Wednesday 31 January 2024

Alienacanthus malkowskii: A highly specialised Placoderm Fish from the Late Devonian Rheic Ocean.

Placoderms are thought to have been the earliest jawed Vertebrates, first appearing in the Silurian and rising to become the most diverse group of Fish in the Devonian, before their extinction at the end of that period. During the Devonian the Placoderms, and in particular the Arthrodires (the most abundant and diverse Placoderm group) produced a wide range of forms, implying an equally diverse range of ecological and feeding strategies. However, Placoderms are known almost entirely from their hard parts, with only a single specimen with a body outline known, and no known stomach contents or soft parts, limiting our ability to interpret the ecology of these diverse early Fish. The jaws of early Placoderms show tend to be similar, apparently adapted to rapid snatching of prey, but later members of the group are much more varied, and have been interpreted to reflect a range of feeding styles from filter feeding to durophagy (the crushing of hard foodstuffs, such as shellfish).

In a paper published in the journal Royal Society Open Science on 31 January 2024, Melina Jobbins of the Department of Palaeontology at the University of ZurichMartin Rücklin of the Naturalis Biodiversity Cente and the University of LeidenMarcelo Sánchez Villagra, also of the Department of Palaeontology at the University of Zurich, Hervé Lelièvre of the Muséum National d’Histoire NaturelleEileen Grogan of the Department of Biology at Saint Joseph’s University, Piotr Szrek of the Polish Geological Institute, and Christian Klug, again of the Department of Palaeontology at the University of Zurich, redescribe a species of Late Devonian Placoderm previously only known from fragmentary material from the Holy Cross Mountains of Poland, on the basis of new material from the eastern Anti-Atlas of Morocco.

Alienacanthus malkowskii was originally described from fragmentary material from two quarries in Poland, as composing large, possibly paired, spines of uncertain origin. Jobbins et al.'s redescription of the species is based upon a nearly complete skull, the left side of a second skull, and a number of more fragmentary remains from sites in Morocco, which reveals the 'spines' to be part of the lower jaw of a large Eubrachythoracid Placoderm.

Alienacanthus malkowskii, skull, PIMUZ A/I 5239. In right (a), (b), left (c), (d) and dorsal (e), (f) view; inferognathals, PIMUZ A/I5238, in lingual (g), lateral (h) and dorsal (i) view. Each bone is differentiated by a separate colour. Black arrow points to lingualdepression. Scale bars correspond to 100 mm. Jobbins et al. (2024).

The inferognathal bones, which form the lower jaws in Placoderms protrude significantly beyond the upper jaw, reaching about twice the length of the rest of the skull, reaching a pointed tip. These jaw elements run closely parallel to one-another over about 60% of their length, although they are not fused at any point. The teeth of both jaws are posteriorly recurved, with the 'teeth' (actually bony protrusions, as in all Placoderms) of the lower jaw continuing forward of the upper jaw, but a significant distance short of the tip of the bone.

Extremely elongated lower jaws are known in a variety of other extant and fossil Fish and marine Tetrapods, including the Carboniferous Chondrichthyan Ornithoprion, the extant ray-finned Halfbeaks, which have a fossil record dating back to the Palaeogene, and the Pliocene Porpoise Semirostrum. Although in none of these are the lower jaws as elongated as they are in Alienacanthus malkowskii, with the longest examples being found in some species of Halfbeak, which can reach about 1.6 times the length of the skull.

Live reconstructions of Alienacanthus. Based on the body morphology of extinct and modern Fish with elongated jaws (elongated, fusiform, bodies). Beat Scheffold & Christian Klug in Jobbins et al. (2024).

The recurved teeth of Alienacanthus malkowskii are strongly suggestinve of a diet of live Fish, mirroring the shape of teeth seen in many other Fish-eating groups, including Ichthyosaurs, Snakes, Choristoderans, and other living and extinct Fish species. However, the lower teeth of Alienacanthus malkowskii continue beyond the upper jaw, with up to twelve teeth forward of the mouth in observed specimens. 

