Sergio A. Martínez

Sergio A. Martínez
Universidad de la República de Uruguay | UdelaR · Instituto de Ciencias Geológicas

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144
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Publications

Publications (144)
Article
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Sobre la costa del Río de la Plata, Uruguay, en la localidad arqueológica de Arazatí, se recuperó el enterramiento de dos niños prehispánicos que murieron hace ca. 500 años AP. El ajuar mortuorio presenta 503 pendientes en Urosalpinx haneti, sumados al descubrimiento reciente de 48 pendientes en Costoanachis sp. y 73 cuentas en valvas de moluscos i...
Article
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The bioinvader bivalve Corbicula fluminea (Müller, 1774) is known in the Río de la Plata River since about 35 years ago. This time lapse fills a gap in taphonomical studies, that comprises usually strictly contemporaneous or at best centuries-old phenomena. We sampled shells of this species in one locality in two occasions with the same methodology...
Article
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The freshwater mussels of the family Hyriidae (Bivalvia) are widespread in the Neotropical region, including several fossil and living species of the genus Diplodon Spix. A specimen assigned to Diplodon sp., recovered from the “Conglomerado osífero” (late Miocene) at La Toma Vieja, north of Paraná City (Entre Ríos Province, Argentina), is described...
Conference Paper
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The present chapter includes an updated synthesis of the knowledegment acquired of the continental and marine molluscan and echinoderm faunas that inhabited the region currently occupied by the province of Chubut, during the Paleogene-Neogene interval. Although those associations were recognized by the middle of 19 th century, it was not until the...
Article
Full-text available
NOTA RESUMEN La tafonomía actualista permite conocer las condiciones ambientales que influyen en la preservación de restos biológicos, e inferir las condiciones de acumulación de restos fósiles. Se explora el uso del gasterópodo invasor Rapana venosa (Valenciennes, 1846) en el Río de la Plata como modelo de tafonomía actualista, utilizando sus rasg...
Article
Full-text available
In the Late Cretaceous fossil record of Uruguay, three morphotypes of Bulimulus (Bulimulidae) have been recorded: Bulimulus klappenbachi and two undescribed ones. A geometric morphometric analysis was conducted to show whether the three morphotypes represent one or more species. With this aim, the three fossils were compared with three extant speci...
Article
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Scutelliforms were diverse and widespread in shallow marine environments during Neogene times in South America. Nevertheless, they have almost never been used as biostratigraphic tools. Objective: To provide a refined stratigraphic frame useful for calibrating temporal dimensions of scutelliform diversity from Argentina and Uruguay and its correl...
Article
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Las investigaciones interdisciplinarias que han comenzado recientemente en el Macrosistema Iberá buscan, entre otros aspectos, ampliar el conocimiento sobre la arqueología regional. En este artículo se dan a conocer los resultados de los análisis realizados sobre la colección de restos óseos humanos, faunísticos, líticos y cerámicos recuperados en...
Chapter
Shelly death assemblages are major sources of information for Actualistic Taphonomy studies. They preserve a sample, often biased, of the living communities, provide biostratinomic evidence useful for taphonomic analyses, allow one to establish shell time averaging and residence time, and are valuable resources in conservation paleobiology studies....
Chapter
The use of alien invasive species is applied for the first time to evaluate the taphonomic damage during a period of up to two decades, in natural conditions. A preliminary study using shells of the gastropod Rapana venosa collected in a microtidal beach showed that the specimens suffered important damage in the considered time span, comparable wit...
Chapter
The study of the current deposits of mollusk shells represents a very important source of analogy to distinguish between the natural and anthropic formation of shell archaeological deposits. This work focuses on the formation dynamics of modern mollusk shell deposits on a Río de la Plata beach, and the main processes involved, both natural and anth...
Book
Highlighting the latest research on Actualistic Taphonomy (AT), this book presents the outcomes of a meeting that took place in Montevideo, Uruguay, in October 2017. Its respective chapters offer valuable insights into South American archaeology, invertebrate and vertebrate fauna, and flora. In recent years, there has been a surge of new research o...
Book
Full-text available
Abstracts from the 1 Jornadas del Cenozoico de Uruguay 1999
Article
New collection work in Mount Flora, Hope Bay, Antarctic Peninsula, has confirmed the presence of bivalve moulds in the Jurassic Mount Flora Formation. In contrast to a twenty-first century article claiming to report the first discovery of fossil freshwater molluscs in Antarctica, evidence of these molluscs was first reported for Antarctica more tha...
