Showing posts with label Vietnam. Show all posts
Showing posts with label Vietnam. Show all posts

Sunday, 8 September 2024

Passage of Typhoon Yagi kills at least 39 people across the Philippines, South China, and Vietnam.

Typhoon Yagi is now known to have killed at least 39 people as it swept across the  Philippines, South China, and Vietnam between 2 and 7 September 2024. The storm was initially detected as a low pressure system to the northwest of Palau by the Japan Meteorological Agency on 30 August 2024. By 1 September it has moved to the northeast, gaining in strength to become a tropical depression as it entered the Philippine Area of Responsibility (an area of the northwest Pacific monitored by the Philippine Atmospheric, Geophysical and Astronomical Services Administration. The system was identified as Tropical Depression 12W by the Joint Typhoon Warning Center, and named Enteng by red by the Philippine Atmospheric, Geophysical and Astronomical Services Administration, then as it intensified to become a tropical storm, formally named Tropical Storm Yagi by the Japan Meteorological Agency.

Typhoon Yagi made landfall in Aurora Province on Luzon Island, the Philippines, at about 2.00 pm local time on Monday 2 September, taking fifteen hours to move across the island before emerging over the South China Sea at about 3.00 am on Tuesday 3 September. During this time the storm lost considerable energy, particularly as it passed over the Cordillera Central mountain range, but still causing significant disruption. The storm raised the waters of the Marikana River, which flows through eastern Manila, to rise by 16 m, leading to flooding in the Metro Manila area, as well as in the provinces of Bulacan, Camarines Norte, Camarines Sur, Cavite, Laguna, Northern Samar, Pangasinan, and Rizal. A number of ships were driven aground in Manila Bay, with two colliding and catching fire. Twenty people are currently known to have died as a result of the storm on Luzon, nine of them in Rizal Province, with at least more 26 missing and at least eighteen injured. Around 28 000 people in Metro Manila, Calabarzon, and Bulacan, lost their electricity supplies during the storm, schools were closed for two days, and most flights to and from Luzon Island cancelled. About 80 000 people were evacuated from low-lying areas, with 459 homes destroyed and another 6128 damaged. Several dams had to be opened to prevent them being damaged by high waters, adding to the flooding in areas beneath them.

Flooding in Rizal Province, the Philippines, on 2 September 2024. AP

After passing over Luzon Tropical Storm passed across the South China Sea, merging with a smaller depression and gaining significantly in strength as it moved west towards China. By 5 September the storm had gained suficient energy that the Japan Meteorological Agency upgraded it to a Super Typhoon, which is to say a typhoon with windspeeds of 240 km per hour or above, the equivalent to a Category 4 or 5 storm on the Saffir–Simpson scale.

In preparation for this 420 000 people were evacuated from low-lying areas on Hainan Island, and 500 000 from low-lying areas in Guangdong Province, with widespread cancelation of flights, non-essential travel, and coastal activities in both provinces as well as Hong Kong.

Typhoon Yagi made landfall near the city of Wenchang on Hainan at about 4.20 pm local time on Friday 6 September, bringing with it sustained windspeeds of 195 km per hour, making it the strongest storm to hit the island since Typhoon Ramassun in 2014. It passed across the island making, and over the provincial capital, Haikou, before briefly making landfall in Xuwen County, Guangdong Province, then passing out over the Gulf of Tonkin. Four people are reported to have lost their lives on Hainan Island, with another 95 injured, and 1.2 million people losing electricity supplies. Aa further nine people were injured in Hong Kong.

Heavy rainfall and fallen trees in Wenchang City on 6 September 2024. Luo Yunfei/China News Service/VCG/Getty Images.

Typhoon Yaagi gained in strength again as it passed over the Gulf of Tonkin, reaching Vietnam as a Category 4 Typhoon (i.e. a storm with sustained winds in excess of 209 km per hour), making it one of the strongest storms ever to hit northern Vietnam. In preparation for the storm schools were closed and fishing and outdoor gatherings advised against, as well as most flights, ferry services, and sporting events cancelled. The storm made landfall over the city of Haiphong, binging high winds and extensive flooding to the Red River Valley. fifteen people are known to have died in Vietnam, including four people hit by flying debris, another four, described as a family, by a landslide in Hoa Binh, and another man in Hai Dong hit by a falling tree.