Teeth forward of the mouth are known in a number of Condrichthyan groups, including Sawfish, Sawsharks, and Rajiform Rays. All of these have teeth on the upper jaw rather than the lower, and are equipped with electroreceptive sensory organs which enable them to detect prey-Fish and strike them with a rapid side-motion of the rostrum. However, thin sections of the jaw of Alienacanthus malkowskii show no signs of the additional neural canals which would be associated with such a system, and the teeth of Alienacanthus malkowskii are directed upwards, rather than sideways, making it unlikely that the elongated jaw was used in the same way as seen in Sawfish. Instead, Jobbins et al. suggest that the presence of teeth forward of the mouth in Alienacanthus malkowskii is a product of the way the living Animal grew, with formerly useable oral teeth being carried forward as the jawbone elongated, probably in a short burst of growth as the Fish approached maturity, although it is still possible that the long lower jaw was used to strike at prey, and that the forward teeth could have inflicted damage on soft-bodied Animals.

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Tuesday 30 January 2024

Tuber itzcuinzapotl: A new species of edible Truffle from Mexico.

Truffles, Tuber spp., are Ascomycote Fungi which from ectomycorrhizal relationships with a range of forest Plants, including Pines, Oaks, Hickories, and Orchids. They are distinguished for their large, tuber-like ascomata (fruiting bodies), which are formed underground, which often have highly distinctive aromas and flavours, leading to some species being traded as high-value gourmet items.

There are currently 25 species of Truffle known from Mexico, mostly from the temperate forests of the north and the mountains of the Neovolcanic axis. However, none of these are currently traded as foodstuffs, despite Mexico a globally leading countries in terms of the number of edible wild Fungi consumed, with about 500 species, making it second only China, where about 1000 are consumed. However, recent efforts have found that the non-native Black Truffle, Tuber melanosporum, will form ectomycorrhizal relationships with native Mexican Oaks, and several species found in Mexico are considered to have potential for commercial development, including the Pecan Truffle, Tuber lyonii, which is commercially exploited in the US and Canada, and can trade for up to US$400 per kg.

In a paper published in the journal Phytotaxa on 26 January 2024, Javier Isaac de la Fuente of the Colegio de Postgraduados at Campus Montecillo, Wendy Rosales-Rosales of the Instituto Tecnológico Superior de Zongolica of the Tecnológico Nacional de México, César Romero Martínez-González of the Instituto Tecnológico de Ciudad Victoria of the Tecnológico Nacional de México, Magdelana Martínez-Reyes, also of the Colegio de Postgraduados at Campus Montecillo, Andrea Carolina Elizondo-Salas, also of the Instituto Tecnológico Superior de Zongolica of the Tecnológico Nacional de México, and Jesús Pérez-Moreno, agian of the Colegio de Postgraduados at Campus Montecillo, describe a new species of edible Truffle from the Coniferous mixed forests of eastern Mexico.

The new species is named Tuber itzcuinzapotl, where 'itzcuinzapotl' means 'Dog's Zapote' in the Nahua language (a Zapote is a type of fruit). This Truffle produces subglobose fruiting bodies with a light brown, verrucous-granular outer surface, and an gray or pale brown interior, reaching up to 28 mm by 28 mm in size, with a distinctive fruity taste and smell. It is found growing in association with Mexcan Weeping Pines, Pinus patula, in Veracruz State, Mexico.

Tuber itzcuinzapotl (Holotype). Fresh ascomata fruiting body. De la Fuente et al. (2024).

Mexico has a significant culture of wild Fungus consumption, with over 500 types of Fungi consumed by members of all ethnic groups, and in particular rural communities living close to woodland. However, almost all consumed Fungi are epigeal, i.e, found above the ground, such as Mushrooms, with very little exploitation of subterranean species occurring. This is surprising, as Mexico is one of the most biodiverse regions in the world for Oaks, and Oaks are particularly associated with Fungi producing underground fruiting bodies. 

