Nivel de satisfacción de los pacientes que asisten al servicio de urgencias frente a la atención de enfermería, en una institución de IV nivel de atención en salud, en Bogotá. Septiembre-octubre de 2008

Enfermero (a)Pregrad

Apendicular remains of an ophthalmosaurid ichthyosaur from the lower Barremian of Villa de Leiva, Colombia

Se describen por primera vez restos apendiculares de ictiosaurio oftalmosáurido procedentes de la Formación Paja de Villa de Leiva, Colombia, cuya edad se establece como Barremiano inferior. Las características morfológicas del espécimen son consistentes con el género Platypterygius. Las aletas presentan un conjunto de caracteres autopomórficos del zeugopodio no presentes en las especies del género de las que se conocen restos apendiculares: (1) faceta para elemento extrazeugodial anterior en el húmero fuertemente cóncava, dirigida anteriormente y con reborde pronunciado; (2) cúbito con hendiduras pronunciadas en sus superficies anterior y posterior; (3) elemento extrazeugopodial anterior en forma de silla de montar con cuatro facetas articulares; (4) pisiforme masivo y en forma distintivamente subtriangular. A pesar de que la procedencia geográfica y estratigráfica del espécimen estudiado es aproximadamente equivalente a la de P. sachicarum, la ausencia de material comparable impide incluir el espécimen en esta especie. Este estudio constituye el primer reporte de restos apendiculares de Platypterygius para el extremo norte de Sudamérica. The appendicular remains of an ophthalmosaurid Ichthyosaur from the Paja Formation in Villa de Leiva, Colombia (Lower Barremian) are here described. The morphological characteristics of the specimen are consistent with the genus Platypterygius. Nonetheless, the forefins of this specimen have a set of autapomorphic zeugopodium characters that differentiate this from other species of the genus whose appendicular remains are known. These include (1) a strongly concave facet for the anterior extrazeugopodial element on the humerus, directed anteriorly with a pronounced flange; (2) ulnar slits in the anterior and posterior surfaces; (3) a saddle-shaped anterior extrazeugopodial element with four facets joints; and (4) a distinctly massive and subtriangular pisiform. While the stratigraphic and geographic origin of the studied specimen is approximately equivalent to P. sachicarum, the absence of comparable material prevents including specimen in this species. This study is the first report of appendicular remains of Platypterygius in northern South America

The extinct marine megafauna of the Phanerozoic

The modern marine megafauna is known to play important ecological roles and includes many charismatic species that have drawn the attention of both the scientific community and the public. However, the extinct marine megafauna has never been assessed as a whole, nor has it been defined in deep time. Here, we review the literature to define and list the species that constitute the extinct marine megafauna, and to explore biological and ecological patterns throughout the Phanerozoic. We propose a size cut-off of 1 m of length to define the extinct marine megafauna. Based on this definition, we list 706 taxa belonging to eight main groups. We found that the extinct marine megafauna was conspicuous over the Phanerozoic and ubiquitous across all geological eras and periods, with the Mesozoic, especially the Cretaceous, having the greatest number of taxa. Marine reptiles include the largest size recorded (21 m; Shonisaurus sikanniensis) and contain the highest number of extinct marine megafaunal taxa. This contrasts with today’s assemblage, where marine animals achieve sizes of >30 m. The extinct marine megafaunal taxa were found to be well-represented in the Paleobiology Database, but not better sampled than their smaller counterparts. Among the extinct marine megafauna, there appears to be an overall increase in body size through time. Most extinct megafaunal taxa were inferred to be macropredators preferentially living in coastal environments. Across the Phanerozoic, megafaunal species had similar extinction risks as smaller species, in stark contrast to modern oceans where the large species are most affected by human perturbations. Our work represents a first step towards a better understanding of the marine megafauna that lived in the geological past. However, more work is required to expand our list of taxa and their traits so that we can obtain a more complete picture of their ecology and evolution

Restos apendiculares de un ictiosaurio oftalmosáurido del Barremiano inferior de Villa de Leiva, Colombia

