Primer registro de Scelidotheriinae Ameghino (Xenartha, Mylodontidae) del Piso/Edad Chasiquense (Mioceno tardío) de la Argentina

he subfamily Scelidotheriinae constitutes a group of mylodontids widely represented in the Quaternary of South America; however, the fossil record of the Neogene taxa is still scarce. In the present paper, a new specimen of this subfamily, corresponding to a right partial hemimandible with complete dental series, is reported. The material was recovered from the lower levels of the Arenisca Albardón Member of the Loma de Las Tapias Formation (San Juan Province, Argentina), assigned to the late Miocene. This finding represents the first record of a member of the Scelidotheriinae from the Chasicoan Stage/Age and provides new information about the anatomical characteristics and the geographic distribution of the Neogene representatives of this subfamily.La subfamilia Scelidotheriinae constituye un grupo de milodóntidos ampliamente representados en el Cuaternario de América del Sur. Sin embargo, el registro fósil de los taxa del Neógeno es aun escaso. En este trabajo se presenta un nuevo ejemplar de esta subfamilia, correspondiente a un fragmento de hemimandíbula derecha con la serie dentaria completa. El material fue recuperado de los niveles inferiores del Miembro Arenisca Albardón de la Formación Loma de Las Tapias (Provincia de San Juan, Argentina), asignados al Mioceno tardío. Este hallazgo representa el primer registro de un Scelidotheriinae para el Piso/Edad Chasiquense y aporta nueva información sobre las características anatómicas y la distribución geográfica de los representantes neógenos de esta subfamilia

Palinología de los géneros Tarasa y Wissadula (Malvaceae, Malveae) de Argentina

Pollen grains of twenty one species of two genera of Malvaceae were studied and described under optical and scanning microscopy; Tarasa Phil.: T. alberti Phil., T. antofagastana (Phil.) Krapov., T. capitata (Cav.) D. M. Bates, T. heterophylla(Griseb.) Krapov., T. humilis (Gill. ex Hook & Arn.) Krapov., T. meyeri Krapov., T. odonellii Krapov., T. tarapacana (Phil.) Krapov., T. tenella (Cav.) Krapov., T. trisecta(Griseb.) Krapov., T. urbaniana (Ulbr.) Krapov., and Wissadula Medik: W. decora S. Moore, W densiflora R.E.Fr., W. glechomaefolia (A. St.-Hil.) R.E.Fr., W. gymnanthemum (Griseb.) K. Schum., W. paraguariensis Chodat, W. parviflora(A.St.-Hil.) R.E.Fr., W. setifera Krapov., W. subpeltata (Kuntze) R.E.Fr., W. tucumanensis R.E.Fr. and W. wissadifolia (Griseb.) Krapov. They showed differences at generic level, excepting Tarasa alberti which has affinities with theWissadula group. Pollen grains are spheroidal, oblate-spheroidal and suboblate, medium to large sized. The apertures show variations in number (three to eight), but all they are colporate and have different distribution patterns: zonocolporate and spiralloid. The sculpture does not show marked differences on the surface; the most of them are echinate, echinulate with nanospinulae and perforations (foveas) between the spines or spinulae. Two keys to determine the species of each genus and distinguish the three recognized pollen types are given: 1) tri-tetracolporate, 2) pentazonocolporate and 3) oligocolporate (6-8 apertures) spiraloid arrangement.Fueron estudiados y descriptos con microscopio óptico y electrónico de barrido, los granos de polen de veintiún especies pertenecientes a dos géneros de Malvaceae; Tarasa Phil.: T. alberti Phil., T. antofagastana (Phil.) Krapov., T. capitata(Cav.) D. M. Bates, T. heterophylla (Griseb.) Krapov., T. humilis (Gillies ex Hook & Arn.) Krapov., T. meyeri Krapov., T. odonellii Krapov., T. tarapacana (Phil.) Krapov.,T. tenella (Cav.) Krapov., T. trisecta (Griseb.) Krapov. y T. urbaniana (Ulbr.) Krapov., yWissadula Medik: W. decora S. Moore, W. densiflora R. E. Fr., W. glechomaefolia (A. St.-Hil.) R. E. Fr., W. gymnanthemum (Griseb.) K.Schum., W. paraguariensisChodat, W. parviflora (A.St.-Hil.) R.E.Fr., W. setifera Krapov., W. subpeltata (Kuntze) R.E.Fr., W. tucumanensis R.E.Fr. y W. wissadifolia (Griseb.) Krapov. Existe diferencia entre ambos géneros, con excepción de Tarasa alberti que tiene más afinidad con el grupo Wissadula. Los granos de polen son esferoidales, oblato-esferoidales y suboblatos, de medianos a grandes; la escultura no muestra gran variabilidad, las especies de ambos géneros son equinadas o equinuladas con nanoespínulas y perforaciones (fóveas) entre las espinas o espínulas. En el género Tarasa las aperturas muestran variación en el número (tres a ocho) y en la distribución: zonocolporadas, y en posición espiraloide. Las especies deWissadula son todas trizonocolporadas. Se presentan dos claves para reconocer las especies de cada género y se establecen tres tipos de polen en base al número y distribución de las aperturas: 1) tri-tetrazonocolporado, 2) pentazonocolporado y 3) oligocolporado (6 a 8 aperturas) en posición espiraloide

