scholarly journals A historical vertebrate collection from the Middle Miocene of the Peruvian Amazon

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Jorge D. Carrillo-Briceño ◽  
Orangel A. Aguilera ◽  
Aldo Benites-Palomino ◽  
Annie S. Hsiou ◽  
José L. O. Birindelli ◽  
...  

AbstractThe Miocene aquatic and terrestrial fossil record from western Amazonia constitute a clear evidence of the palaeoenvironmental diversity that prevailed in the area, prior to the establishment of the Amazon River drainage. During the Miocene, the region was characterized by a freshwater megawetland basin, influenced by episodic shallow-marine incursions. A fossil vertebrate collection from the middle Miocene strata of the Pebas Formation is here studied and described. This historical collection was recovered in 1912 along the banks of the Itaya River (Iquitos, Peru), during a scientific expedition led by two scientists of the University of Zurich, Hans Bluntschli and Bernhard Peyer. Our findings include a total of 34 taxa, including stingrays, bony fishes, turtles, snakes, crocodylians, and lizards. Fishes are the most abundant group in the assemblage (~ 23 taxa), including the first fossil record of the freshwater serrasalmids Serrasalmus, and Mylossoma, and the hemiodontid Hemiodus for the Pebas system, with the latter representing the first fossil be discovered for the entire Hemiodontidae. The presence of a representative of Colubroidea in the middle Miocene of Iquitos supports the hypothesis of arrival and dispersal of these snakes into South America earlier than previously expected. This fossil assemblage sheds light on the palaeoenvironments, and the geographical/temporal range of several aquatic/terrestrial lineages inhabiting the Amazonian region.

2016 ◽  
Vol 66 (3) ◽  
pp. 359-409 ◽  
Author(s):  
Anna Wysocka ◽  
Andrzej Radwański ◽  
Marcin Górka ◽  
Maciej Bąbel ◽  
Urszula Radwańska ◽  
...  

Abstract Studies of Miocene sediments in the Fore-Carpathian Basin, conducted by geologists from the University of Warsaw have provided new insights on the distribution of the facies infilling the basin, particularly in the forebulge and back-bulge zones. The origin of the large-scale sand bodies, evaporitic deposits and large-scale organic buildups is discussed, described and verified. These deposits originated in variable, shallow marine settings, differing in their water chemistry and the dynamics of sedimentary processes, and are unique with regard to the fossil assemblages they yield. Many years of taxonomic, biostratigraphic, palaeoecologic and ecotaphonomic investigations have resulted in the identification of the fossil assemblages of these sediments, their age, sedimentary settings and post-mortem conditions. Detailed studies were focused on corals, polychaetes, most classes of molluscs, crustaceans, echinoderms, and fishes.


Zootaxa ◽  
2019 ◽  
Vol 4656 (3) ◽  
pp. 475-486
Author(s):  
GIOVANNE M. CIDADE ◽  
DANIEL FORTIER ◽  
ASCANIO DANIEL RINCÓN ◽  
ANNIE SCHMALTZ HSIOU

The crocodylomorph fauna of the Cenozoic of South America is one of the richest and most diverse in the world. The most diverse group within that fauna is Alligatoroidea, with nearly all of its species belonging to the Caimaninae clade. Many of the fossil alligatoroid species from the Cenozoic of South America were proposed based on very incomplete remains, and as a result their validity requires revision. Two such species are Balanerodus logimus Langston, 1965, from the middle Miocene of Colombia and Peru, and Caiman venezuelensis Fortier & Rincón, 2012, from the Pliocene-Pleistocene of Venezuela. This study has performed a thorough review of the taxonomic status of these two alligatoroid species, concluding that B. logimus is a nomen dubium and that Ca. venezuelensis is a junior synonym of the extant species Ca. crocodilus. This review offers a significantly more accurate scenario for alligatoroid diversity in the Cenozoic of South America in different epochs such as the Miocene and Pleistocene. Additionally, the record of Ca. crocodilus from the Pleistocene of Venezuela is the first fossil record that can be assigned to this species. 


