Sunday, 14 October 2018

Winnicavis gorskii: A new species of Passerine Bird from the Early Oligocene Menilite Shales of southern Poland.

Passerine Birds are the largest and most successful group of living Birds, and by extension the most specious Dinosaur group ever to have lived. Despite this they have a very poor fossil record, largely due to the very delicate nature of these Bird's bones. The first Eocene Passerine Bird fossil was disovered in Australia in the mid-1990s, leading to the theory that Passerines had a Southern Hemisphere origin, however since then a number of Oligocene Passerine Birds have been discovered in Europe, suggesting that the group was well established and diverse in this area by then, shedding doubts upon the southern origin theory.

In a paper published in the joural Palaeontologica Electronica on 16 August 2018, Zbigniew Bochenski, Teresa Tomek and Krzysztof Wertz of the Institute of Systematics and Evolution of Animals of the Polish Academy of Sciences, Johannes Happ of the Department of Palaeontology at the University of Vienna, Małgorzata Bujoczek of the Department of Forest Biodiversity at the University of Agriculture and Ewa Swidnicka of the Department of Palaeozoology at the University of Wrocław, describe a new species of Passerine Bird from the Early Oligocene Menilite Shales of Podkarpackie Province in southern Poland.

The new Bird is named Winnicavis gorskii, where 'Winnicavis' means 'Winnica-Bird' in reference to the area where the specimen was found, and 'gorskii' honours Andrzej Górski, who discovered the specimen. The specimen comprises Two incomplete wings with a shoulder girdle, plus fragments of at least 12 flight feathers from the right wing, partially articulated, preserved as part and counterpart on a split slab. The affinities of this Bird within the Passerines are unclear, but Bochenski estimate from its wing structure that it has a typical Passerine mode of flight, characterised by flapping phases and pauses.

Winnicavis gorskii from Winnica, Poland, early Oligocene (top left - main slab; bottom left - counterslab) and interpretative drawings (right). Left (L) and right (R) elements are indicated. Abbreviations: cmc, carpometacarpus; cr, os carpi radiale, cu, os carpi ulnare; dmaj, phalanx distalis digiti majoris; pmaj, phalanx proximalis digiti majoris; pmin,  phalanx digiti minoris. Numbers in circles on the slabs: (1) primaries, (2) secondaries, (3) underwing coverts, (4) primary coverts. Zbigniew et al. (2018).

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Haplocookia enghoffi: A new species of Trichopolydesmid Millipede from Tunisia.

Trichopolydesmid Millipedes are found around the Mediterranean Basin, reaching their maximum diversity in Europe, where around 90% of known species are found. North Africa is currently home to only five described species, though the group is poorly studied in the region, and this may be a poor reflection of its real diversity there.

In a paper published in the journal ZooKeys on 26 September 2018, Nesrine Akkari of the Naturhistorisches Museum Wien, and Jean-Paul Mauriès of the Section Arthropodes at the Muséum National d’Histoire Naturelle, describe a new species of Trichopolydesmid Millipede from the Cap Bon Peninsula in Tunisia.

The new species is placed in the genus Haplocookia, and given the specific name enghoffi, in honour of Henrik Enghoff, for his expertise on Millipedes. These Millipedes are a pale cream in colour, and reach 8.0-8.6 mm in length with 20 body rings.

Haplocookia enghoffi, male specimen in latral view. Akkari & Mauriès (2018).

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Evidence of giant Theropods from the Late Jurassic of Asturias, Spain.

During the Late Jurassic high sea levels reduced Europe to a series of island land masses, with variable faunal affinities to both East Asia and North America. The Iberian Massif comprising Portugal and western Spain is one of the few European landmasses of the time to preserve terrestrial faunas in situ (most fossils of Late Jurassic land animals from Europe are known form shallow marine deposits) including numerous Dinosaur trackways. The Vega, Tereñes and Lastres formations of the Asturias Region of northern Spain has produced numerous Dinosaur trackways, as well as the remains of Stegosaurs, Ornithopods, Sauropods and Theropods, though these are fragmentary and consist largely of isolated bones and teeth. Theropods are known from very little material, including a few isolated teeth and a caudal (tail) vertebra, which has not previously been discovered in any detail.

