Chapter 5: Radiation of the Chondrichthyes Flashcards
1
Q
Why is their a loss of bone in Chondrichthyes?
A
Lightens the body and makes it more maneuverable
2
Q
Chondrichthyes can be divided into what two forms?
A
1) Those with a single gill opening on each side of the head
2) Those with multiple gill openings on each side
3
Q
Which group has the single gill opening?
A
Holocephali (ratfish, rabbitfish, and chimera)
4
Q
Which group has multiple openings?
A
Neoselachii (sharks, skates, rays)
5
Q
What is the Ampullae of Lorenzini?
A
Electroreceptors found in the skin of the snout of Chondrichthyans
6
Q
When do sharks make an appearance in the fossil record?
A
Early Devonian period
