Saturday, 3 December 2022

New investigations at Holly Shelter, KwaZulu-Natal, South Africa.

South Africa is considered to be a key area for the understanding of the history both of Hominins as a group and Modern Humans as a species. Despite this importance, only a limited number of sites attributed to the Middle Stone Age, an important developmental stage for Modern Humans, have been excavated within South Africa, and only six from KwaZulu Natal. The Holly Shelter site on Fountainhill Estate near Wartburg is one of only two such rockshelters in KwaZulu-Natal which are not located in coastal areas, the other being Border Cave, on the western scarp of the Lebombo Mountains. 

Holly Shelter was first investigated by archaeologist Gordon Cramb in the 1950s. The site produced both organic material and stone tools, a combination with the potential to yield a great deal of information about the period using modern techniques unavailable in Cramb's time. Recent re-examination of Cramb's material has suggested that it is similar to the assemblage recovered from Sibhudu Cave, about 40 km to the north of Durban, which would make the material likely to be 50-60 thousand years old, although the site itself has not been dated. 

In a paper published in the South African Journal of Science on 30 November 2022, Gregor Bader of the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen, and Manuel Will of the Department of Early Prehistory and  Quaternary Ecology, also at the University of Tübingen, present the preliminary results of a new investigation at Holly Shelter, which aimed to establish whether there are any intact archaeological deposits left at the site, whether the site features a discernible stratigraphic sequence which can be dated, is there any useful preservation of organic remains at the site, and whether distinct techno/typological units can be identified within the stratigraphic sequence.

(a) Location of Holley Shelter and other archaeological and palaeoenvironmental sites mentioned in the text.  (b) Three-dimensional model of the site produced with Agisoft Metashape Professional. Gregor Bader in Bader & Will (2022).

In the early 1950s Gordon Cramb excavated two areas close to the entrance of Holly Shelter, uncovering two distinct layers of occupation, the upper one producing a Later Stone Age technology, and the lower a Middle Stone Age technology, including bone tools. Bader and Will refrained from carrying out excavations close to this area, as there are now several large rock slabs lying on the surface here. Cramb's later investigations concentrated on an are further north, and deeper within the cave, an area which Bader and Will also concentrated on, as it was clear of large surface debris, and appeared more likely to yield a full stratigraphic sequence, excavating two new test trenches.

Excavation plan of Holley Shelter. Cramb Exc. 1 and 2 mark the areas of Cramb’s excavations in the 1950s. Exc. 1 was described by Cramb as the ‘Smaller habitable area’, Exc. 2 as the ‘Larger habitable area’. Green squares were excavated in 2022. Gregor Bader in Bader & Will (2022).

Both of Bader and Will's new trenches confirmed the existence of layered archaeological remains. The northern trench produced an upper layer of disturbed soil 5-10 cm thick, beneath which was a layer of orange-brown sandy silt, with charcoal inclusions. This layer contained several small hearths (former fire sites) as well as Middle Stone Age stone artefacts, predominantly made from hornfells, and a significant amount of faunal remains. Beneath this was a grey sandy silt layer. At the southern site this grey sandy silt produced a large hearth which covered most of the excavated area, as well as a large number of stone artefacts, including numerous splintered pieces similar to the ones identified in the Cramb collection, unifacial points, and frequent blades and points with faceted platforms. This layer also produced a lot of faunal remains, along with large charcoal fragments and Plant fossils. In both layers the finds were concentrated at the hearth sites, with little material in the surrounding area.

(a) West-profile of the northern section with layers redrawn, (b) west-profile of the northern section (original), and (c) three-dimensional model of the northern section at the end of the 2022 excavation season. Gregor Bader in Bader & Will (2022).

The lithic assemblage recovered by Cramb contained a high proportion of modified tools compared to debitage (flakes). This was previously assumed to be bias on the part of the mid-twentieth century archaeologist, who was operating at a time when the importance of small flakes was less well understood, and these were commonly overlooked. However, Bader and Will's assemblage contains a similarly high proportion of large tools, with  splintered pieces and unifacial points being the most common items in both collections. 