Tuber itzcuinzapotl is known to be consumed by members of the Nahua ethnic group living in the Sierra de Zongolica region of Veracruz State, Mexico, where it is referred to as 'itzcuinzapotl' (the specific name chosen for the species). Local folklore has it that people began to consume these Fungi after observing Dogs digging them up and eating them. Knowledge of the Fungus appeared to be restricted to older women in the community. Such local knowledge of wild foodstuffs is considered to be at risk in the region as traditional cultures are eroded, leading to loss of knowledge and a reduction and homogenisation in the number of foodstuffs consumed by Humans both in Mexico and globaly.

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Monday 29 January 2024

Asteroid 2024 BX1 impacts the Earth.

Slightly before 10.50 pm Central European Time (slightly before 9.50 pm GMT) on Saturday 20 January 2024, asteroid hunter Krisztián Sárneczky at the Piszkesteto Mountain Station of the Hungarian Konkoly Observatory observed a previously unknown asteroid on a potentially Earth-impacting trajectory. This observation was reported to the Minor Planet Center, leading other astronomers and automated tracking systems around the world to begin tracking the object, and it quickly became clear that the object was going to impact the Earth, less than two hours after its original discovery, approximately 60 km to the east of Berlin, Germany.

The final image of asteroid 2024 BX1, taken by Luca Buzzi at the Schiaparelli Observatory in Italy. The image is an exposure lasting several seconds, with the asteroid being the elongate object and the points fixed stars, The asteroid started at the centre of the image and moved towards the top. European Space Agency

Objects of this size probably enter the Earth's atmosphere several times a year, though unless they do so over populated areas they are unlikely to be noticed. They are officially described as fireballs if they produce a light brighter than the planet Venus. It is possible on this occasion the object is known to have produced meteorites that reached the surface (an object visible in the sky is a meteor, a rock that falls from the sky and can be physically held and examined is a meteorite).

Fireball over Germany created by asteroid 2024 BX1. Sirko Molau/AllSky7 Fireball Network Europe.

The asteroid is estimated to have been about a metre in diameter, and as will have exploded in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) more than 40 km above the ground. owever, this is not the end of the story as such explosions result in the production of a number of smaller objects, which fall to the ground under the influence of gravity (which does not cause the luminescence associated with friction-induced heating). These 'dark objects' do not continue along the path of the original bolide, but neither do they fall directly to the ground, but rather follow a course determined by the atmospheric currents (winds) through which the objects pass. Scientists are able to calculate potential trajectories for hypothetical dark objects derived from meteors using data from weather monitoring services.

Map showing the location where the small asteroid 2024 BX1 harmlessly impacted Earth’s atmosphere over Germany, about 60 kilometres west of Berlin, on 21 January 2024. NASA's Scout System was able to predict the impact time and location to within 1 second and 100 m. NASA/JPL/CalTech.

On this occasion the advanced detection of the asteroid enabled accurate prediction of the area where the meteorite fragments fell, allowed meteorite hunters to narrow the search area to a few hundred meters, and a number of fragments were located in the days after the asteroid entered the atmosphere. These lacked a distinctive dark fusion crust, something seen on most but not all meteorites. On this occasion the fragments appear to be achondritic, with a light grey colour, a brecciated texture, and large white crystals which may be enstatite, a high magnesium pyroxene silicate mineral frequently found in igneous and metamorphic rocks, as well as some types of meteorite.

A fragment of the Berlin meteorite fall displays a light-grey fusion crust. White crystals that speckle the space rock could indicate the meteor belongs to a rare type called an aubrite. Filip Nikodem/Sky & Telescope.

The asteroid was given the name 2024 BX1, which implies that it was the 48th asteroid  (asteroid X1 - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 26, A2 = 51, etc., which means that X1 = (25 x 1) + 23 = 48) discovered in the second half of January 2024 (period 2024 B - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

Asteroid 2024 BX1 is calculated to have had a 564 day (1.55 year) orbital period, with an elliptical orbit tilted at an angle of 7.29° to the plain of the Solar System which took in to 0.83 AU from the Sun (83% of the distance at which the Earth orbits the Sun) and out to 1.83 AU (1.83 times the distance at which the Earth orbits the Sun, somewhat more than the distance at which the planet Mars orbits). It is therefore classed as having been an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). Asteroid 2024 BX1 is calculated to have had 21 close encounters with the Earth before finally impacting, with the first in January 1930, and the most recent in June 2010.

