Monday 31 August 2015

Glenrosa carentonensis: A new species of Conifer from the Early Cretaceous of Charente-Maritime, France.

Conifers of the genus Glenrosa were first recorded from the Early Cretaceous Glen Rosa Formation of Texas in 1984 (although specimens of the plant had been collected in the area since the 1890s), and subsequently recorded from widely distributed Early Cretaceous from North America, Europe and Asia, suggesting that for a while it was a widespread and dominant plant in the Northern Hemisphere. Glenrosa is distinguished by having small fleshy triangular leaves held close to the stems, with stomata (breathing pores) grouped together in deep stomatal crypts (indentations on the leaves). Such crypts are known only from a single other species of Conifer, Sedites rabenhorstii, which also lived in the Cretaceous, making interpretation of its ecological significance difficult, however similar structures are found in some modern Angiosperms (flowering plants), the majority of which live in arid climates, suggesting that the pores may help to regulate water loss in dry conditions.

In a paper published in the journal PLoS One on 19 August 2015, Jean-David Moreau of Géosciences Rennes at Université Rennes and the European Synchrotron Radiation Facility, Didier Néraudeau, also of of Géosciences Rennes at Université Rennes, Paul Tafforeau also of the European Synchrotron Radiation Facility and Éric Dépré of the Groupement d’Etude et de Contrôle des Variétés et Semences, describe a new species of Glenrosa from material included in flint nodules collected from Early Cretaceous deposits at Font-de-Benon Quarry, between the villages of Archingeay and Les Nouillers in the Charente-Maritime Department of western France.

The new species is named Glenrosa carentonensis, meaning ‘from Charente’ (Carentonia is the Latin name for the River Charente). The species is described from a number of specimens of fragmentary material up to 50 mm in length preserved in flint nodules. Since it is essentially impossible to extract plant remains from hard flint, the specimens were examined using propagation phase-contrast X-ray synchrotron microtomography at the European Synchrotron Radiation Facility.

Plant fossils embedded inside flint nodules. (A) Broken flint nodule with diverse conifer inclusions, SIL_ARC_2. (B) Leafy twigs of Glenrosa carentonensis. (C) Leafy twigs of Glenrosa carentonensis. (D) Leafy axis of Glenrosa carentonensis bearing distally a microsporangiate cone on its distal tip. (E) Detail of the same cone. Moreau et al. (2015).

The leaves of Glenrosa carentonensis are arranged helically around the stems; they are flesh and somewhat claw-shaped, with a waxy cuticle and numerous stomatal crypts, each containing 7-12 stomata. Several male cones were found in the sample, the first time these have been recorded for any species of Glenrosa. These are 2.8–5.0 mm long and 2.3–4.1 mm wide and bear up to 40 microsporophylls regularly distributed along the cone axis. Each microsporophyll bears 6-7 pollen sacs in clusters up to 0.5 mm wide. The pollen could be determined to be 17.3–20.3 μm long and 10–16 μm wide, but no details could be discerned.

Propagation phase-contrast X-ray synchrotron microtomograph, virtual sections of Glenrosa carentonensis reconstructed using a single distance phase retrieval process. (A) Longitudinal section of leafy axis. (B) Transversal section of leafy axis. (C) Longitudinal section of twig and cone. Moreau et al. (2015).

The stomatal crypts, fleshy leaves and thick waxy cuticles of Glenrosa carentonensis all appearto be adaptations to an arid climate, while the inclusion of the material in flint nodules implies a coastal environment (all flint deposits are thought to have originated in shallow-marine environments). Moreau et al. suggest the plants were a major component of a dry coastal Conifer forest, with occasional storm events and possibly haline influences (salt laden winds).

Propagation phase-contrast X-ray synchrotron microtomograph 3D renderings of Glenrosa carentonensis. (A) Helically arranged leafy axis. (B–C) Leafy axes bearing a microsporangiate male cone. Moreau et al. (2015).

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Amber is the mineralized remnants of resins secreted by ancient plants. It is valued by palaeontologists due to the frequent presence of preserved insects, pollen and soft-bodied micro-organisms within amber clasts; it is also widely used in the jewellery industry, and in Chinese medicine. The resins which form amber...

The Chinese Arborvitae, Platycladus orientalis, is a species of Cypress widely grown as an ornamental plant in China, North...

