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New rhino remains recovered from Cova del Rinoceront (Castelldefels, Barcelona) confirm the presence of Stephanorhinus hundsheimensis (Toula, 1902) at the site and the taxon's persistence until the late Middle–early Upper Pleistocene in Europe, that is, its latest documented occurrence. The three individuals recovered from the site are compared with specimens of other Pleistocene species, including those of S. hemitoechus, S. kirchbergensis and Coelodonta antiquitatis, but their anatomical characteristics (a long skull, moderate occipital elevation, partial nasal septum, and slender zygomatic arch) do not coincide with the latter's documented features. Certain similarities are found with the most frequently occurring rhinocerotid at that time in the Iberian Peninsula, S. hemitoechus, but the cranial features of the latter differ. The anatomical characteristics of the Cova del Rinoceront individuals coincide most closely with those of S. hundsheimensis (i.e., a high occipital face, with rounded proximolateral angles and oblique lateral borders, as well as the frontoparietal angle, and facial development). Despite the marked overlaps in the general measurements of S. hundsheimensis and S. hemitoechus, many (cranial and postcranial) dimensions of the Cova del Rinoceront individuals coincide more closely with those of the former, although some bone proportions are more similar to those of the latter specimens. Therefore, S. kirchbergensis and C. antiquitatis can be discarded as they tend to be larger, more robust species. [ABSTRACT FROM AUTHOR]

This is an updated contribution to the Quaternary geology and paleontology from central-western Argentina, focused on San Luis Province. It is mostly based on unpublished data; only some fossils had previously been briefly mentioned in broader faunal contexts. The fossil-bearing sediments correspond to eolian and alluvial environments of moderate energy, dominated by sands and sandy silts. They overlie high-energy fluvial cycles and underlie edaphic horizons. They have a wide distribution, and several radiocarbon dates allow their regional correlation. Stratigraphic sequences with the precise origin of fossils allow for the improvement of lithostratigraphic and faunal correlations with the Pampean Region (central and east Argentina; La Pampa and Buenos Aires provinces), where Pleistocene assemblages are better known, but also with central-western (Cuyo Region), northwestern, and northeastern Argentina. Faunal remains correspond to large mammals, represented by xenarthrans (Cingulata and Tardigrada), macraucheniids (Litopterna), gomphotheres (Proboscidea), and equids (Perissodactyla), a typical Pleistocene mixture of native (xenarthrans and litopterns) and immigrant mammals. [ABSTRACT FROM AUTHOR]

The Huayquerian Stage of the South American chronostratigraphic scheme (named for the Huayquerías del Este, Argentina) was originally based on a poorly known mammal association of six taxa from the Huayquerías Formation. We studied the geology, age and fauna of the Neogene sequence in this area, including the Huayquerías, Tunuyán and Bajada Grande formations. The sequence comprises a monotonous succession of synorogenic epiclastic sediments deposited under arid to semi‐arid conditions. Zircon U–Pb dates from 10 tuffaceous levels (7.2–1.6 Ma) place deposition of the Huayquerías Formation during the late Tortonian or Messinian to early Zanclean, the Tunuyán Formation during the Zanclean–Piacenzian, and the Bajada Grande Formation during the Piacenzian–Calabrian. We present 43 and 31 new mammal taxon records for the Huayquerías and Tunuyán formations, respectively. Progressive faunal change was observed along the sequence. The first records of the Chaco tortoise Chelonoidis chilensis and the notoungulate Xotodon major, and the latest records of Interatheriidae and Typotheriopsis (notoungulates), Metacaremys calfucalel, Phtoramys hidalguense and Lagostomus pretrichodactyla (rodents), Chasicotatus ameghinoi and Macroeuphractus morenoi (xenarthrans) are reported. The faunal associations of the Huayquerías and lower Tunuyán formations are highly similar to each other, and to other coeval localities in Argentina. The Macroeuphractus morenoi Assemblage Biozone is proposed as the basis for redefining the Huayquerian Stage, due to the co‐occurrence of three taxa with wide geographical distribution in southern South America: Macroeuphractus morenoi, Pseudotypotherium subinsigne and Lagostomus pretrichodactyla. The age of this biozone is constrained at c. 8–5 Ma in its type area. [ABSTRACT FROM AUTHOR]

Protypotherium is one of the main genera of the Interatheriidae due to its species richness, abundance, and wide distribution from southern to middle latitudes of Argentina, Bolivia, Uruguay, and Chile. This genus is better known from the species founded by Florentino Ameghino during late 19th century from the prolific Santa Cruz Formation (Santacrucian South American Land Mammal Age (SALMA); Burdigalian–Early Langhian), Santa Cruz Province (Argentina). This contribution provides the taxonomic revision of the Santacrucian species of Protypotherium and the species erected by Florentino within this genus. We conclude that among the initial 21 species, Protypotherium antiquum , Protypotherium australe , Protypotherium praerutilum , Protypotherium compressidens , and Protypotherium claudum are valid, whereas Protypotherium obstructum is a Hegetotheriidae indet. We present a phylogenetic analysis that does not recover Protypotherium as a clade, due to the nesting of Juchuysillu and Caenophilus , and this assemblage appears as the sister taxon of the clade Progaleopithecus plus Archaeophylus. Finally, the interatheriines from the Santa Cruz Formation do not allow a subdivision of this unit, due to their wide geographic and temporal distribution, thus rejecting the biozones preliminary proposed by other authors. The Atlantic coast (east) and Río Santa Cruz (central) regions are similar in their interatheriine content, but both differ from the western area. [ABSTRACT FROM AUTHOR]

