Enterobacter is a genus of common Gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacteria of the family Enterobacteriaceae.nterobacter is a genus of common Gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacteria of the family Enterobacteriaceae.
Trilobite fossil from the Cambrian Period. Photo Credit: Archbob. The first period in the Paleozoic Era is known as the Cambrian Period. Many of the ancestors of the species that have evolved into what we know today first came into existence during the Cambrian Explosion in the early Cambrian Period.
The Proterozoic Eon is also called the Cryptozoic (age of hidden life). About 2.5 billion years ago, enough shield rock had formed to start recognizable geologic processes such as plate tectonics.Geology was about to be joined by biology to continue Earthâs progress from a molten hell to a living planet.he Proterozoic Eon is also called the Cryptozoic (age of hidden life). About 2.5 billion years ago, enough shield rock had formed to start recognizable geologic processes such as plate tectonics.