A Remarkable Neogene Assemblage of Sloths in Colombia

Neogene sloth assemblages (Mammalia, Pilosa) of the Cocinetas Basin (La Guajira, Colombia): implications for the Great American Biotic Interchange

Authors:

Amson et al

Abstract:

We describe sloth assemblages from the Cocinetas Basin (La Guajira peninsula, Colombia), found in the Neogene Castilletes and Ware formations, located in northernmost South America, documenting otherwise poorly known biotas. The tentative referral of a specimen to a small megatherioid sloth, Hyperleptus?, from the early–middle Miocene Castilletes Formation, suggests affinities of this fauna with the distant Santa Cruz Formation and documents a large latitudinal distribution for this taxon. The late Pliocene Ware Formation is much more diverse, with five distinct taxa representing every family of ‘ground sloths’. This diversity is also remarkable at the ecological level, with sloths spanning over two orders of magnitude of body mass and probably having different feeding strategies. Being only a few hundred kilometres away from the Isthmus of Panama, and a few hundred thousand years older than the classically recognized first main pulse of the Great American Biotic interchange (GABI 1), the Ware Formation furthermore documents an important fauna for the understanding of this major event in Neogene palaeobiogeography. The sloths for which unambiguous affinities were recovered are not closely related to the early immigrants found in North America before GABI 1.

PreColumbian Tombs Found in Colombia Date Back 2,000 Years

Colombian archaeologists have identified three tombs dating back more than 2,000 years, pinpointed while working squarely in metropolitan Medellin, officials said Friday.

The "first find" was May 16 in Itagui, Antioquia central Colombia in an Andean valley, said Juan Pablo Diez, whose team was working with the municipality to try to protect national heritage treasures while a local park is being built.

The finds include ceramics, known as Incised Brown Ware, and metalwork bowls, some of which were funeral urns in these farming and metalworking communities.

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Colombian Island has 2 cm Spherulites From the Chicxulub Impact that Wiped out the Dinosaurs

A team of scientists working on the Colombian island of Gorgonilla, in the Pacific, has found fragments of the meteorite that 66 million years ago caused the extinction of the dinosaurs, sources close to the investigation said Tuesday.

“(We have) evidence of the impact of the meteorite, (they are very tiny) particles that are the result when the meteorite hit,” geologist Herman Bermudez told Spanish news agency EFE.

Those remains, called spherulites, which are small, rounded bodies that commonly occur in vitreous igneous rocks, are part of the continental shelf material that is currently the Yucatan Peninsula and they were found with fragments of the meteorite.

The spherulites are 2 cm (about 0.8 inches) in diameter and look like marbles, being made of glass.

Under the microscope small crystals from the meteorite can be seen and they show its composition.

When the meteorite hit Earth, it blasted out a crater 200 km (125 mi.) in diameter known today as Chicxulub, which is on the Yucatan Peninsula.

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Muiscasaurus catheti: A new Ophthalmosaurid Ichthyosaur From Barremian/Aptian Cretaceous Colombia

A new ophthalmosaurid ichthyosaur from the Early Cretaceous of Colombia

Authors:

Maxwell et al

Abstract:

Cretaceous ichthyosaurs were relatively diverse in temperate latitudes, but few species have been described from the palaeotropics. Here, we describe a new ophthalmosaurid ichthyosaur, Muiscasaurus catheti gen. et sp. nov., from the Barremian–Aptian aged Paja Formation of Colombia. This species is known only from a partial skull and differs from all other ichthyosaurs in the unusual configuration of the external narial opening, slender rostrum, narrow postorbital region, and gracile dentition. It is the second ichthyosaur described from the Paja Formation, suggesting moderate taxonomic and ecological ichthyosaur diversity in the region during the Early Cretaceous.