Copyright of Ameghiniana is the property of Argentine Paleontological Association / Asociacion Paleontologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Micro- and macromammal remains from Cerro La Bota (late Miocene; La Pampa Province, Argentina) are taphonomically analysed. All remains form a single sample recovered from Chasicoan sediments (facies FA2) of the Cerro Azul Formation, constituted by a lateral and vertical erosive superposition of sandstone and conglomeratic bodies, formed by episodic development of perennial streams without flow division on a loessic substrate. The analysis reveals that micro- and macromammal remains originally accumulated independently and differently. Once each type of accumulation was buried in a loessic context, the development of streams gave place to a reworking process of fossils that were finally incorporated together into the stream channel. Taphonomic characteristics of micromammals are interpreted as the result of the leftover prey accumulated by predators, probably at a den site. Instead, the macromammals respond to an attritional accumulation of individuals inhabiting the area. Even considering the reworking as an important process that affected this assemblage, the taxonomic and taphonomic evidences suggest a relatively short time for its formation. The different taphonomic histories of the remains evidence a complex association that differs from other assemblages from the Cerro Azul Formation previously analysed, and it is here assigned to the channel-lag taphonomic mode. [ABSTRACT FROM AUTHOR]

Within the notoungulate family Hegetotheriidae, some species have not been analyzed since their original publication more than a century ago. Here we present the first re-evaluation of Tegehotherium burmeisteri, including a detailed description of its holotype in an updated comparative framework, a species presumably coming from the Trelew Member of the Sarmiento Formation (Chubut Province, Argentina). Tegehotherium burmeisteri is included for the first time in a phylogenetic analysis centered in the interrelationships of hegetotheriids and defining clades according to the PhyloCode. Tegehotherium burmeisteri is recovered as a hegetotheriine closely related to Sallatherium and Hegetotherium; Hegetotheriopsis sulcatus is the earliest branch of the clade Hegetotheriidae, whereas Prohegetotherium and Paedotherium turn out to be paraphyletic, reinforcing results obtained in recent studies. The family Hegetotheriidae and both subfamilies, Hegetotheriinae and Pachyrukhinae, are recovered as monophyletic groups and defined phylogenetically, as well as two new clades: Pachyrukhini and Hemihegetotheriomorpha. [ABSTRACT FROM AUTHOR]

Among the great diversity of Oligocene mammals from Quebrada Fiera (Mendoza Province, Argentina), three families of typotherian notoungulates are very abundant. Since the first paper on archaeohyracids in 2010 until the last fieldwork in 2016, numerous unpublished remains were added to the collection. The study of all these remains, together with some revised materials, allows us to provide new anatomical data and some taxonomic decisions on these groups. Within Hegetotheriidae, we present one of the most complete skulls of "Prohegetotherium schiaffinoi" known to date, providing descriptions of certain previously unknown features of the caudal cranium; MCNAM-PV 3984 is discarded as belonging to Hegetotheriopsis sulcatus, as recently suggested, and is considered as Hegetotheriinae indet., like other isolated large specimens and some teeth previously determined as Prohegetotherium sp.; and several well-preserved specimens add to the sample of the pachyrukhine Prosotherium garzoni, including a partial maxilla with erupting P2. Concerning "Archaeohyracidae", Archaeohyrax suniensis is now better represented, recording several ontogenetic stages previously observed in the Bolivian sample of this species. Finally, within Interatheriidae, most new dental material belongs to Argyrohyrax proavus, but an isolated upper molar suggests the presence of a different Interatheriinae at Quebrada Fiera, more similar to the Bolivian Brucemacfaddenia boliviensis than to other Deseadan (late Oligocene) taxa. [ABSTRACT FROM AUTHOR]

Among the great diversity of Oligocene mammals from Quebrada Fiera (Mendoza Province, Argentina), three families of typotherian notoungulates are very abundant. Since the first paper on archaeohyracids in 2010 until the last fieldwork in 2016, numerous unpublished remains were added to the collection. The study of all these remains, together with some revised materials, allows us to provide new anatomical data and some taxonomic decisions on these groups. Within Hegetotheriidae, we present one of the most complete skulls of "Prohegetotherium schiaffinoi" known to date, providing descriptions of certain previously unknown features of the caudal cranium; MCNAM-PV 3984 is discarded as belonging to Hegetotheriopsis sulcatus, as recently suggested, and is considered as Hegetotheriinae indet., like other isolated large specimens and some teeth previously determined as Prohegetotherium sp.; and several well-preserved specimens add to the sample of the pachyrukhine Prosotherium garzoni, including a partial maxilla with erupting P2. Concerning "Archaeohyracidae", Archaeohyrax suniensis is now better represented, recording several ontogenetic stages previously observed in the Bolivian sample of this species. Finally, within Interatheriidae, most new dental material belongs to Argyrohyrax proavus, but an isolated upper molar suggests the presence of a different Interatheriinae at Quebrada Fiera, more similar to the Bolivian Brucemacfaddenia boliviensis than to other Deseadan (late Oligocene) taxa. [ABSTRACT FROM AUTHOR]

Premise: Two Bignoniaceae stems with the distinctive anatomy of a liana are described from the Miocene of South America. They are the first fossil evidence of climbing habit in Bignoniaceae. Methods: The fossil lianas are siliceous permineralizations. Transverse, tangential, and radial thin sections of the woods were prepared for study using standard petrographic techniques and observed under both light and scanning electron microscopy. Results: The stems consist of wood and presumably bark (peripheral tissues). They exhibit phloem wedges, a cambial variant associated with the climbing habit in Bignoniaceae. The wood is diffuse‐porous; solitary and in radial multiples vessels; alternated intervessel pitting; ray‐vessel pitting with distinct borders; simple perforation plates; rays 1–3 seriate, composed of procumbent cells or body ray cells procumbent with one or two‐row of upright or square marginal cells; fibers septate and non‐septate, with simple to minutely bordered pits; axial parenchyma scanty paratracheal, vasicentric, septate; perforated ray cells; prismatic crystals in rays, and rays and fibers irregularly storied. The fossil stems are related to extant Dolichandra unguis‐cati (L.) Miers. Conclusions: The fossils represent a new taxon, Dolichandra pacei sp. nov., which confirms the presence of a neotropical Bignoniaceae liana from the Miocene and provides the first and oldest evidence of the climbing habit in the family. Paleobotanical studies in the Mariño Formation, with the record of Bignoniaceae and Verbenaceae, and phylogenetic and biogeographical studies have great importance to understand plant evolution and diversification in South American Andes. [ABSTRACT FROM AUTHOR]

