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.
exists and is an alternate of . The earth's crust is first thought to have formed around 100 million years after the initial formation of the earth. As such it is likely that there have been earthquakes occurring for approximately 4.4 billion years. The earth's crust is first thought to have formed around 100 million years after the initial formation of the earth.  The earth's crust is first thought to have formed around 100 million years after the initial formation of the earth.