Thursday, 27 November 2014

Fossil Coryphoid Palm leaves from the Deccan Intertrappean beds of Madhya Pradesh, India.


Palms are an important component of modern tropical ecosystems, with the majority of species (~90%) restricted to tropical rainforests, where they are important understory plants. Palms reach their maximum diversity today in Asia (over 1200 species) and the Americas (about 730 species), but are much less diverse in Africa (about 65 species, less than Madagascar), with only one species native to Europe, though it is thought that they were more diverse in these areas prior to the cooling and aridification of the Plio-Pleistocene. Palms are poorly adapted to cooler or drier climates, as they have large evergreen leaves and are incapable of going through dormant periods like many plants, so that they tend to require high levels of sunlight and water all year round and are unable to cope with frost or snow. However one group within the Palms, the Coryphoideae, is more tolerant of cooler and drier conditions than others, with many species found in arid or warm temperate climates.

In a paper published in the journal PLoS One on 13 November 2014, Rashmi Srivastava and Gaurav Srivastava of the Cenozoic Palaeoflorist Laboratory at the Birbal Sahni Institute of Palaeobotany and David Dilcher of the Department of Geology at Indiana University describe a new species of fossil Coryphoid Palm leaves from the Deccan Intertrappean beds of Madhya Pradesh, India.

The Deccan Traps are a massive are of flood basalts covering about 500 000 km2 of modern India, and thought to have originally covered around 1 500 000 km2 of what is now India and the western Indian Ocean. These basalts were produced by extensive volcanic eruptions that began about 69 million years ago and persisted to about 61 million years ago, peaking between 67 and 65 million years ago. The timing of this volcanic activity leads to the inevitable conclusion that it must have played a role in the End Cretaceous Extinction, about 65.5 million years ago, although scientists differ in the weight they give to this and the major impact event that took place at Chixulub (check) on the Yucatan Peninsula at the end of the Cretaceous as causes of this extinction.

The Deccan Intertrappean beds are layers of sedimentary rocks between different layers of basalts within the Deccan Traps. These often represent highly fossiliferous lacustrine (lake) and fluvial (river) environments, which produce large numbers of plant fossils. Clearly these fossils present a potential wealth of knowledge for understanding extinction patterns at the end of the Cretaceous, although interpreting this has proven to be difficult, as there appears to be no direct correlation between episodes of volcanism and plant extinctions.

 Map of India showing fossil locality. (A) Map of India showing extent of Deccan traps. (B) High resolution map showing the fossil locality. Srivastava et al. (2014).

The Palm leaves described by Srivastavaet al. are place in the organ genusSabalites (in palaeobotany an organ genus is applied to a part of an extinct plant, such as a leaf or a root, in the accepted knowledge that other parts of the plant may be named separately; this is because whole, intact plant fossils are a rarity, and palaeobotanists need to be able to name the separate organs to havereference points for other work), and given the specific name dindoriensis, meaning ‘from Dindori’; they were collected from the Ghughua Fossil National Park in the Dindori District of Madhya Pradesh. These beds are thought to be from the end of the Cretaceous to the beginning of the Palaeocene (Maastrichtian–Danian).



Sabalites dindoriensis.(A) Basal portion showing thick costa. (B) Drawing of the same fossil. (C) Middle portion of the fossil leaf showing leaf segments attached to costa. Srivastava et al. (2014).

The species is described from five specimens, the largest of which is roughly 45 x 13.5 cm. None of these specimens are of whole leaves, with one specimen (the largest) showing part of the base of the leaf and the stem, two from the middle part of the leaf and two from the tip.



Sabalites dindoriensis.(A) Specimen seems to be of apical portion showing faint impressions ofrachilla like structure (white arrows). (B) Enlarged portion of the same specimen showing rachilla like structure (white arrows). (C) Specimen seems to be of middle portion. (D) Enlarged portion showing high order venation. Srivastava et al. (2014).

The first Palms are thought to have appeared in Laurasia (Eurasia and North America) about 100 million years ago, with the Coryphoids originating about 87 million years ago. India has a high number of endemic Palm species today, but was an island continent in the Late Cretaceous, and it has generally been thought that Palms first reached India in the Miocene, when it began to collide with Eurasia. The presence of Palm fossils in the Deccan Intertrappean beds clearly indicates that this was not the case, and instead Srivastava et al. suggest an alternative scenario, in which Palms dispersed from Europe into Africa and then across the (narrower) Indian Ocean to India by the end of the Cretaceous.



