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Zigrasimecia
''Zigrasimecia'' is an extinct genus of ants which existed in the Cretaceous period approximately 98 million years ago. The first specimens were collected from Burmese amber in Kachin State, west of Myitkyina town in Myanmar. In 2013, palaeoentomologists Phillip Barden and David Grimaldi published a paper describing and naming ''Zigrasimecia tonsora''. They described a dealate female with unusual features, notably the highly specialized mandibles. Other features include large ocelli, short scapes, 12 antennomeres, small eyes, and a clypeal margin that has a row of peg-like denticles. The genus ''Zigrasimecia'' was originally ''incertae sedis'' (uncertain placement) within Formicidae until a second species, ''Zigrasimecia ferox'', was described in 2014, leading to its placement in the subfamily Sphecomyrminae. Later, it was considered to belong to the distinct subfamily Zigrasimeciinae. Due to the highly specialized mandibles, scientists believe that the ants exhibited habi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zigrasimecia Tonsora JZC Bu-159 Holotype 03
''Zigrasimecia'' is an extinct genus of ants which existed in the Cretaceous period approximately 98 million years ago. The first specimens were collected from Burmese amber in Kachin State, west of Myitkyina town in Myanmar. In 2013, palaeoentomologists Phillip Barden and David Grimaldi published a paper describing and naming ''Zigrasimecia tonsora''. They described a dealate female with unusual features, notably the highly specialized mandibles. Other features include large ocelli, short scapes, 12 antennomeres, small eyes, and a clypeal margin that has a row of peg-like denticles. The genus ''Zigrasimecia'' was originally '' incertae sedis'' (uncertain placement) within Formicidae until a second species, ''Zigrasimecia ferox'', was described in 2014, leading to its placement in the subfamily Sphecomyrminae. Later, it was considered to belong to the distinct subfamily Zigrasimeciinae. Due to the highly specialized mandibles, scientists believe that the ants exhibited hab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zigrasimeciinae
Zigrasimeciinae is a subfamily of ants, known from the Cretaceous period, originally named as the tribe Zigrasimeciini within the subfamily Sphecomyrminae by Borysenko, 2017, it was elevated to full subfamily in 2020. It contains three described genera. They are sometimes known as "iron-maiden ants" in reference to their densely spiked mouthparts, reminiscent of an iron maiden torture device, that were likely used to trap prey. '' Boltonimecia canadensis'' was described from Campanian Canadian amber out of Alberta, Canada, while the species of '' Protozigrasimecia'' and '' Zigrasimecia'' are both exclusively known from Cenomanian Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. ... found in Myanmar. Genera and species * '' Boltonimecia'' ** ''B. canadensis'' *'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphecomyrminae
Sphecomyrminae is an extinct subfamily of ants in family Formicidae known from a series of Cretaceous fossils found in North America, Europe, and Asia. Sphecomyrminae contains eight genera, divided into two tribes Sphecomyrmini and Zigrasimeciini. The tribe Sphecomyrmini contains the six genera '' Armania'', '' Cretomyrma'', '' Gerontoformica'', '' Orapia'', '' Pseudarmania'' and '' Sphecomyrma''; while Zigrasimeciini contains '' Boltonimecia'' and '' Zigrasimecia''. A number of taxa have been removed from the subfamily and placed either in other subfamilies or are now treated as ''incertae sedis'' in Formicidae. Sphecomyrminae is the most basal of the Formicidae subfamilies, but has not been included in several phylogenetic studies of the family. Symplesiomorphies of the subfamily include the structure of the antenna, which has a short basal segment and a flexible group of segments below the antenna tip. The petiole is low and rounded, with an unrestricted gaster and the pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerontoformica
''Gerontoformica'' is an extinct genus of stem-group ants. The genus contains thirteen described species known from Late Cretaceous fossils found in Asia and Europe. The species were described between 2004 and 2016, with a number of the species formerly being placed into the junior synonym genus ''Sphecomyrmodes''. History and classification ''Gerontoformica'' is known from over thirty adult fossil specimens which are composed of complete adult female workers and queens. The first fossil was discovered preserved as an inclusion in a transparent chunk of Charentese amber. The amber is thought to have been formed from resins of the extinct Pinales tree family Cheirolepidiaceae and possibly from the living family Araucariaceae. Paleoecology of the ambers indicates the shore to mangrove type forests were of a subtropical to warm temperate climate, with occasional dry periods The ambers are recovered from deposits exposed in quarries, road constructions, and beach exposures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burmese Amber
Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The amber is of significant palaeontological interest due to the diversity of flora and fauna contained as inclusions, particularly arthropods including insects and arachnids but also birds, lizards, snakes, frogs and fragmentary dinosaur remains. The amber has been known and commercially exploited since the first century AD, and has been known to science since the mid-nineteenth century. Research on the deposit has attracted controversy due to its alleged role in funding internal conflict in Myanmar and hazardous working conditions in the mines where it is collected. Geological context, depositional environment and age The amber is found within the Hukawng Basin, a large Cretaceous- Cenozoic sedimentary basin within northern Myanmar. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myanmar
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explains, the English spellings of both Myanmar and Burma assume a non-rhotic variety of English, in which the letter r before a consonant or finally serves merely to indicate a long vowel: �mjænmɑː, ˈbɜːmə So the pronunciation of the last syllable of Myanmar as ɑːror of Burma as ɜːrməby some speakers in the UK and most speakers in North America is in fact a spelling pronunciation based on a misunderstanding of non-rhotic spelling conventions. The final ''r'' in ''Myanmar'' was not intended for pronunciation and is there to ensure that the final a is pronounced with the broad ''ah'' () in "father". If the Burmese name my, မြန်မာ, label=none were spelled "Myanma" in English, this would be pronounced at the end by al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclusion (mineral)
In mineralogy, an inclusion is any material that is trapped inside a mineral during its formation. In gemology, an inclusion is a characteristic enclosed within a gemstone, or reaching its surface from the interior. According to Hutton's law of inclusions, fragments included in a host rock are older than the host rock itself. Mineralogy Inclusions are usually other minerals or rocks, but may also be water, gas or petroleum. Liquid or vapor inclusions are known as fluid inclusions. In the case of amber it is possible to find insects and plants as inclusions. The analysis of atmospheric gas bubbles as inclusions in ice cores is an important tool in the study of climate change. A xenolith is a pre-existing rock which has been picked up by a lava flow. Melt inclusions form when bits of melt become trapped inside crystals as they form in the melt. Gemology Inclusions are one of the most important factors when it comes to gem valuation. In many gemstones, such as di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amber
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia of New Jersey'', Rutgers University Press, . Amber is used in jewelry and has been used as a healing agent in folk medicine. There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as inclusions. Amber occurring in coal seams is also called resinite, and the term ''ambrite'' is applied to that found specifically within New Zealand coal seams. Etymology The English word ''amber'' derives from Arabic (ultimately from Middle Persian ''ambar'') via Middle Latin ''ambar'' and Middle French ''ambre''. The word was adopted in Middle English in the 14th centu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive because all isotopes of uranium are unstable; the half-lives of its naturally occurring isotopes range between 159,200 years and 4.5 billion years. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordially occurring elements. Its density is about 70% higher than that of lead, and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite. In nature, uranium is found as uranium-238 (99.2739 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiometric Dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of Earth itself, and can also be used to date a wide range of natural and man-made materials. Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geologic time scale. Among the best-known techniques are radiocarbon dating, potassium–argon dating and uranium–lead dating. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the abs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead is a chemical element with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate hardness, soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable nuclide, stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and base (chemistry), bases, and it tends to form covalent bonds. Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