The late Oligocene mammalian fauna of Quebrada Fiera is one of the most diverse of the Deseadan SALMA (South American Land Mammal Age). We describe its endemic xenarthran assemblage, represented by 13 species, consisting of 2 stem sloths and 11 armoured cingulates. The rare folivoran material confirms the presence of Octodontotherium, one of the early known mylodontids, and suggests the existence of a new, small, non‐megalonychid megatherioid, Similhapalops nivis. The lumbar vertebrae of Octodontotherium sp. provide the oldest evidence of xenarthry for the order. The presence at the knee joint of an ossified meniscus and cyamo‐fabella strongly suggests a plantigrade ancestral condition in Mylodontidae. Armoured xenarthrans are represented by the armadillos Eutatini (Meteutatus sp., M. lagenaformis, and Stenotatus ornatus), an undetermined Euphractinii, the 'horned' peltephilids Peltephilus sp. and P. undulatus, and the palaeopeltid Palaeopeltis inornatus; an undetermined Glyptodontidae, the glyptatelines Glyptatelus cf. tatusinus and Clypeotherium sp., and an undetermined propalaehoplophorine. The xenarthrans represent one‐third of the mammals of the Quebrada Fiera fauna, one of the most varied at the end of the Palaeogene in South America. This vertebrate fauna is represented by a mix of endemic taxa and other species of high latitude (Patagonian) origin, but few from low latitude faunas. A detailed study of this mammalian assemblage, complemented by detailed geological and petrographical studies, suggests the existence of strong volcanic activity, and the presence of braided rivers and lagoonal environments in open habitats under a temperate or hot climate, with savannas and/or grasslands and isolated forests during the late Oligocene at the foot of the proto‐Andes. [ABSTRACT FROM AUTHOR]

We describe new remains of notoungulates from the Cerro Azul Formation (late Miocene) in La Pampa Province and reassign others previously studied, helping to precise the taxonomic diversity of 25 fossiliferous localities of this formation. Geomorphological context previously described for the area provides data to place some localities in a temporal sequence. The following Notoungulata are recognised: Protypotherium minutum (Interatheriidae), Paedotherium minor, Tremacyllus impressus, Hemihegetotherium achataleptum, H. torresi, and Hemihegetotherium sp. (Hegetotheriidae), Typotheriopsis silveyrai, T. chasicoensis, and Pseudotypotherium subinsigne (Mesotheriidae), and Pisanodon nazari, Hemixotodon chasicoensis, and cf. Stenotephanos plicidens (Toxodontidae). This study allows adding new localities to the biochronological sequence previously proposed based on the evolutionary pattern of the octodontoid rodents. Chasicoan and early Huayquerian (as herein considered) faunal assemblages present higher diversity of notoungulates than those assigned to late Huayquerian. Some localities lack a representation of taxa significant enough to precise their biochronological position within the late Miocene. The difference in the notoungulates representation along the Chasicoan–Huayquerian ages may be due to climatic changes that affected the centre of Argentina from late Miocene to early Pliocene. [ABSTRACT FROM AUTHOR]

Interatheriinae is one of the most derived subfamilies of South American notoungulates. Several interatheriines have been described since the 19th century, but most of them have not been revised, or been formally re-examined, for more than a century. Most interatheriine taxa were erected based on materials collected from Argentinean Patagonia, particularly from the Santa Cruz Formation (early–middle Miocene), Santa Cruz Province. Within the framework of an exhaustive unpublished systematic revision of Interatheriinae (early Oligocene–late Miocene), we studied the holotype of Santacrucian Icochilus undulatus, leading to the recognition of a new monospecific genus, Neoicochilus gen. nov., and the new combination N. undulatus. In addition, we formalize the taxonomic revision of Cochilius, proposing the following: Paracochilius is the junior synonym of Cochilius; Cochilius consists of C. volvens, C. fumensis, and C. brevirostrus; Paracochilius chubutensis and Protypotherium minor are junior synonyms of Cochilius brevirostrus; Cochilius pendens is the junior synonym of Cochilius columnifer; and the holotype of Cochilius columnifer exhibits the diagnostic features of Protypotherium, so we propose the new combination Protypotherium columnifer, pending publication of our thorough taxonomic revision of Protypotherium. Our taxonomic scheme is supported by a cladistic analysis, which places Neoicochilus undulatus in a derived position within Interatheriinae, as the sister taxon of the monophyletic genus Cochilius, and the clade Neoicochilus plus Cochilius positioned as the sister taxon of Interatherium. Our phylogenetic results support the monophyly of Miocene interatheriines. [ABSTRACT FROM AUTHOR]

The vertebrate fossil record of the Pampean Region of Argentina occupies an important place in South American vertebrate paleontology. An abundance of localities has long been the main basis for constructing the chronostratigraphical/geochronological scale for the late Neogene–Quaternary of South America, as well as for understanding major patterns of vertebrate evolution, including the Great American Biotic Interchange. However, few independently-derived dates are available for constraining this record. In this contribution, we present new 40Ar/39Ar dates on escorias (likely the product of meteoric impacts) from the Argentinean Atlantic coast and statistically-based biochronological analyses that help to calibrate Late Miocene–Pliocene Pampean faunal successions. For the type areas of the Montehermosan and Chapadmalalan Ages/Stages, our results delimit their age ranges to 4.7–3.7 Ma and ca. 3.74–3.04 Ma, respectively. Additionally, from Buenos Aires Province, dates of 5.17 Ma and 4.33 Ma were recovered for "Huayquerian" and Montehermosan faunas. This information helps to better calibrate important first appearances of allochthonous taxa in South America, including one of the oldest records for procyonids (7.24–5.95 Ma), cricetids (6.95–5.46 Ma), and tayassuids (> 3.74 Ma, oldest high-confidence record). These results also constrain to ca. 3 Ma the last appearances of the autochthonous sparassodonts, as well as terror birds of large/middle body size in South America. South American faunal turnover during the late Neogene, including Late Pliocene extinctions, is interpreted as a consequence of knock-on effects from global climatic changes and initiation of the icehouse climate regime. [ABSTRACT FROM AUTHOR]