Diptocarps, Dipterocarpaceae, are the dominant trees of modern South and Southeast Asian rainforests, and are also found in South America, Africa and Madagascar. The group reach their maximum diversity today on the island of Bornea, where there are over 280 described species of Diptocarp, but the earliest fossil Diptocarps...

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Sunday 30 August 2015

Magnitude 3.7 Earthquake in Oklahoma County, Oklahoma.

The United States Geological Survey recorded a Magnitude 3.7 Earthquake at a depth of 5 km in northern Noble County, Oklahoma, before 7.20 am local time (slightly before 0.20 am GMT) on Sunday 30 August 2015. There is little danger of any damage or injuries being caused by an Earthquake of this Magnitude, but people have reported feeling it in the city of Edmond.

The approximate location of the 30 August 2015 Oklahoma County Earthquake. Google Maps.

Oklahoma is naturally prone to Earthquakes, particularly in the southwest of the state, near the Meers Fault Zone, but since 2009 has suffered a sharp increase in the number of small quakes in the central and northeast parts of the state. While most of these quakes have been quite small, a few have been large enough to potentially cause problems, and any unexplained increase in seismic activity is a cause for concern. 

In a paper published in the journal Geology on 26 March 2013, a team of geologists led by Katie Keranen of the ConocoPhillips School of Geology and Geophysics at the University of Oklahoma linked one of the largest of these quakes, a Magnitude 5.7 event in November 2011 which caused damage locally and was felt across 17 states, to the practice of pumping liquids (usually brine) into injection wells, which is common in the hydrocarbons industry and used to displace oil or gas, which can then be extracted from nearby extraction wells (where this is done in bursts at pressure to intentionally break up rock it is called hydraulic fracturing, or fracking). Significantly they suggested that the practice could lead to quakes years or even decades after the actual injection.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organization Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.

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One man has died and at least 24 other have been injured following an outbreak of tornadoes across Oklahoma and parts of Arkansas on Thursday 26 March 2015. The dead man is reported to have died while trying to aid his injured father at the River...

The United States Geological Survey recorded a Magnitude 4.0 Earthquake at a depth of 5 km in eastern Noble County, Oklahoma, before 5.10 am local time...

The United States Geological Survey recorded a Magnitude 3.3 Earthquake at a depth of 5 km in northern Grant County, Oklahoma, slightly after 7.10 pm...

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Global Superpredator: How Human predation affects ecosystems in a way unlike that of any other predator.

Humans are known to modify landscapes in ways quite unlike those of any other animal, and the expansion of Human populations has been linked to mass extinctions of large animals around the globe. However exactly why Human predation has such a profound effect is unclear, which has led to the suggestion that the coincident arrival of Human predators and local mass extinction events on each continent during the Pleistocene was in fact a symptom of outside factors, such as climate change, rather than directly attributable to human activity.

In a paper published in the journal Science on 21 August 2015, Chris Darimont of the Department of Geography at the University of Victoria, Raincoast Conservation Foundation and the Hakai Institute, Caroline Fox of the Department of Geography at the University of Victoria and the Raincoast Conservation Foundation, Heather Bryan, also of the Department of Geography at the University of Victoria, Raincoast Conservation Foundation and the Hakai Institute and Thomas Reimchen of the Department of Biology at the University of Victoria present the results of a mathematical study of the impact of Human and non-Human predation on large Mammal and Fish from ecosystems around the world, and look for explanations for the results of this.

Darimont et al. found that in all ecosystems Humans exploited herbivorous Mammals at a similar rate to local non-Human predators, even though this rate of exploitation varied considerably between regions. However unlike any other carnivore Humans show a strong preference for larger prey, consistently taking large, reproductive adults, which are harder to replace, rather than the younger weaker members of the species targeted by other predators. In addition humans target other carnivores at a far higher rate than any other species, killing medium sized predators at an average rate 4.3 times that of any other animal and large predators at an average rate 9.2 times as high as achieved by any other predator. This means that where available Humans will kill large carnivores at a rate 3.7 times as high as that at which they kill herbivores.

In aquatic ecosystems humans take an average of 14.1 times as much prey as any large aquatic predator, with 50% of aquatic predators taking less than 1% of their own bodymass in Fish each year, compared to 62% of Humans in coastal ecosystems consuming over 10% of their body mass in Fish each year.

Traditional hunter in the Kalahari, Botswana. Michele Westmorland/Getty Images.