Artefacts from the lower layer in the northern section at Holley Shelter: (a)–(c) unifacial points, (d)–(f) splintered pieces, (g), (h), (k), (m), (n), (o) identifiable faunal remains, (i), (j) bone flakes, (l), (p) bones with cutmarks. Gregor Bader in Bader & Will (2022).

Bader and Will's excavations revealed a clear stratigraphic sequence at Holley Shelter, with archaeological evidence including material excellent organic preservation and clearly delineated anthropogenic hearth features. The sedimentology of the tool-bearing layers clearly matches Cramb's original description, as does that of the underlying layers, providing support for the accuracy of Cramb's descriptions.

The low proportion of debitage to finished tools, particularly when compared to assemblages from coastal sites in KwaZulu-Natal, suggests that the tools were not being manufactured on site, and the combination of these with the presence of multiple small hearth features, suggests that the site was repeatedly used as a location for short stays, while the coastal sites were likely to be more permanent settlements.

Bader and Will uncovered numerous pieces of charcoal from both artefact-producing layers at Holley Shelter, which opens the potential to establish a timeline for the site based upon radiocarbon dating. The excellent preservation of much of the organic material recovered from the site also has the potential to reveal much about the climate and ecology of the interior of KwaZulu-Natal during the Late Pleistocene, data which is at present not available. Furthermore, the archaeological evidence has much to tell us about the people living in this area at the time, and how they interacted with the wider environment.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Friday, 2 December 2022

Magnitude 5.7 Earthquake in Hormozgan Province, Iran.

The United States Geological Survey recorded a Magnitude 5.7 Earthquake at a depth of 4.7 km roughly 49 km to the northeast of the port of Bandar-e Lengeh in Hormozgan Province, Iran, slightly after 6.45 pm local time (slightly after 3.15 pm GMT) on Wednesday 30 November 2022. There are no reports of any damage or casualties associated with this event, but many people in the United Arab Emirates reported feeling it.

The location of the 30 November 2022 Hormozgan Province Earthquake. USGS.

Iran is situated on the southern margin of the Eurasian Plate. Immediately to the south lies the Arabian Plate, which is being pushed northward by the impact of Africa from the south. This has created a zone of faulting and fold mountains along the southwest coast of the country, known as the Zagros Thrust Belt, while to the northeast of this the geology is dominated by three large tectonic blocks, the Central Iran, Lut and Helmand, which move separately in response to pressure from the south, stretching and compressing the rock layers close to the surface and creating frequent Earthquakes, some of which can be very large.

The movement of the Arabian Plate and extent of the Zagros Thrust Belt. Rasoul Sorkhabi/Geo ExPro.

The population of Iran is particularly at risk from Earthquakes as, unlike most other Earthquake-prone nations, very few buildings in the country are quake-resistant. The majority of residential buildings in Iran are made of mud-brick, a building material particularly vulnerable to Earthquakes as the bricks often liquefy, trapping people inside and quickly asphyxiating them with dust. This is particularly dangerous at night when the majority of people are inside sleeping.

Section through the Zagros Fold Belt. Sarkarinejad & Azizi (2007).

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Wednesday, 30 November 2022

Eruption on Mauna Loa Volcano, Hawai'i.

Mauna Loa Volcano, located on Big Island Hawai'i, and considered to be the world's largest active volcano, began erupting at about 11.30 pm local time on Sunday 27 November 2022 (about 9.30 am on Monday 28 November GMT), producing effusive lava eruptions from the Moku‘āweoweo Caldera. By the following morning, the eruptive activity had migrated to the upper Northeast Rift Zone, producing lava streams descending the volcano's northern flank. An initial ash advisory was issued but quickly withdrawn, and no properties are currently threatened by the lava flows, which are all contained within the Hawai‘i Volcanoes National Park.

Lava flows moving northeast downslope of Mauna Loa volcano from the Northeast Rift Zone eruption, observed from Saddle Road at 6.00 am Hawai'i time on 29 November 2022. United States Geological Survey.

