Top Posters
Since Sunday
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
r
4
SlideshowReport

The evolution of the vertebrate jaw

Tags
Description
(a) Ancestral fish and extant jawless fish, such as lampreys, have nine cartilaginous gill arches that support eight gill slits. (b) In early jawed fish, such as the placoderms, the first two pairs of gill arches were lost, and the third pair became modified to form a hinged jaw. This left six gill arches to support the remaining five gill slits, which were still used in breathing. (c) In modern jawed fish, the fourth gill arch is also incorporated into the jaw, allowing stronger, more powerful bites to be delivered.
Related Images
Add Comment
Explore
Post your homework questions and get free online help from our incredible volunteers
  906 People Browsing
Your Opinion
Which of the following is the best resource to supplement your studies:
Votes: 249