scholarly journals Neogene Caribbean elasmobranchs: Diversity, paleoecology and paleoenvironmental significance of the Cocinetas Basin assemblage (Guajira Peninsula, Colombia)

Author(s):  
Jorge Domingo Carrillo-Briceño ◽  
Zoneibe Luz ◽  
Austin Hendy ◽  
László Kocsis ◽  
Orangel Aguilera ◽  
...  

Abstract. The Cocinetas Basin is located on the eastern flank of La Guajira Peninsula, northern Colombia (South Caribbean). During late Oligocene through Pliocene, much of the basin was submerged. The extensive deposits in this area suggest a transition from a shallow marine to a fluvio–deltaic system, with a rich record of invertebrate and vertebrate fauna. The elasmobranch assemblages of the early Miocene to late Pliocene succession in the Cocinetas Basin (Jimol, Castilletes and Ware Formations, and Patsúa Valley) are described for the first time. The assemblages include at least 30 taxa of sharks (Squaliformes, Pristiophoriformes, Orectolobiformes, Lamniformes and Carcharhiniformes) and batoids (Rhinopristiformes and Myliobatiformes), of which 24 taxa are reported from the Colombian Neogene for the first time. Paleoecological and paleoenvironmental interpretations are based on the feeding ecology, and on estimates of paleosalinity using stable isotope compositions of oxygen in the bioapatite of shark teeth. The isotopic composition of studied specimens corroborates the paleoenvironmental settings for the studied units suggested on the basis of other proxies. These Neogene elasmobranch assemblages from the Cocinetas Basin, provide new insights of the shark and ray diversity inhabiting the coastal and estuarine environments of the northwestern margin of South America, both during the existence of the gateway between the Atlantic and Pacific Oceans, and following its closure

2019 ◽  
Vol 16 (1) ◽  
pp. 33-56 ◽  
Author(s):  
Jorge Domingo Carrillo-Briceño ◽  
Zoneibe Luz ◽  
Austin Hendy ◽  
László Kocsis ◽  
Orangel Aguilera ◽  
...  

Abstract. The Cocinetas Basin is located on the eastern flank of the Guajira Peninsula, northern Colombia (southern Caribbean). During the late Oligocene through the Pliocene, much of the basin was submerged. The extensive deposits in this area suggest a transition from a shallow marine to a fluvio-deltaic system, with a rich record of invertebrate and vertebrate fauna. The elasmobranch assemblages of the early Miocene to the late Pliocene succession in the Cocinetas Basin (Jimol, Castilletes and Ware formations, as well as the Patsúa Valley) are described for the first time. The assemblages include at least 30 taxa of sharks (Squaliformes, Pristiophoriformes, Orectolobiformes, Lamniformes and Carcharhiniformes) and batoids (Rhinopristiformes and Myliobatiformes), of which 24 taxa are reported from the Colombian Neogene for the first time. Paleoecological interpretations are based on the feeding ecology and on estimates of the paleohydrology (relative salinity, temperature) using stable isotope compositions of oxygen in the bioapatite of shark teeth. The isotopic composition of the studied specimens corroborates paleoenvironmental settings for the studied units that were previously estimated based on the sedimentology and biology of the taxa. These Neogene elasmobranch assemblages from the Cocinetas Basin provide new insights into the diversity the sharks and rays inhabiting the coastal and estuarine environments of the northwestern margin of South America, both during the existence of the gateway between the Atlantic and Pacific oceans and following its closure.


2021 ◽  
Vol 69 (Suppl.1) ◽  
pp. 35-50
Author(s):  
Claudia-J. Del Río ◽  
Sergio Martínez

