Wednesday 6 November 2024

Pothos deleonii: A new species of Arum from Mindanao Island.

Arums of the genus Pothos are hemiepiphytic vines (Plants which begin life as epiphytes growing upon other plants, but which as they grow stronger become self-supporting) found in tropical and subtropical forests in South China, Southeast Asia, Austrolasia, Oceana, and Madagascar. 

In a paper published in the journal PhytoKeys on 15 October 2024, Maria Melanie Medecilo-Guiang of the Center for Biodiversity Research and Extension in Mindanao and Plant Biology Division at Central Mindanao University, and Derek Cabactulan of Cagayan de Oro City, describe a new species of Pothos from Bukidnon Province on Mindanao Island, Philippines.

The new species was first noted as possibly significant on the basis of its remarkable inflorescence, by conservationist and eye surgeon Miguel De Leon at a Robert S. Kennedy Bird Conservancy site in Bukidnon Province during an ornithological expedition in 2019. A subsequent expedition to the same site in February 2024 collected samples of the plant, from which it has been confirmed to be a new species. This is named Pothos deleonii, in honour of the initial discoverer.

Pothos deleonii. (A) Habit with flowering branch, (B) leaf apex, (C) leaf base, (D) venation pattern, (E) inflorescence, (F( detail of spadix. Medecilo-Guiang & Cabactulan (2024).

Pothos deleonii is a root climbing, fibrous liana, with slender, slightly woody, green stems from which slender leaves arise on petioles (leaf stems) at regular intervals. Roots are found along the stem when the plants are young, but become less common as the Plant matures, and tend to be absent around inflorescence-producing termini. Inflorescences are born singularly on elongated peduncles (flower stalks) which hang 16-18 cm below the stem. These inflorescences are a dark wine red, aging to purplish black, with a spadix (spike with a large number of small flowers) up to 6.9 cm long, surrounded by a spathe (petal-like structure) up to 10 cm long and 5.5 cm wide.

Pothos deleonii was found growing at only two locations, climbing on the  base and trunks of Tree Ferns of the genus Alsophila, in an area of degraded secondary, open-canopy Dipterocarp forest, at altitudes of 1150 and 1270 m above sealevel. Once the vines reach about 4-6 m in height they become independent of their host, able to stand free, either on their own base or supported by the surrounding tree canopy. 

Both known sites are within a 5 km² area in the northern foothills of Mt. Kitanglad. This area is protected, and monitored by the Robert S. Kennedy Bird Conservancy, and not considered to be under any threat. However, on the basis of the low number of specimens discovered, and the limited area within which it is found, Medecilo-Guiang and Cabactulan recommend that Pothos deleonii is 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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Friday 1 November 2024

Pheidole praehistorica: A new species of Spiny Ant from Oligo–Miocene Chiapas Amber.

The genus Pheidole is currently considered to be the most diverse genus of Ants, with 1160 living and six fossil species. Although global in distribution, the genus is at its most diverse in the Neotropics, and is presumed to have originated in this region. This is supported by the locations from which the known fossils in the genus have been recovered, with the oldest known species coming from the Eocene of Colorado, and other fossils known from the Miocene of the Dominican Republic (three species), and the Oligo-Miocene of Chiapas State, Mexico (2 species).

In a paper published in the European Journal of Taxonomy on 25 October 2024, Fernando Varela-Hernández & Franciso Riquelme of the Laboratorio de Sistemática Molecular at the Universidad Autónoma del Estado de Morelos, describe a third species of Pheidole from Chiapas Amber.

Chiapas Amber comes from the Simojovel, Totolapa, and Estrella de Belén localities in the Chiapas Highlands of southern Mexico, with the Simojovel site being the main centre of commercial amber extraction. The amber comes from a series of limestone, sandstone, siltstone, shale, and lignite beds of Late Oligocene to Early Miocene age, referred to as either the Simojovel Formation or the La Quinta Formation. The amber here is thought to have derived from a type of Leguminous tree of the genus Hymenaea; resin-producing trees belonging to this genus are also thought to have been responsible for Dominican Amber, which is of approximately the same age as Chiapas Amber, and are still found today across the Neotropics. 

The new species is named Pheidole praehistorica, where 'praehistorica' means 'prehistoric' in reference to the nature of the material from which it is described, five fossil Ants trapped within a single species of amber.

