About
99
Publications
31,832
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,480
Citations
Introduction
Skills and Expertise
Publications
Publications (99)
Roth’s explorations, the resulting collections many now allocated in La Plata, Zurich, Geneva and Copenhagen, and his
significant contributions in geological—especially stratigraphic—and paleontological topics, are a paradigmatic
case for the global history of paleontology and for the Swiss migration history in Latin America. His work included
the...
Occurrence charts of Pleistocene mammals in the Pampean area, eastern Argentina
The Paleogene terrestrial faunal succession and its associated bearing volcaniclastic deposits has been exhaustively studied in central Patagonia, but there is still no acceptable litho-bio-chronostratigraphic ordering for the extra-Andean North Patagonia. The only references on Paleogene mammals bearing deposits north to Chubut River are imprecise...
Evolutionary relationships of the endemic South American ungulates (SANUs), both to each other and to other major placental clades, have been robustly debated for more than a century. Morphological evidence has not provided unambiguous resolution of these controversies, although recent paleoproteomic and paleogenomic analyses have supplied unequivo...
In 1933 George G. Simpson described a remarkably complete skull of Trigonostylops, an Eocene South American native ungulate (SANU) whose relationships were, in his mind, quite uncertain. Although some authorities, such as Florentino Ameghino and William B. Scott, thought that a case could be made for regarding Trigonostylops as an astrapothere, Sim...
Timing and ecological steps of the rise and expansion of grasslands differ not only geographically but also according to the type of available information. Patagonia (Argentina) was largely considered the region where grasslands and grazers early evolved in the Eocene, mostly based on functional morphology of mammals. However, recent paleobotanical...
A South American anthropoid
Although there are many primate lineages in the Old World, it is thought that the New World is home to just one group, the platyrrhine monkeys, which appear to have colonized the region during the Eocene. Seiffert et al. describe a new primate species on the basis of fossil molars found in the Peruvian Amazon that appear...
Astrapotherium is the best-known member of the placental order Astrapotheria. This large herbivore inhabited the Patagonian ecosystems during early and middle Miocene times. The genus is widely represented in the early Miocene Santa Cruz Formation, with a dozen nominal species, of which Astrapotherium magnum and Astrapotherium burmeisteri are the o...
The unusual mix of morphological traits displayed by extinct South American native ungulates (SANUs) confounded both Charles Darwin, who first discovered them, and Richard Owen, who tried to resolve their relationships. Here we report an almost complete mitochondrial genome for the litoptern Macrauchenia. Our dated phylogenetic tree places Macrauch...
Eoastrapostylops riolorense Soria and Powell, 1981, is a primitive meridiungulate mammal known by two specimens from the early Paleogene Río Loro Formation, in NW Argentina. The holotype and most complete specimen is an almost complete skull, mandible, and a few associated postcranial elements. Eoastrapostylops is one of the oldest South American u...
Hegetotheriidae is one of the most advanced clades within the endemic South American placental Order Notoungulata. The species Hegetotheriopsis sulcatus Kramarz & Paz, 2013 differs from all other known hegetotheriids in having a peculiar combination of cranial and dental features, some of them shared with Archaeohyracidae (sister group of Hegetothe...
Abstract. The Cerro Bandera Formation is a mostly pyroclastic continental unit exposed in isolated areas at East central Neuquén Province, Northwestern Patagonia. Several mammals from these deposits were previously reported and support a Colhuehuapian age (early Miocene) for these levels. New findings reveal that this unit bears a much more diverse...
Se presentan los primeros resultados de estudios multidisciplinarios efectuados en la secuencia continental paleógena del O y NO de Sierra Talquino, donde se analizaron seis perfiles y se comprobaron tres Edades Mamífero (EM). La sucesión examinada comprende el Grupo Río Chico (Formaciones Peñas Coloradas, Las Flores, Koluel-Kaike) y la Formación S...