Campamento Vespucio, una nueva localidad con mamíferos pleistocenos en la provincia de Salta, Argentina

In this contribution a new locality with Pleistocene fossil mammals is presented. The materials come from the Quebrada del Aguay, Campamento Vespucio, General Mosconi, Salta province, Argentina; they are tentatively assigned to the Urundel Fm. (late Pleistocene). The palaeofaunistic association includes six taxa: Xenarthra Glyptodontidae: Glyptodon sp. and Panochthidae: Neosclerocalyptus sp.; Tardigrada Megatheriidae: gen. et. sp. indet.; Proboscidea Gomphotheriidae: Stegomastodon sp; Notoungulata Toxodontidae: Toxodon sp. Perissodactyla Equidae: Equus (Amerhippus) sp. This set of Pleistocene mammals presents a wide latitudinal distribution in South America. Some of them (e.g. Neosclerocalyptus) are congruent with arid/semiarid, cold conditions and open environments. In this scenario, this contribution improves the knowledge that we have in northern part of Argentina, very scarce compared with respect to that of the Pampean region.En la presente contribución damos a conocer una nueva localidad con mamíferos fósiles pleistocenos, provenientes de una región poco explorada. Los materiales fueron hallados en la Quebrada del Aguay, en Campamento Vespucio, localidad de General Mosconi, provincia de Salta, Argentina, y tentativamente asignados a la Fm. Urundel (Pleistoceno tardío). Desde un punto de vista taxonómico, se presentan seis taxones que incluyen: Xenarthra Glyptodontidae: Glyptodon sp. y Panochthidae: Neosclerocalyptus sp.; Tardigrada Megatheriidae: gen. et. sp. indet; Proboscidea Gomphotheriidae: Stegomastodon sp; Notoungulata Toxodontidae: Toxodon sp.; Perissodactyla Equidae: Equus (Amerhippus) sp. Este elenco faunístico se encuentra representado por taxones que presentan una amplia distribución latitudinal en América del Sur. Algunos de ellos (e.g. Neosclerocalyptus) indicadores de climas áridos/semiáridos y fríos de ambientes abiertos. Por último, este trabajo contribuye a mejorar la caracterización paleofaunística del Pleistoceno del norte de Argentina, muy poco conocida con respecto a aquella de la región Pampeana

Palynology of the genera <i>Tarasa</i> and <i>Wissadula</i> (Malvaceae, Malveae) from Argentina

