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.
What is the first living life form on earth? The first forms of life on Earth were most likely very similar to bacteria or other prokaryotic organisms. What organism provides the earliest evidence for the life on Earth?   The oldest organism ever to appear on the face of the Earth, was probably the Cyanobacteria.