In a paper published in the journal PeerJ on 5 July 2018, Oliver Rauhut of the Bayerische Staatssammlung für Paläontologie und Geologie, and the GeoBioCenter, and Department for Earth and Environmental Sciences at Ludwig-Maximilians-University, Laura Piñuela of the Museo del Jurásico de Asturias, Diego Castanera, also of the Bayerische Staatssammlung für Paläontologie und Geologie, and the GeoBioCenter at Ludwig-Maximilians-University, and José-Carlos García-Ramos and Irene Sánchez Cela, also of the Museo del Jurásico de Asturias, formally describe the Asturian 

The vertebra is referred to by the specimen number MUJA-1913; it is an anterior caudal vertebra (tail vertebra from close to the body) from a calcareous conglomerate within the Vega Formation. Most of the centrum is preserved, as is the base of the neural arch (dorsal section of the vertebra, including the channel through which the spinal cord runs), but none of the processes upon the neural arch. The forward surface of the centrum has been heavily eroded, but the posterior surface is well preserved, being concave and 140-145 mm in diameter. The centrum is about 150 mm high and 90 mm deep, with an anterior (forward) surface offset from the posterior surface. The neural canal is about 35 mm wide.

Anterior caudal vertebra of a giant megalosaurid from the Vega Formation, MUJA-1913. (A) Left lateral view. (B) Posterior view. (C) Ventral view. (D) Dorsal view. Study sites: ch, chevron facet; d, depression on anterior end of dorsal surface of transverse process; l, lamina dividing the conical postzygocentrodiapophyseal fossa from a shallow dorsal depression; pcd, pleurocentral depression; pcdf, postzygocentrodiapophyseal fossa; pcdl, posterior centrodiapophyseal lamina; vg, ventral groove. Scale bar is 50 mm. Oliver Rauhut and Diego Castanaera in Rauhut et al. (2018).

The size of MUJA-1913 is exceptional, at 150 mm in height it is 15%  larger than the anterior caudal vertebrae of Torvosaurus, the largest known Therapod from the Late Jurassic of the Iberian Massif, and the largest recorded Theropod from Europe to date, and 10% larger than the same bone of Spinosaurus aegyptiacus, possibly the largest Theropod Dinosaur ever. The only comparably large caudal vertebrae come from the largest Cretaceous Carcharodontosaurids and Tyranosaurids, and possibly the largest Late Jurassic Allosaurids of North America. The structure of MUJA-1913 is consistent with that of a large Megalosaurid (the group which includes Torvosaurus), probably around 10 m in length.

The tip of a large Theropod Dinosaur was round at the same level within the formation. This is flattened with evenly spaced carinae (ridges on the cutting edge), and an anastomosing (vein-like) ornamentation, consistent with having come from a Megalosaur.

Tip of a large Megalosaurid tooth fromthe Vega Formation. (A) General view in lingual or labial view. (B) Detail of distal serrations and anastomosing enamel ornamentation. Scale bars are 10 mm. Oliver Rauhut and Diego Castanaera in Rauhut et al. (2018).

Rahaut et al. also report a series of new footprints and trackways from the Lastres Formation (which overlies and is slightly younger than the Vega Formation), all of which belong to Therapod Dinosaurs and are greater than 53 cm in length, with the largest being 82 cm in length and 66 mm in width. These fall into two broad groups anatomically, and are suggested to be evidence of the presence both large Megalosaurids and Allosaurids.

Giant Asturian Jurassic footprints, strongly mesaxonic (Morphotype B). (A) MUJA-1263. (B) MUJA-0213, scale bar: 1 m. (C) Specimen still on Argu¨ero sea cliffs. (D–F) Same specimens, photographs with outline drawings to better illustrate track morphology.  José-Carlos García-Ramos in Rauhut et al. (2018).

