Diana Ochoa

Universidad de Salamanca · Department of Geology

The East Pisco Basin, occupying the coastal plain of Peru between 13°S and 16°S, is widely known for its extensive Eocene to Quaternary biosiliceous deposits and excellent preservation of fossil marine vertebrates. Biochronologic studies published over the past 35 years record a hiatus of about 13 million years (*32–19 Ma) separating the youngest P...

The East Pisco Basin, occupying the coastal plain of Peru between 13°S and 16°S, is widely known for its extensive Eocene to Quaternary biosiliceous deposits and excellent preservation of fossil marine vertebrates. Biochronologic studies published over the past 35 years record a hiatus of about 13 million years (*32-19 Ma) separating the youngest P...

high-resolution pollen plates available at: http://hdl.handle.net/10366/159563

The Peruvian Province, from 6° S in Peru to 42° S in Chile, is a highly productive coastal marine region whose biology and fossil record have long been studied separately but never integrated. To understand how past events and conditions affected today's species composition and interactions, we examined the role of extinction, colonization, geologi...

Database for in press accepted paper: DeVries, Thomas J., Barron, John A, Ochoa, Diana, McDougall, Kristin, in press. Chronology and Paleoenvironment of the Tunga Formation, a new lowermost Miocene sequence in the East Pisco Basin of southern Peru. Stratigraphy, 15, V. 21, n. 3 (September 2024)

Several dolphin lineages have independently invaded freshwater systems. Among these, the evolution of the South Asian river dolphin Platanista and its relatives (Platanistidae) remains virtually unknown as fossils are scarce. Here, we describe Pebanista yacuruna gen. et sp. nov., a dolphin from the Miocene proto-Amazonia of Peru, recovered in phylo...

ABSTRACT—Pliocene South American mammals prior to the Great American Biotic Interchange comprise the evolutionary pinnacle of a long-lasting process of continental isolation, in which large-scale orogeny and climate change were instrumental. These processes resulted in unique assemblages of extinct groups with peculiar anatomies. However, interpret...

A B S T R A C T The Colombian Caribbean is an active margin characterized by constant and intense tectonic activity since the Cretaceous. Nonetheless, recent studies have reported a period of relative stability during the early Oligocene for some Caribbean basins. We have studied the biostratigraphic and well-log record of a 143-m sedimentary succe...

We present a reconstruction of human demography and shell fishing activity in the Sine-Saloum mangrove Delta (Senegal) in the past 6000 years using the summed probability density (SPD) of radiocarbon dates in archaeological shell middens. We explore how this local history relates to the climatic and political history of West Africa. We find that tr...

En el Perú existen protocolos regulados para la vigilancia de los residuos antibióticos en el área alimentaria. No obstante, otros rubros como el sector acuícola, que están en continuo crecimiento, no cuentan con controles de vigilancia rutinarios a pesar del uso de antibióticos en los productos de cultivo. La falta de control se debe e21|n parte a...

This research assessed carbon and nutrient burial during the past ~60 years within a Peruvian coastal marsh ecosystem affected by anthropogenic activities, by examining total organic carbon (TOC), total nitrogen (TN) and isotopes (δ 13 C and δ 15 N) tracers in two dated sediment cores. Significantly higher TOC and TN burial, up to 416.4 ± 65.0 and...

The evolution of crocodylians as sea dwellers remains obscure because living representatives are basically freshwater inhabitants and fossil evidence lacks crucial aspects about crocodylian occupation of marine ecosystems. New fossils from marine deposits of Peru reveal that croco-dylians were habitual coastal residents of the southeastern Pacific...

Over the last decades, rocks from the East Pisco Basin (EPB), on the Central Peruvian coast (13°-16°S), have yielded an abundant and diverse collection of coastal-marine fossils, which are key for characterizing the onset and evolution of the modern Humboldt Current. Despite its paleontological richness, and after almost 40 years of study, the spat...

The file includes character list, character x taxon matrix, data about mandibular measurements and paleobiogeographic analysis of the paper on Archaebalaenoptera eusebioi.

Archaebalaenoptera eusebioi is a new late Miocene (Tortonian) balaenopterid species from the Aguada de Lomas locality in the Pisco Formation, Peru. It is dated to 8.85–7.93 Ma and is represented by a nearly complete skull with cervical vertebrae. Its inferred body length and mass are respectively c. 7 m and 7–11 tonnes. Archaebalaenoptera eusebioi...

[This corrects the article DOI: 10.1007/s00531-021-02003-1.].

Sediments from the Pisco Formation offer an opportunity for studying environmental changes and sedimentary processes associated with variations in productivity levels and oxygenation along the continental margin during the Neogene. In this work, we seek to characterize the detrital and biogenic supply to the East Pisco Basin during the Middle Mioce...

The Plio-Pleistocene (2.7 to 1.4 Ma) marine sediments of the Caracoles Formation have recorded paleoenvironmental changes in one of the areas where the present Humboldt upwelling system is developed. The objective of this study is to characterize the sedimentary processes existing in the Sacaco area (12-14º) and to infer the climatic-environmental...

Lack of constraint on spatial and long-term temporal variability of the El Niño southern Oscillation (ENSO) and its sensitivity to external forcing limit our ability to evaluate climate models and ENSO future projections. Current knowledge of Holocene ENSO variability derived from paleoclimate reconstructions does not separate the role of insolatio...