Hilarcotherium castanedaii: a new Miocene Neogene Astrapotherian Meridiungulatan From Colombia

Hilarcotherium castanedaii, gen. et sp. nov., a new Miocene astrapothere (Mammalia, Astrapotheriidae) from the Upper Magdalena Valley, Colombia

Authors:

Vallejo-Pareja et al

Abstract:

Astrapotheria is an order of extinct South American herbivores recorded throughout the continent, from the late Paleocene to middle Miocene. Here we describe Hilarcotherium castanedaii, gen. et sp. nov., an Uruguaytheriinae astrapothere from sediments of La Victoria Formation (middle Miocene) in the Tolima Department, Upper Magdalena Valley, Colombia. H. castanedaii, represented by a partial skull, mandible, and some postcranial remains, is characterized by (1) unique dental formula, with 0/3i, 1/1c, 1/1p, and 3/3 m; and (2) lower canines with subtriangular transverse section at the base. Hilarcotherium differs from the equatorial Uruguaytheriinae genera Xenastrapotherium and Granastrapotherium in (1) having three lower incisors; (2) the diagonal implantation of the lower canines; (3) lower molars with lingual cingulid; (4) the presence of the hypocone in the third upper molar; and (5) the presence of an anterolingual pocket in the fourth upper premolar. Our phylogenetic analysis supports the monophyly of the subfamilies Astrapotheriinae and Uruguaytheriinae. Within the latter, we confirm the monophyly of the neotropical clade (Hilarcotherium, Xenastrapotherium, and Granastrapotherium). H. castanedaii shows some plesiomorphic features such as the aforementioned presence of the i3 and the developed hypocone in the last upper molar. Its estimated body mass (1303 kg) is intermediate among Astrapotheriidae.

A Turtle Fossil Preserving Blood Vessels and Osteocytes From Paleogene Colombia

A Pelomedusoid Turtle from the Paleocene–Eocene of Colombia Exhibiting Preservation of Blood Vessels and Osteocytes

Authors:

Cadena et al

Abstract:

We describe a Paleocene–Eocene pelomedusoid turtle from tropical South America in a new fossiliferous locality, from Los Cuervos Formation, at the Calenturitas Coal Mine, Colombia. Although no further systematic precision beyond Pelomedusoides incertae sedis can be supported, the presence of an ischial scar positioned far anteriorly to the anal notch, and a strongly decorated ventral surface of the plastron, indicate that this specimen is potentially related to the bothremydid clade formed by Puentemys–Foxemys. We also demonstrate the potential organic preservation of osteocytes and blood vessels for this specimen, indicating that preservation of soft tissue such as vessels and bone cells in the fossil record is independent of bone type, fossil site, or locality; occurring in different lineages of vertebrates; and that it is even possible to occur in tropical depositional environments during a period of maximum global warming such as the Paleocene–Eocene.

Procyonids Dispersed Twice From North America to South America Prior to the Great American Biotic Interchange

Carnivorans at the Great American Biotic Interchange: new discoveries from the northern neotropics

Authors:

Forasiepi et al

Abstract:

We report two fossil procyonids, Cyonasua sp. and Chapalmalania sp., from the late Pliocene of Venezuela (Vergel Member, San Gregorio Formation) and Colombia (Ware Formation), respectively. The occurrence of these pre-Holocene procyonids outside Argentina and in the north of South America provides further information about the Great American Biotic Interchange (GABI). The new specimens are recognized in the same monophyletic group as procyonids found in the southern part of the continent, the “Cyonasua group,” formed by species of Cyonasua and Chapalmalania. The phylogenetic analysis that includes the two new findings support the view that procyonids dispersed from North America in two separate events (initially, previous to the first major migration wave—GABI 1—and then within the last major migration wave—GABI 4—). This involved reciprocal lineage migrations from North to South America, and included the evolution of South American endemic forms.

Eonatator coellensis: a new, Seemingly Ovoviviparous Campanian Cretaceous Mosasaur From Colombia

Eonatator coellensis nov. sp. (Squamata: Mosasauridae), a new species from the Upper Cretaceous of Colombia.

Author:

Páramo-Fonseca

Abstract:

In this study a new mosasaur found in Colombia is given out. The fossil was extracted from Campanian rocks, North of the town of Coello, Tolima Department. It is a nearly complete articulated skeleton with soft tissue remains preserved in its cavities. It was
determined as a new species of the genus Eonatator, E. coellensis, based on the systematics proposed in 2005 by Bardet and others. The anatomy of the anterior part of the skull, as well the morphology and the inter-relationships of the bones of the pelvic girdle and limbs, constitute a new contribution to the genus definition. The Colombian specimen represents the most complete halisaurine mosasaur known so far in the world, and provides new evidence of ovoviviparity in mosasaurs.

Russian Tu-160 Bombers Infringe on Colombian Air Space: Lost, Threatening or Annoying?