Article
The Southern Brazilian or Rio Grande do Sul Coastal Plain (RGSCP) represents the final onshore sedimentation of the Pelotas Basin. It was formed by four lagoon-barrier system depositional events tentatively attributed to MIS 11, 9, 5, and 1. Mollusk assemblages were studied mostly from outcrops, giving scarce and contradictory numerical ages. Here...
Article
Full-text available
In the last 40 years, successive revisions have been introduced to the lithostratigraphy of the Late Cretaceous of the Norte Basin, whose record is formed by predominantly siliciclastic continental fossiliferous sedimentary rocks. A factor that contributed to the terminology proliferation was the misplaced importance attributed to the epigenetic pr...
Article
Systematic and phylogenetic analyses of fossil and extant Pitarinae of the South-Western Atlantic Ocean and Chile have been performed. The group is represented by Eucallista Dall, 1902 Dall, W. H. 1902. Synopsis of the family Veneridae and of the North American Recent species. Proceedings of the United States National Museum, 26, 355–412.[Crossref]...
Article
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A new fossil species of Biomphalaria Preston is described for the Upper Cretaceous of Uruguay (Queguay Formation). The new species is characterized by a conspicuous spiral ornamentation, a unique character within the genus. This new Biomphalaria species is the third known for the Queguay Formation, in addition to B. walteri (Parodiz) and B. reversa...
Article
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The Late Pleistocene marine molluscan assemblage from La Coronilla is one of the richest Quaternary marine deposit from Uruguay. This contribution represents an update of the bivalve and gastropod species composition of this deposit and includes a palaeoecological analysis of the molluscan fauna. The ecological preferences of the recorded species a...
Article
A new fossiliferous level from the Las Chacritas Member (Bajocian-Callovian) of the Cañadón Asfalto Formation, which crops out in the Cañadón Asfalto Basin (Extraandean-Chubut) Argentina was analyzed. The study of this assemblage was made on the basis of paleoecological, sedimentological and taphonomic criteria. This polytypic assemblage is compose...
Article
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The South American fossil record of pulmonate gastropods counts with circa 100species from the Cretaceous to the Pliocene. As this knowledge is largely scattered in the literature, we present here a checklist of these fossils, with relevant data about each species’ type locality, stratum and age, and illustrating the type specimens whenever possibl...
Article
Mollusc-rich shell concentrations are an important source of palaeontological information. Fidelity of fossil assemblages, sedimentologic, stratigraphic and palaeoenvironmental analysis, taphonomic processes and time-averaging are among the most explored topics in shell bed studies. Here, we present a preliminary taphonomic analysis of the Late Ple...
Article
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Paleoecological studies of continental gastropods give valuable information about the depositional environment of the fossil assemblages. In South America, these assemblages from the Late Cretaceous/Paleocene are scarce and poorly studied. Most works focuses on taxonomy, but a paleoecological approach is still missing. We analyzed the assemblages p...
Article
A Sr-isotope chronostratigraphy is presented for Miocene sediments deposited by the “Paranense” Sea along 1200 km of the southwestern Atlantic coast of Argentina and Uruguay. Numerical ages were obtained for shells of Aequipecten paranensis from the Argentinean Puerto Madryn Formation, Facies Balneario La Lobería, “Entrerriense Beds” of the Salado...
Article
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New specimens of Schizaster iheringi de Loriol, 1902 from Early Miocene sedimentites (Chenque Formation, Patagonia, Argentina) allowed to improve its original description, providing by the first time details of the apical system and the oral side of test. The species is included into the genus Brisaster, being this the first unquestionable document...
Article
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Material for all seven South American species of late Oligocene and Miocene scutelliform, non-lunulate sand dollars (Echinoidea: Clypeasteroida) was examined, resulting in revision of several taxa, and description of a new family, Placatenellidae n. fam., to house Placatenella n. gen. and Camachoaster n. gen. Known only from the state of Pará, Braz...
Book
Full-text available
Abstracts from the Workshop Actualistic Taphonomy in South America, Montevideo, 2017
Chapter
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Settlement patterns of the shell middens from the middle-late Holocene of the Santa Lucía basin (left margin of the Río de la Plata), are analyzed concerning the natural resources that they reveal. Spatial relationships among the shell middens and the environment are characterized by means of nearest neighbour index analysis and by correspondence a...