Mauna Loa is a shield volcano (broad, dome-shaped volcano) made up largely of successive layers of basalt lava, which have been flowing from fissures on roughly the same spot for about 700 000 years. The volcano has risen from a seafloor 5000 m beneath the surface to its current altitude of 4170 m above sealevel, making it the world's tallest mountain of any sort (Everest reaches higher, at 8848 m above sealevel, but rises from the Tibetan Plateau, more than 5000 m above sealevel, so it's height is much lower). The volcano covers an area of about 5271 km², and makes up about half the area of Big Island.

Aerial photograph of the dominant fissure 3 erupting on the Northeast Rift Zone of Mauna Loa, taken at approximately 8.00 am Hawai'ian Standard Time on Tuesday 29 November 2022. Fountains were up to 25 m high, and the vent was feeding the main lava flow to the northeast. United States Geological Survey.

Despite being a highly active volcano (with 33 eruptions since 1843), Mauna Loa is not considered to be a particularly dangerous volcano, and injuries associated with its eruptions are rare. This is because most of the activity on the volcano is in the form of slow moving lava flows, which most people are capable of simply walking away from. The last eruption on Mauna Loa occurred in 1984, when lava flows reached within 8 km of the town of Hilo, the largest settlement on Big Island, causing no damage or injuries. However, since the 1980s the population of Big Island has more than doubled, increasing the risk of lava flows reaching populated areas.

Aerial photo captured during an overflight of the Northeast Rift Zone eruption of Mauna Loa between 5.00 and 6.30 pm Hawai'ian Standard Time on 28 November 2022. This photo shows fissure vents erupting above 3 km above sealevel on the Northeast Rift Zone of Mauna Loa. Civil Defence Patrol/United States Geological Survey.

The islands of Hawai'i have formed as a result of hotspot volcanism, with a mantle plume hotspot currently located under Big Island, Hawai'i, and each of the other islands being the result of previous activity from the same hotspot, with the oldest Islands in the northwest and newest in the southeast. A volcanic hotspot is an area where magma from deep inside the Earth is welling up through the overlying plate (in this case the Pacific) to create volcanism at the surface. Volcanoes move as they erupt, swelling as magma enters their chambers from bellow, then shrinking as that magma is vented as lava.

The position of the Hawai'i Hotspot relative to the islands of Hawai'i. Joel Robinson/USGS/Wikimedia Commons.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Tuesday, 29 November 2022

Investigating burial customs in Bronze Age Finland.

Bronze age Scandinavian burial practices are well documented from southern Norway and Sweden, as well as Denmark, where a wide range of burial styles, including large elite burial mounds, gallery graves, cairns and flat ground cemeteries. Away from this area the range of practices is much less diverse. In Finland, where the Bronze Age is thought to have lasted from about 1800 to about 500 BC, the only form of burial known from this period is the cairn. There are, however, a very large number of these cairns, some estimates suggesting as many as 10 000, of which only a tiny fraction have ever been excavated. Furthermore, many of the cairns that have been investigated have yielded no archaeological material. Where material has been found beneath cairns, the most common thing recovered is burned Human bone, apparently produced when the dead were cremated. Since many of the cairns which have been investigated were excavated at a time when methods in archaeology were rather less vigorous, it is possible that many of these also contained burned bone, but that this was overlooked. However, there are other possible explanations for the boneless cairns; they may have formerly contained unburned burials in wooden coffins (something known from southern Scandinavia), which would have decomposed far more quickly than burned bone in the acidic soils present across most of Finland. Alternatively, the interpretation of these sites as burial cairns may be completely wrong, they may simply represent piles of rocks formed as agricultural land was cleared, as landmarks used by sailors, indicators of land ownership, or sacred sites of some other, non-burial related nature. These possible explanations have been debated for over a century, without any evidence being found to favour one theory over another. 

