Monday 30 May 2016

Landslide kills six in Zhejiang Province, China.

Six people have been confirmed dead following a landslide in the city of Jiande in Zhejiang Province, China, which occurred slightly after midnight on Sunday 29 May 2016. The landslide, which engulfed three houses occurred following several hours of extremely heavy rain, with 144 mm being recorded within a two hour period. 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.

The approximate location of the 29 May 2016 Jiande Landslide.  Google Maps.

Jiande has a warm wet climate, with high levels of rain all year round, however the wettest months are typically June, which on average receives over 240 mm of rainfall, and May which typically receives over 220 mm.

See also... five confirmed deaths following landslide in Fujian Province, China.           Thirty five people have been confirmed dead and one is still missing following a landslide in Taining County in Fujian Province in southeast China, on Sunday 8 May 2016. The landslide swept through a... deaths following landslide in Zhejiang Province, China.                                     Eleven people have been confirmed dead and another 26 are still missing following a landslide that buried about 27 houses in the village of Lidong in the Llandu District of Zhejiang Province at about 10.50 pm local time on Friday 13 November 2015. The... in Anhui Province, China, kills at least two.                                                      Two people are known to have died and at least twelve more have been injured following an Earthquake close to the city of Fuyang in Anhui Province slightly before 2.15 pm local time (slightly before 6.15 am GMT) on Saturday 14 March 2015, which was recorded by the...
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Magnitude 1.3 Earthquake in the northwest Highlands.

The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of about 7 km about 5 km to the southeast of the village of Gairloch in the northwest of the Highland Region of Scotland, at about 5.10 am British Summertime (about 4.10 am GMT) on Monday 30 May 2016. This was not a major event, and presented no threat to human life or property, but may have been felt locally.
 The approximate location of the 30 May 2016 Gairloch Earthquake. Google Maps.
Earthquakes become more common as you travel north and west in Great Britain, with the west coast of Scotland being the most quake-prone part of the island and the northwest of Wales being more prone  to quakes than the rest of Wales or most of England.

The precise cause of Earthquakes in the UK can be hard to determine; the country is not close to any obvious single cause of such activity such as a plate margin, but is subject to tectonic pressures from several different sources, with most quakes probably being the result of the interplay between these forces.
Britain is being pushed to the east by the expansion of the Atlantic Ocean and to the north by the impact of Africa into Europe from the south. It is also affected by lesser areas of tectonic spreading beneath the North Sea, Rhine Valley and Bay of Biscay. Finally the country is subject to glacial rebound; until about 10 000 years ago much of the north of the country was covered by a thick layer of glacial ice (this is believed to have been thickest on the west coast of Scotland), pushing the rocks of the British lithosphere down into the underlying mantle. This ice is now gone, and the rocks are springing (slowly) back into their original position, causing the occasional Earthquake in the process. 
(Top) Simplified diagram showing principle of glacial rebound. Wikipedia. (Bottom) Map showing the rate of glacial rebound in various parts of the UK. Note that some parts of England and Wales show negative values, these areas are being pushed down slightly by uplift in Scotland, as the entire landmass is quite rigid and acts a bit like a see-saw. Climate North East.
Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. If you felt this quake, or were in the area but did not (which is also useful information) then you can report it to the British Geological Survey here. 
See also... 1.3 Earthquake in the Highland Regionof Scotland.                                 The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of about 3 km about 2 km to... 1.3 Earthquake near Glencoe, Scotland.                                             The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of about 10 km about 5 km to the west of Glencoe in the district of Lochaber in... 2.2 Earthquake to the south of Loch Shiel, Scotland.                              The British Geological Survey recorded a Magnitude 2.2 Earthquake at a depth of about 11 km to the south...
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Friday 27 May 2016

Garra lorestanensis: A new species of Blind Cave Fish from Loven Cave in Lorestan Province, Iran.