Article
The faunas of the highly fossiliferous Pirabas Formation belong to the southern part of the biogeographical unit known as "Neogene Tropical America". This unit developed prior to the closure of the Central American Seaway by the Isthmus of Panama. Until now, the age of the Pirabas Formation was inferred only from biostratigraphy. The Sr-isotope (87...
Article
Full-text available
Some authors support the idea that an important part of the Miocene marine mollusc fauna is still represented in the Argentinean Province. The fossil mollusc Brachidontes lepida (Philippi) is considered a subspecies of the extant B. rodriguezii (dˈOrbigny), a taxon currently present in the Argentinean Biogeographic Province. The aim of this study i...
Article
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A new species of Pupoides Pfeiffer 1854, subgenus Ischnopupoides Pilsbry 1926, is described for the Late Cretaceous of Uruguay (Queguay Formation), being the oldest record of the genus and subgenus. Pupoides (I.) gnocco new species is characterized by a small dextral fusiform shell, constituted by a spire comprising five slightly convex whorls, obl...
Article
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Zootaxa 4173 (1): 045–054 Abstract A new species of monophorasterid sand dollar, Monophoraster telfordi n. sp., is described from the Early Miocene basal horizons of the Chenque Formation of Patagonia, Santa Cruz Province, in southern Argentina. The new taxon raises the number of known species in the family to six, and represents first unequivocal...
Chapter
Uruguay has several marine deposits of undoubtedly Late Pleistocene age, but there is conflicting evidence when comparing ages obtained by different methods. While 14C datings suggest younger ages (related to Marine Isotope Stage 3—MIS 3), OSL, where available, indicate older times (related to Marine Isotope Stage 5—MIS 5). The analysis of the abun...
Book
Full-text available
This book provides an updated review and criticism of the progress of the continental, transitional and marine Quaternary deposits of Uruguay. It is primarily based on an analysis of the geological and paleontological evidences, synthesizing the time (numerical ages, biostratigraphy), environment and climatic situations involved and highlighting th...
Article
A fossil assemblage collected around 3.5 m amsl from Ezeiza, Buenos Aires province, have AMS 14C ages of ca. 33,000 to ca. 40,000 yr BP, whereas in the literature is a report of a conventional 14C age of >43,000 yr BP. An OSL age from the overlying deposit corresponds to ca. 22,000 yr. The samples contain marine fossils: mollusks, balanids and cora...
Article
Full-text available
The freshwater genus Biomphalaria Preston, 1910 is a well studied genus of freshwater snails, due to its importance as an intermediate host of the human parasite Schistosoma mansoni (Platyhelminthes). Soft parts are used to differentiate among modern species of Biomphalaria, but these parts are not present in fossils. The aim of this paper is to sh...
Chapter
The Continental Quaternary sedimentary beds of Uruguay yield useful information for helping to understand the environmental, climatic, and biotic evolution in this region of South America. Most of the units described have a rich paleontological content encompassing wood, fresh-water mollusks, pollen, trace-fossils, and a panoply of vertebrates, wit...
Chapter
Marine and transitional Quaternary deposits in Uruguay provide useful information about past sea levels and climatic and environmental changes over the last thousands of years. They yield abundant molluskan faunas that are crucial for these interpretations, and other invertebrates, vertebrates, ichnofaunas, microfaunas and microfloras. These deposi...
Chapter
The marine and estuarine beds of Uruguay may be roughly ascribed to two groups, one belonging to the Late Pleistocene and other to the Holocene. In the past, many names and units were introduced in the literature, mainly designating facies, but currently, and thanks to a good data base of numerical ages, we can simplify this former, almost anarchic...
Article
When the young Charles Darwin explored the Atlantic coast of southern South America, he was impressed by its fossils—as he wrote in the first paragraph of the Origin of Species (1859) —and the magnitude of its “wide and desolate” plains (Darwin 1839, p. 124). Although his adventures on the Patagonian plains became more famous, Darwin’s first observ...
Article
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The lithostratigraphic unit "Calizas del Queguay" (Queguay limestones) crop out in the Uruguayan sector of the Paraná Basin and in the Santa Lucia Basin, and marginally in the Argentinean littoral of the Uruguay river. The outcrops are distributed along an important part of the Uruguayan territory, and they are especially important in the Queguay a...
Article
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The fossil Asterozoa of Argentina have received scant attention. Marine rocks of Early Devonian-Late Miocene age yield ten species of Asterozoa (four Asteroidea and six Ophiuroidea), including the new Neogene record of Astropecten sp. presently introduced. Due to homonymy, Marginix nomen novum is proposed as a substitution of Marginura (Ophiuroidea...
