Tuesday, 14 August 2018

Projectile points from a pre-Clovis technology from Central Texas.

The Clovis Culture is known from a distinctive range of artifacts, most notably the style of bifaced spear-head known as a 'Clovis Point', found at locations across North America. These artifacts date from between about 13 200 and about 12 900 years ago, and were for a long time presumed to represent the oldest Human culture in the Americas, thought to have spread across the Bering Straight from northeastern Asia into the Americas, and thought to be ancestral to all subsequent cultures in the Americas, until the arrival of Europeans in the last century. However a string of recent finds have uncovered pre-Clovis artifacts at sites across both North and South America, undermining the status of Clovis as the first American culture, though it is still considered an important step in the history of the continents.

In a paper published in the journal Science Advances on 11 July 2018, Thomas Williams and Michael Collins of the Prehistory Research Project at Texas State University, Kathleen Rodrigues of the Division of Earth and Ecosystem Sciences at the Desert Research Institute, and the Department of Geological Sciences and Engineering at the University of Nevada, Reno, William Jack Rink of the School of Geography and Earth Sciences at McMaster University, Nancy Velchoff, also of the Prehistory Research Project at Texas State University, Amanda Keen-Zebert, also of the Division of Earth and Ecosystem Sciences at the Desert Research Institute, Anastasia Gilmer of SWCA Environmental Consultants Inc., Charles Frederick of Dublin, Sergio Ayala, again of the Prehistory Research Project at Texas State University, and Elton Prewitt of the Texas Archaeological Research Laboratory at The University of Texas at Austin, describe a series of pre-Clovis artifacts from the Gault Site in central Texas.

The Gault Site has been excavated since 2002, and has produced Clovis and later artifacts from a series of layered fluvial (river) deposits. from a river floodplain in the Buttermilk Creek Valley. Collins et al. describe a series of new artifacts from a horizon 65-80 cm below the layer that produced they Clovis material, which has been dated to a minimum of 16 000 years ago.

Stratigraphic profile of the Area 15 excavation block showing the diagnostic cultural materials and components alongside the stratigraphic sequence. Diagnostic projectile points listed on the left were all found within the associated deposits (SMH, St. Mary’s Hall). Stratigraphic unit numbers are shown on the right, and the cultural horizons are highlighted in gray. Collins et al. (2018).

Tha Gault Assemblage artifacts include sophisticated bifaced projectile points with long bevelled blades and sometimes stems with concave margins. These points resemble those assigned to the pre-Clovis Western Stemmed Tradition, but are much older, as the Western Stemmed technology has been dated to between 13 500 and 13 000 years ago. They are also in some ways similar to Clovis Points, though they lack some features seen in Clovis material, such as overshot flaking to produce thinned bifaces, and the flaking on the Gault material is not as fine as that typically seen in Clovis tips.

Gault Assemblage artifacts (A) to (D), (F), and (L) Bifaces. (E) Blade core. (G) Quartz projectile point. (H) and (I) Projectile points. (K) Projectile point tip. (M), (V), and (W) Blade. (N) Unifacial tool. (O) and (T) Gravers. (P) Discoidal biface. (Q) End scraper. (R) to (U) Modified flake tools. (X) and (Y) Lanceolate projectile points. Collins et al. (2018).

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Monday, 13 August 2018

Rioting in Hout Bay, Cape Town, after 'poacher' allegedly shot by fisheries compliance officers.

Rioting broke out in the Hout Bay area of Cape Town, South Africa, on Sunday 12 August 2018, following the apparent death of a diver during a confrontation with officials of the Department of Agriculture, Fisheries, and Forestry, on Saturday 11 August. Deurick van Blerk‚ 25‚ from Hangberg, was one of three divers on a boat which was fired upon by an anti-poaching patrol. The other two men were taken into custody on suspicion of hunting for South African Abelone, Haliotis midae, and West Coast Rock Lobster, Jasus lalandii, but van Blerk fell from the boat and has not been seen since, and is presumed to have been shot by the patrol.