Late Oligocene caviomorphs represent one of the most important early adaptive radiations of this group of rodents. They show a high taxonomic diversity and a wide geographic distribution, with those found in the upper Oligocene of Salla (Bolivia) and Patagonia (Argentina) being particularly diverse. However, caviomorphs from the Deseadan South American Land Mammal Age in other latitudes are still scarcely known. In this contribution, we describe new caviomorph rodents from the Deseadan levels of Quebrada Fiera locality (Mendoza Province; central-western Argentina) and evaluate their systematic and paleobiogeographic significance. The taxonomic composition of the caviomorphs from Quebrada Fiera reveals a complex biogeographic history, as we recognize one endemic Cavioidea (Asteromys puelche sp. nov.) and two Chinchilloidea: one with Patagonian affinities (Cephalomys sp.) and another with a wide distribution in South America (Incamys bolivianus). Asteromys puelche sp. nov., shows closer phylogenetic affinities with the Bolivian A. bolivianus than with the Patagonian A. punctus. These rodents, in common with the whole mammalian association from Quebrada Fiera, show a mix of endemic taxa and others shared with higher and lower latitudes. [ABSTRACT FROM AUTHOR]

Copyright of Ameghiniana is the property of Argentine Paleontological Association / Asociacion Paleontologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Noninvasive computed tomography (CT) scanning techniques performed on the high-quality preserved holotypes of Mendozahippus fierensis (grouped within the paraphyletic 'Notohippidae') and Gualta cuyana (Leontiniidae) allowed a thorough description of both endocasts, not only associated with the brain but also with closely related endocranial spaces, which proved to be highly diagnostic among Notoungulata and relevant from a paleobiological perspective. The specimens come from Quebrada Fiera (Mendoza, Argentina), an upper Oligocene locality extensively studied, especially during the last decade. Regarding brain endocast proportions and neocortical complexity, M. fierensis shows morphological affinities to coeval 'notohippids,' whereas G. cuyana resembles Leontinia gaudryi. An acute olfaction is inferred from the large olfactory bulbs and piriform lobes. Conversely, evidence concerning the development (and implications) of some necortical areas (i.e., somatosensory cortex and auditory cortex) were inconclusive. The encephalization quotients are around those previously reported for 'notohippids' and Toxodontidae Nesodontinae, and slightly lower than in Typotheria (except for Mesotheriidae). Other endocranial traits previously unexplored (such as the transverse diploic communication between the temporal sinuses in M. fierensis and the large temporal sinuses inferred for G. cuyana) show that there is relevant variability within Toxodontia that deserves further research. Extending similar approaches to early diverging taxa will certainly contribute to a better understanding of the morphological evolution of the brain, special sense organs, and associated blood circulation pattern in toxodontians and notoungulates in general. [ABSTRACT FROM AUTHOR]

Hegetotheriidae is one of the most derived families of South American notoungulates, which are known from the late Oligocene to Pliocene. Several genera of hegetotheriids have been described; most of them have been recently re-examined, but the Miocene taxa Hegetotherium and Pachyrukhos have not been revised for more than a century. Numerous species of both genera were described mainly from the Santa Cruz Formation, Santa Cruz Province, but also from the Colhuehuapian beds in Chubut Province, and the Colloncuran beds in Neuquén and Río Negro provinces, Argentina. Recently, Hegetotherium was recorded in Bolivia and Chile. Sinclair was the first reviewer to postulate some synonymies, in the first decade of the twentieth century. The present contribution provides a re-evaluation of these genera, including the study of previously unpublished materials. We conclude that Hegetotherium mirabile and Pachyrukhos moyani are the only hegetotheres in the Santa Cruz Formation (Santacrucian SALMA) with Hegetotherium novum and Pachyrukhos politus in the Colhuehuapian SALMA. Additionally, H. convexum, H. anceps, H. minum and H. andinum are proposed as synonyms of H. mirabile; H. novum is removed from Prohegetotherium; and Hegetotherium arctum is excluded from Hegetotheriidae. This taxonomic revision led to a new phylogenetic analysis of Hegetotheriidae, based on a previous data matrix, but enlarged and corrected, as some taxonomic issues concerning other genera were revealed. The analysis supports the monophyly of Hegetotheriidae and the subfamily Pachyrukhinae, as well as the monophyly of the genera Hemihegetotherium and Paedotherium, if the proposed removal of Pd. kakai from the latter is admitted. In contrast, Hegetotheriinae and Hegetotherium appear to be paraphyletic. The position of H. novum supports its removal from the genus Prohegetotherium, in which it was recently included. [ABSTRACT FROM AUTHOR]

A new hydrochoerine rodent, Cardiatherium calingastaense sp. nov. (Caviidae), is described based on the specimen INGEO-PV 87. It was recovered from the late Miocene Las Flores Formation, cropping out at the Puchuzum locality, San Juan Province, Argentina. The new species is based on a particular combination of characters, among which the following can be highlighted: p4 with internal fissures equally deep as in Cardiatherium paranense, secondary external fissure as in Cardiatherium patagonicum, and lacking the fifth internal fissure and supernumerary internal fissure, as in C. paranense; m3 with a conspicuous labial column in the posterior ramus of the second prism; very deep primary and secondary external fissures in upper cheek teeth, the former producing a labial strong step-shaped profile in M2; sagittal crest on the parietals; bullae small in ventral view; scars of the origin of the masseter medialis muscle with an anterior projection up to the level of the incisive foramen and the maxilla-premaxilla suture. The phylogenetic analysis supports the taxonomic proposal of creating a new species of Cardiatherium and shows C. calingastaense sp. nov. as the sister group of the other species of the genus. The lineage leading to the clade Cardiatherium + largest capybaras would have originated at least during the Chasicoan SALMA (early late Miocene). Cardiatherium calingastaense sp. nov. adds to the previous record of Cardiatherium chasicoense and Cardiatherium paranense in the late Miocene of San Juan and Mendoza provinces, respectively, thus increasing the diversity of capybaras in central-west Argentina. [ABSTRACT FROM AUTHOR]

