalan is based on the Paraglyptodon chapadmalensis biozone. Both the re-evaluation of the type and referred materials and new significant findings from the Chapadmalal and El Polvorín Formations indicate that the diversity of Pliocene Glyptodontidae is more limited than previously supposed. The particular morphology of the exposed surface of the osteoderms that characterizes some of the species actually corresponds to a taphonomic alteration, which results in a non-real ornamentation pattern. Thus, the Glyptodontinae P. chapadmalensis must be replaced as a fossil guide because neither this species nor the species included in the genera Urotherium, Trachycalyptus and Lomaphorus are well characterized. Taking into account the diversity of Glyptodontidae for this lapse, the Glyptodontinae are very scarce (a situation that contrasts with its records in the Pleistocene), whereas Eosclerocalyptus, "Plohophorini" (Plohophorus) and Doedicurinae (cf. Eleutherocercus antiquus) are among the most recorded taxa

Un particular ejemplar de Panochthus (Xenarthra: Glyptodontidae) del Pleistoceno de Río Tercero, Córdoba, Argentina

Panochthus Burmeister es uno de los géneros de gliptodóntidos con mayor distribución latitudinal del Pleistoceno de América del Sur. Las últimas revisiones sugirieren que incluye seis especies: P. intermedius Lydekker, P. subintermedius Castellanos, P. tuberculatus Owen, P. frenzelianus Ameghino, P. greslebini Castellanos y P. jaguaribensis Moreira; recientemente se reconoció una nueva especie, P. hipsilis zurita, zamorano, Scillato-Yané, Fidel, Iriondo y Gillette. En esta contribución se presenta un ejemplar casi completo y en un excelente estado de preservación que procede de sedimentos expuestos en las márgenes del río Ctalamochita en los alrededores de la ciudad de Río Tercero (Córdoba, Argentina) interpretados como depósitos de llanura de inundación asignados tentativamente a la Formación Toro Muerto de edad Pleistoceno Medio. Su morfología general permite su asignación a Panochthus, aunque muestra ciertas particularidades: a) cráneo similar al de P. tuberculatus, pero llamativamente la región fronto-nasal está menos inclinada hacia abajo, y la escotadura de la narina es de contorno más circular; b) el tubo caudal presenta en su extremo distal solo una figura apical, como en P. subintermedius y P. greslebini, y a diferencia de P. tuberculatus, P. intermedius y P. jaguaribensis. Por otra parte, el escudete cefálico, la coraza dorsal y el esqueleto apendicular son similares a P. tuberculatus. Hasta el momento, la paleofauna asociada (e.g., Catonyx tarijensis) indica claramente una antigüedad pleistocena para este ejemplar. Posteriores estudios podrán dilucidar si las diferencias observadas con las especies pampeanas indican que se trata de un nuevo taxón o bien deben ser consideradas como variaciones intraespecíficas.Fil: Zamorano, Martín. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cuadrelli, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Ochoa, Javier G.. Fundación Ameghino; ArgentinaFil: Luna, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Barasoain Goñi, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaReunión de Comunicaciones de la Asociación Paleontológica ArgentinaPuerto MadrynArgentinaAsociación Paleontológica Argentin

À propos du statut de « Urotherium antiquum » (Ameghino) (Xenarthra, Glyptodontidae)

Within the Late Neogene Glyptodontidae of the Pampean region of Argentina, “Urotherium antiquum” was described on the basis of some associated osteoderms of the dorsal carapace, which in addition include a partial skull and left hemimandible. The diagnostic characters are located on the exposed surface of the osteoderms of the dorsal carapace which somewhat resembles those of the Pleistocene genus Neuryurus. Although the relationship of “U. antiquum” to the remaining Glyptodontidae has never been clarified, some cladistic analyses suggest a close phylogenetic affinity with the clade composed of Plohophorus + (Glyptodon + Doedicurus). A careful comparison of “U. antiquum” to well-characterized taxa with similar stratigraphic and geographic provenance reveals that no significant skull differences are observed from Plohophorus figuratus Ameghino. It seems likely that the alleged ornamentation pattern that characterizes this species was produced by a taphonomic alteration of the exposed surface of the osteoderms, a process broadly distributed in glyptodonts having a “rosette” ornamentation pattern. Finally, some characters present in the osteoderms of the type specimen of “U. antiquum” suggest that it may be a juvenile specimen. In summary, “U. antiquum” should be considered a junior synonym of P. figuratus.Fil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Cuadrelli, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Tomassini, Rodrigo Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; ArgentinaFil: De Los Reyes, Martín. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Luna, Carlos. Gobierno de la Provincia de Córdoba. Agencia Córdoba Cultura; ArgentinaFil: Toriño, Pablo. Universidad de la República. Facultad de Ciencias; Urugua

A new species of Plohophorus Ameghino (Cingulata, Glyptodontidae) from the latest Pliocene–earliest Pleistocene of the Pampean Region (Argentina): the last survivor of a Neogene lineage

Within xenarthrans, two large groups are recognized, Pilosa (anteaters and sloths) and Cingulata (armoured xenarthrans). The latter contains Glyptodontidae, one of the most bizarre and enigmatic groups of animals that ever lived. Recent phylogenetic proposals show an early Miocene divergence into two clades, one of northern origin (Glyptodontinae) and the other with its oldest records in the early–middle Miocene of southern South America, which groups most of the recognized diversity. Although knowledge of the ‘austral clade’ has increased recently, several taxa need urgent taxonomic and phylogenetic studies to understand their evolutionary history. One case is represented by the ‘Plohophorini’, a tribe that traditionally included several genera (Plohophorus, Pseudoplohophorus, Phlyctaenopyga, Stromaphorus and Stromaphoropsis), from the late Miocene–Pliocene of the Pampean and North-Western regions of Argentina, and Uruguay. A new and terminal species of Plohophorus, P. avellaneda sp. nov., coming from the El Polvorín Formation (Pampean region of Argentina) is here reported and described, and represents the first case of a Neogene genus of glyptodont crossing the Plio–Pleistocene boundary (c. 2.53 Ma). In addition, the palaeohistological analysis on the osteoderms (the first for ‘Plohophorini’) reveals some characters not observed in other glyptodonts, highlighting its potential phylogenetic importance. The phylogenetic analysis corroborates that the well-characterized species of ‘Plohophorini’ of Uruguay and the Pampean region of Argentina (‘eastern Plohophorini’) constitute a natural group within the austral clade, since both species of Plohophorus (P. avellaneda + P. figuratus) cluster together, and are the sister taxa of Ps. absolutus + Ps. benvenutti. Along the evolutionary history of Plohophorini an increase in body mass is observed, reaching its maximum with P. avellaneda sp. nov. (c. 471 ka). Despite the high frequency of late Pliocene records, Plohophorini disappear completely from the fossil record during the Pleistocene, suggesting that this character was negatively selected.Fil: Quiñones, Sofía Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Cuadrelli, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: de los Reyes, Martin. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; ArgentinaFil: Luna, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Zurita, Alfredo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; Argentin