The platyrrhine primates, or New World monkeys, are immigrant mammals whose fossil record comes from Tertiary and Quaternary sediments of South America and the Caribbean Greater Antilles. The time and place of platyrrhine origins are some of the most controversial issues in primate palaeontology, although an African Palaeogene ancestry has been pre...
The biogeographic hypothesis more accepted today is that Antarctica (West Antarctica) and southern South America (Magellan region, Patagonia) were connected by a long and narrow causeway (Weddellian Isthmus) between the Antarctic Peninsula and South America since the Late Cretaceous (Campanian) until the Early Paleogene allowing terrestrial vertebr...
We describe a new toxodontid species, Nesodon taweretus sp. nov., from the Aisol Formation in Mendoza Province, central-west Argentina. Nesodon is a frequently found Toxodontidae, member of the Notoungulata, an extinct endemic group of Cenozoic South American mammals that are ecologically similar to current hoofed ungulates. The holotype of N. tawe...
An appraisal of Paleogene floral and land mammal faunal dynamics in South America suggests that both biotic elements responded at rate and extent generally comparable to that portrayed by the global climate pattern of the interval. A major difference in the South American record is the initial as well as subsequent much greater diversity of both Ne...
Propyrotherium saxeum is one the least known members of Pyrotheria, an enigmatic group of extinct, giant, endemic South American ‘ungulates.’ The species was originally described based upon two isolated cheek teeth and two tusk fragments. Later authors assigned additional isolated teeth to this taxon, but the position within the tooth row of all th...
Most of the 16 currently recognized astrapothere genera are well known through numerous specimens preserving at least almost complete dentition. One of the exceptions is the enigmatic genus Isolophodon Roth, 1903, based on very scant and fragmentary materials from Paleogene levels of central Patagonia. This taxon was ruled out from almost all taxon...
The endemic South American “ungulates” (SANU) were traditionally assumed to be a monophyletic offshoot of the Granorder Ungulata, but the current reorganization of the extant ungulates in Laurasiatheria and Afrotheria (based on molecular data) leaved them in an undetermined systematic position. The delayed dental eruption versus cranial growth was...
Se presentan los recientes avances en el conocimiento de la estratigrafía y la edad de las unidades volcano-sedimentarias cenozoicas expuestas en el área de sierra de Huantraico-sierra Negra y cerro Villegas (Departamento Pehuenches, provincia del Neuquén, Argentina). Los análisis estratigráficos y de los restos fósiles hallados permiten reconocer...
In southern South America, some regions have been postulated as containing supersite taxa, especially during the Miocenelate Pleistocene lapse. Thus, from the Late Pleistocene (ca. 5828 ka) of the current territory of the Corrientes Province, Argentina, it has been recognized the presence of some taxa, which were extinct from the Pampean region o...
In southern South America, some regions have been postulated as containing supersite taxa, especially during the Miocene-late Pleistocene lapse. Thus, from the Late Pleistocene (ca. 58-28 ka) of the current territory of the Corrientes Province, Argentina, it has been recognized the presence of some taxa, which were extinct from the Pampean region o...
We describe two isolated molariforms recovered from early-middle Eocene (early Lutetian) levels of northwestern Patagonia, Argentina. Comparisons with major lineages of therian and non-therian mammals lead us to refer them to a new genus and species of Gondwanatheria (Allotheria). There is a single root supporting each tooth that is very short, wid...
Toxodon es el primer ungulado nativo en ser descripto y es el último representante de un extraordinario linaje de mamíferos extinguidos que, desde su descubrimiento demostró su singularidad y su marcada diferenciación de los otros órdenes de ungulados entonces conocidos. Precisamente los rasgos que parecían relacionar a Toxodon con diversos grupos...
Toxodon is the first extinct native ungulate to be described; it is the last representative of this extraordinary race, which since its discovery proved its uniqueness and its strong differentiation of the other orders of ungulates then known. Precisely the features that seemed to connect Toxodon with diverse groups of mammals (rodents, perissodact...
