MyxopterusDevonian invertebrate Predator That potentially preyed on ostracoderms

Evolution of jaws from pharyngeal (gill) arches

Hyostylic- Palatoquadrateloosely bound to cranium,Jaw angle supported by hyoid See Fig 5-5

Autostylic palatoquadrate fused to cranium

Hyostylic Jaw at work!

Evolution of paired appendages

Chondrichthyes = Holocephalans = ratfish, chimaeraFig 5-9

Autostylic

Elasmobranchs – “plate gills” sharks, rays skates

Hypotreme skates and raysFig 5-8

Pleurotreme sharks Fig 5-4

Holocephali

Neoselachiii

Squalimorphs

Galeomorphs

Batoidea

Chondrichthyean evolutionary relationships

Cladoselache

HybodusCarcharodon

3 major evolutionary radiations – what was trend? Fig 5-1, 5-2, 5-3

Shark skin - scales and teeth dermal derivatives

Cartilaginous vertebral column with neural and hemal arches and some calcification. Notochord is replaced

Trunk vertebra (no hemal arch)

Sensory Systems and Feeding

Olfaction – a flow-through nostril! “smell blood from a kilometer away!”

Touch – water movement via Lateral Line See Figure 4-4

Vision Large eyes with tapetum and nictitating membrane

Electrical – Ampulla of LorenziniSee Fig 4-7 understand Fig 4-8 experiment

Shark brain size

Body mass

Bra

in m

ass

Birds

Mammals

Sharks

Fish

Reproduction – internal fertilization with claspers on male pelvic fins Fig 5-6

Oviparous

Ovoviparous or Viviparous

“Japanese marine park captures rare shark on film”

Ancient??