Pheidole praehistorica. (A)–(C) Holotype (CPAL.464). (A) Profile view. (B) Frontal view. (C) Closer lateral view of the head and mesosoma. (D) Paratype (CPAL.465), latero-frontal view of the head. (E) Paratype (CPAL.468), profile view. Abbreviations: acl, antennal club; an, antenna; cly, clypeus; ey, eyes; fl, foreleg; ga, gaster; ha, hairs on clypeus; hd, head; hl, hind  leg; mn,  mandible; nck, neck; p, petiole; pn, pronotum; pns, pronotal spine; pp, postpetiole; pps, propodeal spine; sc, scape. Varela-Hernández & Riquelme (2024).

Pheidole praehistorica is smaller than other species from Chiapas Amber, an average length of 2.3 mm, and has shorter pronotal spines (spines on the forward part of the thorax, immediately behind the head) and straight propodeal spines (spines on the rear part of the thorax, immediately before the abdomen. 

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Thursday 31 October 2024

Eclipse observed on Mars.

NASA's Perseverance Rover has observed an eclipse from the surface of Mars, caused by the moon Phobos passing in front of the Sun. Phobos is significantly smaller than our Moon, only 17 km in diameter compared to 3475 km, but orbits much closer to Mars than the Moon does to Earth, an average of 9376 km compared to 384 400 km, which combined with the smaller apparent size of the Sun seen from Mars, which is roughly 1½ times as far from the Sun as the Earth is, means that eclipses are still an observable phenomenon. 

Solar eclipse on Mars, caused by the moon Phobos passing in front of the Sun, recorded by the Perseverance Rover. Images are at 10 second intervals, with the whole event lasting much less time than an eclipse on Earth, due to the closer orbit of Phobos, and the correspondingly higher speed of the Martian moon, which takes only 7.6 hours to orbit the planet. NASA.

The eclipse, which occurred on 30 September 2024, was the second such eclipse observed by Perseverance this year, with the Curiosity and Opportunity rovers also having Martian eclipses. These eclipses are common because, unlike that of our Moon, the orbit of Phobos has very little tilt, effectively remaining above the planet's equator at all times.

An eclipse caused by the passage of Phobos in front of the Sun recorded by the Perseverance Rover on 8 February 2024. NASA.

Mars's second moon, Deimos, does not cause such obvious eclipses, as it is only 6.2 km in diameter, and orbits at an altitude of 23 460 km, making it almost invisible from the planet's surface.

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Wednesday 30 October 2024

Murina yushuensis: A new species of Tube-nosed Bat from a high altitude cave on the Tibetan Plateau.

Tube-nosed Bats, Murina spp., are a large group of Vespertilionid Bats found from northeastern Russia to Papua New Guinea. There are currently 40 described species in the genus about half of which have been described in the past decade, largely from genetic studies which have uncovered many cryptic species, predominantly in South and Southeast China. These Bats are insectivorous, and generally found in lowland forests, with the maximum known diversity in South China and Southeast Asia, although this may be due to a lack of sampling in more northerly parts of China.

In a paper published in the Journal of Mammalogy on 23 October 2024, Xiaoyun Wang of the Key Laboratory of Conservation and Application in Biodiversity of South China at Guangzhou University, Xuesong Han of the Shan Shui Conservation Center and the Center for Nature and Society at Peking University, Gábor Csorba of the Department of Zoology at the Hungarian Natural History Museum, Yi Wu, also of the Key Laboratory of Conservation and Application in Biodiversity of South China at Guangzhou University, Huaiqing Chen also of the Center for Nature and Society at Peking University, Xiang Zhao and  Zhengyi Dong, also of the Shan Shui Conservation Center, Wenhua Yu,again of the Key Laboratory of Conservation and Application in Biodiversity of South China at Guangzhou University, and Zhi Lu, again of the Center for Nature and Society at Peking University, describe a new species of Murina from a high altitude cave on the Tibetan Plateau in Qinghai Province in Northeast China.

On 15 March 2018, a Bat roosting in the entrance to a cave on the bank of the Batang River about 8 km from the city of Yushu and 3770 m above sealevel was disturbed, responding by making a long, high-pitched noise. At the time the significance of this was not realised, but when the significance was realised, several repeat visits were made, with the Bat being found again on 25 December 2018.