High winds caused by Typhoon Yagi on the shore of Phuong Luu Lake in Haiphong. Nhac Nguyen/AFP.

Tropical storms are caused by the warming effect of the Sun over tropical seas. As the air warms it expands, causing a drop in air pressure, and rises, causing air from outside the area to rush in to replace it. If this happens over a sufficiently wide area, then the inrushing winds will be affected by centrifugal forces caused by the Earth's rotation (the Coriolis effect). This means that winds will be deflected clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere, eventually creating a large, rotating Tropical Storm. They have different names in different parts of the world, with those in the northwest Pacific being referred to as typhoons.

The structure of a tropical cyclone. Wikimedia Commons.

Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms. 

The formation and impact of a storm surge. eSchoolToday.

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Thursday, 30 November 2023

Đầu Rằm: A Neolithic jewellery-making workshop in northern Vietnam.

The Neolithic culture of the Red River Delta has been studied since the 1960s, when a series of excavations at Tràng Kênh in n Haiphong Province on the northern edge of the delta uncovered a large amount of distinctive pottery, stone tools, and animal bones, as well as many nephrite body ornaments that include bangles with various cross-sections (including T-shaped sections), small rings, penannular earrings with four circumferential protuberances, and tubular beads, and evidence of the industry responsible for these items. The nephrite was apparently shaped, worked and polished using stone knives, stone drill points, grinders, and polishers, to form a range of jewellery which was traded from the Chinese border to central Vietnam. 

In the 1970s a cluster of archaeological sites was discovered at Đầu Rằm on Tân Island in Quảng Ninh Province, about 16 km to the southeast of Tràng Kênh. Subsequent excavations at these sites revealed two periods of occupation, one by the Bronze Age Đông Sơn people, between about 300 BC and 100 AD, and one by a Neolithic community apparently from the same culture as that at Tràng Kênh, with similar production of nephrite jewellery.

In a paper published in the journal Archaeological Research in Asia on 16 November 2023, Isabella Shaw of the School of Archaeology and Anthropology at the Australian National University, Nguyễn Thị Thúy of the Vietnam Institute of Archaeology, Bùi Xuân Tùng of the Department of Archaeology at the VNU University of Social Sciences and Humanities, Elle Grono, also of the School of Archaeology and Anthropology at the Australian National University, Rachel Wood, again of the School of Archaeology and Anthropology, and of the Research School of Earth Sciences at the Australian National University, Cristina Castillo Cobo of the Institute of Archaeology at University College London, Peter Bellwood and Philip Piper, once again of the School of Archaeology and Anthropology at the Australian National University, and Lâm Thị Mỹ Dung, also of the Department of Archaeology at the VNU University of Social Sciences and Humanities, describe the results of a new series of excavations carried out at Đầu Rằm in 2018, and the conclusions drawn about the methods of the Neolithic nephrite jewellery-makers of the  Red River Delta.

Đầu Rằm is located on the on the southwest side of Tân Island, at the western edge of Ha Long Bay. The island is cut off from the mainland by the Hàm Rồng and Giang rivers. The site comprises two outcrops of kart limestone, Núi Đầu Rằm Lớn to the southeast and Núi Đầu Rằm Nhỏ to the northwest, and an area of sand between the two. It is likely that significant archaeological material was lost from the area during quarrying, which removed most of the karst from both outcrops before the significance of the site was realised. Previous excavations of the site revealed an occupation by the Đông Sơn people, between about 300 BC and 100 AD, overlying an older, Neolithic occupation with evidence for the manufacturing of nephrite jewellery. Shaw et al. excavated two new trenches on the sandy area, one close to the southern face of the Núi Đầu Rằm Nhỏ karst outcrop, and the second on the eastern end of the previous excavations.