Bronze Age cairns in Finland, particularly those found close to the coast, tend to be different to those constructed in the Stone Age (9000-1800 BC), being more monumental in nature. The largest of these Bronze Age cairns are the largest prehistoric monuments in Finland. The practice of cremating the dead appears to have been introduced to Finland at the beginning of the Bronze Age, and to have persisted till the end of the Iron Age, which in Finland is placed at 1050 AD. However, the way in which the cremated remains were buried changed considerably over that time, starting with large stone cairns in the Early Bronze Age, which shrank over time. Later a soil infill between the stones appeared, eventually progressing to the remains being buried beneath the ground in flat cemeteries. 

In a paper published in the International Journal of Osteoarchaeology on 9 June 2022, Kati SaloJarkko Saipio, Maddie Hentunen,  Kristiina Mannermaa, and Markku Oinonen of the University of Helsinki, present a review of cremated bone remains from cairn burials in Bronze Age Finland held in the National Museum of Finland, and provincial museums in Finland. They examine the number of burials beneath each cairn, the location of the cairns in relationship to resources such as agricultural land, and the health of those buried, as reflected by pathologies detectable on the cremated remains. They also look at the distribution of the cairns across Finland, and their timescale, introducing a number of new carbon-dates, and compare the burials to Bronze Age burials elsewhere in Scandinavia and around the Baltic Sea. Salo et al. aim to understanding the relationship between the changing use of food resources, health of the population, and burial customs over the course of the Bronze Age in Finland.

Bone material from 218 cairns was examined, including material from 76 cairns in the Satakunta Region of central Finland, where the densest concentrations of cairns are found, 50 cairns from the northern coast of Ostrobothnia, most of which have been shown to be Iron Age in origin, 36 cairns from the Southwest Finland Region, 33 cairns from the southern coast of the Uusimaa and Kymenlaakso regions, 16 from inland regions, and 7 from the Åland Islands.

Location of the cairn burial sites in this study. Dashed lines represent land uplift isobases. As the land uplift is greatest in the Ostrobothnian area (northern coast), these cairns have also mostly been located near the coastline in the Bronze Age. Wesa Perttola in Salo et al. (2022).

The study concentrates on the Bronze Age, and includes material from 118 cairns dating to this period, but also includes material from 57 Iron Age cairns, 37 cairns that may be either Bronze Age or Iron Age, and 6 cairns that have been shown to contain material from both the Bronze and Iron ages.

The cairns range from 1.6 to 21 m in width, 1 to 20 m in width, and 0.2 to 3 m in height, with an 'average' cairn being roughly 8 m long, 7 m wide, and 1 m high. Ninety seven of the cairns are built on top of identifiable stone rings, made of larger stones than the rest of the cairn, 31 are built around large individual boulders, and 24 are built around stone cists (small stone-built coffin-like boxes or ossuaries used to hold the bodies of the dead).

Bronze Age cairn in Satakunta (Kaupinvuori in Rauma). Leena Koivisto in Salo et al. (2022).

The most common item recovered from the cairns other than bone was ceramic, with 58 cairns producing ceramic fragments. This was followed by iron artefacts, recovered from 42 cairns, bronze objects, recovered from 41 cairns, quartz, 41 cairns, flint, 18 cairns, other lithic items, 37 cairns, and burnt clay, 14 cairns. However, some of the ceramic, stone, and burnt clay items may have come from Stone Age settlements overlain by the cairns, while some of the metal items may post-date cairn construction.

Salo et al. obtained 15 new carbon dates from bone fragments recovered from 14 cairns during the course of the study. These were added to previously obtained carbon dates, contributing to a growing chronological database for Bronze Age Finland. Altogether, 67 dates have now been obtained from 43 cairns. This dating of cairns in Finland has enabled the connection of cairn-building activities to be connected to other events in ancient Finland, such as shifting shorelines.

Nine of the new dates obtained by Salo et al. were from Satakunta, and six were from the Åland Islands. Thirteen were obtained from cremated Human bone, one from cremated Dog bone (which was found with cremated Human bones), and one from a Sheep or Goat bone. The two bones dated from the same cairn were the Dog bone and a Human bone, both from a cairn in the Åland Islands, with both dating from the Late Bronze Age. The Sheep or Goat bone was of Iron Age origin.