Darimont et al. suggest that Human hunting behaviour impacts ecosystems in a number of ways. Firstly humans have a cultural preference for large prey, which suppresses the ability of populations to recover by removing reproductive adults, and significantly alters selective pressure upon prey species; large size usually helps animals escape predation, thus animals such as Elephants, Rhinoceroses and Whales typically escape all attempts at predation by non-Human predators once they reach adult size, but are particularly vulnerable to attacks by Humans. Humans are also intolerant of other large predators, generally seeking to remove these species even where they are not consumed. This behaviour is strongly driven by cultural factors, most obviously the prestige of bringing down the largest most ferocious prey; though these cultural assumptions also drive conservation-orientated decisions, for example fishing restrictions typically restrict the taking of smaller immature Fish, while allowing the taking of larger specimens.

 Italian trophy fisherman Dino Ferrari with a 127 kg Catfish caught with a rod-and-line in the River Po in Februaury 2015. After photographing the catch Mr Ferrari released it back into the wild. Sporting News.

Secondly division of labour and rapid cultural evolution among Humans presents a unique threat to prey species, resulting in Human groups constantly producing novel Hunting methods quicker than prey species can adapt, from stone tools and a symbiotic relationship with Dogs in the Pleistocene to hydrocarbons-fuelled vehicles and satellite-tracking systems in the twenty-first century. This has effectively decoupled Humans from the impact of overhunting, as Human populations are able to support small numbers of highly specialized hunters even where prey species are depleted, through agriculture and trade systems which provide food from distant sources. Human long-distance trade also presents a unique drain on nutrients from ecosystems, as the remains of prey consumed by non-Human predators typically re-enters the local environment, whereas that consumed by Humans is often removed to distant parts of the globe, and typically ends up in either sewage systems or landfill sites.

Modern hunters in Mississippi. William Widmar/Al Jazeera America.

Finally Darimont et al. present a number of measures that would be needed to integrate these findings into conservation efforts. Many conservationists have already suggested that the recovery of natural ecosystems would require humans to become far more tolerant of other large predators, a suggestion which Darimont et al.’s findings support. They also emphasize the need for far tighter controls on fisheries catches, particularly by large fishing vessels which target waters far from their home ports. Darimont et al. note that even the most stringent current fishing restrictions allow harvesting at a rate roughly four times as high as that achieved by non-human predators. Finally the achievement of sustainable hunting by Humans would require a radical shift in the way in which we choose prey from within target populations; this would be challenging both culturally and technologically as it would require a move from targeting large, reproductively significant adult prey (which provide status to the hunter and which are also easily targeted with modern firearms) to smaller, more easily replaced, juvenile animals (which are generally seen as low status kills, as well as being harder to target with modern hunting weapons).

Cheetah with a young Antelope. Like most non-human predators Cheetahs favour juvenile prey. John Langlois/Kenya Workbook.

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In the late 1990s and early 2000s it became apparent that the Oriental White-backed Vulture, Gyps bengalensis, Long-billed Vulture, Gyps indicus, and Slender-billed Vulture,Gyps tenuirostris, were undergoing rapid population declines across Bangladesh, India, Nepal and Pakistan, loosing...

The International Union for the Conservation of Nature's Species Survival Commission Pangolin Specialist Group at the Zoological Society of London published a report on 29 July 2013 warning...

Industrial scale timber extraction began on Borneo in the 1970s and during the period 1980 to 2000 more timber was harvested from Borneo than from Africa and the Amazon Basin combined. In addition much forest has been cleared to make way for monoculture plantations, for the palm oil, rubber and timber industries, as well as being burned in forest fires.  For this reason the island is often assumed to be a hopeless case...

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Asteroid 2015 OV passes the Earth.

Asteroid 2015 OV passed by the Earth at a distance of 11 220 000 km (29.2 times the average distance between the Earth and the Moon, or 7.50% of the average distance between the Earth and the Sun), slightly after midday GMT on Monday 24 August 2015. There was no danger of the asteroid hitting us, though had it done so it would have presented a considerable threat. 2015 OV has an estimated equivalent diameter of 38-120 m (i.e. a spherical body with the same mass would be 38-120 m in diameter), and an object towards the upper end of this range would pass through the atmosphere and directly impact the ground with a force of about 80 megatons (about 4700 times the explosive energy of the Hiroshima bomb), causing devastation over a wide area and creating a crater over 1.5 kilometers across, and resulting in global climatic problems that could last for years or even decades.

The calculated orbit of 2015 OV. JPL Small Body Database.