Locations of the archaeological excavation trenches at Đầu Rằm (Black lines are unpaved tracks). Shaw et al. (2023).

The excavations yielded only Neolithic material, with no sign of the Đông Sơn culture. The soil here was sandy, with a surface layer of dark brown through ash-grey loamy material. A high concentration of shells was found in the sediment, reaching about 1.5 m deep at the karst outcrop, and extending about 10 m southwards. No signs of post holes or pits were found, suggesting that no construction had occurred here, and the distribution of the shells suggests that they may have been discarded from the top of the limestone outcrop. Cultural items were found within this shelly layer, and had probably been discarded in the same way.

The discarded material includes a large number of shells, as well as Animal bones, charred Plant remains, fragments of pottery, stone implements and debitage (left over fragments) from the making of nephrite rings. Two types of pottery were found. The most common type, comprising 98.2% of the assemblage, or 20 152 individual pieces, has a crushed shell temper, and a rim type known as 'miệng mai' (meaning 'house roof') which is only known from the northern Red River Delta, having been found at Đầu Rằm, Tràng Kênh, and Bồ Chuyến, all of which suggests it was made locally. The second type of pottery is a finely manufactured, sand tempered ceramic, otherwise known from the Phùng Nguyên settlements of the upper Red River, in Vĩnh Phúc and Phú Thọ provinces. Twenty two carbon dates were obtained from material from the midden, which indicated that use of the site began between 1782 and 1645 BC, and ended between 1576 and 1441 BC, giving a period of use of between 94 and 293 years.

The most distinctive feature of the Đầu Rằm locality is, however, the nephrite jewellery which appears to have been manufactured there. The most common forms are rings and bangles, although some cylindrical beads have also been recovered from the site.

Based upon the debitage and tool fragments recovered from Đầu Rằm in 2018, Shaw et al. propose a chaîne opératoire (chain of operations) for the production of nephrite rings and bangles. 

The material used in the manufacture is a s tremolitic nephrite, which is usually white or a pale orange colour, sometimes with grey mottling or veins. Where this nephrite came from is not precisely known, but nephrite pebbles can be collected from rivers and streams in Sơn La and Phú Thọ provinces, and nephrite inclusions are also known within the limestones of Thủy Nguyên, Hoành Bồ, and Đông Triều districts of Quảng Ninh province), and elsewhere in the mountains of northern Vietnam. The only evidence for the source material used at Đầu Rằm is a water-worn white nephrite cobble which shows signs of having been worked.

Once obtained the nephrite was cut into blanks (slices which could be further worked) using rasp-like saws made from sedimentary rock, which would have been drawn back and forth across the softer nephrite, probably with the addition of water and sand. These saws were small tools, designed to fit in the palm of the hand. Many had curved backs, which would have enabled them to be controlled by the index finger. Once the rock was cut into squared slices in this way it could then be ground to the desired thickness using a piece of rough sandstone. The corners of the squared slices could then be removed by sawing into the blanks from both sides, then snapping them off, to give a more rounded piece.

Once a near-round shape was achieved, the blank was further shaped by smoothing the edges with a piece of sandstone to achieve a circular disk. Examples of such disks have been found at Đầu Rằm with multiple grinding grooves, indicating that they were used to shape rings of different widths. This shaping of the outer surface of the ring was always completed before the inner core was drilled out, presumably because the rings were less delicate at this stage.

The inner part of the ring is theorised to have been drilled out by mounting the circular blank on a turntable which could be rotated with a wooden bow mechanism, then grinding the moving ring with a stone drill bit attached to a horizontal fixed arm. This would have enabled a circular grove to have been cut into the blank, with adjustment of the position of the fixed arm enabling different sized circles to be cut. The blank would have been worked by carving paired grooves on each side. A wooden bow drill has been found at the Dong Du site, and debitage indicating this modus operandi at Tràng Kênh, while a number of drill bits consistent with this method have been recovered at Đầu Rằm.

