Wikipedia:Main Page history/2022 January 7b
From today's featured articleHammond's rice rat (Mindomys hammondi), also known as Hammond's oryzomys, is a species of rodent in the tribe Oryzomyini of family Cricetidae. Formerly considered to be related with Nectomys, Sigmodontomys, Megalomys, or Oryzomys, it is now placed in its own genus, Mindomys, but its relationships remain obscure; some evidence supports a placement near Oecomys or as a basal member of Oryzomyini. Mindomys hammondi is known only from Ecuador, where it occurs in montane forest; a record from the Amazon basin lowlands is dubious. Reportedly, it lives on the ground and is associated with water; others suggest it lives in trees. A large, long-tailed, and long-whiskered rat, its fur is buff above and abruptly lighter below. The front part of the skull (rostrum) is heavily built. The species is named after the collector who first found it, Gilbert Hammond. He supplied natural history specimens to Oldfield Thomas and others. (Full article...) Did you know ...
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In the news
On this dayJanuary 7: Christmas (Eastern Christianity); Victory over Genocide Day in Cambodia (1979); Flag Day in Italy (1797)
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From today's featured list
Mersenne primes and perfect numbers are two deeply interlinked types of natural numbers in number theory. Mersenne primes, named after the friar Marin Mersenne, are prime numbers that can be expressed as 2p − 1 for some positive integer p. For example, 3 is a Mersenne prime as it is a prime number and is expressible as 22 − 1. Perfect numbers are natural numbers that equal the sum of their positive proper divisors (all divisors excluding the number itself). There is a one-to-one correspondence between the Mersenne primes and the even perfect numbers. This is due to the Euclid–Euler theorem, partially proved by Euclid and completed by Leonhard Euler: even numbers are perfect if and only if they can be expressed in the form 2p − 1 × (2p − 1), where 2p − 1 is a Mersenne prime. (Full list...)
Today's featured picture
This historical coat of arms of Illinois is an illustration from State Arms of the Union by Henry Mitchell, published by Louis Prang in 1876. It depicts a bald eagle perched on a rock carrying a shield with the stars and stripes. In the eagle's beak there is a banner with the state motto, "State Sovereignty, National Union." Illustration credit: Henry Mitchell; restored by Andrew Shiva
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