Many cave systems around the world are home to Cave Fish, populations of Fish that have become isolated within subterranean waterways, and both evolved adaptations to living in these systems and lost adaptations to life in sunlit waterways, most obviously manifested in the absence of pigment and eyes. Loven Cave in the Ab-e Sirum or Ab-e Serum Valley in Lorestan Province, Iran, has been known to be an outlet of a limestone cave system beneath the Zagros Mountains since the mid-twentieth century. Two species of unique Cave Fish have been describd from this cave, both blind and pigmentless; a species of Sucker-mouthed Barb, Garra typhlops, and an Asian Stone Loach, Paracobitis smithi.

In a paper published in the journal FishTaxa on 22 March 2016, Hamed Mousavi-Sabet of the Department of Fisheries at the University of Guilan and Soheil Eagderi of the Department of Fisheries at the University of Tehran, describe a new species of Cave Fish from the Loven Cave.

The new species is also placed in the genus Garra and is given the specific name lorestanensis, meaning 'From Loristan'. The species is described from six adult specimens ranging in size from 27.2-58 mm in length. It differs from Garra typhlops in having a mental disk (disk-shaped structure on the lower jaw, used to attach to the substrate during feeding), which the previously described species lacks; a genetic analysis supported the idea that this was a digannostic for a separate species rather than a variable trait within the species (as with some other species of Garra).

Garra lorestanensis, 55 mm SL; Iran: Loven Cave. Mousavi-Sabet & Eagderi (2016).

See also... nanningensis: A fossil Loach from the Middle Oligocene of Guangxi Province, China.                                                     Loaches, Corbitidae, are freshwater Cypriniform Fish related to Carp and Minnows, found across Eurasia... new species of River Loach from Rakhine State, Myanmar.                                         River Loaches (Nemacheilidae) are ubiquitous members of the Eurasian freshwater fauna, with at least 704 species in 46 genera... new species of blind Cavefish from Indiana.                                                   Cavefish (Amblyopsidae) are a group of predominantly cave-dwelling Perciform Fish from North America. Of the eight currently described species three are found at the surface, predominantly around springs, and...
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Thursday 26 May 2016

Dozens of cars swallowed by sinkhole in Florence, Italy.

Dozens of cars have been swallowed by a giant sinkhole that opened up on the Lungarno Torrigiani beside the Arno River in Florence on Wednesday 25 May 2016. The whole measured 182 m in length, but only about 7 m across, and opened slightly before 6.15 am local time, swallowing a row of parked cars but not causing any injuries.

The scene of the 25 May 2016 Florence sinkhole. Vigu del Fuoco.

Sinkholes are generally caused by water eroding soft limestone or unconsolidated deposits from beneath, causing a hole that works its way upwards and eventually opening spectacularly at the surface. Where there are unconsolidated deposits at the surface they can infill from the sides, apparently swallowing objects at the surface, including people, without trace.

 The proximity of the 25 May 2016 sinkhole to the Arno River. Vigu del Fuoco.

In this case the sinkhole is thought to have been caused by the collapse of a water supply pipe, which was 60 cm in diameter and provided water to homes in the area. An initial split in the pipe is thought to have allowed water to wash away surrounding sediments, causing the overlaying road to collapse onto the pipe. Part of the city around the sinkhole is currently without water, and buildings close to the incident have been evacuated as a precaution.

See also... people evacuated from homes after massive sinkhole opens on Naples Street. Approximately 380 people from 95 families had to be evacuated from their homes after a massive sinkhole opened up in a residential district of Naples on Sunday 22 February 2015. Nobody was injured by the incident, in which a 10 m section of road collapsed abruptly...
Four people are known to have died following landslides in the southern Alps this weekend. On Saturday 15 November 2014 a landslide destroyed... dead in Italian flash flood.                  Four people are known to have died and about twenty more have been injured after a thunderstorm caused a flash flood near Refrontolo in the Veneto Region of northern Italy slightly before midnight on Saturday 2...
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Anebodon luoi: A new species of Zhangheotherid Mammal from the Early Cretaceous of Liaoning Province.

Zhangheotherids are a small group of Mammals known only from the Early Cretaceous of Asia. They have traditionally been placed within the Symmetrodonta, a wider group of Mesozoic Mammals thought to have given rise to the Therians (Marsupials and Placental Mammals), though this group is now considered to be paraphyletic (i.e. not all members share a common ancestor). However more recent examinations of relationships among Mesozoic Mammals have suggested that the Zhangheotherids are closely related to the Therians, with the two groups being placed together to form a higher classification, the Trechnotheria.