In 1889, Florentino Ameghino erected Patriarchus palmidens, based on a specimen from a western outcrop of the Santa Cruz Formation (early Miocene) and associated it with the 'Notohippidian stage'. Later, Ameghino added seven other species to the genus from eastern localities of the same formation. Since 1900, Patriarchus has been considered to be a junior synonym of Protypotherium. Here, we present a systematic revision and recognize the genus Patriarchus as monospecific, with Pa. palmidens characterized by i1–c mesiodistally expanded, labially convex, and similar in size; i1–c with a short lingual sulcus that does not extend to the base of the teeth and 'V'-shaped in occlusal view; p1 labially and lingually bilobate, with trigonid larger than talonid; and i1–p1 in a continuous series without overlapping. Five of the remaining species are recognized as belonging to Protypotherium. Therefore, Patriarchus is presently monospecific (Pa. palmidens) and restricted to the western region of Santa Cruz Province, particularly to the Río Bote locality. Patriarchus is included for the first time in a cladistic analysis to discover its phylogenetic relationships within the Interatheriidae. It is nested within the most derived Interatheriinae and is recovered as the sister group of the Laventan Miocochilius; this clade is, in turn, the sister group of Cochilius plus Interatherium. These results support the hypothesis that the origin of the Miocene Interatheriines was a single evolutionary event. [ABSTRACT FROM AUTHOR]

A new hydrochoerine rodent, Cardiatherium calingastaense sp. nov. (Caviidae), is described based on the specimen INGEO-PV 87. It was recovered from the late Miocene Las Flores Formation, cropping out at the Puchuzum locality, San Juan Province, Argentina. The new species is based on a particular combination of characters, among which the following can be highlighted: p4 with internal fissures equally deep as in Cardiatherium paranense, secondary external fissure as in Cardiatherium patagonicum, and lacking the fifth internal fissure and supernumerary internal fissure, as in C. paranense; m3 with a conspicuous labial column in the posterior ramus of the second prism; very deep primary and secondary external fissures in upper cheek teeth, the former producing a labial strong step-shaped profile in M2; sagittal crest on the parietals; bullae small in ventral view; scars of the origin of the masseter medialis muscle with an anterior projection up to the level of the incisive foramen and the maxilla-premaxilla suture. The phylogenetic analysis supports the taxonomic proposal of creating a new species of Cardiatherium and shows C. calingastaense sp. nov. as the sister group of the other species of the genus. The lineage leading to the clade Cardiatherium + largest capybaras would have originated at least during the Chasicoan SALMA (early late Miocene). Cardiatherium calingastaense sp. nov. adds to the previous record of Cardiatherium chasicoense and Cardiatherium paranense in the late Miocene of San Juan and Mendoza provinces, respectively, thus increasing the diversity of capybaras in central-west Argentina. [ABSTRACT FROM AUTHOR]

The specimens described herein come from the Río Bote locality, Santa Cruz Formation (early Miocene), Santa Cruz Province, Argentina. They include the most complete cranial material of the 'Notohippidae' Notohippus toxodontoides and other remains that increase knowledge of the mandible and dentition. The new remains allow extension of the original description proposed by Ameghino in the 19th century and provide data on ontogenetic variation in the dental traits of this species. Notohippus differs from the Deseadan–Colhuehuapian genus Argyrohippus in the following features: discontinuous dentition; C and p1 absent; shorter P2–M3/p2–m3 series; crown of I1 highly curved; upper molars with less developed parastyle and paracone fold, less undulating ectoloph, deeper distolingual groove of M3 directed more lingually and presence of a very shallow distolabial groove; incisiform lower canine; and lower molars with posterolabial angle of talonid more rounded and narrower trigonid valley. As stated in previous works, our phylogenetic analysis indicates that the 'Notohippidae' do not constitute a monophyletic group, because Argyrohippus, Notohippus, and Toxodontidae are recovered as a clade. Internal relationships within this clade are not resolved in any of the phylogenetic analyses performed here. The presence of N. toxodontoides in the faunal assemblage found at the Río Bote locality adds to its previous records in Santa Cruz (Kar-Aiken and Cerro Centinela localities) Province, Argentina, and Sierra Baguales locality in Chile. [ABSTRACT FROM AUTHOR]

This contribution discusses the interatheriids from Quebrada Fiera, a Late Oligocene locality in the south of Mendoza Province. In addition, the taxonomic status of the Deseadan interatheresPlagiarthrus clivus,Argyrohyrax proavus,Argyrohyrax proavunculus, ?Argyrohyrax acuticostatus,Progaleopithecus fissurelatus,Progaleopithecus tournoueri, andNotohyrax conicusis discussed. We recognise in Quebrada FieraA. proavusandProgaleopithecussp. A possible third taxon is represented by one specimen that shows a combination of features that do not permit accurate assignment. These new remains, in combination with a systematic study of Deseadan interatheres, allow for a better definition of each recognised taxon, extended diagnoses, and clarification of some long-standing taxonomic misconceptions. Indeed, the priority ofA. proavusoverP. clivusis established, and the latter is proposed as anomen dubium. Associated deciduous and permanent dentition and some limb bones provide new data on the ontogenetic variation and postcranial morphology ofArgyrohyrax. Phylogenetic analysis supports the taxonomic determinations and placesA. proavusin a basal position with respect toArchaeophylusorProgaleopithecus. Documented fossil records ofArgyrohyraxandProgaleopithecusin Mendoza extend the known range to middle latitudes in central west Argentina; these taxa expand the list of mammals from Quebrada Fiera with Patagonian affinities. [ABSTRACT FROM PUBLISHER]