2015 OV was discovered on 19 July 2015 (36 days before its closest approach to the Earth) by the University of Hawaii's PANSTARRS telescope on Mount Haleakala on Maui. The designation 2015 OV implies that it was the 21st asteroid (asteroid V) discovered in the second half of July  2015 (period 2015 O).

2015 OV has a 435 day orbital period and an eccentric orbit tilted at an angle of 7.65° to the plane of the Solar System, which takes it from 0.94 AU from the Sun (i.e. 94% of the average distance at which the Earth orbits the Sun) to 1.31 AU from the Sun (i.e. 131% of the average distance at which the Earth orbits the Sun). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that close encounters between the asteroid and Earth are extremely common, with the last having occurred in January 2010 and the next predicted in February 2016.

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Preservation of haemoglobin-derived chemicals in a fossil Mosquito from the Eocene of Montana.

The 1993 film Jurassic Park speculated that Dinosaur DNA might be extracted from blood preserved inside Mosquitoes, Culcidae, trapped in amber during the Mesozoic. Needless to say this is highly improbable for a number of reasons, most notably that fossils preserved in amber, while retaining physical shape, are known to be chemically altered during the preservation process. A less obvious flaw in this story is that Mosquitoes do not typically favour woodland environments, and are therefore rather rare as fossils preserved in amber, though a number of Biting Midges, Ceratopogonidae, are known from amber, and some of these have been found in association with preserved Trypanosome parasites, which are spread by blood-sucking Insects, implying that these fossil Midges were blood-feeders.

In a paper published in the Proceedings of the National Accademy of Sciences of the United States of America on 12 November 2013, Dale Greenwalt of the Department of Paleobiology at the National Museum of Natural History, Yulia Goreva of the Department of Mineral Sciences at the National Museum of Natural History, Sandra Siljeström, also of the Department of Mineral Sciences at the National Museum of Natural History, as well as the Geophysical Laboratory at the Carnegie Institution and the Department of Chemistry, Materials, and Surfaces at the SP Technical Research Institute of Sweden, Tim Rose, again of the Department of Mineral Sciences at the National Museum of Natural History and Ralph Harbach of the Department of Life Sciences at the Natural History Museum in London describe the presence of haemoglobin-derived chemicals in a fossil Mosquito from the Middle Eocene Kishenehn Formation of Montana.

The Kishenehn Formation comprises finely bedded shales laid down in anoxic conditions at the bottom of a lake about 46 million years ago. These shales have produced a number of very well preserved Mosquitoes, which have been assigned to two species, Culiseta kishenehn and Culiseta lemniscata, both interpreted to be small Bird-feeding species. One of these appears to be a blood-engorged female (only female Mosquitoes suck blood, and then only before producing eggs), which Greenwalt et al. chose for testing for haemoglobin derived products. This specimen was well enough preserved to assign it to the genus Culiseta but not to a specific species, though the abdomen region was well preservesd.

Culiseta species (Diptera: Culicidae), a blood-engorged female from the Middle Eocene Kishenehn Formation of northwestern Montana. Note the distended and opaque dark-coloured abdomen. Scale Bar is 2 mm. Greenwalt et al. (2015).

The most obvious indicator of haemoglobin is iron; however iron is a very common element in fossil preservation, particularly is fossils such as those from the Kishenehn Formation which were preserved in anoxic waters, where sulphur-iron Bacteria typically play a role in preservation. In order to establish whether the engorged female Mosquito contained more iron than would be expected, Greenwalt et al. also tested a male Mosquito from the same formation (male Mosquitoes do not suck blood). Samples of material from the abdomens of both specimens were tested for iron with mass spectrometry, revealing that the female did indeed contain raised levels of iron, suggesting the presence of haemoglobin derived chemicals.

Culiseta species (Diptera: Culicidae), a male from the Middle Eocene Kishenehn Formation of northwestern Montana. The white dots indicate the areas of that were analysed. Scale Bar is 2 mm. Greenwalt et al. (2015).

Next Greenwalt et al. tested the specimens for porphyrins, a group of proteins from which haemoglobin molecules are constructed, and which it breaks back down to as it decays. These could be used to definitively indicate the presence of vertebrate blood in the Mosquito at the time of death. Porphyrins are not exclusively produced by vertebrates; chlorophyll is composed of porphyrins as are the haemocyanin molecules used to transport oxygen in some invertebrates (but not Mosquitoes), and many microorganisms also use porphyrins. However no known organism produces porphyrins in any appreciable quantities in an anoxic environment, so any porphyrins found in the specimens are likely to have got there before the Mosquitoes died.