In a paper published in the journal Scientific Reports on 24 May 2016, Shundong Bi of the Department of Biology at the Indiana University of Pennsylvania and the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, Xiaoting Zheng of the Shandong Tianyu Museum of Nature and the Institute of Geology and Paleontology at Linyi University, Jin Meng of the Division of Paleontology at the American Museum of Natural History and the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, Xiaoli Wang, also of the Shandong Tianyu Museum of Nature and the Institute of Geology and Paleontology at Linyi University, Nicole Robinson, also of the Department of Biology at the Indiana University of Pennsylvania and Brian Davis of the Department of Anatomical Sciences and Neurobiology at University of Louisville, describe a new species of Zhangheotherid Mammal from the Early Cretaceous Yixian Formation of Liaoning Province, China.

The new species is named Anebodon luoi, where 'Anebodon'  means 'young-tooth', in reference to the last premolar, which appears to have been replaced by an adult tooth late in the development if the animal, and 'luoi' honours palaeontologist Zhe-Xi Luo of the Univeristy of Chigaco for his work on Mesozoic Mammals. The species is decribed from a single partial skull and jaw, showing complete dentition.

Stereophotographs of the skull of the Zhangheotheriid Anebodon luoi, in dorsal (a), ventral (b), right lateral (c) and left lateral (d) views; illustrations of the skull in dorsal (e), ventral (f), and left lateral (g) views. Illustrations are enlarged to show detail and are not to same scale as photographs. Dotted fill represents matrix. Abbreviations: al, anterior lamina of petrosal; as, alisphenoid; ax, axis; bs, basisphenoid; ef, ethmoidal foramen; fdv, foramen for frontal diploic vein; fr, frontal; if, incisive foramen; iof, infraorbital foramen; lac, lacrimal; lf, lateral flange of petrosal; mapf, major palatine foramen; mpf, minor palatine foramen; mx, maxilla; na, nasal; os, orbitosphenoid; otc, anterior opening of orbitotemporal canal; pa, parietal; pal, palatine; pmx, premaxilla; smx, septomaxilla; spf, sphenopalatine foramen. Bi et al. (2016).

See also... transylvanicus: A red-toothed Multituberculate Mammal from the Late Cretaceous of Haţeg Island.                                 Small, isolated islands often produce distinctive... Eutherian Mammal from the Late Cretaceous of Kazakhstan.                    Biologists studying modern mammals divide them into three groups, the egg-laying Monotremes, the pouched Marsupials, and the large-baby-producing... Eutherian Mammal from the Jurassic of China.                                                      Modern mammals are divided into three groups by biologists: the monotremes which lay eggs, the marsupials which give birth to underdeveloped live young then raise these young in pouches, and the placental mammals which give birth to large, well developed young. Palaeontologists rarely get the... 
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Wednesday 25 May 2016

Multicellular Eukaryotic organisms from the 1.56-billion-year-old Gaoyuzhuang Formation of North China.

Sediments across the Earth contain numerous macrofossils (fossils of big things that can be found with the naked eye, as opposed to smaller microfossils which are found by sieving sediments or examining thin slices of rock under a microscope) from the Cambrian Explosion (542 million years ago) onwards, with numerous such fossils also now known from the Ediacaran Period (635-542 million years ago) and even some from the later part of the Cryogenian (720-635 million years ago). Earlier than this the fossil record is harder to interpret, with several disputed claims of multicellular organisms, as well as uncertainty as to whicj are the earliest cells that can be described as tuly Eukaryotic (having cells with a nulceus like animals and plants, as opposed to Prokaryotic cells which lack such nuclei, as in Bacteria and Archeans).

