Sunday 25 September 2022

Tulipa toktogulica: A new species of Tulip from the western Tien-Shan Mountains of Kyrgyzstan.

Tulips, Tulipa spp., are one of the most instantly recognisable groups of flowers, with their popularity supporting a billion Euro cultivation industry, and the Plants being considered culturally important in many countries. Despite this, the taxonomy of the group is still somewhat unclear, with estimates of the number of known species varying between 70 and 100, depending on the classification system used. This is because Tulips are highly variable in traits such as flower shape, colour, and even genome size, even within species, making the delimitation of species difficult, and often debatable.

In a paper published in the journal Phytotaxa on 22 September 2022, Brett Wilson of the Department of Plant Sciences at the University of Cambridge, Georgy Lazkov of the Institute of Biology at the National Academy of Sciences of the Kyrgyz Republic, Kaiyrkul Shalpykov of the  Institute of Chemistry and Phytotechnology at the National Academy of Sciences of the Kyrgyz Republic, and Samuel Brockington, also of the Department of Plant Sciences at the University of Cambridge, describe a new species of Tulip from the Toktogul area of the JalalAbad Region, in the western Tien-Shan Mountains of Kyrgyzstan.

Map of specimens collected for the phylogenetic analysis, excluding Tulipa iliensis and Tulipa altaica, which both lacked GPS information. Populations of the new species Tulipa toktogulica are labelled in order of discovery. Wilson et al. (2022).

The new species is named Tulipa toktogulica, in reference to the region where it was found. It is established as a new species on the basis of analysis of analysis of four regions of the genome, which established Tulipa toktogulica as the sister species to a group comprising Tulipa talassica and Tulipa lemmersii.

Tulipa toktogulica only produces three leaves, with the outermost reaching about 125 mm in length and 15 mm in width, and a solitary flower, about 35 mm in length, slightly fragrant and yellow in colour, apart from the red outer tepals. 

(A) Side view of a flower. (B) Flower from above. (C) Side view of a closed flower. (D) Inner and outer tepals, stamen and ovary. (E) Prolonged tunic on bulb. (F) Seed pod. (G) Habitat at population one. (H) Habitat at population two and three. (I) Habitat at population four. Brett Wilson in Wilson et al. (2022).

Only four populations of Tulipa toktogulica are known, all from the area to the northeast of the Toktogul Reservoir, with one of these, s in pastureland of the Zagyra Mountains to the south-east of Torkent, in an area heavily grazed by Sheep and Cattle. Wild collecting of Tulips occurs in the area, but there is no commercial trade in the flowers. On the basis of the small number of known populations, and the threat presented to them by overgrazing and climate change, Brett et al. recommend that Tulipa toktogulica be classified as Endangered under the terms of the International Union for Conservation of Nature's Red List of Threatened Species.

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Saturday 24 September 2022

Jupiter comes to opposition.

The planet Jupiter will come to opposition (be directly opposite the Sun) at 7.25 pm GMT on Monday 26 September 2022. This means that it will be at its closest to the Earth this year, about 3.95 AU (3.9 times the average distance between the Earth and the Sun, or about 591 295 000 km), and completely illuminated by the Sun. While it is not obvious to the naked eye observer, the planets have phases just like those of the Moon; being further from the Sun than the Earth, Jupiter is 'full' when directly opposite the Sun.  

The orbit and position of Jupiter and the planets of the Inner Solar System on 26 September 2022. In the Sky.

While the relative positions of the planets have no direct influence on life on Earth, the opposition of Jupiter does present the best opportunity for observations of the planet by Earth-based observers. On Monday 26 September Jupiter will appear as a bright object in the constellation of Pisces. Seen through a moderate sized telescope both the planet and its larger moons should be visible, and coming the day after a New Moon, viewing will potentially be very good this year.

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Warnings issued to mariners and aviators after Home Reef Volcano, Tonga, erupts eight times in forty eight hours.