Finally, once the grooves on each side of the blank were deemed sufficiently deep, the core would have been removed by striking it with a hammerstone to form a ring. This last part of the operation appears to have been quite tricky, with a risk of breaking the thin ring in the process. At least one ring apparently broken at this stage has been found at Đầu Rằm, as well as ten hammerstones, with percussion marks on multiple facets, probably indicating they were used for a variety of tasks; one of these was notably small, and could have been easily held in one hand for precision tasks such as striking out the core of a ring.

This process would have left a sharp, uneven, flange around the inside of the ring, so the next task would have been to remove this by inserting a cylindrical grinder which could be used to smooth this inner surface by manual rotation. Four such cylindrical grinders have been found at Đầu Rằm, three of which appear to have been used at both ends. 

Finally, the ring would have been polished to a smooth surface using a dense, fine-grained stone polisher (one example of which has been found at Đầu Rằm), and then probably a piece organic material such as Bamboo, wood, or leather.

The chaîne opératoire of manufacture for nephrite rings at Đầu Rằm: (a) Initial raw material cutting and sawing; (b) grinding a preform to a desired thickness; (c) cutting a preform to an appropriate size; (d) removing corners; (e) grinding to a circular shape; (f) drilling out a core (from both sides); (g) using a ‘punch’ to remove a core; (h) grinding the inside of a ring; (i) grinding the exterior; (j) polishing to produce a surface gloss. Shaw et al. (2023).

Previous excavations at Đầu Rằm produced material from two phases of occupation, with the majority of the material coming from the younger Bronze Age Đông Sơn culture. However, Shaw et al.;s 2018 excavations found no trace of this younger material. Both dating evidence and the material recovered suggest that the earlier phase of occupation at Đầu Rằm was Neolithic, and the common style of pottery and nephrite working strongly indicates that the culture here was the same as the one at the nearby Đầu Rằm, Tràng Kênh, and Bồ Chuyến sites, with archaeologists referring to this common culture as the Tràng Kênh culture, as this site was discovered first. 

Radiometric dates obtained from both Tràng Kênh and Đầu Rằm suggest that this culture was active during the early-to-middle second millennium BC, although the results were not considered accurate enough for a more detailed chronology. Occupation at the Tràng Kênh site continued into the Bronze Age, which has been dated here to the end of the second millennium BC.

The artisans at Đầu Rằm used a standardised tool kit and methodology to manufacture rings, which would have required both a high degree of skill and a level of technical understanding which enabled the manufacturing and maintenance of the equipment needed for this process. This process also appears to have been used at Tràng Kênh, where evidence for a range of other manufacturing processes, not seem at Đầu Rằm has also been discovered. Items seen at Tràng Kênh but not Đầu Rằm include earrings with four protuberances, penannular earrings and T-sectioned bangles. T-sectioned bangles have also been found at sites in the upper Red River Valley associated with the Phùng Nguyên Neolithic culture, and at Mán Bạc in Ninh Bình Province, a site confidently dated to between 2000 and 1300 BC, indicating manufacture clearly pre-dating the onset of the local Bronze Age.

The difference between the wider range of manufactured items found at Tràng Kênh than Đầu Rằm poses questions about the nature of the two sites. It is possible that Tràng Kênh was simply larger than Đầu Rằm, and could therefore support a greater range of craftsmen, but it is also possible that some of the skills used at Tràng Kênh were effectively trade secrets which the people of Đầu Rằm did not possess.

Examples of the various artefacts, debitage and implements used in the production of nephrite rings at Đầu Rằm; (a) nephrite raw material, the black arrow indicates where attempts have been made to shape the piece; (b) sandstone saw (working edge at bottom); c. corner offcuts with saw lines and flanges along their edges; (d). and (e) external grinders; (f) polished drill bit; (g) inner cores of various sizes, note misalignment in the coring of the two smallest specimens on the right (arrow: internal flange); (h) one working end of an internal ring grinder of sandstone; (i) hard, fine-grained sandstone grinder; (j) almost completed ring. Shaw et al. (2023).