The calculated orbit of asteroid 2024 BX1. JPL Small Body Database.

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Sunday 28 January 2024

Two musuems in London agree to loan looted Asante items back to Ghana.

The British Museum and Victoria and Albert Museum in London have agreed to loan a series of artefacts, mostly looted from the Asante Kingdom in the nineteenth century, back to a museum in Kumasi, Ghana, for three years, to mark the Silver Jubilee of the current Asantehene (Asante King), Otumfuo Osei Tutu II. The loans come about following a visit to London by the Asantehene in 2023, in which he spoke to leaders at both museums, as well as the British King Charles III. National museums in the UK (including the British Museum and Victoria and Albert Museum) are currently banned from giving up ownership of objects, even where it is known their provenance is problematic, something which could only be changed by act of parliament (something the current British Prime Minister, Rishi Sunak, has stated he is opposed to doing). However, the leadership of both museums have expressed that they would not object to the loan of the objects being extended beyond three years.

Asante ceremonial cap ('denkyemkye') made of antelope hide and featuring antelope fur alongside twenty gold-covered ornaments (with wood cores) and cockle shells. Looted from the royal palace, Kumasi, by British forces during the Anglo-Asante War, 1895–6. This formed part of official government loot. British Museum.

The oldest item in the British Museum's collection, and one of the items being loaned to Ghana, is a small gold ornament in the form of a lute-harp (sankuo), which was presented to the British diplomat Thomas Bowdich by the Asantehene Osei Bonsu during trade negotiations in 1817. Bowdich reported that the Asantehene intended the item for the British Museum, where it could serve to represent the wealth and status of the Asante nation.

A small gold ornament in the form of a lute-harp (sankuo), presented to the  British diplomat Thomas Bowdich in 1817. British Museum.

The rest of the items in the collections have a darker history. In 1874 the British Army invaded the Asante Kingdom, following a dispute over the ownership of the Port of Elmina, sacked Kumasi, deposed the Asantehene Kofi Karikari, and forced him to pay 'indemnity' for the cost of invading his kingdom. The British Museum acquired three separate collections of artefacts known or believed to have been taken during the campaign of 1974. The first of these was a collection of 24 items obtained from the London goldsmiths R & S Garrard & Co., who had been appointed to sell items surrendered in indemnity by Kofi Karikari. A further 89 items were obtained from the Crown Agents for the Colonies in 1876, although it is unclear whether these were taken as 'indemnity' or simply looted.  In the same year, two Asante items were obtained from Phillips Brothers, another goldsmiths, again with no clear history.

Silver-gilt dish, made by Garrard's, London, in 1874, containing in the centre an Asante star-shaped pendant made of gold that inspired the European decoration around it. The gold pendant formed part of the gold indemnity forcibly extracted by British forces from the deposed Asantehene Kofi Karikari in 1874. An inscription on the back of the dish records that the Asante disc was 'a portion of the indemnity paid' by the Asante King to the British forces led by General Sir Garnet Wolseley. British Museum.

The Victoria and Albert Museum acquired thirteen items in an auction of gold looted by the British Army from Kumasi in 1874, all of which are thought to have been part of the Asante Royal Regalia. These include a gold peace pipe, three cast gold soul-washers’ badges, seven sections of sheet-gold ornament, a silver straining spoon, and a pair of silver anklets. Two further items were obtained separately, another section of sheet-gold ornament purchased from a military family in 1874, and another cast gold soul-washer’s badge purchased in 1883 from an unknown source. 

An Asante gold ornament, looted from Kumasi in 1874. Victoria and Albert Museum.

In 1895-1896, the British invaded Kumasi again, deposing the Asantehene Prempeh I, and forcing him to  sign over his kingdom to the 'protection' of the British Crown, and sending him into exile in the Seychelles with a number of senior Asante nobles. This military campaign was again associated with extensive looting. The British Museum received a collection of about 300 Asante objects from the Government of the Gold Coast (the colonial name for Ghana) following the 1896 confict, including silver and gold items, glass beads and amuletic jewellery. It is known that at least some of these items were looted, although the provenance of many items was not recorded.

