Monday, 20 August 2018

Juvenile pedal ungual of a juvenile Spinosaur from the Cretaceous Kem Kem Beds of Morocco.

The Kem Kem Beds of southeastern Morocco and neighbouring areas of Algeria are noted for the production of numerous Late Cretaceous Vertebrate fossils, including Fish, Crocodylomorphs, Turtles, and Dinosaurs, particularly large Theropods. These fossils appear to have come from a wide range of environments, and are poorly sorted stratigraphically (i.e. not arranged in time related order), and are generally thought to be the result of geological mixing.

In a paper published in the journal PeerJ on 30 May 2018, Simone Maganuco and Cristiano Dal Sasso of the Museo di Storia Naturale di Milano describe a pedal ungual (toe claw) from the Kem Kem Beds, which they interpret as having come from a juvenile Spinosaur.

Spinosaurs were exceptionally large Theropod Dinosaurs (the biggest species, Spinosaurus aegyptiacus is thought to have exceeded Tyrannosaurus, Giganotosaurus and Carcharodontosaurus in size, reaching about 11 m in length) with a distinctive morphology, including a long, Crocodile-like snout and a sail on the lower back and tail. The Spinosaurs are divided into two groups, the Baryonychines from Laurasia (North America, Europe and Asia) and the Spinosaurines in Gondwana (Africa, South America, India, Madagascar, Antarctica, Australia and New Zealand, though the group is not known from all these areas). However while the closely related Megalosaurs are well established in the Middle Jurassic, almost all known Spinosaur specimens come from the Cretaceous, making the origins of the group somewhat obscure. 

The specimen described by Maganuco and Dal Sasso is a 18.2 mm in length, though it is thought to have lost about 2 mm from its tip, and closely resembles the pedal ungual of Spinosaurus aegyptiacus, with a flattened profile, a slightly convex upper surface and a porous structure. The specimen is, of course considerably smaller than the pedal ungual of Spinosaurus aegyptiacus, with the holotype for this species (i.e. specimen from which the species was named) having toe claws between 87 and 130 mm in length, however Spinosaurs were Tetanurans, a group which is thought to have changed little in morphology as they grew and developed, and isolated uguals of intermediate size have been referred to the genus Spinosaurus on this basis. Maganuco and Dal Sasso suggest that if the proportions did remain constant in life, then this specimen would have come from a Spinosaur about 1.78 m in length, the smallest known member of the group.

Pedal ungual phalanx of Spinosaurus. Specimen MSNM V6894 in right lateral (A), left lateral (B), dorsal (C), plantar (D), proximal (E), and distal (F) views. Abbreviations: as, articular surface; co, cortex; et, extensor tubercle; sb, spongy bone; vf, vascular furrow. Scale bar equals 5 mm. Michele Zilioli in Maganuco & Dal Sasso (2018).

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Sunday, 19 August 2018

Cretoparacucujus cycadophilus: A Cycad-associated Beetle from Cretaceous Burmese Amber.

Cycad’s are of particular interest to botanists and horticulturalists due to their unique evolutionary heritage; they are Gymnosperms (non-flowering Seed Plants), members of the group that includes Conifers and Ginkos, but among the closest non-flowering relatives of the Angiosperms (Flowering Plants). They large attractive plants, superficially resembling Palms, but producing large and often brightly coloured strobili, structures intermediate between cones and flowers; these are often pollinated by Beetles or Thrips.  Cycads are thought to have originated during the Permian, and became dominant Plants in many ecosystems during the Jurassic and Cretaceous, but suffered heavily during the End Cretaceous Extinction, and there are about 330 species surviving today, predominantly in the Southern Hemisphere, most of which diversity is thought to have arisen from a post-Cretaceous radiation.

In a paper published in the journal Current Biology on 16 August 2018, Chenyang Cai of the Key Laboratory of Economic Stratigraphy and Palaeogeography at the Nanjing Institute of Geology and Palaeontology, the Center for Excellence in Life and Paleoenvironment of the Chinese Academy of Sciences, and the School of Earth Sciences at the University of Bristol, Hermes Escalona of the Centre for Molecular Biodiversity Research at the Museum Alexander Koenig, and the Australian National Insect Collection, Liqin Li, also of the Center for Excellence in Life and Paleoenvironment of the Chinese Academy of Sciences, and of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, Ziwei Yin of the Department of Biology at Shanghai Normal University, Diying Huang, again of the the Center for Excellence in Life and Paleoenvironment of the Chinese Academy of Sciences, and the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, and  Michael Engel of the Division of Entomology at the Natural History Museum of the University of Kansas, the Department of Ecology & Evolutionary Biology, also at the University of Kansas, describe a new species of Cycad associated Beetle from Cretaceous Burmese Amber.