Se describen por primera vez restos apendiculares de ictiosaurio oftalmosáurido procedentes de la Formación Paja de Villa de Leiva, Colombia, cuya edad se establece como Barremiano inferior. Las características morfológicas del espécimen son consistentes con el género Platypterygius. Las aletas presentan un conjunto de caracteres autopomórficos del zeugopodio no presentes en las especies del género de las que se conocen restos apendiculares: (1) faceta para elemento extrazeugodial anterior en el húmero fuertemente cóncava, dirigida anteriormente y con reborde pronunciado; (2) cúbito con hendiduras pronunciadas en sus superficies anterior y posterior; (3) elemento extrazeugopodial anterior en forma de silla de montar con cuatro facetas articulares; (4) pisiforme masivo y en forma distintivamente subtriangular. A pesar de que la procedencia geográfica y estratigráfica del espécimen estudiado es aproximadamente equivalente a la de P. sachicarum, la ausencia de material comparable impide incluir el espécimen en esta especie. Este estudio constituye el primer reporte de restos apendiculares de Platypterygius para el extremo norte de Sudamérica. The appendicular remains of an ophthalmosaurid Ichthyosaur from the Paja Formation in Villa de Leiva, Colombia (Lower Barremian) are here described. The morphological characteristics of the specimen are consistent with the genus Platypterygius. Nonetheless, the forefins of this specimen have a set of autapomorphic zeugopodium characters that differentiate this from other species of the genus whose appendicular remains are known. These include (1) a strongly concave facet for the anterior extrazeugopodial element on the humerus, directed anteriorly with a pronounced flange; (2) ulnar slits in the anterior and posterior surfaces; (3) a saddle-shaped anterior extrazeugopodial element with four facets joints; and (4) a distinctly massive and subtriangular pisiform. While the stratigraphic and geographic origin of the studied specimen is approximately equivalent to P. sachicarum, the absence of comparable material prevents including specimen in this species. This study is the first report of appendicular remains of Platypterygius in northern South America

Shark-cetacean trophic interactions during the late Pliocene in the Central Eastern Pacific (Panama)

We provide a description of the remains of a fossil whale from western Panama. The record consists of appendicular remains of a mysticete, which has been assigned to Balaenopteridae. These remains, found in the sediments of the late Pliocene Burica Formation, represent the first record of a marine mammal in the Neogene sedimentary succession of the Burica Peninsula. Two different types of shark bite marks, serrated and deep-unserrated, found on the radius and phalanges suggest scavenging by at least two white shark (Carcharodon) individuals. The deep, unserrated marks were possibly caused by continual biting by sharks. Both the morphology of the shark bite marks and their relative location on the whale limb bones constitute evidence of shark-cetacean trophic interaction. Although the specimen lacks diagnostic features that would allow a species-level identification, it does provide new information on the vertebrate fauna of a very poorly prospected Central Eastern Pacific exposure, thus opening an opportunity for exploring the marine fauna during a critical episode in Earth history, the Plio-Pleistocene transition. Dirley Cortés. Redpath Museum, McGill University, 859 Sherbrooke St. W., Montreal QC H3A 0C4, Canada. Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá. [email protected] Carlos De Gracia. Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá. [email protected] Jorge D. Carrillo-Briceño. Paläontologisches Institut und Museum, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland. Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá. [email protected] Gabriel Aguirre-Fernández. Paläontologisches Institut und Museum, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland. [email protected] Carlos Jaramillo. Smithsonian Tropical Research Institute, Balboa-Ancón 0843–03092, Panamá, Panamá. ISEM, U. Montpellier, CNRS, EPHE, IRD, Montpellier, France. [email protected] Aldo Benites-Palomino. Smithsonian Tropical Research Institute, Balboa-Ancón 0843-03092, Panamá, Panamá. Departamento de Paleontología de Vertebrados, Museo de Historia Natural, Universidad Nacional Mayor de San Marcos; Avenida Arenales 1256, Lima 14, Perú. [email protected] Joaquín Enrique Atencio-Araúz. Colegio Punta Burica, Chiriquí Province, Panamá. [email protected] Keywords: Mysticeti; shark bite marks; Neogene; late Pliocene; Central America; trophic interactio

The Miocene La Venta Biome (Colombia): A century of research and future perspectives

The La Venta deposits (Colombia) record one of the most fossil-rich regions in tropical South America and offers an exceptional opportunity to study the effect of the Miocene climatic changes and the evolution of extinct and extant clades in a low-latitude ecosystem. Land and freshwater vertebrates, and less commonly plants and invertebrates, constitute most of the La Venta fossils. The mammal record has been used to define the Laventan Age/Stage c. 13.5-11.8 million years old. La Venta has been studied for nearly a century, but the last major collecting efforts were done several decades ago. Recently, Colombian and international researchers have begun studies at La Venta, with the valuable participation of the local community. The joint efforts resulted in the establishment of a new La Venta natural history museum (Museo de Historia Natural La Tatacoa). This new wave of paleontological and geological studies has resulted in an improved stratigraphy of La Venta and new paleobiological and evolutionary hypotheses of several vertebrate groups, and in the museum’s educational and outreach activities. Here, we review the current geological and paleontological knowledge of La Venta, identify knowledge gaps, and discuss future research directions. A century after the first paleontological expedition, La Venta’s fossil record continues to illuminate the evolution of the South American tropical biodiversity during the Miocene. KEY WORDS South America, La Venta, tropics, paleobiology, geology, Miocene