The wide area over which jewellery apparently manufactured at Tràng Kênh and Đầu Rằm have been found implies that these settlements were embedded in an extensive trade network. It has been suggested that the raw materials from which this jewellery was made was itself imported, which if true, would suggest that the location of the settlements was chosen for access to waterways, and therefore trade networks. 

Items made from nephrite have been found at more than 70 Neolithic Phùng Nguyên culture sites on the plains around the lower Red River. Some of these sites, such as Hồng Đa, show evidence of local manufacture of this jewellery, presumably from imported materials, but it is quite likely that many were importing finished jewellery from Tràng Kênh and Đầu Rằm. Pottery thought to have been manufactured in the lower Red River Valley has been found at both Tràng Kênh and Đầu Rằm, implying that this was another item traded between communities.

The Neolithic trade networks in nephrite jewellery and other goods were, nevertheless, quite restricted compared to the Iron Age trade networks which emerged in the region with goods being traded from Thailand and Cambodia to Taiwan and the Philippines. The Neolithic trade network appears to have extended at least as far south as Cồn Nền, a Bàu Tró culture site on the coast of Quảng Bình Province. This is consistent with other evidence, which suggests that by about 4000 years ago, two distinct and separate trade networks had emerged in northern and southern Vietnam.

Elsewhere, there appears to have been trade between Taiwan and southeast China during the Neolithic, where workshops appear to have made similar cylindrical beads, rings and penannular earrings at Fengtian in eastern Taiwan, around the Zhujiang Delta, and at Yunglong in Hong Kong. Some of the techniques used at these Chinese workshops resemble those used at Tràng Kênh and Đầu Rằm, possibly implying a both groups shared a common ancestry, possibly from the lower Yangtze region of central China, where Neolithic workshops are known from around 4000 BC onwards.

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Wednesday, 2 August 2023

At least five dead amid flooding and landslides in Vietnam.

At least five people have died and several more are missing in a series of flooding and landslide events in south and central Vietnam, after several days of continuous heavy rain associated with the southwest (summer) monsoon, which has affected Lam Dong, Bình Thuận, Bà Rịa–Vũng Tàu, Bạc Liêu, Cà Mau, An Giang, Hậu Giang, and Kiên Giang provinces. On Saturday 29 July 2023, a 47-year-old woman was swept away by flood waters in Bình Thuận Province, and was later found dead. On the same day a fishing boat off the same province's coast capsized in high winds, with one of the four crew, a 41-year-old man, missing since the event. A house collapsed amid high winds and heavy rain in Bạc Liêu Province, killing 36-year-old Dang Kim Men, and injuring her 37-year-old husband, Dang Van Dung and their eight-year-old son. A total of 59 nine houses are reported to have been destroyed in the province, and a further 52 to have lost their rooves. Three traffic police officers have been confirmed dead after a landslide hit the station at which they were based at in the Bảo Lộc Pass in Lam Dong Province, at about 2.30 pm local time on Sunday 30 July; a member of the public is still missing following the incident.

Rescue teams searching the site of a landslide in which three people are now known to have died and one is still missing in Lam Dong Province, Vietnam, on Sunday 30 July 2023. Vietnam Global.

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.

Much of Southeast Asia has two distinct Monsoon Seasons, with a Northeast Monsoon driven by winds from the South China Sea that lasts from November to February and a Southwest Monsoon driven by winds from the southern Indian Ocean from March to October. 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.

This years rains have been unusually heavy across Southeast Asia, despite there being an El Niño system over the South Pacific, which would usually bring drier conditions. This is probably linked to the rising global temperature, with the record for the Earth's highest average temperature over a 24 hour period being broken three times in July, which has led to higher rates of evaporation from all oceans, leading to unusually high rainfall in many parts of the world.

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Saturday, 24 December 2022

Quercus mangdenensis: A new species of Oak from Vietnam.

