U/Pb LA‐MC‐ICP‐MS Zircon Geochronology and Geochemistry from a Postcollisional Biotite Granite of the Baja Guajira Basin, Colombia: Implications for Late Cretaceous and Neogene Caribbean–South American Tectonics

2009 ◽  
Vol 117 (6) ◽  
pp. 685-692 ◽  
Author(s):  
A. Cardona ◽  
V. Valencia ◽  
G. Bayona ◽  
C. Jaramillo ◽  
G. Ojeda ◽  
...  
Zootaxa ◽  
2005 ◽  
Vol 932 (1) ◽  
pp. 1 ◽  
Author(s):  
HARRY M. SAVAGE ◽  
R. WILLS FLOWERS ◽  
WENDY PORRAS V.

A new genus, Tikuna, is described based on recent collections of adults and nymphs of Choroterpes atramentum Traver from western Costa Rica. All recent collections are from streams on or near the Nicoya Complex, the oldest geological formation in Lower Central America. Tikuna belongs to a lineage of South American Atalophlebiinae (Leptophlebiidae: Ephemeroptera) whose origin is hypothesized to have been in the late Cretaceous–early Tertiary. Some implications of the distribution of Tikuna for theories on the origin of Costa Rica’s biota are discussed.


2011 ◽  
Vol 83 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Juan D. Porfiri ◽  
Jorge O. Calvo ◽  
Domenica dos Santos

Here we report on a new small deinonychosaurian theropod, Pamparaptor micros gen. et sp. nov., from the Late Cretaceous of Patagônia, Argentina. Pamparaptor micros exhibits a pedal structure previously unknown among South Américan deinonychosaurians. The new material provides new evidence about the morphology and taxonomic diversity of Patagônian deinonychosaurs. Pamparaptor is the smaller non-avialae Patagônian deinonychosaur, probably with about 0.50-0.70 meters, long. The pedal construction resembles, that of Troodontid or basal Dromaeosaurids. Nevertheless, up to now, we considered Pamparaptor a peculiar Patagônian Dromaeosaurid with troodontid-like pes.


2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Cecily S. C. Nicholl ◽  
Eloise S. E. Hunt ◽  
Driss Ouarhache ◽  
Philip D. Mannion

Notosuchians are an extinct clade of terrestrial crocodyliforms with a particularly rich record in the late Early to Late Cretaceous (approx. 130–66 Ma) of Gondwana. Although much of this diversity comes from South America, Africa and Indo-Madagascar have also yielded numerous notosuchian remains. Three notosuchian species are currently recognized from the early Late Cretaceous (approx. 100 Ma) Kem Kem Group of Morocco, including the peirosaurid Hamadasuchus rebouli . Here, we describe two new specimens that demonstrate the presence of at least a fourth notosuchian species in this fauna. Antaeusuchus taouzensis n. gen. n. sp. is incorporated into one of the largest notosuchian-focused character-taxon matrices yet to be compiled, comprising 443 characters scored for 63 notosuchian species, with an increased sampling of African and peirosaurid species. Parsimony analyses run under equal and extended implied weighting consistently recover Antaeusuchus as a peirosaurid notosuchian, supported by the presence of two distinct waves on the dorsal dentary surface, a surangular which laterally overlaps the dentary above the mandibular fenestra, and a relatively broad mandibular symphysis. Within Peirosauridae, Antaeusuchus is recovered as the sister taxon of Hamadasuchus . However, it differs from Hamadasuchus with respect to several features, including the ornamentation of the lateral surface of the mandible, the angle of divergence of the mandibular rami, the texture of tooth enamel and the shape of the teeth, supporting their generic distinction. We present a critical reappraisal of the non-South American Gondwanan notosuchian record, which spans the Middle Jurassic–late Eocene. This review, as well as our phylogenetic analyses, indicate the existence of at least three approximately contemporaneous peirosaurid lineages within the Kem Kem Group, alongside other notosuchians, and support the peirosaurid affinities of the ‘trematochampsid’ Miadanasuchus oblita from the Maastrichtian of Madagascar. Furthermore, the Cretaceous record demonstrates the presence of multiple lineages of approximately contemporaneous notosuchians in several African and Madagascan faunas, and supports previous suggestions regarding an undocumented pre-Aptian radiation of Notosuchia. By contrast, the post-Cretaceous record is depauperate, comprising rare occurrences of sebecosuchians in north Africa prior to their extirpation.


2018 ◽  
Vol 306 ◽  
pp. 189-208 ◽  
Author(s):  
Daianne Francis Höfig ◽  
Juliana Charão Marques ◽  
Miguel Angelo Stipp Basei ◽  
Ronei Osório Giusti ◽  
Cassiano Kohlrausch ◽  
...  

2012 ◽  
pp. 675-705 ◽  
Author(s):  
Alain Cocherie ◽  
Michèle Robert
Keyword(s):  

2020 ◽  
pp. 1-115
Author(s):  
Luis Pachón-Parra ◽  
Paul Mann ◽  
Nestor Cardozo

The Putumayo foreland basin (PFB) is an underexplored, hydrocarbon-bearing basin located in southernmost Colombia. The PFB forms a 250-km long segment of the 7000-km-long corridor of Late Cretaceous-Cenozoic foreland basins produced by eastward thrusting of the Andean mountain chain over Precambrian rocks of the South American craton. We use ∼4000 km of 2D seismic data tied to 28 exploratory wells to describe the basin-wide structure and stratigraphy of an underexplored hydrocarbon basin. Based on seismic interpretation and comparison with published works from the southward continuation of the PFB into Peru and Ecuador, three main across-strike, structural zones include: 1) the 20-km-wide, Western structural zone closest to the Andean mountain front characterized by inversion of older, Jurassic half-grabens during the late Miocene; 2) the 45-km-wide, Central structural zone characterized by moderately-inverted Jurassic half-grabens; and 3) the 120-km-wide, Eastern structural zone characterized by the 40-km-wide, N-S trending Caquetá arch. The five mainly clastic tectonosequences of the PFB include: 1) Lower Cretaceous pre-foreland basin deposits; 2) Upper Cretaceous-Paleocene foreland basin deposits; 3) Eocene foreland basin deposits related to the early uplift of the Eastern Cordillera; 4) Oligocene-Miocene underfilled, foreland basin deposits; and 5) Plio-Pleistocene overfilled, foreland basin deposits. We used 3D flexural modeling to identify the elastic thickness (Te) of the lithosphere below the PFB, in order to model the location of the sedimentary-related and tectonically-related forebulges of Cretaceous to Oligocene age. Flexural analysis shows two pulses of rapid, foreland-related subsidence first during the Late Cretaceous-early Paleocene and later during the Oligocene-Miocene. Despite the present-day oblique thrusting of the mountain front, flexure of the PFB basement has produced a tectonic forebulge now located in the Eastern structural zone and controls a basement high that forms the eastern, updip limit for most hydrocarbons found in the PFB.


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