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.


Geodiversitas ◽  
2011 ◽  
Vol 33 (2) ◽  
pp. 331-345 ◽  
Author(s):  
Cyrielle Goillot ◽  
Pierre-Olivier Antoine ◽  
Julia Tejada ◽  
François Pujos ◽  
Rodolfo Salas Gismondi

AI Magazine ◽  
2018 ◽  
Vol 39 (4) ◽  
pp. 19-22 ◽  
Author(s):  
Yiling Chen ◽  
Gabriella Kazai

The Association for the Advancement of Artificial Intelligence’s Sixth AAAI Conference on Human Computation and Crowdsourcing was held on the campus of the University of Zurich in Zurich, Switzerland from 5–8 July 2018. This report, based on the preface to the HCOMP-18 proceedings and program, summarizes the event.


Author(s):  
Loïc Epelboin ◽  
Carole Eldin ◽  
Pauline Thill ◽  
Vincent Pommier de Santi ◽  
Philippe Abboud ◽  
...  

Abstract Purpose of Review In this review, we report on the state of knowledge about human Q fever in Brazil and on the Guiana Shield, an Amazonian region located in northeastern South America. There is a contrast between French Guiana, where the incidence of this disease is the highest in the world, and other countries where this disease is practically non-existent. Recent Findings Recent findings are essentially in French Guiana where a unique strain MST17 has been identified; it is probably more virulent than those usually found with a particularly marked pulmonary tropism, a mysterious animal reservoir, a geographical distribution that raises questions. Summary Q fever is a bacterial zoonosis due to Coxiella burnetii that has been reported worldwide. On the Guiana Shield, a region mostly covered by Amazonian forest, which encompasses the Venezuelan State of Bolivar, Guyana, Suriname, French Guiana, and the Brazilian State of Amapá, the situation is very heterogeneous. While French Guiana is the region reporting the highest incidence of this disease in the world, with a single infecting clone (MST 117) and a unique epidemiological cycle, it has hardly ever been reported in other countries in the region. This absence of cases raises many questions and is probably due to massive under-diagnosis. Studies should estimate comprehensively the true burden of this disease in the region.


Author(s):  
I. V. Trenkler

The history and contemporary state of global aquaculture of sturgeons and paddlefish are reviewed. The paddlefish Polyodon spathula became first object of cultivation of Acipenseriformes in USA. The paddlefish has high rate of growth in ponds using natural feeds, mature females can produce about 15% of their body weight in roe similar to eggs of star sturgeon Acipenser stellatus. Some liabilities include juveniles vulnerable to bird predation, poor tolerance to high densities, low oxygen and handling stress, waiting period of at least 7 years before females produce eggs. The paddlefish farming is carried out mainly in Kentucky, Indiana, Missouri and Alabama in polyculture with canal catfish Ictalurus punctatus or freshwater shrimp Macrobrachium rosenbergii. The most important object of North-American sturgeon breeding is white sturgeon Acipenser transmontanus, the biggest and fast-growing species of Acipenser genera. The largest commercial sturgeon farms are located in California, Idaho and Florida. A research program on biotechnology of white sturgeon farming has been initiated by the University of California at Davis in December 1979. The first successful artificial propagation of white sturgeon from Sacramento River was carried out in 1980, the first hatchery females matured in 1994. The hatchery progeny of Snake River white sturgeon was received in 1988, the first females matured in 2000. The first caviar was processed only after maturation of second generation. In Florida and North Carolina farmers used for cultivation small number of Russian sturgeon A. gueldenstaedti, Siberian sturgeon A. baeri, sterlet A. ruthenus, beluga Huso huso and star sturgeon A. stellatus. The total annual volume of sturgeon farming in USA was equal to 1285 tons (1166 MT). In Canada the only object of sturgeon farming is white sturgeon with annual production near 2 tons of caviar. In South America Uruguay has developed sturgeon culture with one large farm created in 1994 using help of Russian specialists.


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