In a paper published in the journal Nature Communications on 17 May 2016, Shixing Zhu of the Tianjin Institute of Geology and Mineral Resources of the China Geological Survey and the State Key Laboratory of Biogeology and Environmental Geology at the China University of Geosciences, Maoyan Zhu of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, Andrew Knoll of the Department of Organismic and Evolutionary Biology at Harvard University, Zongjun Yin and Fangchen Zhao, also of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, Shufen Sun, aslo of the Tianjin Institute of Geology and Mineral Resources of the China Geological Survey, Yuangao Qu of the Centre for Geobiology at the University of Bergen, Min Shi, also of the State Key Laboratory of Biogeology and Environmental Geology at the China University of Geosciences and Huan Liu, again of the Tianjin Institute of Geology and Mineral Resources of the China Geological Survey, describe a series of Multicellular Eukaryotic fossils from the 1.56-billion-year-old Gaoyuzhuang Formation of North China.

At 1.56-billion years old the Gaoyuzhuang Formation is considered to be Calymmian, or Early Mesoproterozoic, in age, though these are definations based upon age rather fossil content as with later geologic periods. It comprises a series of calcarous shales and mudstones that outcrop across a wide area of North China, though fossils were found only at two locations, one in Qianxi County in Guizhou Province and the other in Kuancheng County in Hebei Province.

Zhu et al. found four different fossil forms, linear forms with parallel sides but no preserved ends, leaf-shaped forms which taper at one end, oblong forms with rounded ends and parallel sides, and tounge-shaped forms. All forms show well defined margins on at least two sides, unlike algal mats which spread amorphously, and one small example of a leaf-shaped form was found to have a stipe (stem) and holdfast similar to that seen in modern seaweeds. 

 Macroscopic fossils from the Gaoyuzhuang Formation. (a) Linear fossil without preservation of either end (a(1)) and fragment of tongueshaped fossil (a(2)), Qg98017. (b) Linear fossil without preservation of either end (b(1)) and tongue-shaped fossil with longitudinal striations (b(2)), Qg20011; (c,d) Cuneate fossils, 07kg1332 (c), Qg20017 (d). (e) Oblong fossil with possible holdfast, 07 kg1331. (f) Cuneate fossil preserved with differentiated holdfast, Qg98021; (g) linear fossil without preservation of either end. Scale bars, 5 cm (in a,b,g), 20mm (in c), 40mm (in d) and 5mm (in e,f). Zhu et al. (2016).

These morphologies strongly support the idea that these were photosynthetic multicellular organisms with pre-determined growth patterns, albeit simple ones, similar to moder marine Macro-Algae (Seaweeds). Of the three modern groups of Macro-Algae (Red, Green and Brown) two (Red and Green) have been predicted by some studdies to have shared a common ancestor in the Early Mesoproterozoic (Brown Algae are thought to be quite unrelated and much younger). The Gaoyuzhuang fossils could potentially be representatives of this ancestral Algal group, though the presence of similar morphologies in the unrelated Brown Algae indicates that this simple bodyplan has evolved at least twice in Eukaryotes, raising the possibility that similar forms could have arisen quite separately in an extinct group of Eukaryotes in the Early Mesoproterozoic.

In addition to examening macrofossils Zhu et al. took sediment samples from the Gaoyuzhuang Formation and treated them by acid maceration (mashing up and disolving in acid). This yielded a number of fragments of cellular material, up to 1 mm across, comprised of tightly packed masses of polyhedral cells 6–18 μm in diameter. These were found to be made of altered carbon-based material, strongly supporting the idea that these were remains of living material, though evidence of internal structure could not be found. These cannot be directly linked to the macrofossils, but they are large enough to be clearly Eukaryotic in origin, and in the absense of any other structures from which they might have come, are thought to provide further evidence for the idea that the macrofossils represent Multicellular Eukaryotic Algae.

Polygonal cells forming a multi-layered network from the Gaoyuzhuang Formation. Scale bar is 20 μm. Zhu et al. (2016).

See also... Earth’s earliest fossils.                           In the nineteenth century the origin of life seemed an intractable problem for palaeontologists, with large complex animal fossils appearing in the Cambrian explosion, but scientists having access to neither examples of earlier fossils nor the means with which to examine them... the primordial soup; did the first life emerge in volcanic pools?                          The blood plasma and lymph of modern animals is similar in chemical composition to seawater, strongly supporting the idea that animal life began in the oceans, but the liquid inside our cells has a quite different chemistry, suggesting that cells... oldest animals - Pre-Ediacaran Sponges from Namibia(?)                                     Sponges are curious creatures. They are considered to be animals as they are multicellular and some of them have fixed body shapes, however they show no...