The new species is described from this single male specimen, and is named Murina yushuensis, where 'yushuensis' means 'from Yushu'. The single specimen is 30.44 mm long (small for a member of the genus). with dark skin and small round ears, lacking the notch seen in some members of the genus. The fur of the dorsal surface is about 10 mm in length, with the basal 7 mm being black in colour, and the 3 mm at the tip being a golden brown. The fur of the ventral surface is slightly shorter, which the basal black portion being about 6 mm, and the 3 mm of the tip being pale. 

Holotype specimen of Murina yushuensis, GZHU 20077. Wang et al. (2024).

The Batang River is a tributary of the Yangtze running across the Tibetan Plateau, at altitudes of between 3860 m and 3530 m above sealevel. The area where Murina yushuensis was discovered has a mean annual temperature of only 2.9°C, and an annual average precipitation of 487 mm. The vegetation is largely meadows of Feathergrass with scattered shrubs and patches of Juniper woodland. This is a distinctly unusual environment for a member of a genus usually found in lowland tropical and subtropical forests. Murina yushuensis was discovered at the highest altitude any member of the genus has ever been recorded at, with the previous record being a specimen of the Little Tube-nosed But, Murina aurata, found at 2500 m. However, Wang et al. consider that while Murina yushuensis may seem exceptional, it is also potentially an indicator that other species of the genus may be living at high and intermediate altitudes, and not yet discovered due to a lack of sampling.

Surrounding environment of the cave where Murina yushuensis was discovered in March 2018. Wang et al. (2024).

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Sunday 27 October 2024

What abandoned grinding stones can tell us about the medieval town of Handoga in Djibouti.

The abandoned town of Handoga in southern Djibouti covers an area of about 600 m north-to-south and 300 m east-to-west, and is located about 13 km from the border with Ethiopia. Archaeological investigations have suggested that the site was initially used in the twelfth century as an occasional campsite by nomadic herders passing through the region, becoming a permanent settlement in the thirteenth century, from when it evolved into a town, with buildings with stone-built lower portions and wattle-and-daub upper portions coming to replace earlier temporary structures. The town was abruptly abandoned in the sixteenth century, with no sign of any violent upheaval preceding this event. As well as dwellings, the town had a range of open spaces which may have been squares, junctions of streets, or other public spaces, as well as two mosques, both at the northern end of the settlement, and a cemetery, at its southern end.

In a paper published in the journal World Archaeology on 30 September 2024, Jorge de Torres Rodríguez of the Instituto de Ciencias del Patrimonio in Santiago de Compostela, Spain;, and Valeria Franco Salvi of the Instituto de Humanidades at the Universidad Nacional de Córdoba in Argentina present the results of an analysis of grinding stones recovered from C-6000, the first structure at the northern end of Handoga to be the subject of archaeological investigations.

Location of Handoga in the Horn of Africa. De Torres Rodríguez & Salvi (2024).

The C-6000 site comprises two circular stone structures, linked by a series of walls enclosing a central open area, interpreted as having been used for food preparation and other domestic activities. The remains unearthed within this area resemble those found within courtyards excavated towards the southern end of the settlement, with two notable exceptions. Firstly, the site has yielded a quantity of well-preserved charred fruits, seeds, and wood fragments, which are currently under study, and which it is hoped will yield radiocarbon dates which will enable a chronology of the site to be built up. Secondly, excavations at the site have produced 88 fragments of grinding stone stones of different types, the largest collection of such stones not just from Handoga, but from any medieval Islamic site excavated to date, providing a rare opportunity to analyse how these objects were made and used, and any changes in their use over time.

Compound C-600 with main rooms and areas. De Torres Rodríguez & Salvi (2024).

Grinding stones were found across the site, with roughly two thirds coming from collapse layers, while about one third were found on original occupation layers. Grinding stones were found in all areas, with 47% coming from Room A, identified as the principal occupation site, 11% from Room B, identified as a storage area, and 34% from the central area. The stones can be split into two types, passive grinding stones, upon which grains would have been ground, and handstones, which would have been used to grind grains upon the grinding stones. Of the two, passive grinding stones are more common (55, compared to 33 handstones).

Handstones (upper rows) and one of the passive grinding stones (bottom) found at C-6000. De Torres Rodríguez & Salvi (2024).

