Myxopterus

1
Myxopterus Devonian invertebrate Predator That
potentially preyed on ostracoderms
2
Evolution of jaws from pharyngeal (gill) arches
3
Autostylic palatoquadrate fused to cranium
Hyostylic- Palatoquadrate loosely bound to
cranium, Jaw angle supported by hyoid See Fig
5-5
4
Hyostylic Jaw at work!
5
Evolution of paired appendages
6
Chondrichthyes Holocephalans ratfish,
chimaera Fig 5-9
Autostylic
7
Elasmobranchs plate gills sharks, rays skates
8
Pleurotreme sharks Fig 5-4
Hypotreme skates and rays Fig 5-8
9
Chondrichthyean evolutionary relationships

Galeomorphs
Squalimorphs
Neoselachiii
Batoidea
Holocephali
10
3 major evolutionary radiations what was trend?
Fig 5-1, 5-2, 5-3
Cladoselache
Carcharodon
Hybodus
11
Shark skin - scales and teeth dermal derivatives
12
Cartilaginous vertebral column with neural and
hemal arches and some calcification. Notochord
is replaced
Trunk vertebra (no hemal arch)
13
Sensory Systems and Feeding
14
Olfaction a flow-through nostril! smell blood
from a kilometer away!
15
Touch water movement via Lateral Line See
Figure 4-4
16
Vision Large eyes with tapetum and nictitating
membrane
17
Electrical Ampulla of Lorenzini See Fig 4-7
understand Fig 4-8 experiment
18
Mammals
Shark brain size
Birds
Sharks
Brain mass
Fish
Body mass
19
Reproduction internal fertilization with
claspers on male pelvic fins Fig 5-6
Oviparous
Ovoviparous or Viviparous
20
Japanese marine park captures rare shark on
film
Ancient??