Chihuahua Dog Breed. First discovered in Mexico, the Chihuahua is best known for being the smallest dog breed in the world. Extremely loyal to its owner, the breed has recently become a popular culture icon in the United States, most notably Paris Hilton's Chihuahua, Tinkerbell. Physical Characteristics.
Earth formed around 4.54 billion years ago by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean; but the atmosphere contained almost no oxygen and so would have been toxic to most modern life including humans.
How long ago did the first living forms appear on earth? the earliest known life form were single celled organisms which roamed the earth they appeared around two billion years ago Answer: The Earth formed about 4.5 billion years â¦ ago. 700 million years later (3.8 to 3.5 billion years age) life started.5 people found this useful.he earliest known life form were single celled organisms which roamed the earth they appeared around two billion years ago Answer: The Earth formed about 4.5 billion years â¦ ago. 700 million years later (3.8 to 3.5 billion years age) life started. 5 people found this useful.