Using time-of-flight secondary ion mass spectrometry Greenwalt et al. were able to detect haemoglobin-derived porphyrin molecules in the female Mosquito, but not the male, suggesting that this specimen was indeed gorged with vertebrate blood at the time of death. This is the first detection of blood derived chemicals in a blood-feeding Insect known in the fossil record.

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Non-biting Midges (Chironomidae) are small Flies closely related to the Biting Midges, Solitary Midges and Blackflies. They closely resemble Mosquitoes, but despite their appearance and relationships, they are quite harmless, lacking biting mouthparts. It was...

Mosquitoes are small Flies notorious for their habit of sucking blood. Only the females do this, the males...

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Saturday 29 August 2015

Nisada stipitata: A new species of Cyanobacteria from the coast of Oaxaca State, Mexico.

Cyanobacteria are filament-forming photosynthetic Bacteria which often form dense mats by extruding polysaccharide films, which bind the individual filamentous colonies together as well as attaching them to surfaces. These mats are among the first biological traces found in the geological record, with stromatolites (deposits in which thin layers of microbial mat alternate with other sedimentary deposits such as limestone or sands) being found in some of oldest sedimentary formations on Earth. Modern Cyanobacteria are found in all modern ecosystems where there is light, including desert sands and the surfaces of glaciers, but their full diversity is poorly understood, though the group is no longer thought to be monophyletic (it is no longer thought that all members of the group are descended from a single common ancestor) and there are likely to be many undiscovered species living in poorly explored environments.

In a paper published in the journal Phytotaxa on 24 July 2015, Michelle Gold-Morgan, Laura González-Resendiz, Hilda León-Tejera and Gustavo Montejano of the Departamento de Biología Comparada at the Universidad Nacional Autónoma de México describe a new species of Cyanobacteria from rocky shores on the coast of Oaxaca State, Mexico.

The new species is named Nisada stipitata, where ‘Nisada’ means ‘marine’ in the indigenous Zapotec language spoken in parts of Oaxaca State and ‘stipitata’ meand ‘stipulate’ (having dots) in Latin. The species is described from colonies found living on granitic rocks on the coast of Oaxaca near San Agustín in Huatulco, where the Sierra Madre del Sur mountains meat the sea in a series of rocky bays and cliffs. Nisada stipitata forms colonies up to 5 mm thick, with each colony consisting of a biofilm to which numerous coccoid (spherical) cells are attached by short stipes (stems).

Morphology of Nisada stipitata. (A) Macroscopic view of partially covered rock (black portion). (B) Macroscopic view of strip of biofilm on rock. (C) Pseudofilament apices in fluorescent microscopy. (D) Edge of biofilm with pseudofilaments in a row. (E) Apices of morph 2 before cell division (single arrow) and after division but before separation (double arrow). Gold-Morgan et al. (2015).

The coccoid cells show distinct polarity, which is to say that they have distinct ends, despite being spherical. The stipes of the cells form distinct rows in on the biofilm, with each stipe supporting one-to-three cells; this is connected to the way in which the cells divide, either in or at 90˚ to the plane of the stipe-row, with each parent cell apparently splitting into two daughter cells, one of which then itself splits in two, resulting in three cells on the stipe. Further divisions after this are not seen, and numerous stipes were found without cells, suggesting a distributive phase (cells leaving the stipe and either settling in the biofilm or forming new colonies).

Line drawings of Nisada stipitata. (A) Edge of biofilm with pseudofilaments in a row. (B) Complete pseudofilament of morph 1. (C) Complete pseudofilament of morph 2. Ps, pseudofilament sheath; dc, daughter cell; c, cup; mc, mother cell; st, stipe; p, pad; cs, colonial sheath. Scale bars: (A) 8 μm, (B, C) 6 μm. Gold-Morgan et al. (2015).

Insufficient material of Nisada stipitata was recovered to allow a DNA comparison to other Cyanobacteria (which is generally considered the best way to compare and classify any Bacterium), and it did not prove possible to cultivate the species in the lab. However reproductive strategies and in particular splitting plains are considered significant in the classification of these organisms, and the pattern of splitting seen in Nisada stipitata is sufficiently unique that Gold-Morgan et al. are confident in their diagnosis of the colonies as a new species.

(Top) Line drawing of life cycle of morph 1. (Bottom) Line drawing of life cycle of morph 2. . Gold-Morgan et al. (2015).

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