The dates obtained showed that many late Bronze Age cairns in Satakunta were built on top of Late Neolithic or Early Bronze age settlements, something which had previously been suspected, but which archaeologists had been unable to confirm by now. Late Bronze Age cairns in Satakunta were also often built around large solitary stones, generally glacial erratics (large stones deposited away from their source after being carried by glaciers). Furthermore, they demonstrate a connection between the distribution of Late Bronze Age cairns and agricultural land; in the Early Bronze Age cairns tended to be built on high up on prominent features, while Late Bronze Age cairns are typically located close to good agricultural land, and often known Bronze Age settlements. In Gotland (Sweden) the Late Bronze Age saw the appearance of permanent settlements, and across southern Scandinavia population levels are known to have risen from about 1000 BC onwards, leading people to expand into new areas. These changes are likely to have been linked to changing economic circumstances. An increase in the number of bronze artefacts originating from Scandinavia has also been recorded in Satakunta in the Late Bronze Age, something not observed in other parts of Finland. 

Salo et al. were able to identify the remains of a minimum of 212 individual Humans from 164 cairns. The majority of the cairns (132) nappeared to hold only a single burial, with 32 cairns holding the remains of between two and five individuals. The single cairn that contained the remains of at least five individuals also yielded Iron Age material, but with a single Bronze Age metal item. Two cairns in the Luistari cemetery in Eura were shown to contain at least four individuals. Both appear to have been repeatedly used over a long period of time, but with their oldest remains dating to the Late Bronze Age. 

Five left zygomatic bones (cheekbones) from the Salo Palomäki Cairn, indicating a minimum of 5 individuals were buried beneath the cairn. Kati Salo in Salo et al. (2022).

Iron Age cairns were more likely to contain multiple burials than Bronze Age cairns, although it is also possible that all the cairns contained more individuals than have been recorded, since the numbers are based upon the minimum number of individuals that could have produced the recovered remains. One Iron Age site, Cairn 89 from Rieskaronmäki, in Nakkila, in the Satakunta Region, is thought to contain five-to-six individuals, buried at different locations within the cairn over a period of about 270 years, based upon radiocarbon dates.

Single-burial cairns are also common in Bronze Age Sweden, although here double-burials are more common. Salo et al. also note that several other burial types are present in Bronze Age Sweden, and that in some of these multiple burials are more common. 

Ninety five cairns were shown to contain identifiable Animal bones, 53 of which also contained Human remains. A further 15 cairns contained unidentifiable Animal remains; although in all of these cases the sample of material was very small, i.e. less than 3 g. The majority of these Animal bones were uncremated; 27 of the cairns were found to contain cremated Animal bones alongside cremated Human remains, but these were all dated to the Iron Age. Additionally, some of the cremated Animal bones found in Bronze Age cairns may actually come from older, Stone Age, settlements covered by the monuments. This absence of cremated Animal remains from Bronze Age cairns in Finland appears to be significant, implying that the burning of Animals with the deceased and/or the deposition of burned Animal remains alongside the deceased, was not a common practice. These practices were common in Middle and Late Iron Age burials in Finland, and in Bronze Age burials elsewhere in Scandinavia. This difference in timing may be linked to the later adoption of field-cultivation in Finland than elsewhere in Scandinavia.

Iron Age cairns in Finland were also more likely to contain artefacts than Bronze Age cairns, and were more likely to be built on top of older settlements, which may also reflect improving agricultural knowledge.

Between fifteen and eighteen individuals from fifteen Bronze Age cairns and seven individuals from Iron Age cairns could be diagnosed with porotic hyperostosis; a pathological condition in which patches of spongy bone form on the cranium as a result of anemia, which in turn may be a result of malnutrition or a genetic condition. A further nineteen cairns, ten of which could be dated to the Bronze Age, produced remains with signs of osteoarthritis.