Burning vehicles set on fire by protesters following the death of a diver in a confrontation with an anti-poaching patrol. City of Cape Town.
Both South African Abalone and West Coast Lobster are valuable commercial species in the Western Cape, with a system of quotas operated by the Department of Agriculture, Fisheries, and Forestry to prevent over-fishing. Concerns about excess harvesting have led to no permits to collect Abalone being issued for several years, while the Lobsters have a closed season between June and November. Despite this, there is still a highly lucrative harvesting industry, with police seizing Abalone worth an estimated 3.5 million rand from a single illegal drying plant on Sunday 12 August, and several similar events occurring in June and July.

Abalone seized during a raid on an illegal drying plant in Cape Town on Sunday 12 August 2018. South African Police Service.

However, the Department of Agriculture, Fisheries, and Forestry has been accused of unfairly targetting members of the Khoisan community, who claim to be forced to act illegally as they are excluded from the formal licencing system, and that by doing so they are excercising a right to harvest traditional food sources.

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Three dead and one missing as flash floods hit Metro Manila area of Luzon Island, the Philippines.

Three people have been confirmed dead and another one is missing follwing a series of flash floods in the  Metro Manila area of Luzon Island, the Philippines, this week. The three people who died have been identified as RJ Basuecos, 26, of Manila, Dioscoro Camacho, 36, of Marikina, and Gloria Mendoza, 61, of Quezon. The missing man is Edgar Bugaay, 50, of Quezon, who has not been seen since he was swept away by floodwaters on Sunday 12 August 2018. The incidents have been caused by heavy rains associated with the Southwest Monsoon, which lasts from May to October in The Philippines. 

Flooding in Marinka in the Metro Manila region of Luzon Island this week. Reuters.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate.

Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

Much of Southeast Asia has two distinct Monsoon Seasons, with a Northeast Monsoon driven by winds from  the South China Sea that lasts from November to February and a Southwest Monsoon driven by winds from the southern Indian Ocean from March to October. Such a double Monsoon Season is common close to the equator, where the Sun is highest overhead around the equinoxes and lowest on the horizons around the solstices, making the solstices the coolest part of the year and the equinoxes the hottest.  

The winds that drive the Northeast and Southwest Monsoons in Southeast Asia. Mynewshub.

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Sunday, 12 August 2018

Caihong juji: A new species of Deinonychosaur from the Middle-to-Late Jurassic Yanliao Biota of Hebei Province, China.

The Yanliao Biota of northeastern China outcrops across much of  western Liaoning, northern Hebei, and southeastern Inner Mongolia provinces, providing a series of deposits with exceptional preservation laid down over a period of about 10 million years in terrestrial settings. These deposits include the Daohugou phase (about 168–164 million years ago) and the Oxfordian Linglongta phase (164–159 million years ago). These fossils provide a valuable insight into a variety of emerging taxa in across the boundary between the Middle and Late Jurassic, including Insects, Mammals and Paravian Dinosaurs, the group which includes Dromaeosaurs, Troodontids and Birds.

In a paper published in the journal Nature Communications on 15 January 2018, Dongyu Hu of the Paleontological Museum of Liaoning at Shenyang Normal University, Julia Clarke of the Department of Geological Sciences and Integrated Bioscience at the University of Texas at Austin, Chad Eliason, also of the Department of Geological Sciences and Integrated Bioscience at the University of Texas at Austin, and of the Integrative Research Center at the Field Museum of Natural History, Rui Qiu, also of the Paleontological Museum of Liaoning at Shenyang Normal University, Quanguo Li of the State Key Laboratory of Biogeology and Environmental Geology at the China University of Geosciences, Matthew Shawkey of the Evolution and Optics of Nanostructures Group at the University of Ghent, Cuilin Zhao, again of the Paleontological Museum of Liaoning at Shenyang Normal University, Liliana D’Alba also of the Evolution and Optics of Nanostructures Group at the University of Ghent, Jinkai Jiang, once again of the Paleontological Museum of Liaoning at Shenyang Normal University, and Xing Xu of the Key Laboratory of Vertebrate Evolution and Human Origins at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, describe a new species of Paravian Dinosaur from the Late Jurassic Tiaojishan Formation of northern Hebei.

