Macrofossils from the Early Ediacaran Brachina Sequence of the central Flinders Ranges, South Australia.

Fossils of soft-bodied organisms were first discovered in the Ediacaran Hills, part of the Flinders Ranges of South Australia in 1946. At the time, these fossils were presumed to be Medusae (Jellyfish) of Early Cambrian age, since it was believed that there were no Precambrian fossils. In the 1950s, fossils were found in reliably-dated Precambrian rocks in Charnwood Forest, England, showing that this presumed Cambrian appearance of life was incorrect. Furthermore, the Charnwood fossils closely resembled fossils previously described from Namibia (then Southwest Africa) in the 1930s, suggesting that these were of similar age.

Eventually, all of these fossils were grouped together as the 'Ediacaran Fauna', found at numerous locations in the world, and eventually split into three separate assemblages, each with its own distinct fossils, laid down in different environments at different times; the Avalon Assemblage, which appeared about 578 million years ago, and persisted to about 555 million years ago, the White Sea Assemblage, which included the Ediacaran Hills fossils, and which appeared about 560 million years ago, and persisted to about 551 million years ago, and the Nama Assemblage, which appeared about 555 million years ago, and disapeared 539 million years ago (around the onset of the Cambrian).

The earliest of these Ediacaran fossil assemblages seemed to have appeared slightly after the Gaskiers Glaciation, between 580.9 and 579.2 million years ago, taken as a middle point for the Ediacaran Period, leading to the assumption that the appearance of large Metazoans post-dated this event. However, a number of locations have subsequently produced Ediacaran-type fossils that apparently predate the Gaskiers Glaciation. Notably, the Charnwood Forest fossils can be dated to 603 million years before the present (Early Ediacaran), while the Lantian Biota of Anhui Province, China, has been dated to  605 million years ago. 

Since the discovery of the original Ediacaran Hills fossils, sporadic attempts have been made to find older fossils within the Flinders Ranges, although an absence of obvious fossils, combined with a perception that they were unlikely to exist, has tended to limit such searches. In 2021, Philip Plumber of the Department of Earth Sciences at the University of Adelaide, reported finding macro-fossils in the approximately 700 million years old (Cryogenian) Areyonga Formation, and 970–950 million years old (Tonian) Heavitree Formation of Central Australia, opening the possibility that pre-Middle Ediacaran fossils might be more widespread in Australia.

In a paper published in the journal Transactions of the Royal Society of South Australia on 2 September 2024, Philip Plumber reports macrofossils from the Early Ediacaran Brachina Sequence of the Flinders Ranges. 

The Brachina Sequence spans the interval between the end of the end of the Marinoan Glaciation, 635 million years before the present, which marks the boundary point between the Cryogenian and the Ediacaran periods, and the Acraman Asteroid Impact, 580 million years ago, which is coeval with the onset of the Gaskiers Glaciation. The Brachina Sequence begins with the Nuccaleena Dolostones, which overlay the Marinoan glacial deposits, above which lies the purple Moolooloo Siltstone, made up of clastic deposits brought into a shallow marine basin by turbid bottom currents. Around 620 million years ago, the tectonic situation changed, causing a delta to spread across the basin from the southwest. These delta deposits form the ABC Range Quartzite, formed in a shallow, wave-dominated environment, while other parts of the basin were covered by a tidal flat environment, recorded as the Moorillah Siltstone. 

Stratigraphic column (not to chronostratigraphic scale) showing positions of the fossiliferous Ediacara and Nilpena members (Pound Subgroup) and Moorillah Siltstone (Brachina sequence) within the Ediacaran succession. Plumber (2024).

The first fossil described by Plumber was first recorded in 1969 by palaeontologist Martin Glaessner, who identified it as a trace fossil, Bunyerichnus dalgarnoi, apparently made by a 'bilaterally symmetrical animal which used rhythmic muscular contractions rather than discrete appendages for propulsion'. The exact stratigraphic position where this fossil originated is unclear, but it was found on a surface bedding plane on a partly cross-laminated dark purplish micaceous siltstone, at the entrance to Bunyeroo Gorge in the central Flinders Ranges, which would imply it came from either the upper Moolooloo Siltstone or the lower Moorillah Siltstone.