Introduction: 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 correlation with the molluscan assemblages previously proposed. Methods: A detailed survey of their geographic and stratigraphic provenance was carried out. We revised both the bibliography and collections (institutional and from our own field work). Results: The group is represented by 14 species belonging to six genera, and four assemblages were identified. Numerical dates of the Neogene marine rocks obtained recently allowed their placement in a chronological scheme: “Iheringiella” sp. A is restricted to the late Oligocene, the genera Camachoaster and “Eoscutella” and the species Monophoraster telfordi to the early Miocene, Abertella gualichensis and Abertella miskellyi to the middle Miocene, and Monophoraster duboisi, Amplaster coloniensis and Amplaster ellipticus to the late Miocene. Non-lunulate scutelliforms are not restricted to the late Oligocene as previously supposed. The oldest occurrence of the genus Monophoraster corresponds to the early Miocene, and along with Iheringiella are long-living taxa that embrace the 25.3 Ma-18.1 Ma (Iheringiella patagonensis) and approximately 15 Ma-6.48 Ma (Monophoraster darwini) intervals. The presence of Iheringiella in the early Miocene of northeastern Patagonia is corroborated, reaching there its northernmost distribution. Monophoraster darwini has a temporal range from the late Miocene (where it was previously thought to be restricted) back to the middle Miocene, since this is the species yielded in the well-known and discussed “Monophoraster and Venericor Beds”. Conclusions: The Paleogene-Neogene scutelliforms of Argentina and Uruguay range from the late Oligocene to the late Miocene. There is a good correspondence among the numerical ages, molluscan biozones and scutelliform assemblages.


2021 ◽  
Vol 19 ◽  
Author(s):  
Cristina Sequero ◽  
Giovanna Della Porta ◽  
Beatriz Bádenas ◽  
Marcos Aurell

Bulk carbon and oxygen stable isotopes of ancient shallow-marine carbonates can record the effects of multiple palaeoenvironmental factors, but also the imprint of several post-depositional processes, which may alter the original marine isotopic composition. In this study, carbon and oxygen stable isotope analyses were performed on bulk carbonate, bivalve calcitic-shell (Trichites) and calcite vein samples from two stratigraphic sections (Tosos and Fuendetodos, present-day distance 15km), representing proximal inner- and distal mid-ramp environments, respectively, of the uppermost Kimmeridgian ramp facies deposited in the northern Iberian Basin (NE Spain). These successions underwent different diagenetic pathways that altered the primary marine isotopic composition in each section in different ways. Different burial histories, tectonic uplift and a variable exposure to meteoric diagenesis from the end of the Kimmeridgian to the Cenozoic (following Alpine tectonic uplift) are reflected in the different alteration patterns of the carbon and oxygen stable isotope signatures. A significant deviation to lower values in both δ13O and δ18O is recorded in those carbonates mostly exposed to meteoric diagenesis (distal mid-ramp Fuendetodos section), because of post-depositional tectonic uplift (telogenesis). On the other hand, the deposits mainly affected by burial diagenesis (proximal inner-ramp Tosos section) only record low δ18O with respect to expected values for pristine Kimmeridgian marine carbonates. The different burial and tectonic uplift histories of these deposits in each sector, due to their different tectonic evolution in this part of the basin, resulted in a variable degree of diagenetic resetting. However, in spite of the different diagenetic resetting reported of the carbon and oxygen stable isotope signatures in each section, these carbonates show similar cement types in termsof fabrics and cathodoluminescence properties. The diagenetic resetting reported for these carbonates prevents the use of the δ13O and δ18O records for addressing palaeoenvironmental interpretations, but instead highlights useful features regarding the variable diagenetic overprint of the studied shallow-marine carbonate successions concerning their specific post-depositional history.


2017 ◽  
Vol 43 (2) ◽  
pp. 208 ◽  
Author(s):  
Daniele Cristine Hoffmann Schlesener ◽  
Jutiane Wollmann ◽  
Juliano De Bastos Pazini ◽  
Anderson Dionei Grützmacher ◽  
Flávio Roberto Mello Garcia

Drosophila suzukii (Diptera, Drosophilidae) is an exotic species, endemic to Asia and currently a pest to small and stone fruits in several countries of North America and Europe. It was detected in 2013 for the first time in South America, in the south of Brazil. Unlike most drosophilids, this species deserves special attention, because the females are capable of oviposit inside healthy fruits, rendering their sale and export prohibited. Despite the confirmed existence of this species in different states of Brazil, this insect is yet been to be given the pest status. Nevertheless, the mere presence of this species is enough to cause concern to producers of small fruits and to justify further investigation for it’s control, especially chemical control for a possible change in status. Therefore, the goal of this work was to evaluate, in laboratory, mortality of D. suzukii adults and ovicidal effect when exposed to different insecticides registered for species of the Tephritidae and Agromyzidae families in different cultures. The insecticides deltamethrin, dimethoate, spinosad, fenitrothion, phosmet, malathion, methidathion, and zeta-cypermethrin resulted in mortality to 100 % of the subjects three days after the treatment (DAT). Regarding the effects over eggs, it was  established that the insecticides fenitrothion, malathion, and methidathion deemed 100 % of the eggs not viable, followed by phosmet and diflubenzuron, which also caused elevated reduction in the eclosion of larvae two DAT.