Global sea-level changes and substantial vertical displacement along the Monte Grande Fault (MGF) in the lower Río Ica Valley of south-central Peru influenced the accumulation of bioclast-bearing and diatom-bearing Miocene siliciclastic sediments in an area of the East Pisco forearc basin (EPB) colloquially known as Laberinto. Two depositional hiat...

Significance Explaining the greening of the Sahara during the Holocene has been a challenge for decades. A strengthening of the African monsoon caused by increased summer insolation is usually cited to explain why the Sahara was vegetated from 14,000 to 5,000 y ago. Here, we provide a unique climate record of quantified winter, spring, and summer p...

The highly productive waters of the Humboldt Current System (HCS) host a particular temperate ecosystem within the tropics, whose history is still largely unknown. The Pisco Formation, deposited during Mio-Pliocene times in the Peruvian continental margin has yielded an outstanding collection of coastal-marine fossils, providing an opportunity to u...

Facial compartmentalization in the skull of extant pygmy whales (Kogiidae) is a unique feature among cetaceans that allows for the housing of a wide array of organs responsible for echolocation. Recent fossil findings indicate a remarkable disparity of the facial bone organization in Miocene kogiids, but the significance of such a rearrangement for...

The Peruvian coast experiences the largest interannual variability of sea surface temperature in the world due to the combined influence of the coastal upwelling and El Niño Southern Oscillation (ENSO). Although biological impacts of El Niño events have been widely reported, their effects on rocky intertidal communities remains largely unknown in P...

La Formación Pisco tiene un registro excepcional de rocas y fósiles que permite reconstruir las características y evolución de los ambientes y ecosistemas marino-costeros existentes a lo largo del margen Pacífico peruano. Los fósiles han documentado ampliamente la fauna de vertebrados marinos típica del Pacífico sudeste durante el Mioceno tardío y...

The climatic origin of astronomically induced sedimentary cycles in the Mediterranean and adjacent areas during the late Neogene and Quaternary remains puzzling; as cycles have been linked to concomitant but seasonally opposite changes in African summer monsoon precipitation (Eastern Mediterranean sapropels) and Atlantic regulated winter-precipitat...

Late Neogene floras of North America are mainly represented by sites located along the east coast Piedmont and the Great Plains. To date, there are only two upper Neogene inland localities in the eastern half of North America, the Pipe Creek Sinkhole (Indiana) and the Gray Fossil Site (Tennessee). At both sites, a lacustrine environment was formed...

The current interpretation of the Messinian Salinity Crisis (MSC) involves the deposition of peripheral or marginal evaporites in onshore basins as well as the erosion of the margin and the deposition of thick evaporites in deep basins. The so-called intermediate basins are formed in domains between the onland outcrops and the deep basins. The Bale...

Marine gateways play a critical role in the exchange of water, heat, salt and nutrients between oceans and seas. As a result, changes in gateway geometry can significantly alter both the pattern of global ocean circulation and associated heat transport and climate, as well as having a profound impact on local environmental conditions. Mediterranean...

Keywords: Balearic Promontory bedded unit betic corridor evaporites Messinian Salinity Crisis Primary Lower Gypsum The Messinian Salinity Crisis (MSC) was a major ecological crisis affecting shallow and deep-water settings over the entire Mediterranean basin. However, the evolution of the MSC and its ecological impacts have mainly been explained on...

In spite of 40 years of multi-disciplinary research conducted on the Messinian Salinity Crisis (MSC) event, modalities, timing, causes, chronology and consequence at local and planetary scale of this event are still not yet fully understood, and the MSC event remains one of the longest-living controversies in Earth Science. A key factor for the con...

We present new data on the stratigraphy of the Miocene in northwestern Colombia, in the Pacific Basin. The sedimentological and biostratigraphic study, based on an analysis of calcareous nannofossils, foraminifera, palynomorphs, and diatoms, has enabled a new framework to be constructed that allows the closing process of the Isthmus of Panama to be...

The pollen genus Cyclusphaera was first described from the Campanian of Peru. The distinctive pollen is spherical to ovoid and disc shaped, with two large openings, resembling pores, opposite each other on the pollen grain. We emend the description of Cyclusphaera scabrata from the Cenozoic of northern South America, based on new data from transmis...

Deformation of the Eastern Cordillera, as a double-verging thrust belt that separates the Magdalena Valley from the Llanos Basin, is a defining moment in the history of the northern Andes in South America. Here we examine the age and depositional setting of the youngest stratigraphic unit in three sectors of the Eastern Cordillera: (i) the Santa Te...

The Gray Fossil Site, northeastern Tennessee, is formed by multiple karst sub-basins filled with lacustrine sediments. The oldest sediments found were recently dated as Paleo-Eocene by palynological means, whereas the youngest sediments are considered Mio-Pliocene based on their faunal assemblage. In this study, we examined the Mio-Pliocene lacustr...

Temperatures in tropical regions are estimated to have increased by 3° to 5°C, compared with Late Paleocene values, during the Paleocene-Eocene Thermal Maximum (PETM, 56.3 million years ago) event. We investigated the tropical forest response to this rapid warming by evaluating the palynological record of three stratigraphic sections in eastern Col...

IntroductionEvolution of the Amazonian CratonModern cratonic rivers of Amazonia: classification and composition of the sediment loadClimate and weathering in the cratonic source areaCratonic rivers, past and present: evidence from the sedimentary record in AmazoniaConclusions The shift from cratonic- to Andean-dominated fl uvial systemsAcknowledgem...