Porotic hyperostosis in Rauma Huhdanniska (KM2800:17A), Eura Junnila (KM8307:2), Parainen Trollberg (KM20434:2), Harjavalta Kaasanmäki (KM5104:12), Laihia Murhaasto (KM10858:1), and Vöyri Viskusbacken (KM9385:14). Cribra orbitalia from Nakkila Kuusisto site (KM6126:38). Kati Salo in Salo et al. (2022).

Two Iron Age Cairns and two Bronze Age cairns produced remains with signs of having lost teeth before death. Two Bronze Age cairns produced remains with signs of periapical lesions (tissue produced by a bone or tooth in response to an infection), and one Bronze Age and one Iron Age cairn produced remains with signs of  periosteal bone formation, which is generally provoked by an injury. Osteochondritis dissecans, caused by repetitive trauma to a joint, was observed in remains from a Bronze Age cairn, and may also be present in remains from an Iron age Cairn. One Bronze Age cairn produced a vertebra with a possible Schmorl's node, a form of spinal disk herniation, which would probably have been caused by repetitive injury.

Joint conditions. Possible Schmorls node from Eura Kivimäki site (vertebral body, KM 7412:4). Signs of degerative joint disease from Uusikaarlepyy Råbacken (vertebral body, KM24015:20), Nakkila Rieskaronmäki (articular facet of a rib, SatM16455:4), Laihia Riitasaari (body of a cervical vertebra, KM10435:1), Pedersöre EsseLillmossbacken (scapula, glenoid KM10105:9), and Isokyrö Kaaminmäki (atlas, articular facet for dens axis KM10678:60). Possible osteochondritis dissecans (first hand phalanx, proximal) from Eura Uotinmäki (KM5629:232) and Laihia Riitasaari (KM 10435:1) sites. Kati Salo in Salo et al. (2022).

The commonest form of pathology seen in archaeological material is dental. However, teeth seldom survive cremation, and the material used in Salo et al.'s study was no exception to this, with only small fragments of tooth found. Some of the alveolar fragments found showed signs of dental problems - tooth loss and periapical lesions - showing that these conditions were present in the population, but providing little other information. 

Cribra orbitalia and porotic hyperostosis, spongy bone formation around the orbit and cranium, respectively, both of which are caused by chronic iron deficiencies, were observed in several sets of remains. These can be caused by a direct shortage of iron in the diet, by other dietary problems, such as a lack of vitamin B12, or genetic conditions, something which today is most common among people living around the Mediterranean Basin. Similar conditions can also be caused by Malaria, something common in Finland until the early twentieth century.

The mostly densely populated areas in Bronze Age Finland were around the coast, making it highly likely that Fish were an important dietary resource. Remains from archaeological sites close to the coast around Europe over a wide range of times have been shown to be more prone to porotic hyperostosis and cribra orbitalia than inland populations, and it has been suggested that these conditions might have been caused by parasites contracted from Fish. 

The adoption of agriculture has been widely linked to declining health in many Human populations, and the Bronze Age is thought to have been the period during which agriculture became widespread in Finland.

Cribra orbitalia and porotic hyperostosis have been shown to be rare in populations from the Neolithic-Bronze Age transition in southern Sweden, and the Late Bronze Age of Estonia. These conditions have been shown to be very common in Early Bronze Age Poland, where they are found in more than 20% of the population, however, this is in a sample of remains with much better overall preservation, so direct comparison is difficult.

The other common pathology found in the collection is marginal osteophytes, or signs of osteoarthritis. This is found in 10 individuals, who are typically older than the majority of the samples. Of the 10 individuals, all but one were found in Satakunta, and all but one were found in cairns built on top of former settlements. The majority of the remains with osteophytes appear to have been male, which is common in ancient populations. This may be a sign that the individuals had been undertaking hard physical labour, associated with agriculture, which is believed to have been adopted in Satakunta before other regions of Finland. The practice of building cairns on top of former dwelling sites appears to have been linked to the adoption of agriculture, something which had happened by the Late Bronze Age in Satakunta, but which did not happen until the Iron Age in other parts of Finland. Other studies have shown that early agriculturalists were particularly prone to osteoarthritis of the vertebral joints, which seems to be the area most affected in the individuals from Satakunta.