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Landslide at Myanmar jade mine kills at least twelve.

Twelve people have been confirmed dead and another eleven have been injured following a landslide at a jade mine at Hpakant in Kachin State, Myanmar, on Tuesday 24 May 2016. It is feared that many more people may be trapped beneath the rubble following the event, which occurred on a spoil heap produced by a large mining concern that was itself being worked by smaller artisanal miners looking for pieces of jade missed by the larger operation.

The scene of the 24 May 2016 Hpakant landslip. AFP.

Myanmar is the world's largest producer of jade, though much of this is produced (along with other precious and semi-precious minerals such as amber) at unregulated (and often illegal) artisanal mines in the north of the country, from where it is smuggled into neighbouring China. Accidents at such mines are extremely common, due to the more-or-less total absence of any safety precautions at the site. At many sites this is made worse by the unregulated use of explosives to break up rocks, often leading to the weakening of rock faces, which can then collapse without warning. The majority of people in this industry are migrant workers from the surrounding countryside, not registered with any local authority, which can make it difficult for rescuers to identify victims following such events, or even gain accurate assessments of the number of people likely to have been involved in such accidents.

The approximate location of the Hpakant jade mines. Google Maps.

See also... kills at least five at mine in Kachin State, Myanmar.                                          Five people have been confirmed dead and as many as fifty more may be missing following a landslide at a jade mine at Hpakant in Kachin State, Myanmar, on Friday 25 December 2015. The precise number of people involved is unclear because the... feared dead following landslide at Myanmar jade mine.                                    One hundred and five people have now been confirmed dead and over a hundred are still thought to be missing following a landslide at a jade mine at Hpakant in Kachin State, Myanmar on Saturday... kills at least nine at Myanmar jade mine.                                                            Nine people have been confirmed dead and about twenty more are thought to still be missing following a rockslide on a spill heap at a jade mine at Hpakant in Kachin State, Myanmar, on Monday 20 March 2015. All the people caught in the landslide are understood...
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Dramatic rise in Cephalopod populations across the globe.

In the past few decades marine biologists have become aware of many dramatic changes in the world's oceans, including dramatic falls in many commercially exploited Fish species, rising temperatures and widespread pollution and marine litter. During this time several studies have shown that as Fish populations have fallen in many areas, they have been replaced by rising Cephalopod numbers, leading some experts to wonder if this might be a global trend, though to date the data has not been examined to test this hypothesis.

In a paper published in the journal Current Biology on 23 May 2016, Zoë Doubleday and Thomas Prowse of the School of Biological Sciences and The Environment Institute at the University of Adelaide, Alexander Arkhipkin of the Fisheries Department of the Falkland Islands, Graham Pierce of the Oceanlab at the University of Aberdeen, Jayson Semmens of the Institute for Marine and Antarctic Studies at the University of Tasmania, Michael Steer of the South Australian Research and Development Institute, Stephen Leporati of the Department of Fisheries Western Australia, Sílvia Lourenço of the Instituto Português do Mar e Atmosfera, Antoni Quetglas of the Centre Oceanogràfic de les Balears of the Instituto Español de Oceanografía, Warwick Sauer of the Department of Ichthyology and Fisheries Science at Rhodes University and Bronwyn Gillanders, also of the School of Biological Sciences and The Environment Institute at the University of Adelaide, present a detailed analysis of Cephalopod population statistics from around the globe since 1953.

A Caribbean Reef Squid, Sepioteuthis sepioidea, on Bari Reef in the Caribbean Netherlands. Betty Wills/Wikimedia Commons.

Doubleday & Prowse et al. examined records from all major oceanographic regions in both hemispheres from 1953 to 2013, examining all key taxonomic groups (Squid, Octopus and Cuttlefish) and life history groups: demersal (living close to the bottom), benthopelagic (living on the bottom, but also swimming higher into the water column at times), and pelagic (living in the water column away from the bottom).

 A Two-spot Octopus, Octopus bimaculoides. Monterey Bay Aquarium.

