This document provides information about sharks, skates, and rays (Chondrichthyes). It discusses their habitats in temperate and cold, deep waters. It describes how they hunt and feed near coastal areas. The document also outlines the evolution of Chondrichthyes, noting their appearance in the Devonian period and placoderm ancestors. Key adaptations like cartilage skeletons, spiral valves, and specialized jaws are also summarized.

1. For all the lovely men or women out their who prefer cartilage over bone! Briana Speiss Sharks, Skates, and Rays!

2. Where Can You Find Me? In the water! Skates and Rays Warm, temperate seas Sharks Cold, deep, water Favorite spot: the ocean floor Marine habitat Move towards the coast for feeding

3. What Do I Like to Do? “ Deep-sea diving” Lots and lots of swimming Depending on what type of Chondrichthye I am…hunting! Move around

4. Geneology Made our appearance during the Devonian Ancestors: Placoderms/Gnathostomata Different snouts (longer, weaker) Upper jaws were fixed (restricted size of food and prey) Smaller brains Teeth Overall structure was the same

5. Specialized Structures and Adaptations Cartilage Digestive system – spiral valves No bone Well developed jaws Size Gills

6. What Am I Looking For? A nice young shark, ray, or skate that will go on long luxurious swims with me in the deep, dark, cool ocean. I love someone that I can have fun swimming around with and preying on little, innocent sea creatures. Call me! 215-555-0938

7. Bibliography &quot;Chondrichthyes.&quot; Chondrichthyes. 1994. Microsoft Encarta 96 Encyclopedia. 27 Apr. 2008 <http://www.cyhaus.com/marine/sharks.htm>. Valuable information that was very well organized. Found the habitat and eating habits of this class. Long, Doug. &quot;Jaws.&quot; Introduction to Chondrichthyes. 8 Oct. 2007. Berkeley. 26 Apr. 2008 <http://www.ucmp.berkeley.edu/vertebrates/basalfish/chondrintro.html>. Credible source. I read about the different specializations of this class including the advantages of their adaptations. Martin, R. A. &quot;Biology of Sharks and Rays.&quot; Jaws Then and Now. 7 July-Aug. 06. ReefQuest Centre for Shark Research. 27 Apr. 2008 <http://www.elasmo-research.org/education/evolution/jaws.htm>. This was a great website where I found out all about the ancestors of this class. There were great comparisons between the ancestors and the modern chondrichthyes. &quot;Sharks, Rays, Skates.&quot; Class Chondrichthyes. 1994. MDC. 27 Apr. 2008 <http://www.woodbridge.tased.edu.au/mdc/Species%20Register/class_chondrichthyes.htm>. This was just another general site that hit everything I needed to know for this project. Although the information was not very specific at some points, I found out what I needed to know. Talked about the gills and other specialized structures.