Warnings have been issued to air and sea traffic after Home Reef Volcano, an ephemeral island volcano in Tonga, erupted eight times in a 48 hour period between 18 and 20 September 2022. Aviators have been warned not to approach within three kilometres of the volcano, due to the dangers of volcanic ash to aircraft engines, and mariners have been advised not to approach the volcano and to be vigilant for rafts of floating pumice (volcanic rock with numerous large pore-spaces which can float on water), which can be damaging to boats.

Image of an eruption on Home Reef captured by the Operational Land Imager-2 instrument on the Landsat-9 satellite on 14 September 2022. NASA/Earth Observatory.

Home Reef is usually beneath the water, but the formation of temporary islands from ash effusions which are subsequently washed away has previously recorded in 1852, 1857, 1984 and 2006. The volcano began to erupt again on 10 September 2022, and by 17 September had formed an island with an area of 24 300 m², which by 23 September had grown to 32 375 m².

Home Reef lies on the Tonga/Kermadec Ridge, and is fed by the subduction of the Pacific Plate beneath the Australian Plate along the Kermadec/Tonga Trench. As the Pacific Plate sinks into the Earth, it is warmed by the heat from the planets interior. This leads to partial melting of the Pacific Plate, with some of the melted material rising through the overlying Australian Plate as magma, fuelling the volcanos of the Kermadec/Tonga Ridge.

Diagram showing subduction along the Tonga Trench, and how this feeds the volcanoes of the Tonga Volcanic Arc. York University.

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Thursday 22 September 2022

Gastroliths, Theropod teeth, and Plant remains associated with an Ornithopod skeleton from the Early Cretaceous of Montana.

The Ornithopod Dinosaur Tenontosaurus tilletti is known from about 80 skeletons and partial skeletons, recovered from the Early Cretaceous Cloverly Formation of Wyoming and Montana. Slightly older skeletons from other sites in the American Midwest have been assigned to a second species of TenontosaurusTenontosaurus dossi. The Cloverly Formation also produces a variety of other Dinosaur skeletons, including Ankylosaurs, Sauropods, Ornithomimids, Hypsilophodonts, and Dromaeosaurids, as well as Turtles, Frogs, Crocodiles, and Triconodont Mammals.

In a paper published in the journal Cretaceous Research on 11 August 2022, John Nudds and Dean Lomax of the Department of Earth and Environmental Sciences, at the University of Manchester, and the late Jonathan Tennant, formerly of the Institute for Globally Distributed Open Research and Education, describe some material associated with a specimen of Tenontosaurus tilletti obtained from the Cloverly Formation in Montana, and currently in the collection of the University of Manchester Museum.

The specimen, MANCH LL.1227, was found on the Kelly Ranch in Wheatland County, Montana, by rancher Robert Kelly in 1994, and obtained for the Manchester Museum by John Nudds in 1999, where it became the centrepiece of the (then) newly refurbished Fossil Gallery. The fossil was prepared and mounted, and came with what were described as 'gastroliths' and 'Cycad seeds' found in the stomach region, and two 'Deinonychus teeth' found associated with a cervical vertebrae, and was described as having arthritis in one hand. The specimen was replaced as the centrepiece of the gallery in 2004, when it was replaced with a cast of a Tyrannosaurus skeleton, and placed into storage. The specimen was later studied by Jonathan Tennant, and fully described as a Master's Thesis, published on the arXiv database.

Tenontosaurus tilletti skeleton (MANCH LL.12275) fully articulated and mounted in bipedal stance for 1999 Lottery-funded gallery display at Manchester University Museum. Nudds et al. (2022).

The specimen has been disassembled, although parts of it remain attached to the metal frame upon which it was displayed. Some parts of the skeleton have been modified, mostly by the addition of plaster sections to make up for missing bones or portions of bones. Many of the more slender bones of the skeleton are broken, some beyond repair, while others, such as the ossified tendons, are missing. The whole was painted with a coloured varnish, which has now been removed. The museum intends to reconserve the skeleton for inclusion in a future display.