In all cases Cephalopod numbers were found to have grown over the period examined. Doubleday & Prowse et al. suggest several possible explanations for this. Cephalopods are highly adaptable and intelligent, enabling them to colonise new areas and exploit novel resources, and have shorter life-cycles than comparably sized fish. In addition almost all Cephalopods, regardless of adult lifestyle, have a planktonic larval phase enabling them to reach suitable new habitats quickly. In addition recent studies have shown that rising temperatures tend to reduce generation times in Cephalopods (i.e. they reach maturity and reproduce more quickly). Furthermore many such larval Cephalopods are subject to predation by Fish species that have undergone dramatic population declines in recent years, potentially enabling more larval Cephalopods to survive to adulthood and reproduce.

Broadclub Cuttlefish, Sepia latimanus. Nick Hobgood/Wikipedia.

Doubleday & Prowse et al. note that such a rise in Caphalopod numbers is likely to have knock-on effects, most notably a rise in predation on species targeted by Cephalopods and an increase in food supply to species targeting Cephalopods (including many Humans). However they also observe that the current rise in Caphalopod numbers does not necessarily imply that in future Cephalopod populations will continue to rise, noting that the group are potentially vulnerable to future threats, such as rising ocean acidification and increased targeting by Human predation as Fish populations decline.

See also... the environments favored by Late Cretaceous Ammonites.              Ammonites are almost ubiquitous fossils in Mesozoic Marine deposits, and as such have been used extensively in interpreting and dating these deposits. They were free-swimming Cephalopods, related... behaviour in a Deep-sea Octopus.  Most Octopus reproduce only once in their life cycle, with the female undertaking an extended period of brooding in which she tends her eggs, keeping them clean and oxygenated and protected from predators, expiring at the end of this period. In most species the female does not feed at all during this... masses of the Diamond-shaped Squid in the Canary Islands.                                       The Diamond-shaped Squid, Thysanoteuthis rhombus, is a large (up to 100-130 cm, excluding tentacles) ocean-going Squid found in tropical and...

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Tuesday 24 May 2016

Truncospora wisconsinensis: A new species of Bracket Fungus from Wisconsin.

Bracket Fungi, Polyporales, are Basidiomycote Fungi that predominantly grow on dead, rotting, wood, though some species are significant pathogens of trees and woody plants. They produce distinctive fruiting bodies on the outside of the wood, which are shelf or bracket shaped with the spore-producing basidia on the underside. Bracket fungi found in commercial woodlands and those which attack structural timber have been well studied, but the group is know to be much more diverse in old-growth woodland, where it has been little studied.

In a paper published in the journal Phytotaxa on 14 April 2016, Chang-Lin Zhao, Feng Xu and Donald Pfister of the Farlow Herbarium of Cryptogamic Botany at Harvard University describe a new species of Bracket Fungus from Lakeshore Nature Reserve in Dane County, Wisconsin.

The new species is placed in the genus Truncospora and given the specific name wisconsinensis, meaning 'from Wisconsin'. The Fungus was found growing on fallen Oak trees, where it produces white fruiting bodies. A genomic phylogenetic analyses suggests that this species is closely related to two other North American Bracket Fungi, Truncospora ohiensis and Truncospora arizonica.

Fruiting body of Truncospora wisconsinensis. Scale bar is 1 cm. Zhao et al. (2016).

See also... excelsum: A new species of Fungi from the Brazil Nut Tree Ecosystem in the Amazon Basin.                                           Fungi of the genus Penicillium are considered to be highly important both ecologically and economically. They act as major biodegrading agents in many ecosystems, helping to recycle a wide range of biological material, but this also makes them spoiling agents capable of rotting food and man made... purpurea: A new species of Ascomycote Fungo from Martinique. Ascomycote Fungi of the order Jahnulales are aquatic wood decomposing Fungi found almost exclusively in freshwater environments (one species is known from Mangroves). Members of the genus Jahnula, from which the family gets its name, are primarily tropical... new species of Coral Fungi from the Ozark region of Arkansas.                                      Coral Fungi of the genus Ramariahave been extensively studied in the temperate rainforests of the American Pacific Northwest, and to a lesser extent in the forests of America’s Eastern Seaboard, but are...
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Monday 23 May 2016

Decapod Crustaceans from the Tarioba Shell Mound.