The new species is named Caihong juji, where 'Caihong' means 'rainbow' and 'juji' means 'big crest'. It is described from a single, almost complete skeleton and associated plumage preserved as part and counterpart on a split slab. The specimen is estimated to have been about 400 mm in length, and to have weighed about 475 g when it was alive, and is thought to have been an adult. It had a pair of prominent crests on its lacrimal bones (the bone that joins the nose to the eye-socket in Humans, and the hind-part of the snout in Theropod Dinosaurs), something very unusual in Paravians. Caihong juji is assessed to have been a Deinonychosaur on the basis of its anatomy (i.e. the sub-group of Paravians that includes Dromaeosaurs ans Troodontids, but not Birds.

Caihong juji. Photographs of the slab (a) and counter slab (b) and line drawing (c) of the specimen based on both slabs. Photograph (d) and line drawing (e) of a composite of the rostrum of the skull and mandible exposed on the counter slab and the post-rostrum cranium exposed on the slab. Arrows indicate lacrimal crests. Question mark indicates uncertain identification. Scale bars: 10 cm in (a)–(c), 1 cm in (d) and (e). Abreviations aof, antorbital fenestra; cav, caudal vertebra; cev, cervical vertebra; dr, dorsal rib; dv, dorsal vertebra; ect, ectopterygoid; emf, external mandibular fenestra; en, external naris; f, feather; fu, furcula; ga, gastralia; hy, hyoid; il, ilium; is, ischium; la, left angular; lar, left articular; lc, left coracoid; lcr, lacrimal crest; ld, left dentary; lf, left frontal; lfe, left femur; lh, left humerus; lj, left jugal; ll, left lacrimal; lma, left maxilla; lm, left manus; ln, left nasal; lp, left pes; lpa, left palatine; lpo, left postorbital; lq, left quadrate; lqj, left quadratojugal; lr, left radius; ls, left scapula; lsp, left splenial; lsa, left surangular; lsq, left squamosal; lt, left tibiotarsus; lu, left ulna; ma, mandible; mf, maxillary fenestra; o, orbit; p, parietal; pm, premaxilla; pt, pterygoid; pu, pubis; rar, right articular; rc, right coracoid; rd, right dentary; rfe, right femur; rh, right humerus; rm, right manus; rp, right pes; rpra, right prearticular; rq, right quadrate; rr, right radius; rs, right scapula; rt, right tibiotarsus; ru, right ulna; scl, sclerotic bones; sk, skull; sy, synsacrum. Hu et al. (2018).

Much of the plumage of Caihong juji is exceptionally well preserved, retaining the microstructure of the melanosomes (pigment cells). Comparison of these cells to those of modern Birds leads Hu et al. to conclude that this Jurassic Dinosaur had brightly coloured iridescent plumage.

Platelet-like nanostructures in Caihong juji and melanosomes in iridescent extant feathers. (a)–(d) Fossilized nanostructures from Caihong feathers preserved as molds in a neck feather (a) and three-dimensional preservation in a neck feather, with SEM stage rotated 45° to show 3D platelet morphology; (b) a back feather with SEM stage at 0° (c) and a neck feather showing nanostructure packing; (d), (e) Anna’s Hummingbird, Calypte anna, showing overlapping melanosomes within a feather barbule; (f) White-tailed Starfrontlet, Coeligena phalerata, showing stacking and interior morphology (air bubbles) of melanosomes in a feather barbule; (g) Black-tailed Trainbearer, Lesbia victoriae, showing exterior surface and morphology of isolated melanosomes in a feather barb; (h) Moustached Treeswift, Hemiprocne mystacea, showing densely packed melanosomes in the barbule of a crown feather. Inset in (d) illustrates 3D stacking of platelet-shaped nanostructures. All scale bars are 1000 nm. Hu et al. (2018).

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