Life On Earth Study Guide

1. The movie Life on Earth focused on how fossils are glimpses of a distant past because they explain how life evolved on earth. They also used a Cladogram to explain the cladistic relationship between a number of species. The first organism with a nucleus lived one and a half million years ago. An animal with a braincase and a beginning of a backbone appeared 500 million years ago. Amniotes were split into two main lineages. One is identified by a hole that evolved in the skull behind the eye socket called synapsid opening. The second lineage is recognized by a pair of holes that evolved in the palate; this was the beginning of Sauropsids, or reptiles. The first dinosaur was recognized by a hole in its hip socket. This allowed the hind legs to go straight down from the hips, which allowed them to run upright and with greater endurance than other reptiles. Then, 65 million years …show more content…
Birds are dinosaurs because they descended from the first theropod and the first dinosaur. A 3-toed hind foot was an adaptation from moving rapidly and catching prey. The 3-toed of meat-eaters such as Tyrannosaurus has survived as the 3-toed foot in birds. The elongated arm bones that support the wing evolved in the first coelurosaur. An Apatosaurus and tyrannosaurus rex are extremely different from each other. An Apatosaurus lived in the Late Jurassic, while a tyrannosaurus lived in the Late Cretaceous. An Apatosaurus was an Herbivorous; while a tyrannosaurus was a carnivorous. An Apatosaurus was also almost twice of a Tyrannosaurus’ size.
4. The Ornithischian dinosaur, or "bird-hipped" dinosaurs, and the Saurischian dinosaur, or "lizard-hipped" dinosaurs. The most visible difference between the two types of hip is the orientation of the pubis. There is evidence that a large asteroid or comet struck the earth causing the end of the Age of Dinosaurs. Dinosaurs were unable to survive through the altered temperatures, reduced sunlight, generated acid rain, or major volcanic