During the past quarter century, the uplifted nearshore sediments comprising the Eocene La Meseta Formation (LMF) of Seymour (Marambio) Island have produced a diverse assemblage of terrestrial mammals that closely, but not exactly, resembles late Early Eocene faunas from southern Patagonia. This assemblage includes the only astrapothere and litopte...
In this contribution we describe the astrapotheriid Comahuetherium coccaorum gen. nov. sp. nov. from Colhuehuapian (early Miocene) sediments of the Cerro Bandera Formation in Neuquén Province, Northern Patagonia, Argentina, also recorded in levels of equivalent age at the Gran Barranca south of Lake Colhué Huapi, in Chubut Province, central Patagon...
During the past quarter century, the uplifted nearshore sediments comprising the Eocene
La Meseta Formation (LMF) of Seymour (Marambio) Island have produced a diverse assemblage
of terrestrial mammals that closely, but not exactly, resembles late Early Eocene faunas
from southern Patagonia. This assemblage includes the only astrapothere and litopte...
The discovery of abundant fossil mammals from two different levels of the lowest third of the Chinches Formation (Manantiales basin) located in Cordillera Frontal of San Juan, between 32°30’ and 33°S, is reported. These synorogenic Miocene deposits were deposited by the structural evolution of Cordón de La Ramada fold and thrust belt. Two diverse f...
Astraponotus Ameghino, 1901, the only valid Mustersan (late Eocene) astrapothere, typifies the Ameghino's "Capas Astraponotenses". This taxon is traditionally interpreted as structurally ancestral to all the Oligocene-Miocene astrapotheriids. However, it was imperfectly known: only isolated teeth and very partial mandibles have hitherto been descri...
The mammalian fauna of Cenozoic South America is known from the scientific literature to be mainly composed of a series of different aggregate waves of migrants, which originally were recognized and characterized by Simpson (1950) as the first to the third "strata." The living mammal fauna of South America still retains members of the three "strata...
A recent internet search revealed the homonymy of the generic name Notolophus, proposed by Bond, Reguero, Vizcaíno, and Marenssi (2006: 166) for an Early Eocene-Late Eocene Antarctic sparnotheriodontid litoptern. We propose the replacement name Notiolofos.
Two new fossil mammal localities from the Paleogene of central-western Patagonia are preliminarily described as the basis for a new possible biochronological unit for the early Eocene of Patagonia, correlated as being between two conventional SALMAs, the Riochican (older) and the Vacan subage of the Casamayoran SALMA. The mammal-bearing strata belo...
SYNOPSIS The new genus and species Maddenia lapidaria from pre-Deseadan (Oligocene) deposits at the southern cliff of Lake Colhue Huap (Chubut Province, Argentina) is described. This small Oligocene astrapothere represents an adaptive type that is distinct from the usual one proposed for post-Casamayoran (Eocene) forms. Because of its small body si...
Parastrapotherium Ameghino, 1895 is one of the most characteristic faunal elements of the Deseadan South American Land Mammal Age (Late Oligocene) of Patagonia, and seven species have been described for that Age. The genus was traditionally differentiated from Astrapotherium by its giant size and by having a higher number of upper and lower premola...
A new form of Xenungulata Paula Conic, 1952 from red levels of the Penas Coloradas Formation in a locality near Puerto Visser (45 degrees 17'S, 67 degrees 01'W), Chubut province, Argentina, is represented by a fragmentary left jaw with the m3 (MPEF-PV 1871). Notoetayoa gargantuai n. gen. and n. sp. is the first ever found in direct association with...
Ameghiniana was created 50 years ago. During this lapse, the late Cenozoic paleomastozoology developed exponentially in Argentina. Many of the papers dealed with systematics. However, fossil mammals were
also used for establish the chronological scale based on a biostratigraphic sequence of faunas mainly from the Pampean area. This scale proved val...
In the last 50 years, several causes contributed to increase the knowledge of Paleogene continental mammals in Argentina. Among them, the efforts focused in prospecting new localities, the increasing amount of re-searchers and the application of new techniques are the most important. The interest of paleontologists in these subjects is reflected in...
