Club mosses , ferns , horsetails , gymnosperms , and flowering plants are vascular plants. The spine is made up of many vertebrae. Vertebrates evolved during the Cambrian period, over 500 million years ago. Other vertebrates include the amphibians, reptiles, birds, and mammals. Kingdom Metazoa, Phylum Chordata, Subphylum Vertebrata.
People are viviparous.
When a volcano erupts, it spews out lava and gases from deep inside the Earth. The Cretaceous period was a time of high volcanic activity. As stated in our privacy policy , we fully respect your privacy and will not use your e-mail address for any purpose other than the newsletter subscription. Search the Web with our sponsor, Overture. Without our visitors' support, Enchanted Learning would soon be off-line.