Cretaceous ‘Burmese Amber’ has been extensively worked at several sites across northern Myanmar (though mostly in Kachin State) in the last 20 years. The amber is fairly clear, and often found in large chunks, providing an exceptional window into the Middle Cretaceous Insect fauna. This amber is thought to have started out as the resin of a Coniferous Tree, possibly a Cypress or an Araucaria, growing in a moist tropical forest. This amber has been dated to between 105 and 95 million years old, based upon pollen inclusions, and to about 98.8 million years by uranium/lead dating of ash inclusions in the amber.

The new Beetle is named Cretoparacucujus cycadophilus, where 'Cretoparacucujus' derives from 'Cretaceous' and 'Paracucujus', a modern genus of Beetles to which the nes species is thought to be related, and 'cycadophilus' means 'Cycad-lover'. It is considered to be a member of the Boganiidae, a small group of Beetles related to Ladybirds and Fungus Beetles, which are specialist pollen-feeders and pollinators, and within that group to the Paracucujinae, which are pollen-feedimg Beetles found today in southern Africa, Australia and New Caledonia.

Cretoparacucujus cycadophilus. (A) General habitus, dorsal view, under epifluorescence. (B) Head, dorsal view, under normal reflected light. Cai et al. (2018).

Cretoparacucujus cycadophilus has a large, wide head and a smooth, hairless surface. It has large hair-lines cavities on its mandibles, a feature associated with pollen-feeding. It appears to be closely related to the living genera Paracucujus from southwestern Australia, which is associated with the  Cycad Macrozamia riedlei, and Metacucujus, which is found in Southern Africa and associated with Cycads of the genus Encephalartos.

The Beetle was found associated with a number of pollen grains which appear to have been derived from a Cycad. Cai et al. note that such pollen-grains are hard to identify, as Cycad pollen is similar to the pollen of  Bennettitales, Czekanowskiales, Ginkgoales, Peltaspermales, Pentoxylales, and a few basal Angiosperm lineages, but feel that the excellent three-dimensional preservation of the pollen in amber allows for confident assignment. This is the first time Cycad remains have been described from Burmese amber, either as pollen or as fragments of plant material. The pollen grains are found in clumps, rather than individually, which is generally a feature of Insect (rather than wind) pollination, something which may explain the general absence of Cycad pollen from Burmese Amber.

Photomicrographs of Cycad pollen grains Associated with  Cretoparacucujus cycadophilus. (A) General view of Cretoparacucujus cycadophilus and aggregations of pollen grains by the beetle. (A’) Enlargement of an aggregation of three pollen grains. (A’’) Enlargement of a single grain. (B) Enlargement of three larger aggregations of pollen grains. (C) Enlargement of (B), showing 14 aggregated pollen grains. (D) Enlargement of (B), showing six aggregated pollen grains. Cai et al. (2018).

The Cycads Macrozamia  and Encephalartos are also closely related, forming the Tribe Encephalarteae. Genetic studies have suggested that these Cycads shared a most recent common ancestor in the Miocene, but this is in conflict with their distribution, on two fragments of the Gondwanan continent that split apart in the Jurassic. The discoverey of a Beetle that appears to have been associated with this group of Cycads in amber from the Cretaceous of Myanmar supports the idea that this group of Cycads is more ancient than assumed from molecular-clock evidence.

Geographic distribution of the known entomophilous Cycads of the Tribe Encephalarteae and their Boganiid pollinators. The phylogenetic relationships and divergence time of the widely separated lineages within Boganiinae are shown. The arrow indicates the divergence time estimated by separation of Gondwana in the Jurassic. Abbreviations: AU, Australia; MM, Myanmar; ZA, South Africa. Cai et al. (2018).

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Thursday, 16 August 2018

Fourteen confirmed deaths following explosion at Balochistan coal mine.

Fourteen miners have now been confirmed dead following an explosion at a coal mine in Sanjidi, near Quetta in Balochistan Province, Pakistan, on Sunday 12 August 2018. Nineteen miners were reportedly about 1200 m below the ground when the explosion occurred, and while rescue workers are still attempting to locate the five missing men, their attempts are being hampered by a build-up of piousness gas in the mine, and there is thought to be little chance of finding any survivors.

The approximate location of the Sanjidi coal mine. Google Maps.

Coal is formed when buried organic material, principally wood, in heated and pressurised, forcing off hydrogen and oxygen (i.e. water) and leaving more-or-less pure carbon. Methane is formed by the decay of organic material within the coal. There is typically little pore-space within coal, but the methane can be trapped in a liquid form under pressure. Some countries have started to extract this gas as a fuel in its own right. When this pressure is released suddenly, as by mining activity, then the methane turns back to a gas, expanding rapidly causing, an explosion. This is a bit like the pressure being released on a carbonated drink; the term 'explosion' does not necessarily imply fire in this context, although as methane is flammable this is quite likely.

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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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