Article
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La identificacion de concheros arqueologicos para la costa uruguaya es un hecho relativamente reciente. Se expone el estudio de concheros en relacion a los paradigmas teorico-metodologicos predominantes en la Arqueologia uruguaya. Se presentan nuevos enfoques y perspectivas para su estudio, el que se desarrolla especialmente en el margen izquierdo...
Article
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The study of mollusk accumulations (“middens”) in the archaeological record in Uruguay is relatively recent. One of the key aspects of this type of research is the distinction between accumulations formed by natural events (storms, subtidal deposits, etc.) and those that are voluntarily or involuntarily made human constructions. This situation is p...
Article
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Farina et al. [[1][1]] suggest the possibility of human presence ca 30 ka in the Arroyo del Vizcaino site (AVS) (southern Uruguay). This is based mainly on the record of cutmarks made by human artefacts on Pleistocene animal bones. They also inform of the finding of a single tiny stone tool and
Article
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Drillholes represent direct evidence of ecological interactions in the fossil record. Most of them have been interpreted as predatory in origin and enable the analysis of behavioral information of both predator and prey. Drillholes have been found in a variety of fossil organisms, but this is the first report of a bored fossil chiton plate. It was...
Article
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The genus Ctenomys present a wide 2n and NF variation in Uruguay and throughout their distribution across the South of the Neotropical region. In this study we analyze chromosome variation of this genus in Uruguay using G and C bands. G bands comparison makes clear that this chromosome variation is reduced if we take into account entire chromosomes...
Article
Criticisms of Bracco et al. (2013) about Martínez and Rojas (2013) are commented. We still claim that the sea level curve shown in the latter paper is the first statistically, testable curve produced for Uruguay. Previous attemps were made by hand. With the exception of some typographical errors correctly signaled by Bracco et al. (2013), it is dem...
Article
Numerical ages based on 87Sr/86 Sr dating of calcitic shells belonging to the pectinid Chlamys” actinodes (Sowerby) document the only late Miocene (Tortonian) sea flooding event in the Austral Basin at Cabo Buentiempo (8.95 ± 0.82 Ma, 2 s.e.), and provide evidence of the first documented early Pliocene (Zanclean) transgression in Argentina recorded...
Chapter
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We investigated the current patterns of diversity by country and by class of echinoderms, and analyzed their biogeographical, depth, and habitat or substratum affinities, using the database of the appendix of this book. Traditionally, the area has been divided into five biogeographical Regions and nine Provinces that cover a wide climate range. Cur...
Article
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Mollusks recovered from three cores taken from the Cananéia-Iguape estuarine-lagoonal system (São Paulo State, Brazil) were studied. The sampled sediments cover a period beginning approximately two centuries ago and end at the present, including a period when the system suffered significant changes of anthropogenic origin – that is, the constructio...
Chapter
Along the coast of the Southwestern Atlantic area, there are two currents which cause the thermal gradient in the region: the warm Brazilian current, flowing from north to south, and the cold Malvinas (Falkland) one (MC), that flows northwards. Both currents converge at about the isobaths of 100 and 200 m developing a complex oceanographic area pla...
Chapter
Quaternary molluskan faunas, specially the Holocene ones, are relatively abundant along the eastern coast of the Southern South American continent and have been studied with different scopes by Feruglio (1933, 1950), Aguirre and Whatley (1995), Forti-Esteves (1974), Martínez et al. (2001, 2006), De Souza et al. (2010) and Aguirre et al. (2011) (and...
Chapter
As stated in previous chapter, temperature is the main factor influencing the distribution of recent Southwestern Atlantic molluskan species, and surely, the same situation prevailed during Pleistocene and Holocene times. But, as already discussed, the spatial distribution of species was not exactly the same than today in similar latitudes. In this...
Chapter
The present paper records almost two-thirds more species in the Holocene than in the Pleistocene, as a consequence of three main factors: 1—the Pleistocene is under-represented, with a less number of recognized deposits than the Holocene; 2—the rather bad preservation of Pleistocene shells; 3—there are still many Pleistocene deposits that have not...
Chapter
Early essays on the regionalization of the marine fauna were made by Dana (1853), Forbes (1856), and in reference to mollusks, by Woodward (1856) in his Manual of Conchology. Lately, several authors improved the knowledge of the global distributional patterns of the marine organisms; Briggs (1995) among others offered a synthesis. A tripartite sche...