The study of juvenile remains ofPaedotheriumBurmeister from Cerro Azul Formation (La Pampa Province, Argentina; late Miocene) is presented. Upper and lower deciduous dentition (or permanent molars supposed to be associated with non-preserved deciduous teeth) are recognised. Several ontogenetic stages are distinguished among juveniles, according to the degree of wear and the replaced deciduous teeth. Besides, some morphological and metrical differences are observed along the crown height. Deciduous cheek teeth are high-crowned and placed covering the apex of the corresponding permanent tooth. The height of the crown and the degree of wear allow establishing the pattern of dental replacement of deciduous and permanent premolars in a posterior–anterior direction (DP/dp4–2 and P/p4–2), as well as the eruption of M/m3 before DP/dp4 is replaced. Some of the studied remains are recognised as young individuals ofTremacyllusAmeghino, but with complete permanent dentition, which leads to propose a different timing in the dental replacement with respect toPaedotherium; they also allow the establishment of an opposite premolar eruption pattern, from P/p2 to P/p4. This knowledge of the deciduous dentition ofPaedotheriumsuggests the need of revising the morphological and metrical characters previously used for defining species within this taxon. [ABSTRACT FROM PUBLISHER]

During the last decade, the Deseadan (late Oligocene) Quebrada Fiera locality, Mendoza Province, Argentina, has provided a large amount of mammal remains. Taxonomic studies have shown the presence of faunal elements common with other Deseadan associations from Patagonia and lower latitudes (Salla, Bolivia), as well as endemic taxa of different groups of mammals (Notohippidae, Leontiniidae, Homalodotheriidae, Hegetotheriidae, and Metatheria) and even a gastropod. In this work, we present a taxonomic and phylogenetic analysis of a set of postcranial fossils of three families of the suborder Toxodontia (Notoungulata). The postcranial elements are assigned to taxa previously recognized at Quebrada Fiera, such as the leontiniid Gualta cuyana and the homalodotheriid Asmodeus petrasnerus, but also to the family Toxodontidae that is represented by Proadinotherium sp. and another larger toxodontid; a few dental remains of Proadinotherium are also included as this is the first time that toxodontids from Quebrada Fiera are described. In the case of A. petrasnerus, an almost complete calcaneum allows us to expand the diagnosis of this taxon. The bones assigned to G. cuyana enlarge the anatomical knowledge of this species. In turn, the presence of the genus Proadinotherium extends its geographic distribution in Argentina and adds to the extra-Patagonian record of P. saltoni from Salla, Bolivia. Phylogenetic results do not differ much from previous analyses using postcranial characters, and the obtained consensus trees show low node supports. The various phylogenetic analyses performed here provide a more robust framework to interpret the relationships of the studied taxa. [ABSTRACT FROM AUTHOR]

During the last decade, the Deseadan (late Oligocene) Quebrada Fiera locality, Mendoza Province, Argentina, has provided a large amount of mammal remains. Taxonomic studies have shown the presence of faunal elements common with other Deseadan associations from Patagonia and lower latitudes (Salla, Bolivia), as well as endemic taxa of different groups of mammals (Notohippidae, Leontiniidae, Homalodotheriidae, Hegetotheriidae, and Metatheria) and even a gastropod. In this work, we present a taxonomic and phylogenetic analysis of a set of postcranial fossils of three families of the suborder Toxodontia (Notoungulata). The postcranial elements are assigned to taxa previously recognized at Quebrada Fiera, such as the leontiniid Gualta cuyana and the homalodotheriid Asmodeus petrasnerus, but also to the family Toxodontidae that is represented by Proadinotherium sp. and another larger toxodontid; a few dental remains of Proadinotherium are also included as this is the first time that toxodontids from Quebrada Fiera are described. In the case of A. petrasnerus, an almost complete calcaneum allows us to expand the diagnosis of this taxon. The bones assigned to G. cuyana enlarge the anatomical knowledge of this species. In turn, the presence of the genus Proadinotherium extends its geographic distribution in Argentina and adds to the extra-Patagonian record of P. saltoni from Salla, Bolivia. Phylogenetic results do not differ much from previous analyses using postcranial characters, and the obtained consensus trees show low node supports. The various phylogenetic analyses performed here provide a more robust framework to interpret the relationships of the studied taxa. [ABSTRACT FROM AUTHOR]

The present paper deals with the leontiniid remains recovered from the Late Oligocene (Deseadan) levels of Quebrada Fiera, Mendoza Province, central-western Argentina. The material consists of an almost complete skull associated with 11 vertebrae, as well as some maxillary and mandibular fragments and postcranial elements of different individuals, enabling a life reconstruction. The comparative study allows morphological differences with respect to other Deseadan taxa to be established, such asScarrittia,Leontinia,Ancylocoelus,AnayatheriumandElmerriggsia, leading to the proposal of the new taxonGualta cuyanagen. et sp. nov. The new genus and species is close toScarrittia canquelensisin having upper I1 more developed than I2–3, mainly by its greater crown-height, and the canine overlapping the P1; it differs from this species by the longer, narrower nasals, longer rostrum, I2 not reduced, P3–4 with shallow lingual sulcus, shorter cervical vertebrae, and shorter calcaneum, lacking navicular facet. The complete dentition and/or the larger I1 differentiateGualta cuyanafromLeontinia,AncylocoelusandAnayatherium ekecoa, as well as from the MioceneColpodon. The lingual sulcus on P3–4 is much shallower than inScarrittia barranquensis,Leontinia,AnayatheriumandElmerriggsia. The phylogenetic analysis shows poorly resolved relationships among leontiniids; when using equal weights, the analysis shows thatGualta cuyanais more related to the species ofAnayatheriumandScarrittia canquelensis, whereas under implied weights, the new taxon is basal to other Palaeogene taxa.Gualta cuyanaadds to other endemic taxa of the peculiar Deseadan assemblage from Quebrada Fiera. The new leontiniid constitutes a low percentage of fossil mammals within the Quebrada Fiera fauna, as is also true for this family in Salla (Bolivia), but in contrast with some Patagonian localities or the Brazilian Tremembé Formation where leontiniids are the best-represented mammal group. http://zoobank.org/urn:lsid:zoobank.org:pub:17749C84-4028-4FC8-A140-E1A6FE02466D [ABSTRACT FROM PUBLISHER]