Shell mounds are archaeological sites common in coastal areas around the world. In Brazil there are hundreds of such mounds, mostly dating to between 8000 and 1000 years ago, with the greatest abundance being found in Espírito Santo and Santa Catarina States. The Tarioba Shell Mound is located in Rio das Ostras Muncipality in eastern Rio de General State. It was discovered in 1967, but not excavated until 1998-1999, when the site was completely excavated, with the material being relocated to a museum, with the site subsequently being developed. The site had five layers, dated to between 3620 and 3440 years ago, though the site shows signs of overturning with the oldest layer at the top. A total of 47 Mollusc species have been described from the site, as which also yielded numerous Decapod Crustacean specimens, predominantly chelae (claws).

In a paper published in the journal Check List on 28 March 2016, Felipe Barta Rodrigues, Michelle Rezende Duarte and Rosa Cristina Corrêa Luz de Souza of the Laboratório de Genética Marinha e Evolução at the Universidade Federal Fluminense, Abílio Soares‑Gomes of the Laboratório de Ecologia de Sedimentos Marinhos, also at the Universidade Federal Fluminense and Edson Pereira Silva, again of the Laboratório de Genética Marinha e Evolução at the Universidade Federal Fluminense, analyze and describe the Crustacean material from the Tarioba Shell Mound.

Rodrigues et al. describe nine species of Decapod from five layers, these being Callinectes danae, a type of Swimming Crab, Callinectes sapidus, the Atlantic Blue Crab (another type of Swimming Crab and a species still widely eaten and considered economically important in the United States), Cardisoma guanhumi, the Blue Land Crab, Goniopsis cruentata, the Mangrive Root Crab, Menippe nodifrons, the Cuban Stone Crab, Mithrax hispidus, the Shaggy Climbing Crab, Ocypode quadrata, the Atlantic Ghost Crab, Ucides cordatus, the Atlantic Mangrove Crab and Panopeus austrobesus, the South American Mud Crab.

Voucher specimens, with morphological characters used for identification. (A) Callinectes danae (elongated dactyl format. Teeth arranged in a single row, with two small followed by a larger one pattern. More pointed teeth than the Callinectes sapidus); (B) Callinectes sapidus (elongated dactyl format, teeth arranged in a single row, with two small followed by a larger one pattern); (C) Cardisoma guanhumi (rounded tubers, arranged in a row, the largest tuber near to the palm); (D) Goniopsis cruentata (curved dactyl format, with teeth distributed in four rows); (E) Menippe nodifrons (large tuber at the base, followed by other smaller tubers); (F) Mithrax hispidus (curved dactyl format, teeth arranged in a single row, with the largest tooth near to the palm); (G) Ocypode quadrata (small tubers arranged in four rows, it has small thorns arranged in a single row); (H) Ucides cordatus (tubers arranged in three rows with other dispersed, it has thorns records); (I) Panopeus austrobesus (curved dactyl format, with a large basal tooth). Scale bars are 5 mm. Rodrigues et al. (2016).

The most biodiverse layer was the uppermost (oldest), in which all the species were present, with the other layers each having eight species. The presence of more species in the oldest layer could be taken as indication of loss of biodiversity due to consumption over the time the site was occupiedm however Rodrigues et al. do not consider the loss of diversity to be significant given the overall low number of samples.

See also... a 500-year-old Inca child mummy.                                                         In recent years the development of methods for sequencing ancient DNA has led to a greater understanding of how many ancient peoples are related to modern populations, particularly in Europe. However the method has been little used... infection in a Pre-Columbian skull from south Jamaica.                                               The Taíno people are thought to have colonized the Caribbean Islands by island hopping from northern South America from about 500 BC onwards, reaching Jamaica by around 645-898 AD. They were skilled agriculturalists, introducing crops such as Cassava and Maize from South America and... rock carving from Brazil; possibly the oldest art in the Americas.                      The earliest people arrived in the Americas some time between 12 000 and 13 500 years ago. They are known from burials and tools scattered (albeit thinly) across both North and South America. Art made by...
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