2010 ◽  
Vol 42 (6) ◽  
pp. 727-737 ◽  
Author(s):  
David J. GALLOWAY

AbstractAspiciliopsis macrophthalma, Placopsis fusciduloides, P. gelidioides and P. tararuana are reported for the first time from southern South America. New records for 13 species of Placopsis in southern South America are reported, and a revised key to 22 species of Placopsis and A. macrophthalma in the region is given.


Paleobiology ◽  
2021 ◽  
pp. 1-21
Author(s):  
Mariana Viglino ◽  
Maximiliano Gaetán ◽  
Mónica R. Buono ◽  
R. Ewan Fordyce ◽  
Travis Park

Abstract The inner ear of the two higher clades of modern cetaceans (Neoceti) is highly adapted for hearing infrasonic (mysticetes) or ultrasonic (odontocetes) frequencies. Within odontocetes, Platanistoidea comprises a single extant riverine representative, Platanista gangetica, and a diversity of mainly extinct marine species from the late Oligocene onward. Recent studies drawing on features including the disparate tympanoperiotic have not yet provided a consensus phylogenetic hypothesis for platanistoids. Further, cochlear morphology and evolutionary patterns have never been reported. Here, we describe for the first time the inner ear morphology of late Oligocene–early Miocene extinct marine platanistoids and their evolutionary patterns. We initially hypothesized that extinct marine platanistoids lacked a specialized inner ear like P. gangetica and thus, their morphology and inferred hearing abilities were more similar to those of pelagic odontocetes. Our results reveal there is no “typical” platanistoid cochlear type, as the group displays a disparate range of cochlear anatomies, but all are consistent with high-frequency hearing. Stem odontocete Prosqualodon australis and platanistoid Otekaikea huata present a tympanal recess in their cochlea, of yet uncertain function in the hearing mechanism in cetaceans. The more basal morphology of Aondelphis talen indicates it had lower high-frequency hearing than other platanistoids. Finally, Platanista has the most derived cochlear morphology, adding to evidence that it is an outlier within the group and consistent with a >9-Myr-long separation from its sister genus Zarhachis. The evolution of a singular sound production morphology within Platanistidae may have facilitated the survival of Platanista to the present day.


Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 186
Author(s):  
Luana Bontempo ◽  
Daniela Bertoldi ◽  
Pietro Franceschi ◽  
Fabio Rossi ◽  
Roberto Larcher

Umbrian tobacco of the Virginia Bright variety is one of the most appreciated tobaccos in Europe, and one characterized by an excellent yield. In recent years, the Umbria region and local producers have invested in introducing novel practices (for production and processing) focused on environmental, social, and economic sustainability. Due to this, tobacco from Umbria is a leading commodity in the global tobacco industry, and it claims a high economic value. The aim of this study is then to assess if elemental and isotopic compositions can be used to protect the quality and geographical traceability of this particular tobacco. For the first time the characteristic value ranges of the stable isotope ratios of the bio-elements as a whole (δ2H, δ13C, δ15N, δ18O, and δ34S) and of the concentration of 56 macro- and micro-elements are now available, determined in Virginia Bright tobacco produced in two different areas of Italy (Umbria and Veneto), and from other worldwide geographical regions. The ranges of variability of elements and stable isotope ratios had slightly different results, according to the three geographical origins considered. In particular, Umbria samples presented significantly lower content of metals potentially dangerous for human health. The results of this first exploratory work highlight the possibility of characterizing tobacco from Umbria, and suggest widening the scope of the survey throughout Italy and foreign regions, in order to be used to describe the geographical origin of tobacco in general and verify the origin of the products on the market.


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