Colombia is preparing a letter of protest to Russia after two Russian bomber planes twice entered the Andean nation's airspace without authorization when flying between Venezuela and Nicaragua last week, President Juan Manuel Santos said on Tuesday.

Santos said the two planes crossed Colombian airspace on Friday flying from Venezuela to Nicaragua. They re-entered Colombian territory on their return journey but flew out of the zone when intercepted by two of Colombia's Kfir military planes.

"As they are military and government planes, they needed to request permission but didn't. We have simply requested that the Foreign Ministry make the respective notification to the Russian government," Santos told reporters after a government meeting on security issues.

Military sources told Reuters the planes were Russian-made Tupolev Tu-160 bombers flying from the Venezuelan coastal city of Maiquetia to Nicaragua's capital, Managua. The sources said the bombers flew into Colombian airspace over its San Andres y Providencia archipelago in the Caribbean Sea.

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Climate Change at the Paleocene-Eocene Boundary in the Bogotá Basin, Colombia

Climate change during the Early Paleogene in the Bogotá Basin (Colombia) inferred from paleosol carbon isotope stratigraphy, major oxides, and environmental magnetism

Authors:

1. Sara Morón (a, c)
2. David L. Fox (a)
3. Joshua M. Feinberg (a, b)
4. Carlos Jaramillo (c)
5. German Bayona (d)
6. Camilo Montes (e)
7. Jonathan I. Bloch (f)

Affiliations:

a. Department of Earth Sciences, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN, 55455-0231, USA

b. Institute for Rock Magnetism, University of Minnesota, 100 Union Street SE, Minneapolis, MN, 55455, USA

c. Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Ancon, Panama

d. Corporación Geológica Ares, Calle 44a # 53-96, Bogotá D.C., Colombia

e. Geociencias, Universidad de los Andes, Calle 1A # 18A-10, Edificio IP, Bogotá D.C., Colombia

f. Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800, USA

Abstract:

Paleosols in the Bogotá Basin, Colombia, record an increase in chemical weathering across the Paleocene–Eocene (P–E) transition. Rock magnetic properties and major element geochemistry exhibit an abrupt change in an interval identified as including the P–E boundary, as established by previously published biostratigraphy and a U/Pb date on volcanic zircons (56.2 ± 1.6 Ma). During the stratigraphic interval that contains the P–E transition, magnetic susceptibility increases significantly, with an order of magnitude higher concentration of magnetite/maghemite and hematite. The preponderance of pure stoichiometric magnetite in the paleosols of this interval indicates that the increase in magnetic susceptibility is due to changes in the rate of pedogenesis, rather than an increase in the erosion of nearby volcanic rocks, which would contribute titanomagnetite. Pedogenic structures preserved within the paleosols, a lack of iron oxides as cement, friability of the sandstones, and previously published thermochronologic data are not consistent with burial diagenesis as an explanation for the origin of the magnetic mineral assemblage. These enhanced pedogenesis and related chemical weathering is also confirmed by increases in the concentration of Fe2O3 and Al2O3 and loss on ignition values. An increase in mean precipitation across this interval is inferred by the lack of carbonate nodules and a decrease in SiO2 in paleosols. Thus, we hypothesize that there was an intensification of chemical weathering during the interval that contains the P–E transition.

The Olinguito: the First Carnivore to be Described From the New World in 35 Years

Observed in the wild, tucked away in museum collections, and even exhibited in zoos around the world--there is one mysterious creature that has been a victim of mistaken identity for more than 100 years. A team of Smithsonian scientists, however, uncovered overlooked museum specimens of this remarkable animal, which took them on a journey from museum cabinets in Chicago to cloud forests in South America to genetics labs in Washington, D.C. The result: the olinguito (Bassaricyon neblina)--the first carnivore species to be discovered in the Western Hemisphere in 35 years. The team's discovery is published in the Aug. 15 issue of the journal ZooKeys.

The olinguito (oh-lin-GHEE-toe) looks like a cross between a house cat and a teddy bear. It is actually the latest scientifically documented member of the family Procyonidae, which it shares with raccoons, coatis, kinkajous and olingos. The 2-pound olinguito, with its large eyes and woolly orange-brown fur, is native to the cloud forests of Colombia and Ecuador, as its scientific name, "neblina" (Spanish for "fog"), hints. In addition to being the latest described member of its family, another distinction the olinguito holds is that it is the newest species in the order Carnivora--an incredibly rare discovery in the 21st century.