The Proterotheriidae have been recorded from Upper Paleocene until Holocene [«Land-mammal Ages» (= SALMAs) Itaboraian-Lujanian]. They are mainly braquiodonts, with cursorial habits, small to medium sized, and an early tendency toward the monodactily. The objectives of this paper are: 1) to analyze the changes in the diversity and faunistic exchan...
A fragmentary right maxilla with the deciduous and permanent canines, recovered from the Chapadmalalan (late Pliocene) of Argentina, was originally described as a sabertooth marsupial (Thylacosmilidae). A latter reviewer suggested that it could be a placental carnivore (Carnivora). In this paper we review the status of this specimen and conclude th...
A new specimen of Toxodontidae, consisting of a partial mandibular ramus with three molars, is described from the Middle Member of the Urumaco Formation and compared with type and referred material from all four taxa previously reported from Venezuela and with several better known taxa of advanced Toxodontidae. Incomplete preservation and postmorte...
We describe the oldest South American Tertiary therian mammal
from Danian-equivalent strata of northwestern Chubut
province, Argentina. The specimen is an isolated lower
molar most likely pertaining to a polydolopimorphian marsupial,
a group known from the Late Cretaceous of North America as
well as later Paleocene and Eocene deposits in South Amer...
Notolophus arquinotiensis, a new genus and species of the family Sparnotheriodontidae (Mammalia, Litopterna), is represented by several isolated teeth from the shallow-marine sediments of the La Meseta Formation (late Early–Late Eocene) of Seymour Island,Antarctic Peninsula, which have also yielded the youngest known sudamericids and marsupials. Th...
The Proterotheriidae have been recorded from Upper Paleocene until Holocene [«Land-mammal Ages» (= SALMAs) Itaboraian-Lujanian]. They are mainly braquiodonts, with cursorial habits, small to medium sized, and an early tendency toward the monodactily. The objectives of this paper are: 1) to analyze the changes in the diversity and faunistic exchange...
Se realiza una revisión sistemática de los materiales referidos a Toxodontidae (Notoungulata) provenientes del Lujanense (Pleistoceno tardío-Holoceno temprano) de las Provincias de Corrientes y Chaco, Argentina. Previamente, diversos autores habían reconocido en esta área la presencia de los siguientes Toxodontidae: Toxodon gezi, T. cf. T. gezi, T....
The present study includes a review of the geographic and stratigraphic distribution of short-faced bears (Ursidae, Tremarctinae) in South America. In addition, the authors discuss biogeographic hypotheses regarding the origin of South American tremarctines. The Tremarctinae subfamily is distributed exclusively in America, from Alaska to southern P...
The Litopterns from the Pinturas Formation (Ameghino's "Astrapothericulan beds") are examined. Four species referable to the Proterotheriidae are recognized for the lower and middle sequences of this unit: Picturotherium migueli gen. et sp. nov, Lambdaconus lacerum (Ameghino), Tetramerorhinus prosistens (Ameghino), and T. fleaglei Soria. These spec...
The Cerro Bandera Formation comprises a series of isolated outcrops that represent the relicts of an old alluvial filling developed on small local valleys. It is composed of a succession of reworked pyroclastic deposits alternating with primary pyroclastic and scant sandstone levels. These deposits were originally recognized at the northeast of Bar...
The Cerro Bandera Formation comprises a series of isolated outcrops that represent the relicts of an old alluvial filling developed on small local valleys. It is composed of a succession of reworked pyroclastic deposits alternating with primary pyroclastic and scant sandstone levels. These deposits were originally recognized at the northeast of Bar...
The fossil remains of the mammal deposit known as the "Gran Hondonada" (Sarmiento Fm., Mustersan "land-mammal age") were found in sediments of fluvial channels, disjointed, without transport evidence, and chaotically deposited. The taphonomic study was made on 1539 remains, 65% of which were determined. Most of the fossil remains correspond to Isot...