Various associated materials were obtained along with the skeleton. These include twelve stones identified as gastroliths and two spherical objects identified as Cycad seeds which were found in the gut region of the skeleton, as well as two Theropod teeth, identified as Deinonychus antirrhopus, which were associated with the cervical vertebrae, and a sample of the sediment in which the fossil was buried, identified as volcanic ash.

Gastroliths (MANCH LL. 12278a-l) found in the gastric region of MANCH LL.12275. Scale bar is 3 cm. Nudds et al. (2022).

The gastroliths, if correctly identified, would lend support to the theory that early-branching Ornithopods, such as Tenontosaurus tilletti, lacked the chewing capacity of later branching forms such as Hadrosaurs. Gastroliths have been found in three Orinithopod specimens to date, all of which were early-branching forms, namely Gasparinisaura cincosaltensis, from the Late Cretaceous of Argentina, Haya griva, from the Late Cretaceous of Mongolia, and Changmiania liaoningensis, from the Early Cretaceous of China. Possible gastroliths have also been reported from Notohypsilophodon comodorensis, also from the Late Cretaceous of Argentina. Therefore, if the pebbles associated with MANCH LL.12275 are in fact gastroliths, then they are the second oldest known example of such in an Ornithopod. The specimen came with a (less than perfect) photograph of the stones in place within its body cavity, and with no other such pebbles visible elsewhere. Furthermore, the specimen was buried within a fine-grained matrix, from which such pebbles are unlikely to have been derived, and within which any pebbles present are unlikely to have been preferentially sorted to form an accumulation. On the basis of this, Nudds et al. conclude that, while they cannot completely rule out another origin, the most likely explanation for the pebbles is that they were in fact gastoliths.

Also found within the body cavity of MANCH LL.12275 were two spherical objects interpreted as Cycad seeds. These were subjected to computerised tomographic scanning, which revealed that they have an irregular amorphous core, surrounded by an outer radial structure, quite different from the structure of Cycad seeds.

Computerised tomographic scan showing a cross section of one of the spherical structures (MANCH LL. 12279b) revealing internal radial structure with central core. Nudds et al. (2022).

While the structure of these objects rules out a Cycad origin, it is consistent with their being derived from a member of the  Bennettitales, an extinct order of Gymnosperms, which produced cones with a radial structure similar to that seen on the spherical structures. Notably, the structures are very similar to cones of the Bennettitalean Williamsonia from the Late Cretaceous of Vancouver Island.

However, further examinations made by cutting one of the structures into thin sections revealed that the core is composed of iron oxyhydroxides (goethite/limonite), and the outer radial structures are probably the highly insoluble baryte with a feathery texture. Such a composition is highly unlikely to have derived from any plant source, but rather probably formed as the skeleton was exhumed, and nodules of pyrite or marcasite, which nucleated around some form of decaying organic matter as the specimen was first buried, were exposed to oxidising conditions. Under such circumstances these iron minerals will oxidise to goethite/limonite, with iron sulphites and barium ions dissolved within pore fluids being extruded and forming baryte. Thus the structures are thought likely to be of entirely mineral origin, and not informative about the diet of the living Animal.

Two teeth were found associated with one of the cervical vertebrae of MANCH LL.12275, and identified as belonging to the Therapod Dinosaur Deinonychus antirrhopus. One of these teeth has subsequently been lost. The presence of these teeth in association with a skeleton of Tenontosaurus tilletti would appear to be a rare example of a direct predator-prey interaction, something seldom seen in Dinosaurs. Curiously, remains of Deinonychus antirrhopus and Tenontosaurus tilletti are quite often found in association, while Tenontosaurus tilletti remains have never been found in association with even fragmentary remains (such as shed teeth) of other predators known to have been present in the Cloverly ecosystem, such as Crocodiles. The reasons for this are unclear, though the association of two Deinonychus antirrhopus teeth with MANCH LL.12275 does suggest that at least one of these Theropods (it is thought possible that Deinonychus may have hunted in packs) was feeding upon the carcass of this Dinosaur before it was burried.

