ERTH 2401 Lecture : Lecture16-Marine Reptiles.doc
Document Summary
What are the features of turtles: anapsid"s, most primitive group of living reptiles, ancestry is poorly known, odontochelys from china 10 mill years older than: Seas and estuaries: water level drops, sea level is moving out and the rivers carve a basin as they actually move further and further out to sea, feeding grounds, safer. Limbs are modified into hydrofoils: using all 4 limbs as wings under water, warm-blooded. 4m in flipper span: cretaceous, no complete bony carapace due to weight, bony framework. Since early jurassic living at the water edge. 6 tons, possibly 18 tons: duckbill dinosaurs as prey, ceratopsian. Position of holzmaden during jurassic time: a site of extraordinary marine reptile preservation, crinoids look like plants but are animals. Jurassic in southern germany: over 60 million years europe partly covered by water forming smaller basins, stagnant-reduced oxygen exchange, posidonienschiefer, example: ichthyosaurs, well- preserved skin.