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New isolated teeth with maxillary and mandibular fragments from the Chinji Formation of the Lower Siwaliks are described and determined as Gaindatherium browni and Gaindatherium vidali. This material comes from the Middle Miocene of Lava and Dhok Bun Ameer Khatoon localities, northern Pakistan, and significantly increases the number of remains previously known for this rhinocerotid genus. Specimens from the Lava site determined as G. vidali present morphological differences with respect to those of G. browni, being similar to those of G. vidali from the Nagri Formation, showing a greater size. Previously, G. vidali was reported only from the Nagri Formation of the Middle Siwaliks and the new material thus significantly widens the chronological distribution of this species in the continental deposits of the Siwaliks. This record implies that both species are not successive but rather coeval during the late Middle Miocene. [ABSTRACT FROM AUTHOR]

We describe a new metatherian mammal,Fieratherium sorexgen. et sp. nov., found in western Argentina (Quebrada Fiera locality, southern Mendoza Province), in Late Oligocene deposits (Agua de la Piedra Formation, Deseadan age). The only known specimen is a juvenile with fragments of both dentaries, the right maxilla and a fragment of the left premaxilla with dentition. The loci and the number teeth preserved suggest a dental formula of I?3/i3, C1/c1, P3/p3, M?3/m?3.Fieratherium sorexhas a convergent shrew-like appearance and a unique combination of features among metatherians and other South American mammals of Palaeogene age, including the well-known faunas of Patagonia. An analysis of its phylogenetic affinities suggests thatFieratheriumis the sister-group of the Paucituberculata. As already described by other authors for several mammalian taxa, the mainly Patagonian South American Palaeogene fossil record offers little information to understanding the evolution of northern lineages.Fieratheriummay represent a taxon belonging to a lineage that had its origin in Neotropical regions, so far unrecorded in the southern region of South America. http://zoobank.org/urn:lsid:zoobank.org:pub:5F6D3A50-6345-4E66-BE3E-7FEF6CC66A9B [ABSTRACT FROM AUTHOR]

ABSTRACT—Notohippidae (Notoungulata) specimens from the late Oligocene Quebrada Fiera locality (Mendoza, Argentina) were previously identified as a new taxon,Mendozahippus fierensisCerdeño and Vera. New cranial, mandibular, and postcranial remains allow enhanced description of this species and its ontogenetic variation. The ectocuneiform corresponding to the holotype (MCNAM-PV 4004) ofM. fierensiswas discovered when reexamining a block belonging to the sediment surrounding the holotype. It corresponds with the metatarsal III that was associated with the holotype skull. On the other hand, MCNAM-PV 3851, a poorly preserved maxillary fragment, is recognized as a second notohippid taxon, which differs fromM. fierensisin the different position and relative size of I3–C. The canine is placed labially to P1 and its section shows a similar size to that of the latter; ahead of the canine, the preserved root of I3 is also labially placed, and its section is clearly larger than that of the canine. This condition differs from other Deseadan notohippids. Enlargement of the muzzle at the level of I3–C and a developed paracone on premolars are present inEurygeniumandPascualihippus; the convergence of the premaxillae anterior to I3 in MCNAM-PV 3851 is closer to the condition inEurygenium. The incompleteness of this specimen, however, prevents its proper definition and it is considered as Notohippidae indet. [ABSTRACT FROM AUTHOR]

A partial mesotheriine skeleton (Notoungulata, Mesotheriidae) from the Late Miocene Casira locality, southern Bolivia, is fully described and reinterpreted taxonomically. This specimen (MNHN-Bol-V-003724) was partially described previously without a taxonomic discussion, as it was considered to be Plesiotypotherium sp. After comparison with other Bolivian, Argentinean and Chilean mesotheres, we recognize a new species of the genus Plesiotypotherium Villarroel, P. casirense sp. nov., characterized by: nasals slightly enlarged posteriorly; zygomatic arch with strong antero-distal angle; zygomatic plate starting at the level of P4 and reaching the level of the anterior part of M3; lacrimal bony process; large infraorbital foramen; posterior border of the mandible very convex; P4 without lingual groove and with narrow and projected parastyle; M3 with simple third lobe; larger and more robust skeleton than other Plesiotypotherium species. Most postcranial elements are described in detail for the first time for Plesiotypotherium. The incomplete skull GB-KKL 740 from the same locality is also referred to the new taxon. P. casirense is the sister group of P. achirense Villarroel in the phylogenetic analysis, but the genus Plesiotypotherium appears as paraphyletic. The revised partial skull GB-ACH 100 from Achiri, Bolivia, which was labelled as Plesiotypotherium sp., does not belong to this genus, and it appears phylogenetically closer to Pseudotypotherium and Mesotherium. Plesiotypotherium casirense sp. nov. increases the known diversity of the Mesotheriidae in both the Miocene of Bolivia and the South American faunal context. [ABSTRACT FROM PUBLISHER]

The article presents a study on the systematic implications of the Chilotherium intermedium from the Siwaliks of Pakistan. The researchers observed available material of Chilotherium from the Nagri and the Chinji formations, which comprise a part of the left and right mandibular ramii with p2-m3 and the right maxilla with P3-M3. They likened Subchilotherium with Chilotherium and considered Chilotherium as a valid taxon for the Siwalik chilotheres. They found that the record of C. intermedium in Pakistan lasted from the Middle Miocene until the Late Miocene, which agreed with the past concepts.

Since 2006, new field studies at the late Oligocene site of Quebrada Fiera (Mendoza, Argentina) have increased the previous faunal record from these levels that are presently considered as the base of the Agua de la Piedra Formation. Former faunal lists included Pyrotherium and Proborhyaena gigantea, representatives of the Deseadan Age. Among new materials, a complete skull and two associated metatarsals, two maxillary fragments with left I1-M2 and right I1-P3, and five isolated upper teeth represent the Family Notohippidae. Even though some characters are not comparable between the skull and maxillaries, shared features lead us to consider them as a unique and new taxon, Mendozahippus fierensis, gen. et sp. nov., and the isolated molars as cf. M. fierensis. As in previous phylogenies, our analysis indicates the Family Notohippidae is a paraphyletic group. The inclusion of Plexotemnus, Pampahippus, and Puelia within Notohippidae is not supported, but without them, the group is still paraphyletic. Leontiniids appear as basal taxa to the remaining notohippids and toxodontids. Mendozahippus presents one autapomorphy (lingually projected protocone of M3) and four homoplastic characters. It occupies a basal position with respect to other notohippids plus toxodontids. Mendozahippus increases the diversity and geographic distribution of Notohippidae during the late Oligocene. This and other taxa add some distinctiveness to this Deseadan fauna compared to other better-known assemblages from Patagonia or Salla (Bolivia), whereas other groups maintain clear affinities. The intermediate latitudinal position of Mendoza might explain these faunal characteristics. [ABSTRACT FROM AUTHOR]