Subsequent to this discovery, other intepretations of Bunyerichnus have been put forward. The curving shape of the fossil led to the suggestion that it might be a portion of a Medusa, but this did not explain why the specimen appeared to taper to one end. An alternative suggestion is that the specimen might be a trace left by a Rangeomorph (frond-like) Ediacaran sweeping over the sediment in a shallow setting. Plumber notes that Rangeomorph fronds were described from the base of the ABC Range Quartzite in 1985 (when the age of these deposits was unknown, although they were recognised as being stratigraphically significantly lower) by Ian Dyson of Flinders University, and that these would have been of approximately the same age as Bunyerichnus.

(a) Partial fossil of the Medusoid Paramedusium showing radial marking across its outer ring compared to (b) arcuate Bunyerichnus from the lower to mid Brachina sequence, Bunyeroo Gorge, Flinders Ranges. (c) Impression of the rangeomorph Akrophyllas (South Australian museum specimen SAM P24593) and (d) sketch of the rangeomorph Pteridinium showing transverse ridges extending from a central stem similar to Bunyerichnus. Plumber (2024).

Plumber also notes a number of circular features 0.5 to 1.0 cm in diameter from the base of the Moorillah Siltstone about 22 km southeast of Bunyeroo Gorge. These were first described by Plumber in 1980, when he interpreted them as inorganic fluid escape structures. However, subsequent examination of the specimens by Jim Gehling of the South Australian Museum led them being re-interpreted as examples of Aspidella, a Rangeomorph holdfast impression, with a fallen frond-lying next to the largest example. Plumber dates the horizon from which these fossils were recovered to about 620 million years before the present, firmly within the Early Ediacaran, older than the Charnwood Forest fossils, and about 60 million years older than the Ediacaran Hills biota.

(a) Several circular Aspidella on the bedding plane of a fine sandstone, near the base of the Moorillah Siltstone (lower Brachina Sequence), southeast of Wilpena Pound, Flinders Ranges (South Australian Museum specimen SAM P59911). (b) Enlargement of fallen frond (outlined) compared to (inset) the type specimen of the Ediacaran fossil Charniodiscus arboreus (South Australian Museum specimen SAM P19690a). Plumber 2024.

The Moorillah Siltstone of the Brachina Sequence has been dated to between 620 and 605 million years before the present. Philip Plumber reports the presence of frond-like Rangeomorph fossils near the base of the Moorillah Siltstone, suggesting that these must therefore be close to 620 million years in age. Such fossils are roughly coeval with the Lantian Biota of South China, and at least 40 million years older than the global Avalon Assemblage. These fossils therefore contribute to growing body of evidence for the emergence of Metazoan life before the Gaskiers Glaciation in the Middle Ediacaran Period.

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Numenius tenuirostris: The Slender-billed Curlew declared extinct.

The Earth's biodiversity is considered to be facing a crisis at a global level, with many experts believing that species may be going extinct at a rate as high as during the great extinctions recorded in the fossil record. Despite this, it is very hard to determine how many species are going extinct, in part because many species have never been documented, but also because it is generally impossible to tell whether a species is extinct, unless it can be confidently asserted that all populations were being monitored prior to extinction. The best recorded organisms tend to be Vertebrates, and one of the most extensively monitored Vertebrate groups are the Birds, a group which tend to be highly visible, and which are often recorded extensively by non-professional citizen-science groups. Despite this attention, many species of Birds have not been seen for a long time, and this cannot always be taken as evidence that they have become extinct: for instance, the Black-browed Babbler, Malacocincla perspicillata, was rediscovered in 2020 after not being observed in 180 years. The apparent extinction of species can be problematic, causing conservationists to cease efforts to protect a species which is close to extinction; conversely failure to realise that a species has become extinct can lead to efforts being dedicated to preserving it which could otherwise have been directed towards other species which might still be saved.

In a paper published in the journal Ibis on 17 November 2024, Greame  Buchanan of the RSPB Centre for Conservation Science, Ben Chapple of the Centre for Biodiversity and Environment Research at University College London, Alex Berryman of BirdLife International, Nicola Crockford of the Royal Society for the Protection of Birds, Justin Jansen of the Naturalis Biodiversity Center, and Alexander Bond of the Bird Group at the Natural History Museum, formally declare the Slender-billed Curlew, Numenius tenuirostris, to be extinct.