Palaeogeographic map at 65.5 Ma showing possible dispersal path of Coryphoideae from Europe to India via Africa (red broken line). Srivastava et al. (2014).

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http://sciencythoughts.blogspot.co.uk/2014/09/how-changes-in-plant-ecology-shed-light.html
How changes in Plant ecology shed light on the End Cretaceous Extinction Event.
One of the two main theories that seeks to explain the extinction event at the end of the Cretaceous postulates that a large bolide (extra-terrestrial object such as a comet or asteroid) smashed into the Yucatan Peninsula in Mexico close to the modern town of Chicxulub, resulting in a devastating explosion and long term climate change. Such an event would have led to a...


 Sixty-five million years ago the world was a very different place; the land was dominated by giant dinosaurs, pterosaurs filled the skies and the seas swarmed with giant marine reptiles and ammonites. Then overnight (in geological terms) everything changed. The non-avian dinosaurs disappeared, as did the pterosaurs, ammonites and all the marine reptiles except turtles and sea-snakes (crocodiles have since...



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Five dead after Magnitude 6.3 Earthquake in western Sichuan Province, China.

The China Earthquake Networks Center recorded a Magnitude 6.3 Earthquake in about 25 km to the northwest of Kanding in eastern Sichuan Province, slightly before 11.20 pm local time (slightly before 3.20 pm GMT) on Tuesday 25 November 2014. Five people are reported to have died as a result of the quake, with 54 more injured, six of whom ae described as being in critical conditions, and five more described as severly injured. The majority of the injuries are reported to have occured at a primary school in Tagong, close to the epicentre of the quake, where the event caused children to stampede. The Earthquke is also reported to have caused damage to around 25 000 homes. There have been several aftershocks since the original event.

Rescuers taking an injured man to hospital following the 25 November 2014 Sichuan Earthquake. Xinhua.

Much of western China and neighbouring areas of Central Asia and the Himalayas, are prone to Earthquakes caused by the impact of the Indian Plate into Eurasia from the south. The Indian Plate is moving northwards at a rate of 5 cm per year, causing it to impact into Eurasia, which is also moving northward, but only at a rate of 2 cm per year. When two tectonic plates collide in this way and one or both are oceanic then one will be subducted beneath the other (if one of the plates is continental then the other will be subducted), but if both plates are continental then subduction will not fully occur, but instead the plates will crumple, leading to folding and uplift (and quite a lot of Earthquakes). The collision of the Indian and Eurasian plates has lead to the formation of the Himalayan Mountains, the Tibetan Plateau, and the mountains of southwest China, Central Asia and the Hindu Kush.

The approximate location of the 25 November 2014 Sichuan Earthquake. Google Maps.

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A new species of Fanged Frog from Sarawak.


Fanged Frogs of the genus Limnonectes get their name from fang-like protrusions on the jaws of the male Frogs. They are unusual for Frogs in that the males are larger than the females (the reverse is usually the case), and apparently defend territories through physical contests with other males, with females mating with the males with the best territories. The males also often have greatly enlarged heads, sometimes forming as much as half the body, apparently also an adaptation to this lifestyle.

In a paper published in the Raffles Bulletin of Zoology on19 September 2014, Masafumi Matsui and Kanto Nishikawa of the Graduate School of Humanand Environmental Studies at Kyoto University and Koshiro Eto of the Kyoto University Museum describe a new species of Fanged Frog from Samarahan Division in the state of Sarawak in East Malaysia (Borneo).

The new species is named Limnonectes cintalubang, meaning ‘hole-lover’ in Malay, due to its being found dwelling in burrows. The species is described from nine specimens, one male, two females and seven juveniles. The male was 45 mm in length, the females 32.0 mm and 43.1 mm. The Frogs are a dark chocolate brown colour, with pale undersides and small blue-white spots. They did not appear to dig their own burrows, instead occupying what appeared to be abandoned Rat burrows – although no Rats could be found living in the area. The skin of Limnonectes cintalubang is exceptionally fragile, which Matsui et al. suggest may be a defence mechanism, the Frog losing part of its skin to an attacker to evade capture.

Limnonectes cintalubang, male. Matsui et al. (2014).

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Fanged Frogs of the genus Limnonectesare found across southern China and Japan, as well as the Philippines, Southeast Asia and much of Indonesia. They are unusual in that the males are considerably...

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 Cryptic species are species which resemble one-another physically, and which cannot generally be separated using traditional taxonomic methodology, but which are nevertheless genetically and reproductively isolated. Genetic studies of many groups of...
 