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Landslides and flash floods kill 36 in North and West Sumatra.

Twenty nine people have died in a series of flash floods and landslides in North Sumatra associated with the onset of the Northeast Monsoon, on Friday 12 October 2018. The worst incident occurred in the village of Muara Saladi in Mandailing Natal District, where a landslide hit an Islamic School sweeping away 29 pupils and several teachers. The majority of these were rescued alive, but twelve of the children died. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall. A further twelve people were killed in flash floods elsewhere in Mandailing Natal District, with waters up to two metres deep that swept away seventeen houses and a number of cars. Flash floods are a particular problem in areas where urban sprawl has resulted in areas where the ground is covered by non-porous concrete of similar materials, preventing rainwater from sinking into the soil. In neighbouring Sibolga District a further four people died as landslides destroyed 29 homes and floods hit about a hundred more. In West Sumatra five people including two children were killed in Tanah Datar District, and four in Padang Pariaman and West Pasaman districts.

The remains of an Islamic School in Mandailang District, North Sumatra, destroyed by a landslide on Friday 12 October 2018. Antara Foto/Reuters.

Sumatra has a wet tropical climate, with a rainy season that lasts from October to April, when rainfall typically reaches 200-300 mm per month and a dry season from May to September, when rainfall is usually below 200 mm per month (though the area is never truly dry. This is driven by the Southeast Asian Monsoon Seasons, with the Northeast Monsoon driven by winds from  the South China Sea fuelling the wetter rainy season and the Southwest Monsoon driven by winds from the southern Indian Ocean the drier dry season. Such a double Monsoon Season is common close to the equator, where the Sun is highest overhead around the equinoxes and lowest on the horizons around the solstices, making the solstices the coolest part of the year and the equinoxes the hottest.

 The winds that drive the Northeast and Southwest Monsoons in Southeast Asia. Mynewshub.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate.

 Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.
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Saturday, 13 October 2018

Asteroid 2018 EB passes the Earth for second time thid year.

Asteroid 2018 EB passed by the Earth at a distance of about 5 918 300 km (15.4 times the average distance between the Earth and the Moon, or 3.96% of the distance between the Earth and the Sun), slightly before 1.25 am GMT on Wednesday 7 October 2018. There was no danger of the asteroid hitting us, though were it to do so it would have presented a significant threat. 2018 EB has an estimated equivalent diameter of 86-270 m (i.e. it is estimated that a spherical object with the same volume would be 82-260 m in diameter), and an object at the upper end of this range would be predicted to be capable of passing through the Earth's atmosphere relatively intact, impacting the ground directly with an explosion that would be about 4000 times as powerful as the Hiroshima bomb. Such an impact would result in an impact crater over 4 km in diameter and devastation on a global scale, as well as climatic effects that would last years or even decades.

 The calculated orbit of 2018 EB Minor Planet Center.

2018 EB was discovered on 1 March 2018 by the  Wide-field Infrared Survey Explorer satellite. The designation 2018 EB implies that it was the second asteroid (asteroid B) discovered in the first half of March 2018 (period 2018 E).

2018 EB has a 374 day orbital period and an eccentric orbit tilted at an angle of 29.4° to the plane of the Solar System, which takes it from 1.00 AU from the Sun (i.e. 100% of he average distance at which the Earth orbits the Sun) to 1.03 AU from the Sun (i.e. 103% of the average distance at which the Earth orbits the Sun). It is therefore classed as an Amor Group Asteroid (an asteroid which comes close to the Earth, but which is never closer to the Sun than the Earth is). As an asteroid probably larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, 2018 EB is also classified as a Potentially Hazardous Asteroid. Close encounters between the 2018 EB and Earth are extremely common, with the last having happened in April this year and the  next predicted in April 2019.

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