The International Union for the Conservation of Nature's Red List of Threatened Species currently lists the Slender-billed Curlew as Critically Endangered, on the assumption that the total population is less than 50 Birds and declining. The species is believed to be restricted to the Palaearctic biogeographical region, breeding in central Asia and migrating to Europe, North Africa, the Middle East, and the Arabian Peninsula. Slender-billed Curlews are thought to breed to the east of the Ural Mountains, in the area around Omsk in southern Russia. Isotope studies of museum specimens suggest that the species may also have bred further south, in northern Kazakhstan, while some eggs assigned to the species, also in museum collections, indicate that the species may also have bred to the west of the Urals. Outside of the breeding season the Birds ranged west as far as Western Europe and the Atlantic coast of North Africa, being known from across the Mediterranean Region, the Middle East, the Arabian Peninsula, and the Pannonian Plains of southeast Central Europe.

Once widespread in Europe, Slender-billed Curlews were last observed in Brittany, France, in February 1968, and in North Yemen in January 1984. A colony, thought to be the last, was known on the Atlantic coast of Morocco in the 1990s, with the last reported sighting in the winter of 1997/8, although a flock of Slender-billed Curlews was photographed in southern Italy in  March 1995. No subsequent observations of the species have been made, despite extensive searches across its former range, including the Middle East and Central Asia.

The last known photograph of a group of Slender-billed Curlews, taken in southern Italy in March 1995. Marco Basso in van den Berg (1995).

The Slender-billed Curlew was first observed breeding in 1912 by Russian ornithologist Valentin Ushakov, who first noted that the species appeared to be in decline. The possibility that Slender-billed Curlews might be at risk of extinction was first raised in 1943 by German ornithologists Erwin Stresemann and Hermann Grote, but it was not until 1988 that the species was identified as Threatened by the International Union for the Conservation of Nature. The species was listed as Critically Endangered in 1994, following a re-assessment of its status, and an action plan for its recovery was produced in 1996. 

Based upon this long absence from its known range, and the extensive, yet unproductive, searched which have been made in the last three decades, combined with the declining number of sightings recorded throughout the twentieth century, Buchanan et al. carried out a statistical analysis of the probability that the species might still exist. Based upon this, they conclude that is most likely that the species became extinct in the 1990s, with only a miniscule possibility that the species might still exist in the 2020s.

If this analysis is correct, then the Slender-billed Curlew is only the third species of Bird known to spend a large part of its annual cycle in the Western Palaearctic to have become extinct since 1500, joining the Great Auk, Pinguinus impennis, last reported in 1844, and the Canarian Oystercatcher, Haematopus meadewaldoi, last observed in 1913. 

A preserved museum specimen of a juvenile male Slender-billed Curlew, Numenius tenuirostris. Naturalis Biodiversity Center/Wikimedia Commons.

It is difficult to directly assess the cause of the extinction of the Slender-billed Curlew, since it is likely that the species finally died out around the time that an action plan for its survival was first drawn up. When that plan was produced, it identified that the species was threatened by habitat loss across its range, and potentially being hunted in some areas as well. 

The only records of breeding by the Slender-billed Curlew are those made by Valentin Ushakov in southern Russia in the early twentieth century. It is possibly that the main breeding area for the species was further south, on the steppes of northern Kazakhstan, which were extensively converted to croplands by the Russian Empire and Soviet Union in the nineteenth and twentieth centuries, in the process destroying extensive wetlands, which might have served as breeding grounds for Slender-billed Curlews, however, without further evidence, this is purely speculative. 

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Global number of Measles cases rose by 20% in 2023.

The number of Measles cases recorded worldwide rose by 20% in 2023 (compared to 2022), with 10.3 million cases recorded globally, according so a joint press release issued by the World Health Organization and the U.S. Centers for Disease Control and Prevention. The main driver of this rise in cases is thought to be inadequate immunization coverage.

Two doses of Measles vaccine is sufficient to protect against infection with the disease, but 17% of children who should have received their first dose of the vaccine in 2023 are thought not to have done so (more than 22 million children), while 26% of children who should have received a second dose in 2023 did not do so. A vaccine coverage rate of 95% or higher for both vaccine doses is thought to be needed to prevent Measles spreading within a population.

Fifty seven countries are thought to have suffered Measles outbreaks due to gaps in vaccination coverage, a 60% rise on the 36 countries which suffered such outbreaks in 2022. The World Health Organization's African, Eastern Mediterranean, European, South-East Asia and Western Pacific regions were affected, with over half of outbreaks occurring in the African Region. Only the Americas Region was not affected by a Measles outbreak in 2023.