Pollen grains of twenty one species of two genera of Malvaceae were studied and described under optical and scanning microscopy;&nbsp;Tarasa&nbsp;Phil.:&nbsp;T. alberti&nbsp;Phil.,&nbsp;T. antofagastana&nbsp;(Phil.) Krapov.,&nbsp;T. capitata&nbsp;(Cav.) D. M. Bates,&nbsp;T. heterophylla(Griseb.) Krapov.,&nbsp;T. humilis&nbsp;(Gill. ex Hook &amp; Arn.) Krapov.,&nbsp;T. meyeri&nbsp;Krapov.,&nbsp;T. odonellii&nbsp;Krapov.,&nbsp;T. tarapacana&nbsp;(Phil.) Krapov.,&nbsp;T. tenella&nbsp;(Cav.) Krapov.,&nbsp;T. trisecta(Griseb.) Krapov.,&nbsp;T. urbaniana&nbsp;(Ulbr.) Krapov., and&nbsp;Wissadula&nbsp;Medik:&nbsp;W. decora&nbsp;S. Moore,&nbsp;W densiflora&nbsp;R.E.Fr.,&nbsp;W. glechomaefolia&nbsp;(A. St.-Hil.) R.E.Fr.,&nbsp;W. gymnanthemum&nbsp;(Griseb.) K. Schum.,&nbsp;W. paraguariensis&nbsp;Chodat,&nbsp;W. parviflora(A.St.-Hil.) R.E.Fr.,&nbsp;W. setifera&nbsp;Krapov.,&nbsp;W. subpeltata&nbsp;(Kuntze) R.E.Fr.,&nbsp;W. tucumanensis&nbsp;R.E.Fr. and&nbsp;W. wissadifolia&nbsp;(Griseb.) Krapov. They showed differences at generic level, excepting&nbsp;Tarasa alberti&nbsp;which has affinities with theWissadula&nbsp;group. Pollen grains are spheroidal, oblate-spheroidal and suboblate, medium to large sized. The apertures show variations in number (three to eight), but all they are colporate and have different distribution patterns: zonocolporate and spiralloid. The sculpture does not show marked differences on the surface; the most of them are echinate, echinulate with nanospinulae and perforations (foveas) between the spines or spinulae. Two keys to determine the species of each genus and distinguish the three recognized pollen types are given: 1) tri-tetracolporate, 2) pentazonocolporate and 3) oligocolporate (6-8 apertures) spiraloid arrangement.</div

First record of Scelidodon chiliense (Lydekker)(Phyllophaga, Scelidotheriinae) from the Lujanian Stage (Late Pleistocene - Early Holocene) of Argentina

The Scelidotheriinae constitutes a group of sloth with numerous problematics, mainly related to their origin and phylogenetic relationships. This subfamily is principally characterized by a narrow and elongated skull, a coincident modification of the dental series and having a medium size. It is reported the first record of Scelidodon chiliense (Lydekker) (Phyllophaga, Scelidotheriinae), exhumed from Lujanian sediments (Late Pleistocene - Early Holocene) belonging to the Uspara Formation of San Luis Province (Argentina). The fossil (MHIN-UNSL GEO V-199) consists of a sub-complete skull without teeth, except the right M1. The specific assignation is mainly based on: sagittal and temporal crests with little development and parietal and squamosal bones separated by an horizontal suture. This reports broad the geographical distribution of the species, known so far only for northern Chile, Bolivia, Peru and Ecuador. Finally, it allows raising and discussing some hypothesis related to its presence into the current territory of Argentina

A review of the Quaternary Scelidotheriinae (Mammalia, Xenarthra, Tardigrada) from the Tarija-Padcaya basin, Bolivia

ABSTRACT The Mylodontidae Scelidotheriinae (Mammalia, Xenarthra, Tardigrada) are a diversified clade of South American fossil ground sloths, with a wide geographic distribution, especially in high and middle latitudes. According to the last revision, the Quaternary diversity includes the genera Scelidotherium, Catonyx, and Valgipes. The clade Scelidotheriinae is well represented in the Pleistocene of the Tarija-Padcaya basin, and the first mention of these ground sloths correspond to the middle of the XIX Century. Since then, several species (i.e., Scelidotherium tarijensis, Scelidodon tarijensis, Scelidotherium capellini) have been reported as inhabiting the Tarija-Padcaya basin during the Pleistocene. Despite the abundance of fossil records of Scelidotheriinae in this area, no modern taxonomic revisions are available. In consequence, in this contribution a revision of the remains assigned to Scelidotheriinae from the Tarija-Padcaya basin is accomplished, and some biostratigraphic and geographic implications are discussed. Our results show that one single species (Catonyx tarijensis) can be recognized in the studied area, whereas a supposed smaller one (Scelidotherium patrium) actually corresponds to juvenile specimens of C. tarijensis