 
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A new species of freshwater Goby from Sulawesi.


Gobies are small, benthic (bottom dwelling) members of the Perch Order, found in marine and freshwater environments around the world, but most numerous and diverse in the Indo-Pacific region. There are large numbers of highly endemic (i.e. found over only a very small area) species in the ancient lakes of Indonesia and Malaysia.

In a paper published in the Raffles Bulletin of Zoology on 5 November 2014, Helen Larson of the Museum and Art Gallery of the Northern Territory and School of Marine and Tropical Biology at James Cook University, Matthias Geiger of the Sektion Ichthyologie at the Zoologisches Forschungsmuseum Alexander Koenig, Renny Kurnia Hadiaty of the Research Center for Biology of the Indonesian Institute of Sciences and Fabian Herder, also of the Sektion Ichthyologie at the Zoologisches Forschungsmuseum Alexander Koenig, describe a new species of freshwater Goby from Lake Towuti in central Sulawesi.

The new species is placed in the genus Mugilogobius and given the specific name hitam, meaning ‘black’ in Bahasa Indonesia. The species is described from eight specimens, all collected from warm shallow (less than 2 m) waters in Lake Towuti in central Sulawesi. The specimens ranged from 25.6 to 42.5 mm in length, and were black or blackish brown in colour, with some reddish areas on the head and pectoral, caudal and anal fins.

Mugilogobius hitam, captive specimen. Hans-Georg Evers in Larson et al. (2014).

Mugilogobius hitam was found to breed very readily in captivity, depositing eggs on hard substrates and guarding them; Larson et al. were not able to successfully rear any captive bred specimens to maturity, though they did find evidence that the species was being traded in the aquarium trade in Europe under the name ‘Mugilogobius amadi’, implying that either it is being bred in captivity or else collected from the wild for sale in Europe.

Map of the Malili Lakes in Sulawesi. The locality where Mugilogobius hitam was discovered is denoted by an asterisk. Larson et al. (2014).

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Gobies are small, elongate Fish related to Perches. They are a highly successful group with other 2000 species and are found across the globe. There are both marine and freshwater Gobies, as well as one group, the Mudskippers, that can survive out of water for...

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Japanese Gobies of the genus Clariger are small eel-like fish in the Goby Family (Gobiidae) noted for their...


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Wednesday, 26 November 2014

Asteroid 2014 WH6 passes the Earth.

Asteroid 2014 WH6 passed by the Earth at a distance of 11 200 000 km (29.13 times the average distance between the Earth and the Moon, or 7.5% of the average distance between the Earth and the Sun), slightly before 5.05 pm GMT on Monday 24 November 2014. There was no danger of the asteroid hitting us, though had it done so it would have presented only a minor threat. 2014 WH6 has an estimated equivalent diameter of 21-65 m (i.e. it is estimated that a spherical object with the same volume would be 21-65 m in diameter), and an object of this size would be expected to break up in the atmosphere between 22 and 4 km above the ground, with only fragmentary material reaching the Earth's surface.

The calculated orbit of 2014 WH6. JPL Small Body Database Browser.

2014 WH6 was discovered on 17 November 2014 (seven days before its closest approach to the Earth) by the University of Hawaii's PANSTARRS telescope on Mount Haleakala on Maui. The designation 2014 RT17 implies that it was the 444th asteroid (asteroid T17) discovered in the first half of September 2014 (period 2014 R).

While 2014 WH6 occasionally comes near to the Earth, it does not actually cross our orbital path. It has an elliptical 1627 day orbit, at an angle of 14° to the plane of the Solar System, that takes it from 1.04 AU from the Sun (1.04 times the average distance at which the Earth orbits the Sun), slightly outside our orbit, to 4.37 AU from the Sun, (4.37 times the distance at which the Earth orbits the Sun, and almost three times the average distance at which the planet Mars orbits the Sun). As a Near Earth Object that remains strictly outside the orbit of the Earth it is classed as an Amor Family Asteroid.

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In 1984 palaeontologists David Raup and Jack Sepkowski of the Department of Geophysical...


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A new species of Vetulicolian from the Early Cambrian of Kangaroo Island, South Australia.