A doctor examines a girl with measles at the Republican Infectious Diseases Clinical Hospital, Bishkek city, Kyrgyzstan. Danil Usmanov/World Health Organization.

'Measles vaccine has saved more lives than any other vaccine in the past 50 years,' according to Tedros Adhanom Ghebreyesus, the Director General of the World Health Organization. 'To save even more lives and stop this deadly virus from harming the most vulnerable, we must invest in immunization for every person, no matter where they live.'

Measles is a human disease caused by a Virus in the Paramyxovirus family. The Virus infects the respiratory tract, then spreads throughout the body. It can lead to major epidemics with significant morbidity and mortality, especially among vulnerable people. Among young and malnourished children, pregnant women, and immunocompromised individuals, including those with HIV, cancer or treated with immunosuppressives.

Thin-section transmission electron micrograph revealing the ultrastructural appearance of a single Viron, of the Measles Virus. The measles Virus is a Paramyxovirus, of the genus Morbillivirus. It is 100-200 nm in diameter, with a core of single-stranded RNA, and is closely related to the Rinderpest and Canine Distemper Viruses. Two membrane envelope proteins are important in pathogenesis. They are the F (fusion) protein, which is responsible for fusion of virus and host cell membranes, viral penetration, and hemolysis, and the H (hemagglutinin) protein, which is responsible for adsorption of virus to cells. Centers for Disease Control and Prevention/Wikimedia Commons.

It is estimated that 107 500 people died of Measles in 2023, most of them children below the age of five. This is an eight 8% drop in fatalities compared to 2022. The reason for this lower fatality rate in 2023, despite a higher infection rate, is thought to be that more cases of Measles were reported in 2023 in countries with generally better healthcare and childhood nutrition rates, where infected children are less likely to die. However, this is not all good news, as even where Measles is not fatal, it can cause a number of severe health problems, including blindness, pneumonia, and encephalitis (swelling of the brain, often leading to brain damage).

Measles is one of twenty life-threatening diseases which it was hoped could be eliminated through vaccination campaigns by 2030 under the remit of the Immunization Agenda 2030 program. In the first week of November 2024, Brazil was declared to be Measles-free, meaning that the disease had been eliminated in the Americas Region, and at least one nation in each of the other regions, with the exception of Africa, also having Measles-free status. However, the decline in vaccine-uptake, and the subsequent rise in Measles cases around the world, means that this project is now threatened.

The African and Eastern Mediterranean regions are thought to be in particular need of urgent and targeted interventions to ensure vaccine availability and uptake, particularly in conflict-affected and other vulnerable settings. Greater surveillance for cases is also needed in all regions, in order to facilitate prompt responses to outbreaks when they occur.

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Chyliza colenutti: A new species of Chylizine Rust Fly from the Eocene of the Isle of Wight.

Rust Flies, Psilidae, are small-to-medium sized Dipteran ('True') Flies with elongate bodies and rounded heads, found largely in temperate regions of the Northern Hemisphere. Their larvae are parasitic on Plants, and some species, such as the Carrot Fly, Chamaepsila rosae, are considered to be significant agricultural pests. The Family Psilidae is divided into three subfamilies, the Chylizinae and Psilinae, which are considered to be sister groups, and the Belobackenbardiinae, which forms a sister to the other two groups combined. The oldest known fossil Rust Fly is Electrochyliza succini from Baltic Amber, which is probably Late Eocene in age. Electrochyliza succini is not placed within any extant subfamily, being considered to be a sister taxon to Chylizinae and Psilinae closer than Belobackenbardiinae, which suggests it appeared after the ancestor of these groups split from the Belobackenbardiinae, but before they had themselves diverged. 

In a paper published in the journal Insect Systematics and Diversity on 13 November 2024, Andrew Ross of the Department of Natural Sciences at National Museums Scotland, Jiale Zhou of the Key Laboratory of Zoological Systematics and Evolution at the Institute of Zoology of the Chinese Academy of Sciences and the Department of Entomology at the China Agricultural University, Christel Hoffeins of Hamburg in Germany, and Bill Crighton, also of the Department of Natural Sciences at National Museums Scotland, describe a new species of Chylizine Rust Fly from the Late Eocene Insect Limestone Bed of the Bembridge Marls of the Isle of Wight, England.