Oaks, Quercus spp., are a large and diverse group of deciduous and evergreen trees, found throughout the temperate woodlands of the Northern Hemisphere, and extending south into subtropical and even tropical areas in some areas. In Southeast Asia they form a significant component of tropical montane forests, with 52 species known from Vietnam alone, seven of which were described as new species within the past five years, suggesting that the diversity of the group in this area is still not fully understood.

In a paper published in the journal Phytokeys on 15 December 2022, Nguyen Van Ngoc and Hoang Thi Binh of the Faculty of Biology at Dalat University, describe a new species of Oak from Kon Tum Province, Vietnam.

The new Oak was discovered while carrying out fieldwork around the town of Mang Den in Kon Plong District, at the northern end of the Central Highlands of Vietnam. The area has a cool tropical climate, with average temperatures varying between about 18.7 and 24.9°C over the course of the year, and a rainy season which lasts from August to February.

Type locality of Quercus mangdenensis. (A) Map of Vietnam. (B) Map of Kon Tum Province. (C) map of Kon Plong District, the red star indicated the type locality: Mang Den Town, Dak Long Commune. Ngoc & Binh (2022).

The new species is named Quercus mangdenensis, where 'mangdenensis' means 'from Mang Den'. It is an evergreen tree reaching 20-25 m high, with a trunk diameter of 60-80 cm. Leaves are lance-shaped with entire margins, and darker above than below. Bark is pale grey, except on the newest twigs, where it is green. Acorns are large, reaching 6-10.5 cm high and 4-5 cm wide. 

Quercus mangdenensis. (A) Twigs with young fruit. (B) Terminal buds. (C) Infructescences. (D) Fallen mature fruit. (E), (F) Adaxial and abaxial surface of the leaves. (G) Nuts. (H) Outside of cupule. (I) Densely reddish hairs inside of cupules. (J) Basal scar of the nut. (K), (L) Inside and outside of bud scale. Ngoc & Binh (2022).

Ngoc and Binh were able to find five subpopulations of Quercus mangdenensis, all growing at between 1050 and 1200 m above sealevel in fragmented evergreen forest. The area is under pressure from logging, farming and other Human activities, with the majority of the trees belonging to the new species on the border between forest clumps and farmland. For this reason Ngoc and Binh recommend that Quercus mangdenensis be classified as Critically Endangered under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species.

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Thursday, 13 January 2022

Angustopila coprologos & Angustopila psammion: Two new species of cave-dwelling Snails from Laos and Vietnam, and the smallest terrestrial Snails described to date.

Miniaturisation presents both new opportunities and novel challenges to Animal species, in so far as a small size often enables species to access resources and ecological niches unavailable to similar but larger species. The smallest parasitic Wasps specialise in targeting the eggs of other small Insect species, and can have adult sizes as small as 0.3 mm, enabling them to utilise a food source unavailable to larger species. Tiny Mites and Feather-wing Beetles are able to live in soil where the only food particles are to small to sustain larger species, and hide in cracks and crevices also beyond the reach of bigger Arthropods. The size of the space between soil particles probably also controls the lowest possible size for Snails living in these environments; with the accessibility of a space given by the ability of the Snail to pull its shell through gaps, since this is the only rigid part of its body. The past few years have seen the description of several new Snail species, each of which has replaced the one before as the smallest known terrestrial Snail.

In a paper published in the journal Contributions to Zoology on 5 January 2022, Barna Páll-Gergely of the Plant Protection Institute at the Centre for Agricultural Research, Adrienne Jochum of the Naturhistorisches Museum der Burgergemeinde Bern, the Institute of Ecology and Evolution at the University of Bern, and the Senckenberg Forschungsinstitut und Naturmuseum, Jaap Vermeulen and Katja Anker of JK Art and Science, András Hunyadi of Budapest, Aydin Örstan of the Section of Mollusks at the Carnegie Museum of Natural History, and Ábel Szabó of the Lithosphere Fluid Research Laboratory at Eötvös University, describe two new species of Land Snail from Laos and Vietnam, both of which are smaller than any previously described species, making the smaller of the two the new official smallest known species.

Both new species belong to the genus Angustopila, a genus which also contains two other species that have held the title of 'Smallest Land Snail' since 2015.