The fossil remains of the mammal deposit known as the “Gran Hondonada” (Sarmiento Fm., Mustersan “Land-mammal Age”) were found in sediments of fluvial channels, disjointed, without transport evidence, and chaotically deposited. The taphonomic study was made on 1539 remains, 65% of which were determined. Most of the fossil remains correspond to Isot...
ABSTRACT. We describe an isolated molariform tooth excavated from ?Eocene deposits
at Santa Rosa, Peru´ . The specimen most probably belongs to a mammal, and it
may correspond to a left upper last molar. Analysis of its enamel and dentine microstructure
leads to no definite conclusion as to its relationships, or even as to its enamel–
dentine struc...
The Tinguiririca Fauna of the Andean Main Range of central Chile is remarkable for its abundant and diverse archaeohyracids. This study recognizes four relatively large-bodied spe- cies from the Tinguiririca Fauna, two of which are new. Together with two previously described small-bodied forms, the total of six species makes the archaeohyracid asse...
New remains of toxodont (Mamalia, Notoungulata) in the strata of the Chucal Formation, Miocene, Altiplano of Arica, northern Chile. Three dental pieces of a notoungulate mammal, found in the strata of the upper part of the Chucal Formation, Altiplano of Arica, northern Chile (18-19°S) are described. The morphological characters allow to refer the a...
Two genera of the subfamily Pachyrukhinae (Notoungulata, Hegetotheriidae), Paedotherium and Tremacyllus, are revised. The material comes from late Miocene (Chasicoan) to early Pleistocene (Marplatan) localities in Argentina and Bolivia. The genus Raulringueletia is here considered a synonym of Paedotherium. Three valid species of Paedotherium are r...
The Notopithecinae Interatheriidae are a group of very small typotherian notoungulates, very frequent in the Patagonian Paleogene. Generally, they have been considered as ancestral for the more advanced Interatheriinae subfamily. The paper describes Punapithecus minor n. genus and species, from the Geste Formation (Pastos Grandes Group) in Antofaga...
In this paper the mammalian fauna from the Paleogene Casa Grande Formation is presented. Martinmiguelia fernandezi gen. et sp.nov. (Leontiniidae, Notoungulata) is described, based on cranial and mandibular remains. Also other notoungulate remains pertaining to the family Isotemnidae are described, being represented by isolated upper teeth, and an i...
The relationships between sequence stratigraphy and evolutionary succession on land mammal communities of Paleocene beds in coastal Patagonia (45º S) are analyzed. We found that there exists a harmonic correspondence between the discontinuities in strata and mammal sequences. More specifically, we conclude that: (1) each of the Patagonian Paleocene...
The first record of Scarrittia outside Argentina is herein presented. New evidence supporting the generic distinction between Scarrittia and Leontinia in mandibular morphology and an emended diagnosis of Scarrittia is offered: deep lingual groove in the trigonid of m3, size of the canine intermediate between i3 and p1 and shorter symphysial length...
The first Notohippidae (Notoungulata, Toxodonta) from the Lumbrera Formation, Pampahippus arenalesi gen et sp. nov., is described. Its brachydont and closed teeth, entoconids isolated in p3-p4, persistent paraconids on m1-m3 suggest that it is a primitive member of the family Notohippidae. The taxonomical affinities of some Patagonian Notoungulata...
The most complete record of the continental mammal-bearing Cenozoic of South America comes from Argentina (Marshall et al., 1983a, 1984). This record, representing the southernmost part of the continent, became a unique example in which to study the evolutionary events affecting its mammal communities in relation to the outstanding climatic and env...
The Notopithecinae Interatheriidae are a group of very small typotherian notoungulates, very frequent in the Patagonian Paleogene; generally, they have been considered as ancestral for the more advanced Interatheriinae subfamily. Here, is described Punapithecus minor n. genus and species, from the Geste Formation (Pastos Grandes Group) in Antofagas...