The Insect Limestone is a single bed of fine-grained micrite found within the Bembridge Marls member of the Bouldnor Formation on the Isle of Wight. This bed is noted for the production of exquisitely preserved Insects, which often show three-dimensional preservation, for which reason it is sometimes known as 'opaque amber'. This bed has been precisely dated to 34.3 million years before the present.

The new species is described upon the basis of a single specimen collected by George William Colenutt, a prominant Isle of Wight solicitor and amateur geologist, and donated to the Oxford University Museum of Natural History in 1931. The species is placed in the genus Chyliza, the sole genus in the subfamily Chylizinae, on the basis of comparison of its wing venation to that of living members of the genus, and named Chyliza colenutti in honour of the collector.

Chyliza colenutti, Holotype; (A) part, OUMNH M.177; (B) counterpart, OUMNH M.175; Insect Limestone, Bembridge Marls, north-west Isle of Wight, UK. Colenutt Collection. Scale bar is 5 mm. Ross et al. (2024).

The specimen is preserved in a split block as part and counterpart, and has a preserved body length of 3.9 mm and a maximum abdomen width of 1 mm. The forewing is 3.6 mm in length and 1.4 mm wide. All of the wings appear coloured towards their tips.

Prior to the description of Chyliza colenutti, the oldest described Chylizine Rust Fly was a Middle Miocene specimen identified as Chyliza sp. from the Middle Miocene Upper Freshwater Molasse of southwestern Germany, which is thought to be between 15 and 12 million years old. 

The dating of Baltic Amber can be problematic, as it ranges from Middle Eocene to Middle Oligocene in age (i.e. is between 48 and 27  million years old), and tends to reach collections via amber dealers, often trading hands several times before coming to the attention of a scientist, with any data on the location and age of the specimens often being lost. However, the majority of Baltic Amber comes from the Upper Blue Earth Member of the Prussian Formation, which has been dated to between 36.5 and 33.5 million years old. 

Electrochyliza succini in Baltic amber. Hoffeins Collection CCHH 1829-10. Scale bar is 1 mm. Ross et al. (2024).

This gives a gap of around 20 million years between Electrochyliza succini and Chyliza sp., which led many palaeoentomologists to conclude that there was a long gap between the divergence of the Belobackenbardiinae from the common ancestor of the Chylizinae and Psilinae, and the splitting of these two groups, particularly as no specimens assigned to either of these groups have been found in Insect-rich deposits such as the Dominican and Mexican ambers. However, if Ross et al.'s interpretation of Chyliza colenutti as a Chylizine is correct, then the group was present 34.2 million years ago, making it unlikely that it is more than two million years younger than Electrochyliza succini.

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Uranus approaches opposition.

The planet Neptune will reach opposition (i.e. be directly opposite the Sun seen from Earth) at 2.36 am GMT on Saturday 16 November 2024. This means that it will both be at its closest to the Earth this year, about 18.57 AU (18.91 times the average distance between the Earth and the Sun, or about 2 778 000 000 km), and completely illuminated by the Sun. While it is not visible to the naked eye observer, the planets have phases just like those of the Moon; being further from the Sun than the Earth, Neptune is 'full' when directly opposite the Sun. 

The orbits and positions of Earth, Uranus, and the planets of the Outer Solar System at 2.00 am GMT on Saturday 16 November 2024. JPL Small Body Database.

While the relative positions of the planets have no direct influence on life on Earth, the opposition of Saturn does present the best opportunity for observations of the planet by Earth-based observers. Uranus is never visible to the naked eye, but on Saturday 16 November the planet will be visible with a reasonable telescope in the constellation of Taurus, reaching its highest in the sky at about midnight.

Image of Uranus made with the Near-Infrared Camera on the James Webb Space Telescope, showing Uranus’s seasonal north polar cap and dim inner and outer rings, as well as  9 of the planet’s 27 moons – clockwise starting at 2 o’clock, they are: Rosalind, Puck, Belinda, Desdemona, Cressida, Bianca, Portia, Juliet, and Perdita. NASA/European Space Agency/Canadian Space Agency/Space Telescope Institute.

Uranus orbits the Sun at an average distance of 19.2 AU, completing one orbit around the Sun every 84 years. This means that the planet is almost stationary compared to the faster moving Earth, so that it reaches Solar Opposition only four days later each year than the year before, and reaches conjunction (when it is directly behind the Sun seen from the Earth), roughly six months later.

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