One of the Deinonychus teeth (MANCH LL. 12277) found associated with the cervical vertebrae of MANCH LL. 12275. Scale bar is 0.5 cm. Nudds et al. (2022).

The sediment layer from which MANCH LL. 12277 was excavated was identified by its discoverers as volcanic ash. However, analysis of the sediment supplied with the specimen found that it was 87% calcium carbonate and 7% silica, with any potentially ash-derived minerals being present only at trace levels. This is unsurprising for the Cleverly Formation, where ash inclusions are rare. 

Determining the way in which extinct prehistoric Animals behaved in life is one of the greatest problems faced by palaeontologists. For the most part, this must be done entirely by analysis of the morphology of the fossils these Animals leave behind, but on rare occasions, it is possible to recover direct evidence of interactions from fossils.

MANCH LL. 12277 is one of the most complete Tenontosaurus tilletti specimens known, and was initially interpreted as providing several lines of evidence about the world that it lived in and how it interacted with that world. The specimen was originally reported to have been found buried in a volcanic ash matrix, neither of these turned out to be true, with the specimen found to be buried in a limestone sand, while the 'Cycad seeds' were found to be diagenetic features of non-biological origin. 

However, the teeth found associated with the skeleton do appear to be evidence of a trophic relationship (i.e. one organism feeding on another), while the presence of gastroliths within the body cavity of the specimen is a new discovery for this species (albeit not an unexpected one), and provides us with insight into this Dinosaurs diet and feeding habits.

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Tuesday 20 September 2022

The September Equinox.

The September Equinox falls on Friday 23 September this year (2022), when the day and night will be of equal length in both of the Earth's hemispheres. The Earth spins on its axis at an angle to the plain of the Solar System. This means that the poles of the Earth do not remain at 90° to the Sun, but rather the northern pole is tilted towards the Sun for six months of the year (the northern summer), and the southern pole for the other six months (the southern summer). This means that twice a year neither pole is inclined towards the Sun, on days known as the equinoxes.

Simplified diagram showing the tilt of the Earth throughout the year. Not to scale. National Weather Service.

The equinoxes fall each year in March and September, with the March Equinox being the Spring (or Vernal) Equinox in the Northern Hemisphere and the Autumn Equinox in the Southern Hemisphere, while the September Equinox is the Autumn Equinox in the Northern Hemisphere and the Spring Equinox in the Southern Hemisphere. On these two days the day and night are both exactly twelve hours long at every point on the planet, the only days on which this happens.

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Monday 19 September 2022

Magnitude 6.8 Earthquake in Taiwan kills at least one.

The Taiwan Central Weather Bureau reported a Magnitude 6.8 Earthquake at a depth of 7.0 km in Taitung County, Taiwan, slightly before 2.45 pm local time (slightly before 7.45 am GMT) on Sunday 18 September 2022. The event is reported to have killed at least one person, with several more injured, and to have caused the collapse of a three story building in Hualien and a bridge in Yuli, as well as damage to numerous other structures.

Rescue workers pulling a five-year-old girl from a collapsed building in Hualien City, Taiwan, following a Magnitude 6.8 Earthquake on Sunday 18 September 2022. AP.

Taiwan has a complex tectonic setting, lying on the boundary between the Eurasian and Philippine Plates, with the Eurasian Plate being subducted beneath the Philippine Plate in the South and the Philippine Plate being subducted beneath the Eurasian in the East. Subduction is not a smooth process even in simple settings, with plates typically sticking together as pressure from tectonic expansion elsewhere builds up, then suddenly breaking apart and shifting abruptly, causing Earthquakes.

The motion of the tectonic plates beneath Taiwan. The University of Memphis.