Another practice that appears to have been adopted earlier in Satakunta than other areas is that of placing more than one individual beneath the same cairn. These cairns with more than one internment were also the ones which had the highest rates of osteophytes and porotic hyperostosis, with these individuals also being more likely to be male. Thus these were older male individuals who had been involved with hard manual labour, probably agriculture related, and were suffering from iron-deficiency, something also associated with the adoption of agriculture, which led to lower levels of meat consumption. Analysis of Animal bone from Late Bronze Age cairns in Satakunta suggests that Seal meat was disappearing from the diet at this time. 

Other pathologies, such as trauma or periostitis, were much less common, but this does not mean that they were absent from the population. Other studies of cremated remains have shown that these are generally much less common, suggesting that this is related to the cremation process, rather than the health of the population, possibly because new bone growth tends to split away from older bone when burned. Degenerative joint disease and porotic hyperostosis are more likely to survive cremation, and have been shown to be more common in other populations where cremation was practised.

It is likely that future excavations will uncover more remains from cairns in Finland, and that this will lead to a more detailed understanding of cairn-building people and the lives they lead. Salo et al. suggest that more detailed studies of Iron Age cairns may lead to a better understanding of the transition to an agricultural lifestyle across Finland. 

Strontium isotope analysis could potentially be used to determine the origin of the individuals within the cairns. Studies using this method have been carried out in Estonia, and Gotland (Sweden), where genetic analysis of Bronze Age burials has also been undertaken, although this is not likely to be possible in Finland, where cremation appears to have been a universal practise, as DNA cannot usually be recovered from cremated remains.

The Bronze Age is the earliest period in Finland where sufficient remains exist for a large scale comparison between sites, and Salo et al.'s study provides insights into this little-known area of the European Bronze Age. The common Bronze Age practise appears to have been to bury a single individual beneath a large cairn, although this appears to have changed over time, with multiple burials appearing in the Late Bronze Age and becoming more common in the Iron Age, apparently reflecting a change in burial custom associated with the spread of agriculture. These single burials appear to have been much less likely to have been accompanied by Animals or artefacts than contemporary burials in southern Scandinavia, probably reflecting cultural and economic differences between the two areas. Porotic hyperostosis is more common than in other Bronze Age populations around the Baltic Sea, and osteophytes are seen to appear earlier in Satakunta than other areas of Finland, apparently connected to an earlier adoption of agriculture.

See also...


Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Thursday, 24 November 2022

Acanthaster benziei: A new species of Crown-of-thorns Starfish from the Red Sea.

Crown-of-thorns Starfish, Acanthaster spp., are highly distinctive Starfish found across the tropical Indo-Pacific region from the east coast of Africa to the west coast of Mexico, which get their popular name from the covering of long, venomous spines found in most species. They are typically corallivorous, feeding on Coral Polyps by extruding their stomachs and digesting them externally. Notably, Crown-of-thorns Starfish can undergo sudden rapid population increases, known as outbreaks, which can lead to large areas of Coral Reefs being denuded of their living Polyps, something of great concern to conservationists at a time when Coral Reefs are facing a range of other threats, which has led to them being one of the most extensively studied groups of Marine Invertebrates.

Crown-of-thorns Starfish were first described by the German naturalist Georg Eberhard Rumphius in 1705, and given their own generic name, Acanthaster, by the French palaeontologist François Louis Paul Gervais  in 1841. For a long while, only two species were described within the genus, Acanthaster planci, the typical, long-spined, venomous, corallovorous form, and Acanthaster brevispinus, a shorter-spined, non-venomous form, which does not feed on Corals. However, genetic studies carried out within the past three decades have shown that Acanthaster planci is in fact a species cluster, made up of a number of physically very similar species (cryptospecies), which are nevertheless genetically distinct, which often appear to have diverged from one-another a long time ago. 

