From today's featured articleApororhynchus is a genus of small, parasitic spiny-headed (or thorny-headed) worms, the only genus in the order Apororhynchida. A lack of features commonly found in Acanthocephala suggests an evolutionary branching from the other three orders of class Archiacanthocephala. The distinguishing features of this order are a highly enlarged proboscis containing small hooks, and differently structured musculature around this proboscis in its receptacle and receptacle protrusor. The genus contains six species that are distributed globally, being collected sporadically in Hawaii, Europe, North America, South America, and Asia. These worms exclusively parasitize birds by attaching themselves around the cloaca using their hooks and adhesives secreted from cement glands. The bird hosts are of different orders, including owls, waders, and passerines. Infection by an Apororhynchus species may cause enteritis and anemia. (Full article...)
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Did you know ...![]() Reema Juffali in her Formula 4 car at Thruxton Circuit, 2019
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Thomas Linley the elder (b. 1733) · Alva Belmont (b. 1853) · Mateiu Caragiale (d. 1936)
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Between 1989 and 1999, 173 singles topped the Hot Rap Singles chart. Hot Rap Songs is a record chart published by the music industry magazine Billboard which ranks the most popular hip hop songs in the United States. With hip hop having greatly increased in mainstream popularity in the late 1980s, Billboard introduced the chart in their issue of March 11, 1989, under the name Hot Rap Singles. The inaugural number-one single on Hot Rap Singles was "Self Destruction" by the Stop the Violence Movement. From its 1989 inception until 2001, the chart was based solely on each single's weekly sales. "Hot Boyz", by Missy Elliott and featuring Nas, Eve and Q-Tip, was the final number-one single of the 1990s. The single's 18-week reign at the top spot extended into the next decade, and it holds the record for the most weeks at number one in the chart's history. LL Cool J (pictured) and Puff Daddy each attained nine number-one hits on the Hot Rap Singles chart during its first 11 years, the most for any artist during this period. (Full list...)
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Scissors are hand-operated cutting tools consisting of two blades, each sharpened on one side, joined at a pivot that acts as a fulcrum. Scissors cut material by applying local shear stress that exceeds the material's shear strength at the cutting location. The earliest known scissors appeared in Mesopotamia some 3,000 to 4,000 years ago; they were of the "spring" type, the blades being connected at the handle end by a thin, flexible strip of metal. These spring scissors continued in use in Europe until the 16th century, but were then superseded by scissors with a central pivot, which had been invented by the Romans around AD 100. Modern scissors, with holes in the handles for finger control, come in a range of types designed for various purposes, with left-handed scissors being designed for use with the left hand. Larger tools tend to be called "shears". Photograph credit: Chris Woodrich
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