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Sunday 18 September 2022

New material from the Middle Stone Age Dorothy Garrod archaeological site, in the Olduvai Gorge, Tanzania.

The Olduvai Gorge in Tanzania is famous for its archaeological sites, notably those associated with early Hominins and the appearance of the genus Homo. However, the area also produces later material, and in particular is home to a number of important Middle Stone Age sites, providing incite into a key stage in the development of Modern Humans. The Middle Stone Age material of the Olduvai Gorge is found within the Ndutu Beds, a succession of tuffacious (volcanic ash), aeolian (wind-blown) and fluvial (river deposited) sediments. These beds can be divided into Upper and Lower units, and are overlain by the Naisiusiu Beds, which produce Later Stone Age material.

Various attempts have been made at dating the Ndutu Beds, none of which is considered definitive. In the 1970s, Richard Hay used amino-acid dating to estimate that the Lower Unit of the Ndutu Beds was laid down between 400 000 and 60 000 years ago, while the Upper Unit is between 60 000 and 32 000 years old. In 1993 Paul Manega used  single‑crystal laser fusion to estimate that the Lower Unit is between 450 000 and 210 000 years old, and that the bottom of the Naisiusiu Beds dates from 42 000 years ago, while a decade later a team led by Anne Skinner dated the start of the Naisiusiu Beds to 62 000 years ago using electron spin resonance.

Two sets of fragmentary Human remains have been recovered from the Ndutu Beds, a palate and maxillary arch considered robust by modern standards, and which was consequently assigned to Homo sp., was described by Mary Leaky in 1971, and  partial calvaria (top part of the skull) assigned to Homo sapiens was described by a team led by Whitney Rainer in 2017. Both of these specimens are derived from the Upper Member of the Ndutu Beds, but neither has been directly dated.

The palate and maxillary arch were found at a location called Dorothy Garrod, which is on the northern side of the Main Olduvai Gorge, 200 m to the west of the KK Fault and opposite the junction with the Side Gorge. Mary Leaky believed the material here was related to the Middle Stone Age material from the Ngaloba Beds at Laetoli, but was not able to date it more precisely. In 1990 Audax Mabulla revisited the area, but again was unable to date the location. In the 2010s a team led by Metin Eren gathered a series of Middle Stone Age stone tools from Dorothy Garrod, but were not able to produce a date for the site.

In a paper published in the journal Archaeological and Anthropological Sciences on 18 August 2022, a team led by José Manuel Maíllo‑Fernández of the Department of  Prehistory and Archaeology at the Universidad Nacional de Educación a Distancia, and the Institute of Evolution in Africa at Alcalá University, presents the results of excavations at Dorothy Garrod, carried out in February and July 2018 and February 2019.

The same team previously carried out excavations at  the Victoria Cabrera Site, 400 m to the southwest of Dorothy Garrod, revealing several layers containing Middle Stone Age tools and faunal remains, which they were able to date to between 86 000 and 75 000 years before the present. 

(A)–(C) Location of Dorothy Garrod Site (DGS) and Victoria Cabrera Site (VCS) in the Olduvai Gorge; (D) view of the Dorothy Garrod Site excavation. Maíllo‑Fernández et al. (2022).

All of the exposed sediments at Dorothy Garrod are attributed to the Upper Unit of the Ndutu Formation, and are assumed to be slightly older than the sediments at Victoria Caberera, based upon their stratigraphic context, but has not been dated more accurately than this.

Excavations were carried out to a depth of 3.5 m, exposing a series of layers identified as Levels 1-4. Level 4, at the base of the sequence, is a perfectly sorted and cemented sand layer interpreted as aeolian in origin. Level 3 is a well sorted but poorly cemented tuffaceous silt, also interpreted as aeolian in origin, which yielded a variety of Middle Stone Age material. Level 2 is a well sorted and cemented tuffaceous silt, again interpreted as aeolian in origin, which produced no archaeological material. Level 1 is a well sorted and cemented very fine sand, which again produced no archaeological material.