The first of these new species is named Angustopila coprologos, meaning 'dung-gatherer' in Greek, in reference to the mud granules, assumed by Páll-Gergely et al. to be faeces, which the species places upon its shells. This species is known only from 19 empty shells, which were found in a limestone gorge in Bolikhamsai Province, Laos, following a season of heavy rain, and are thought to have been washed down from crevices in the limestone cliffs above.

 
Angustopila coprologos (holotype). Páll-Gergely et al. (2022).

Angustopila coprologos has a strongly depressed-globular shell with a wide umbilicus, and strong spiral sculpture consisting of a series of coarse elevations (flat-topped beads) in a chain-like pattern and four well-developed teeth around the aperture to its shell. The specimens found were 0.66–0.76 mm high and 0.49–0.58 wide.

The habit of placing granules of mud or other debris on their shells is quite common in terrestrial Snails, with many distantly related species doing this. It is generally thought that the Snails do this for camouflage purposes, enabling them to blend in better with their environment. However, Angustopila coprologos is thought to live in crevices in limestone cliffs, possibly around the root systems of cliff-dwelling Plants, where it is difficult to see how such camouflage would be useful. The grains on the shell of Angustopila coprologos tend to accumulate in the umbilicus of the shell, suggesting that they are placed spirally and are overgrown as the shell grows, Páll-Gergely et al. suggest that these particles might be the faeces of the Snail, essentially mud that has been passes through the gut of the Snail to extract micro-organisms and other food, then bound together with mucus to make a pellet which is attached to the shell, and that this might be a means of signalling to other members of the species in some way, or possibly help the Snails conserve water in what can be a dry environment.

 
Granules on the shell surface of Angustopila coprologos shells. (A)–(B) shows a shell with brown ‘mud’, whereas (C)–(D) shows a shell with white (calcareous) granules. Páll-Gergely et al. (2022).

The second new species described is named Angustopila psammion, where 'psammion' means a grain of sand in Greek. The species is described from 416 empty shells collected in small sediment deposits along the walls of a dry cave (Cap La Cave in Quang Ninh Province, Vietnam), in complete darkness. Páll-Gergely et al. assume that the sediment had fallen in through crevices in the rock, because it contains a species-rich assemblage of bleached, opaque shells of surface-dwelling terrestrial Gastropods, although the shells of Angustopila psammion appear fresh and are probably local to the environment where they were found rather than washed in from elsewhere.

 
Angustopila psammion. (A) Paratype, (B)–(I) holotype. Páll-Gergely et al. (2022).

The shells of Angustopila psammion are depressed-globular shell with dome-shaped spires, thick spiral striae, and kidney-shaped apertures with a single parietal denticle not reaching the parietal callus. The shells range from 0.6 to 0.68 mm in height and from 0.46 to 0.57 mm in width, making it the smallest yet reported species of terrestrial Gastropod.

In 2015 a team led by Barna Páll-Gergely reported the discovery of Angustopila dominikae from southern China, which had a maximum shell height of 0.86 mm, making it the smallest known terrestrial Gastropod at that time. However, only two months later another team, led by Jaap Vermeulen, reported an even smaller Snail, Acmella nana, from Sabah Province on Malaysian Borneo, with a shell height of 0.60–0.79 mm, and a  shell width of 0.50–0.60 mm. In 2016, Mohammad Effendi Marzuki and Jun Kitt foom described an even smaller species, Arinia micro, from Perak State in Peninsular Malaysia, with a shell height of 0.80–0.90 mm, and a shell width og 0.34–0.35 mm. Most recently, a team led by Pongrat Dumrongojwattama reported the discovery of Angustopila pallgergelyi, with a shell width of 0.76–0.85 mm and a shell height of 0.59–0.71 mm, from eastern Thailand.

 
Size comparisons of the former record holders, Angustopila pallgergelyi,, Acmella nana, Notharinia micro, the smallest marine snail, Ammonicera minortalis, and the two new species described by Páll-Gergely et al. Páll-Gergely et al. (2022).

