GEOSCI 107 Study Guide - Midterm Guide: Quaternary, Paleo-Indians, Rodent
Document Summary
Secondarily acquatic means that they have a terrestrial ancestor; all secondarily acquatic vertebrates have lungs, no evidence of gills; either return to land to lay their eggs or they give birth to live in the water. Sea turtles, marine iguana, sea snakes and salt water crocodiles. Sea turtles, marine iguanas, and saltwater crocs return to land to lay ther eggs. 47/50 spieces of sea snakes alive give birth to the live young in the water. Many marine reptiles evolve during the mesozoic; more commonly had land dwelling ancestors with sprawling postures as opposed to up right postures. These sprawling postures is better suited for swimming. These chalk beds consist of cocolith (calcite plates) and lots of fossils. Deposited at the bottom of western interior seaway: interior of north america was submerged from the gulf of. Contains fossils of mosassaurs and pleiosaurs (2 extinct marine reptiles) Contains fossils of sharks, fish, turtles, pterosaurs, diving bird and clam.