Stratigraphic section of the Dorothy Garrod Site. Maíllo‑Fernández et al. (2022).

The faunal remains recovered from Dorothy Garrod comprise 247 fragments of bone, 27 teeth and fragments of teeth, two Ostrich shell fragments, and four terrestrial Mollusc shell fragments. Two of the teeth could be identified as those of Equids (Horses, Asses, Zebras etc.), a mandible could be assigned to the Hippotragini (Grazing Antelopes), and four teeth to the Alcelaphini (Wildebeest, Hartebeest, Bonteboks etc.). None of the other tooth or bone fragments could be identified. The bones were generally poorly preserved, at least in part due to the presence of sediment concretions which had affected the surface of many bones. Fifty eight of the bones show evidence of burning, while two (both interpreted as the long bones of Ungulates) have notches cut into them; only one has a carnivore tooth mark.

Faunal remains from the Dorothy Garrod Site. (1) Femur of Ungulate of size 1b with fresh bone breakage; (2) fragment of a femur of an Ungulate of size 2 with generalised sediment concretions; (3) fragment of a vertebra with burning; (4) fragment of a long bone of size 2 with burning damage; (5) fragment of a vertebra of ungulate of size 3 with generalised sediment concretions. Maíllo‑Fernández et al. (2022).

A total of 1179 lithic items were recovered from Level 3 at Dorothy Garrod, 40 of which showed signs of reatouching. Of these tools 113 were excluded from the study due to subsequent alteration, the majority of these being made from phonolite. 

Only six pieces showed signs of rounding (i.e. shaping by being rolled in an aquatic environment), and in only one case was this severe, so hydraulic damage (which can sometimes break rocks in a way that can resemble early stone tools) can be ruled out as a cause of the lithic assemblage. 

The assemblage included 615 blanks (pieces of rock of suitable size and shape to make stone tools from) with pseudo‑retouching (damage which at first site resembled the actions of a toolmaker). The majority of these are likely to have been caused by trampling, but a few may have been caused by a knapping process, in which they were removed from a rock source.

The majority (79.9%) of the tools at Dorothy Garrod are made from Naibor quartzite, a metamophicly recrystalized sandstone which outcrops at Naibor Soit Hill, 2 km to the north of the Olduvai Gorge. Another 8.2% are made from phonolite, derived from the Engelosen Volcano, 7 km to the north, and 3.6% are made of a basalt derived from the Lemagrut Volcano, 10-12 km to the south. The remainder of the material appears to be locally sourced, including sandstone (6.1%), hyaline quartz (1.4%), chert (0.3%), quartzite (0.1%), and gneiss (0.1%).

Only 7% of the blanks were completely covered by a cortex (the natural surface of a rock caused by chemical weathering, which is removed during toolmaking), while 18% had a partial cortex surface; over 75% had no cortex at all on at least one side.

Of the 757 worked blanks found, 458 could not be associated with any toolmaking scheme, while the remainder were either single platform blanks, or prepared core blanks, either discoid or Levallois. There were no bipolar cores.

Discoidal knapping (removing chips to be used as tools from the surface of a rock by working around it in a circular pattern) was the most common toolmaking method, with 26 discoid cores found, and 222 blanks with chips removed in a discoid pattern. Chips had been removed both unifacially (all from one side) and bifacially (from both sides). The most commonly used rock for this was Naibor quartzite, but some basalt and local quartzite were also used. The knapping had been used to produce chordal flakes, pseudo Levallois points, square f lakes, and flakes wider than they are long.

Lithics from Dorothy Garrod. (1) Discoid core; (2)–(4) discoid flakes. All on Naibor quartzite. Maíllo‑Fernández et al. (2022).