Many of the passive grinding stones were highly fragmented, with 17 deemed intact enough for study. All were made from a vesicular-textured basalt, which probably came from an outcrop about 500 m from the settlement. Such a rock would have been ideal for grinding dehydrated or floury products, as it would be relatively easy to clean, and would have maintained a rough surface through use. These grinding stones appear to have been made from nodules or similar, with most made from approximately spherical or approximately cylindrical pieces of rock, with minimal shaping to achieve the desired shape. Despite the fragmentary nature of the grinding stones. about 60% still weighed between 2 kg and 5 kg, with the remaining 40% weighing under 2 kg. Twelve of the grinding stones are thought to have been portable, while the remaining five would have been large objects, presumably immobile during their working lives. The average grinding surface of these stones is 373 cm², with the largest having a surface area of 495 cm².

(1) Outcrop where the material for grinding stones was likely collected. (2) Compound C-6000. De Torres Rodríguez & Salvi (2024).

A much lower number of handstones (32) were recovered, these being largely fragmented, and scattered about with no sign of having been stored. They were apparently left where they lay between uses, and then abandoned once they became to worn for use.  Few showed any signs of maintenance during use, and none of any attempts to prolong their lives. Many of the handstones had been worn-down to the point of uselessness. The often had two wear-facets, showing their users had attempted to gain the maximum utility from them. All the handstones weighed less than 1 kg, with about 40% weighing less than 500 g. The handstones were made from rock which could be collected from within less than a kilometre, with the majority being made from basalt, although granite examples were also present, and one was made from quartzite.

While there appears to have been some variation in the way in which grinding stones were made and used at Handoga, the defining feature that appears to link all of them is an apparent lack of care. Only a minimal amount of work appears to have been put into modifying stones from their natural state to make them into tools, and little investment in their upkeep has been made during their lifetimes. There was no apparent standardized way to make these tools, which suggests that they were not manufactured by specialist craftspeople.

One consistent pattern which can be seen throughout the sample is the division into handstones and passive grinding stones, with grinding stones being larger and made from a single material, vesicular basalt, while handstones are smaller and made from denser and smoother material, with more variation in the selection of that material. A similar pattern has been seen at sites in Cameroon and Mali. There was also a difference in the distribution of these two elements, although the significance of this is unclear.

Large passive grinding stone found during a survey in Handoga. De Torres Rodríguez & Salvi (2024).

De Torres Rodríguez and Salvi suggest that this apparent lack of importance placed upon the manufacture and conservation of grinding stones suggests that these objects were not particularly valued by the people of Handoga. They further suggest that this lack of importance has implications for how we understand the settlement itself. Handoga was initially interpreted as an agricultural settlement, likely deriving water from the nearby Wadi Chekheiti, and trading Sorghum and Millet with the surrounding nomadic groups. However, no archaeobotanical studies have been carried out at Handoga, so there has been no evidence to date to either support or counter this hypothesis. 

In agricultural societies, grinding stones are typically high value items, of considerable economic significance, whereas at Handoga they appear to have been poorly valued, and used within domestic settings. This leads de Torres Rodríguez and Salvi to conclude that while agriculture was probably caried out at Handoga, it was likely a low-status activity, not having the same prestige as traditional nomadic activities such as herding and trade.

This in turn has implications for the history of Handoga. The settlement appears to have been initially used on a temporary camp by nomads in the twelfth century, gradually becoming more permanent, and transitioning to a town with stone buildings sometime in the fourteenth century. De Torres Rodríguez and Salvi reason that the low importance given to the processing of agricultural products suggests that despite becoming a permanent settlement, Handoga never really lost it's nomadic emphasis, something which is also reflected in the design of its buildings.

This in turn helps to explain why Handoga was abandoned so easily in the mid-sixteenth century. During the sixteenth century the Sultanate of Barr Saʿd al-Dīn, which ruled over much of the Red Sea coast of the Horn of Africa, collapsed following a series of disastrous wars with Abyssinia, severely disrupting trade routes, and causing many settlements to be abandoned. For peoples who had become truly sedentary in nature, this would have been a difficult process, either abandoning practices such as agriculture and having to relearn nomadic ways or relocate to other settlements, possibly some distance away. However, if the inhabitants of Handoga had retained an essentially nomadic nature with their main income deriving from pastoralism, the abandonment of the town may have been a less painful process than for more settled communities.

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