Asante state sword (afena) with cast iron blade and carved wooden bar-bell-shaped hilt covered with gold leaf. Taken from the royal palace, Kumasi, by British forces during Anglo-Asante war, 1895–6, and formed part of official government loot. British Museum.

In 1900 the Governor of the Gold Coast, Sir Frederick Hodgson, demanded to be allowed to sit on the Golden Stool of the Asantehene during a visit to Kumasi. This object was (and is) considered sacred by the Asante people, with legend claiming that it was sent down from the heavens as a symbol of the authority of the Asantehene, and only the reigning Asantehene is allowed to touch it. Sir Frederick Hodgson's demand prompted an uprising in Kumasi led by the Queen Mother, Yaa Asantewaa. Although this was quickly put down and Yaa Asantewaa was sent into exile with her son.  Following this conflict the British Museum obtained a further 63 items from the Government of the Gold Coast, although many of these are thought to have been taken in 1896. These include several gold leaf-hilted state swords (afena), a ceremonial helmet with gold ornaments and amulets (denkyemkye), and a Mpomponsuo sword on which the Asantehene Prempeh I swore an oath to serve his people during his enstoolment ceremony.

Both the British Museum and Victoria and Alberst Museum subsequently obtained a number of smaller collections and individual items from private owners, either by sale or donation, including soldiers, colonial officials, mining engineers, and their families.

An Asante gold ring donated to the Victoria and Albert Museum in 1921 by Victor Ames, an art collector, who reported having bought the item in Venice. Victoria and Albert Museum.

The items will be displayed in the Manhyia Palace Museum in Kumasi, at an exhibition which marks the Silver Jubilee of the Enstoolment of the Asantehene Otumfuo Osei Tutu II, the 100th anniversary of the return of Asantehene Prempeh I to Kumasi following his exile to the Seychelles by the British, and the 150th anniversary of the looting of Kumasi in 1874.

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Four new Emperor Penguin colonies discovered in satellite images of Antarctica.

All current predictions for the future of Emperor Penguns, Aptenodytes forsteri, suggest that the species is in serious trouble, due to the effects of anthropogenic climate change, with predictions suggesting that all known colonies will be extinct or quasi-extinct (the point at which a population has shrunk so much that it is unlikely to be able to recover) by the end of the century if carbon dioxide emissions continue to rise at the current rate. If conservation measures are to be developed which will give the species any hope of survival, then monitoring Emperor Penguin colonies is essential. However, the extremely remote location of these colonies makes observing them from the ground impractical. This has caused scientists studying Emperor Penguins to turn to satellite imagery as a way to detect and monitor colonies of these Birds. This has proven to be a useful method not just for monitoring the health of Penguin colonies, but also of discovering new ones, with eight new colonies located in 2019, using data from the European Space Agency's Sentinel-2 satellite.

In a paper published in the journal Antarctic Science on 20 January 2024, Peter Fretwell of the British Antarctic Survey reports the discovery of four new Emperor Penguin colonies, using imagery from Sentinel-2 and Maxar WorldView.

The first new colony described by Fretwell lies on the Dronning Maud Land coast on the northern side of the Lazarev Ice Shelf, and is tentatively named the 'Lazarev North Colony'. A colony has previously been recorded on the Lazarev Ice Shelf. This colony known as the 'Lazarev Colony' was first observed by the Soviet Antarctic Survey in 1959, and was subsequently found in a number of satellite images. However, it has not been seen since 2014, and was recorded as being extinct in 2019. 

Map of Lazarev Ice shelf sites, showing the old location and the new location. Note that the new breeding site is around 65 km around the coast from the old site and although not yet counted, looks much smaller than the 4,500 pairs recorded in 2013. Fretwell (2024).

Fretwell considers it highly likely that the Lazarev North Colony is a relocated remnant of the old Lazarev Colony. The oldest image in which it is visible dates to 2018, and it can be seen in images from 2019, 2020, 2021, and 2022, although it is not present in all images over this period. No very high-resolution images of this colony, which would enable an estimate of the population size, but it appears to be significantly smaller than the Lazarev Colony in 2014, which contained about 4500 pairs of breeding Penguins. Fretwell suggests the colony may have relocated due to the extension of the ice tongue or a change in sea-ice conditions.