Vetulicolians are an enigmatic group of Cambrian fossils known from the Chengjiang and Guanshan biotas of South China, Sirius Passet in Greenland and the Burgess Shale in western Canada. They have segmented bodies that caused them to be initially classified as Arthropods, but have never been found to have limbs, and the discovery of structures interpreted as gill slits, a mesodermal skeleton and a possible notochord have led to them being interpreted as Chordates (the group of animals that includes Vertebrates) in most modern studies, although opinions on how they might be related to other Chordates varies. 

In a paper published in the journal BMC Evolutionary Biology on 21 October 2014, Diego García-Bellido and Michael Lee of the School of Earth and Environmental Sciences and Environment Institute at the University of Adelaide and Earth Sciences Section at the South Australian Museum, Gregory Edgecombe of the Natural History Museum in London, James Jago of the Barbara Hardy Institute at the University of South Australia, James Gehling, also of the School of Earth and Environmental Sciences & Environment Institute at the University of Adelaide and Earth Sciences Section at the South Australian Museum and John Paterson of the Division of Earth Sciences at the University of New England describe a new species of Vetulicolian from the Early Cambrian Emu Bay Shale Konservat-Lagerstätte on Kangeroo Island in South Australia.

The new species is named Nesonektris aldridgei, where ‘Nesonektris’ means ‘island swimmer’ and ‘aldridgei’ honours the late Dick Aldridge, who led attempts to resolve the affinities of Vetulicolians. The species is described from over 150 specimens, the largest of which is 125 mm in length, but with incomplete specimens that suggest a maximum length of about 170 mm. The specimens have a roughly square forward section, with an oral margin connected to dorsal and ventral keels, a narrow lateral groove, and no trace of any gills. The rear part of the fossils comprises a series of seven segments apparently supported by a rod-like structure, with two lobes on the terminal segment connected by a flat notch.

The Early Cambrian Vetulicolian Nesonektris aldridgei. (A–C) Specimen with distal end of posterior body region (S4–S7) folded over itself, anterior towards left; (A) part, anterior rim exposed by preparation (arrow points to cuticle wall under the rod); (B) counterpart, with severed notochord (detail in Figure 2B); (C) camera lucida drawing, grey indicates sediment infill; (D) nearly complete specimen, only lacking one side of anterior region body; (E) nearly complete specimen; (F) nearly complete but folded specimen; showing fold on anterior region (oblique arrow) and continuous connection between anterior and posterior body regions along the dorsal margin (vertical arrow); (G) reconstruction; abbreviations: dk = dorsal keel; eb = epibionts; ism = intersegmental membrane; lg = lateral groove; nc = notochord; om = oral margin; vk = ventral keel; S1–S7 = posterior body region segment number; scale bars, 5 mm. García-Bellido et al. (2014).

The structure interpreted as a notochord in Vetulicolians, upon which the interpretation of them as Chordates is based, is problematic as this structure is disproportionately large compared to the body, and indeed would be exceptional compared to the notochords of even the largest modern Chordates. It has been suggested that this structure may instead be a gut or coelomic cavity, however a gut of this size would also be highly disproportionate to the size of the body.

The ‘notochord’ of several specimens of Nesonektris aldridgei appears to be made up of a series of offset blocks. García-Bellido et al. consider this to be similar to the situation seen in Cephalochordates (Lancets), larval Urochordates (Sea Squirts) and some larval Vertebrates, notably Lampreys, in which the notochord consists of a series of stacked disks in a thin sheath, which can decpme disarticulated as the dead animal decays, supporting the Chordate hypothesis for the affinities of Vetulicolians.

(E) Detail of displaced notochord in specimen of Nesonektris aldridgei, with small offsets at regular intervals (white arrowheads) corresponding to discs and larger displacement into blocks of discs (yellow arrowheads); (F) partially decayed Hagfish notochord, showing displacement of discs. (E) Scale bar 5 mm. García-Bellido et al. (2014). (F) Scale Bar 2 mm. Robert Sansom in García-Bellido et al. (2014).

García-Bellido et al. also consider that the body-plan of Vetulicolians is very similar to that of larval Tunicates, with a similar two-part body, comprising a front portion with a terminal mouth, and a rear tail portion supported by a notochord, and suggest that the two groups are probably closely related, a theory supported by a computer generated phytogenic analyses of Chordate groups.

Phylogenetic position of Vetulicolians within Deuterostomia. Maximum parsimony analysis strict consensus of 65 cladograms (Vetulicolians collapsed into a single terminal. Blue box encapsulates phylum Chordata; daggers and red branches represent extinct taxa known only from fossils. Parsimony-bootstrap values (above branches) and Bremer support (below) are shown for analyses including/excluding the non-Vetulicolian fossil taxa. García-Bellido et al. (2014).

García-Bellido et al. suggest that the common ancestor of Tunicates and Vetulicolians may have been a free-swimming animal with a thick cuticle and a large pharynx used for filter feeding. The Tunicates subsequently changed their lifestyle to become attached benthic animals during their adult phase, while the Vetulicolians evolved into larger, free swimming filter feeders, a niche otherwise unoccupied in the Cambrian. These animals would have been sightless and reliant on a thick cuticle for protection.

Artist’s impression of Nesonektris aldridgei in life. Katrina Kenny in García-Bellido et al. (2014).

See also…

The Vetulicolians are are group of organisms known from Cambrian deposits at a number of sites around the world. They Have segmented bodies superficially resembling those of Arthropods, but lack any visible limbs. Since palaeontologists and biologist theorize that the earliest Arthropods lacked limbs, having evolved from...



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Tuesday, 25 November 2014

The origin of the ‘King of Flowers’.


The Domestic Tree Peony, Paeonia suffruticosa, has a long history of cultivation in China, where records of the plant growing in gardens go back at least 1400 years. Domestic Tree Peonies are noted for their beauty and fragrance, and are known as the ‘King of Flowers’ in China. However the precise origin of the domestic Tree Peony is obscure, with most experts believing that it is a hybrid of two or more of the wild Tree Peony species found in China, but with no consensus as to which plants might be involved.

In a paper published in the Proceedings of the Royal Society: SeriesB, Biological Sciences on 5 November 2014, a team of scientists led by Shi-Liang Zhou of the State Key Laboratory of Systematic and Evolutionary Botany at the Institute of Botany at The Chinese Academy of Sciences describe the results of a genetic study of Paeonia suffruticosa and the nine wild Tree Peony species found in China, in order to determine the relationships of the domestic plant.

The ‘King of Flowers’, Paeonia suffruticosa, at Prague Botanic Garden. Karel Jakubec/Wikimedia Commons.

Zhou et al. found that Paeonia suffruticosais a hybrid of at least five wild species, Paeonia cathayana, Paeonia rockii, Paeonia qiui, Paeonia ostii and Paeonia jishanensis, with most of the cultivars obtained by hybridizing female Paeonia cathayana flowers with males of another species, though sometimes other plants had been used as the female, and many cultivars had been achieved by further hybridization.

Zhou et al. further note that all the wild Tree Peony species involved come from central China, the area in which the domestic plant was first cultivated, and that the majority are now rare or endangered. In particular they note that only a single specimen of Paeonia cathayana, the species that appeared to contribute the most to the origin of the domestic plant, could be found growing in the wild, in the mountains to the south of Louyang. Paeonia ostii also seemed to be reduced to a single wild specimen, this time on a cliff in central Anhui Province, and Paeonia qiui was found only in a handful of small populations in western Hubei Province. Paeonia jishanensis still has several relatively large populations, but this species is known to reproduce vegitatively (non-sexually), so it is unclear how genetically diverse these populations are (low genetic diversity populations can be extremely vulnerable to disease, and apparently large and healthy populations are sometimes wiped out suddenly). Only one species, Paeonia rockii, is still relatively widespread, being found across a large area of central and western China, but this is widespread population is largely composed of widely scattered very small populations and individuals, making this species also vulnerable.

The distribution of nine wild tree peony species. (1) Paeonia ludlowii; (2) Paeonia delavayi; (3) Paeonia decomposita; (4) Paeonia rotundiloba; circle, Paeonia rockii; diamond, Paeonia jishanensis; square, Paeonia ostii; triangle, Paeonia qiui; hexagon, Paeonia cathayana. Zhou et al. (2014).

Approximately one tenth of the dry land surface of the Earth has now been converted to agricultural purposes by Humans, and that while this has benefitted us enormously, it has come at great cost to many wild species, particularly the progenitors (wild ancestors) of most of our crops, which for the most part formerly grew in the best areas for growing their domestic relatives. This is known to present food security problems for Human populations, as domestic crops tend to be less genetically diverse and therefore more vulnerable to disease than their wild relatives, and the loss of these wild relatives reduces the available genetic diversity that might be needed to breed crops resilient to as yet unknown threats. Zhou et al. observe that in addition to this known problem with agricultural plants, the widespread cultivation of ornamental plants in parks and gardens presents an additional threat to biodiversity, that should also be a focus for botanists and conservationists.

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