Páll-Gergely et al. note, however, that while Angustopila psammion is the smallest Snail in terms of height, Arinia micro is considerably narrower, and could potentially fit through smaller gaps. This suggests that height might not, alone, be a suitable measure of the smallest species, and a slightly more analytical method might be needed. To do this they found the smallest clearly adult specimen of each species (the aperture teeth do not develop in these Snails until the Animal is fully grown), and took the average of the height and width of these specimens as a measure of smallness. This produced a result of 54.5 mm for Angustopila psammion, making it the smallest species, and 59.5 for Acmella nana, the second smallest species.

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Sunday, 2 January 2022

Lomariopsis longini & Lomariopsis moorei: Two new species of Lomariopsid Ferns from Vietnam, China, and Taiwan.

The genus Lomariopsis currently contains about 60 species from the Neotropics, Africa, the islands of the Indian Ocean, Asia, and the Oceanian region. However, this is probably an underestimation of the true diversity of the genus, and it is thought to be understudied, and recent reviews have left out regions where it is likely to be more specious, notably Asia and Oceania. This is made more complicated by the ability of some species to produce gametophyte-only populations, which can establish as long-lived, asexual colonies (unlike Seed Plants, Ferns have a two stage life-cycle, with the familiar Plant being the diploid sporophyte; this produces spores that grow into a haploid gametophyte, which are either male, producing sperm, or female, producing eggs, with the fertilised female egg growing into a new sporophyte), which can sustain themselves through vegetative reproduction, meaning that quite different-looking Plants can be different stages of the same species.

In a paper published in the journal Phytokeys on 20 December 2021, Yi-Hsuan Wu of the Institute of Molecular & Cellular Biology at the National Tsing Hua University, Chih-Yun Sun of the Department of Life Science at the National Tsing Hua University, Atsushi Ebihara of the Department of Botany at the National Museum of Nature and Science, Ngan Thi Lu of the Department of Biology at the Vietnam National Museum of Nature, and the Graduate University of Science and Technology of the Vietnam Academy of Science and Technology, Germinal Rouhan of the Institut de Systématique, Evolution, Biodiversité at the Muséum national d’Histoire naturelle, the  Centre national de la recherche scientifique, the Sorbonne Université, the École pratique des hautes études, and the Université des Antilles, and Li-Yaung Kuo, also of the Institute of Molecular & Cellular Biology and Department of Life Science at the National Tsing Hua University, describe two new species of Lomariopsis with distributions in Vietnam, south China, and Taiwan.

The first new species is named Lomariopsis longini, where 'longini' aludes to the Lance of Longinus, which was reputedly used to pierce the side of Jesus during his crucifixion, in reference to the shape of the terminal pinnae of sterile leaves. This Fern grows from a scaley red underground rhizome, producing both sterile and fertile fronds about 60 cm long, though the fertile (spore-bearing) fronds have notably more contracted pinnae (leaflets) than the sterile ones. This species was found growing in the understory of evergreen broad leaf forests, at altitudes below 1000 m, in Nghe An, Quang Binh, Quang Tri, and Vinh Phuc provinces in northern Vietnam, and Yunnan Province in southwest China. 

 
Illustration of Lomariopsis longini based on the holotype. Wu et al. (2021).

The second new species is named Lomariopsis moorei, where 'moorei' honours Shann-Jye Moore, a noted Taiwanese expert on Ferns, after whom the Mr. Shann-Jye Moore Memorial Scholarship of the Taiwan Society of Plant Systematics is named. This species also grows from a scaley red subterranean rhizome, reaching about 50 cm high. It can be distinguished by a swollen ring at the region of articulation on the abaxial side of the pinnae (especially the upper pinnae). This species was found growing in the understory of evergreen broad leaf forests, at altitudes below 1000 m, in Taiwan and Hainan Province, China.

 
Illustration of Lomariopsis moorei, based on the holotype. A fallen fertile pinna is at the left bottom. Wu et al. (2021).

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