Sentinel-2 image of the Lazarev North Colony. Arrow shows the location of the Penguins. Fretwell (2024).

The second new colony is located at Verleger Point on the coast of Marie Byrd Land in West Antarctica. This colony is visible in all Sentinal-2 images of the region from 2018 to 2022, and is also visible in the higher resolution Maxar WorldView images, allowing the size of this colony to be estimated at about 500 pairs of Birds. \The colony is about 53 km to the east of the abandoned Soviet Russkaya research station, which was abandoned in 1990, although if the scientists at this base ever made observations of Penguins in the area, they did not publish them.

(Top) Map of the location of Verleger Point colony. This small colony is located equidistant from Ledda Bay and Curzon Island. It is approximately 53 km east of the site of the abandoned Russkaya research station. (Bottom) Sentinel-2 image of the Verleger Point Colony. Arrow shows the location of the Penguins. Fretwell (2024).

The third new colony is located on the eastern side of the West Ice Shelf. It is some way offshore, on stable fast ice which has formed around icebergs which have grounded on the shallow seas of the area. This colony is located about 65 km to the east of the Karelin Bay colony and about 180 km to the west of the Burton Glacier Ice Shelf colony, with all three colonies appearing to exist at the same time. Another colony was reported at Gaussberg, about 150 km from the new colony, in 1958. This colony appears to have subsequently vanished, making it possible that one of the current populations is in fact this colony relocated. However, since the closest population to the old Gaussberg colony site id the Burton Glacier Ice Shelf colony, Fretwell feels it is unlikely that the new colony is that colony, and suggests that this is instead a well-established colony, which was missed in earlier surveys because it is so far from shore. Because there is already a colony named for the West Ice Shelf, Fretwell names this colony the 'Vanhoeffen Colony' in honour of Ernst Vanhoeffen, the biologist on board the First German South Polar Expedition of 1901-1903.

Map showing the location of the Vanhoeffen Colony. There are a number of other breeding sites in the general area of this large new site, satellite imagery shows that there all exists at the same time and are not a movement of one group. Fretwell (2024).

The Vanghoeffen Colony is visible in all Sentinal-2 images from 2018-2022, as well as in very high-resolution Maxar WorldView images, allowing an estimate of the size of the colony to be made, at about 5000 breeding pairs of Penguins.

Sentinel-2 image of the Vanghoeffen Colony. Arrow shows the location of the Penguins. Fretwell (2024).

The final new colony described is located on the northten side of the Gipps Ice Rise, which itself forms the southern margin of the Larsen C Ice Shelf. This is a noteworthy discovery, as no colony has been discovered between the Jason Peninsula and Dolleman Island until now, despite a number of searches. 

Location of Gipps Colony. Fretwell (2024).

This colony is extremely small, estimated at about 200 breeding pairs of Penguins, and located in an area which is often obscured by cloud cover, making it extremely hard to detect in satellite images, although once identified it could be found in Maxar WorldView images dating back as far as 2016. The colony was located against ice cliffs or in a small ice creek north of the ice rise, until 2021, when the calving of a large ice berg changed the topology of the region, forcing the Penguins onto open fast ice, where the colony became easier to detect.

Sentinel-2 image of the Gipps Ice Rise Colony. Arrow shows the location of the Penguins. Fretwell (2024).

The discovery of the four new colonies, together with the re-discovery of a colony at Umbeashi in Amundsen Bay, which was thought to be extinct in 2019, but reformed in 2021 and 2022, brings the number od known Emperor Penguin colonies to 66, as well as filling several gaps in the distribution of these Birds. Despite this, it only raises the known global population of Emperor Penguins by about 5700 pairs. Given that the former Lazarev Colony was thought to comprise about 4500 pairs, and the new Lazarev North Colony is thought to be much smaller, this probably does not represent a major increase in the total Emperor Penguin population.

Newly reported emperor penguin colonies, shown in red boxes. Light blue boxes denote other known extant colony sites. Fretwell (2024).

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