The continental deposits of the Cuyana Basin, western Argentina, have yielded the most diverse, but so far almost unstudied, Triassic ichthyofaunas of South America. Here, we review these faunas and show that only eight of the 29 named taxa can be considered valid, including the chondrostean Neochallaia, the acrolepid Challaia, Guaymayenia, a taxon of uncertain affinities, and five species of the perleidiform family Pseudobeaconiidae. The first three taxa most probably come from Middle Triassic sediments, while the pseudobeaconiids are of Late Triassic age. Other material, although not diagnostic, probably represents other species, and thus, the diversity of actinopterygians in the Cuyana basin is certainly higher than currently recognized. For the Late Triassic fish fauna, the absence of crown-group neopterygians and a single record of a sarcopterygian is noteworthy and probably indicates some degree of endemism in this fauna, also supported by the high abundance of pseudobeaconiids, which are unknown from other areas. Furthermore, on the basis of the age indicated by the fishes and the available geological information, we discuss the age of the local fauna of the Cerro Bayo, close to the city of Mendoza, and the Agua de la Zorra Formation, Uspallata. [ABSTRACT FROM AUTHOR]

The Spanish material of Alicornops simorrense constitutes the best representation of the species in Western Europe. It provides interesting data on the metrical and morphological intraspecific variation of A. simorrense and its evolutionary trends from late Middle Miocene to the early Late Miocene. From late Aragonian to early Vallesian, a slight increase in size is observed, but without clear limits among series. During the late Vallesian, A. simorrense evolved in central Spanish basins into a second species, A. alfambrense, greater in size and with more robust proportions. In the Vallés-Penedés basin, A. simorrense shows a noticeable increase in size, while maintaining its proportions, during the Vallesian. A. simorrense was a very abundant species, an open woodland dweller, with gregarious behaviour, whose extinction was probably linked to the climatic change that took place at the end of the Vallesian and the beginning of the Turolian. [ABSTRACT FROM AUTHOR]

Hegetotheriidae are one of the most derived families of the Order Notoungulata. It is composed of two subfamilies: Hegetotheriinae, which resolves as paraphyletic in most recent phylogenies, and Pachyrukhinae, which historically is considered monophyletic. The family is recognized from late Oligocene to Pliocene and is well diversified from its earliest records. Most papers on the family are systematic studies and, to a lesser degree, investigate its phylogenetic relationships, but paleobiogeographic approaches are rare. A phylogenetic analysis was carried out using TNT, based on a previous matrix that was augmented with additional taxa and characters. Previous results are supported, viz., the paraphyly ofHegetotheriumAmeghino andPaedotheriumBurmeister, and the monophyly of Pachyrukhinae, but new conclusions arise, such as the paraphyly ofHemihegetotheriumRovereto and the monophyly ofProhegetotheriumAmeghino and Hegetotheriinae. In this work, a paleobiogeographic analysis on hegetotheriids is carried out by means of the Bayesian method using the RASP program, with the aim of estimating the possible ancestral area and vicariance, dispersal, and extinction events. This analysis shows that Hegetotheriidae and both subfamilies originated in central Patagonia (southeast of Chubut and northeast of Santa Cruz provinces). The analysis also reveals that dispersals were the predominant events, and they are related to Cenozoic dispersals to lower latitudes as global cooling advanced and new lands emerged. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free atwww.tandfonline.com/UJVP Citation for this article: Seoane, F. D., S. Roig Juñent, and E. Cerdeño. 2017. Phylogeny and paleobiogeography of Hegetotheriidae (Mammalia, Notoungulata). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1278547. [ABSTRACT FROM AUTHOR]

ABSTRACT—This study describes new remains of Hegetotheriidae (Notoungulata), including a new species, from the Deseadan (late Oligocene) of Quebrada Fiera, Mendoza Province, Argentina. The assemblage is composed of four hegetotheriines,Prohegetotheriumcf.P. sculptum,Prohegetotheriumsp.,Prohegetotherium schiaffinoi, andProhegetotherium malalhuense, sp. nov., and the pachyrukhinePropachyrucoscf.P. simpsoni. The presence ofProsotheriumcannot be totally discounted because lower molariforms are rather similar between the two pachyrukhine genera. The new speciesProhegetotherium malalhuense, sp. nov., differs from all previously described hegetotheriines by having a lingually projecting, sharp parastyle and marked parastyle groove on the ectoloph of M2–3; talonid of m1–2 posterolabially projected; talonid of m3 with marked posterolabial groove; and the smaller size. Its phylogenetic affinities are not well resolved.Prohegetotheriumis paraphyletic, withP. sculptumsister taxon to the remaining hegetotheres, and the new taxon more closely related toHegetotherium mirabilethan toP. schiaffinoi. The recognition ofP. schiaffinoiandProhegetotheriumcf.P. sculptumemphasizes that the fauna from Quebrada Fiera shares elements with roughly contemporaneous Deseadan faunas from northern and southern latitudes, but important faunal particularities distinguish the region as well. The record of pachyrukhines at Quebrada Fiera more closely resembles Deseadan faunas in Patagonia than temporally correlative faunas from Bolivia and Uruguay, and indicates the presence of suitable habitats in mid-latitudes of Argentina for this hypselodont clade. Faunal affinities together with particular taxa from Quebrada Fiera appear to support a significant faunal provinciality in South America during the late Oligocene. http://zoobank.org/urn:lsid:zoobank.org:pub:9DF1C9A9-92ED-4C50-BB5A-738D075E5F54 SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER]