What is the early Carboniferous period known as?

Age of birds

Age is crinoids

Age of mammals

Age of dinosaurs

The correct answer is 'Age is crinoids'. A crinoid is a type of echinoderm, which include sea stars and sea urchins. It is though that the numerous shallow seas during this period allowed dense thickets of crinoids to flourish. Evidence of this remains as thick beds of fossil remains.