Based upon this, it was suggested that the original species should be split into four different species, each inhabiting a different geographical area; the Pacific, the Southern Indian Ocean, the Northern Indian Ocean and the Red Sea, which each of these species probably needing further division into several subspecies. Subsequent studies have indeed confirmed that the Pacific, North Indian Ocean, and South Indian Ocean populations are in fact separate species, although genetic material from the Red Sea population has not, until now, been available.

In a paper published in the journal Zootaxa on 17 November 2022, Gert Wörheide of the Department of Earth and Environmental Sciences Palaeontology and Geobiology, and the GeoBio-Center at Ludwig-Maximilians-Universität München, and the Bavarian State Collection of Palaeontology and Geology, Emilie Kaltenbacher and Zara-Louise Cowan, also of the Department of Earth and Environmental Sciences Palaeontology and Geobiology at Ludwig-Maximilians-Universität München, and Gerhard Haszprunar, also of the GeoBio-Center at Ludwig-Maximilians-Universität München, and of the Bavarian Zoological State Collections, describe the Red Sea population of Crown-of-thorns Starfish as a new population.

The new species is named Acanthaster benziei in honour of marine biologist John Benzie, for his extensive work on Crown-of-thorns Starfish. The description is based upon four specimens collected from species within the territorial waters of Saudi Arabia by  Sara Campana and OliverVoigt in 2017.

Typical colouration of Acanthaster benziei. (A) GW4081 (Paratype, hiding during the day under a crevice), Al-Lith, Saudi Arabia, (B)–(D) Thuwal Reefs, Saudi Arabia. Approximate diameter of specimens is 25–30 cm. Oliver Voigt & Gert Wörheide in Wörheide (2022).

Acanthaster benziei is a large Starfish with a convex disk and 11-14 arms (the range for the genus being 10-25), of uneven lengths, and tapering to a point. Each arm has two rows of ambulacral tube feet, which have flattened tips and lack suckers. The central disk of the species is 28-65 mm across, with an aboral (upper surface) covered in papulae (pimples) arranged in an apparently random manner. Both surfaces are covered in calcareous ossicles (plates) and spines. These Starfish are grey-green to grey-purple in colour, although the aboral spines are orange or red. The papulae on the aboral surface of the central disk can form darker patterns, giving this surface a 'bulls-eye' appearance.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Tuesday, 22 November 2022

Magnitude 5.6 Earthquake in West Java kills at least 162 people

The Baden Meteorologi, Klimatologi, dan Geofisika recorded a Magnitude 5.6 Earthquake at a depth of 10 km in the Cianjur Districs of West Java Province, Indonesia, slightly after 1.20 pm local time (slightly after 6.20 am GMT) on Monday 21 November 2022. The event triggered a series of landslides, as well as causing a large number of building collapses, and is now known to have killed at least 162 people. 

The approximate location of the 21 November 2022 West Java Earthquake. United States Geological Survey.

Many of those who have died are reported to have been children, with at least one school having been severely damaged by the Earthquake, which struck with very little warning. Many homes have also been destroyed and damaged, a hospital in Cianjur District damaged. Much of the area has been left without power, and many roads have been damaged, making communication with more remote areas very difficult. Nurses from the Indonesian Red Cross are reported to be trying to reach several remote villages on motorbikes.

Damage to a school in the Cianjur District of West Java, Indonesia, following an Earthquake on 21 November 2022. ABC News.

The Indo-Australian Plate, which underlies the Indian Ocean to the south of Java, Bali and Lombok, is being subducted beneath the Sunda Plate, a breakaway part of the Eurasian Plate which underlies the islands and neighbouring Sumatra, along the Sunda Trench, passing under the islands, where friction between the two plates can cause Earthquakes. As the Indo-Australian Plate sinks further into the Earth it is partially melted and some of the melted material rises through the overlying Sunda Plate as magma, fuelling the volcanoes of Java and neighbouring islands.

Subduction along the Sunda Trench beneath Java, Bali and Lombok. Earth Observatory of Singapore.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.