Only 24 blanks and 1 core had been exploited using the Levallois technique; forming a striking platform at one end of a stone tool, then trimming the core's edges by flaking off pieces around the outline of the intended lithic flake, prior to separating the tool with a final blow, which creates a tool with a distinctive plano-convex profile, and leaves a core with a rounded 'tortoiseshell' pattern. The core and the majority of the blanks were made using the centripetal Levallois technique, which can be difficult to tell from the discoidal method, and possibly evolved from it, with the remainder using the preferential, unidirectional, and bidirectional variants of the technique. No Levallois points were found.

Single platform knapping had been used to make 38 flakes and a single core. These were again predominantly made of Naibor quartzite, with phonolite, basalt, and hyaline quartzite also used.

Other cores at the site appeared to have been worked using the polyhedric and/or oportunistic methods (which can be hard to tell apart. A single Kombewa flake (large flake made by striking a core from two different sites) was discovered.

The majority of the retouched items were denticulate tools, followed by retouched flakes, notches, and sidescrapers. Two large retouched items were found, a bifacial and a transversal sidescraper. Again, the majority of these were made from Naidor quartzite. 

Lithics from Dorothy Garrod. (1) Unipolar Levallois flake; (2) pseudo Levallois flake; (3) preferential Levallois flake; (4) discoid flake; (5) denticulate on ordinary flake; (6) sidescraper on ordinary flake; (7) Centripetal Levallois core; (8) Centripetal Levallois flake; (9) unifacial discoid core. Raw materials: (1), (2), and (8): basalt; (2)–(7) and (9): Naibor quartzite. Maíllo‑Fernández et al. (2022).

The combination of a plentiful lithic assemblage and faunal remains showing signs of Human modification make the Dorothy Garrod Site a regionally important Middle Stone Age locality. The precise age of this deposit is still unknown, but only an area of 28 m² has been excavated, so it is quite possible that datable material will be uncovered in the future. The material does not appear to be preferentially orientated or abraded, suggesting that it has not been moved significantly by post-depositional processes. 

None of the Mammal remains are well preserved, but the vast majority appear to represent Ungulates, and many show signs of modification, either by burning or breaking. Although burning of bones is common, no charcoal usable for dating was recovered. Evidence of modification of the bones by non-Human predators was almost absent.

The majority of the tools found were made for which a manufacturing technique could be identified were made using the discoidal or Levallois methods, with single platform and opportunistic knapping being much less common, and only a single bifacial tool was found, and Levallois points were completely absent. A small number of tools showed signs of retouching. The majority of the tools were made from Naibor quartzite, sourced from a hill 2 km to the north.

The absence of datable material makes it hard to assess the age of the Dorothy Garrod Site, but it may be contemporary with the Kisele industry, found at Mumba Cave near Lake Eyasi and the Nasera Rockshelter in the Ngorongoro Conservation Area, and the Loiyangalanian industry from Loiyangalani in the Serengeti National Park. However, such comparisons are difficult to make; discoidal manufacture is common at almost all Middle Stone Age sites in East Africa, as is the use of materials obtained fairly locally, and while the tool-making appears closest to the Kisele and Loiyangalanian industries, both unifacial and bifacial points are common components of the Kisele industry, but absent at Dorothy Garrod, and bipolar knapping also absent at Dorothy Garrod, is a common feature at Loiyangalani. The low level of retouching at Dorothy Garrod may reflect the material being used; quartzite lends itself to this far less well than chert (rare at Dorothy Garrod) or obsidian (absent altogether).

Although Maíllo‑Fernández et al. have expanded on previous work at Dorothy Garrod, they consider the site still has much more to reveal. The site records a Middle Stone Age technology along with faunal remains almost certainly left by the tool-makers. The site has not been dated, but based upon comparison to tools from other sites it is probably dates from Marine Isotope Stage 5-Marine Isotope Stage 4 (i.e. is between 130 000 and 71 000 years old).

Further excavations at Dorothy Garrod have the potential to resolve the dating of the site, as well as shedding light upon Middle Stone Age patterns of settlement, and how these people interacted with their environment.

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