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Phyla Hemicordata and Chordata

BIO 2215

Oklahoma City Community College

Dennis Anderson

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Porifera

Cycliophora

CnidariaCtenophora

SipunculaMolluscaAnnelida

OnychophoraTardigrada

Bryozoa

Platyhelminthes

Nemertea

Rotifera

GnathostomulidaGastrotricha

NematodaNematomorpha

PriapulidaKinorhynchaLoricifera

PhoronidaBrachiopoda

Echinodermata

ChordataHemichordata

Arthropoda

Adapted from Lesser Known ProtostomePhyla. SICB 2001. J.R. Garey.

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Phylum Hemichordata• Three body regions

– Proboscis– Collar– Trunk

• Deuterostome• Gill slits• Open circulatory

system• Dorsal and ventral

nerve cord

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Phylum Chordata

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Phylum Chordata• Notochord• Gill slits or

pharyngeal pouches

• Dorsal hollow nerve cord

• Postanal tail• Segmented

muscles• Deuterostome

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Chordate SubphylaPhylum.Phylum. Chordata Chordata

Subphylum.Subphylum. Urochordata UrochordataSubphylum.Subphylum. Cephalochordata CephalochordataSubphylum.Subphylum. Vertebrata Vertebrata

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Subphylum Urochordata

• Sea squirts• Notochord

– Only in larva• Adult has tunic

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Urochordates

MouthMouth

AtriumAtrium

PharyngealPharyngealgill slitsgill slits

StomachStomach

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Subphylum Cephalochordata

• Amphioxus• Notochord length of

body• Dorsal hollow nerve

cord• Gill slits• Segmented muscles

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Subphylum Vertebrata

• Vertebrae replace notochord during embryonic development

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Fig. 48.8

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Superclass Agnatha

• No jaws• No paired

appendages• Notochord as adult

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Ostracoderms

• Earliest vertebrate• Paleozoic era• Filter feeders

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Hagfish and Lamprey

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Parasites

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Superclass Gnathostomata

• Jaws• Paired appendages

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Fig. 48.13

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Class Condrichthyes

• Cartilage skeleton• Notochord• No opercula• No swim bladder

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Class Osteichthyes

• Boney skeleton• Swim bladder• Opercula

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Fig. 48.16

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Subclass Actinopterygii

• Rays in fins

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Salmon

Pectoral FinPelvic Fin

Anal FinCaudal Fin

Dorsal Fin Adipose Fin

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Subclass Dipneusti

• Breathe air when lake or river dries up

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Subclass Crossopterygii*

• Coelacanth• Lobed fins

– muscles

*Class Sarcopterygii

Order Crossopterygii

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Class Amphibia• Land and water• Skin with mucoid

secretions– Respiration

• No scales, feathers or hair

• Heart with 3 chambers– 2 atria– 1 ventricle

• One cervical vertebra• Ectothermic

Transitional TetrapodsSkull, teeth, limbs similar to lobe-

finned fish

IchthyostegaAcanthostega

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Order Caudata (Urodela)

• Salamanders• Long tail• Four legs

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Order Anura

• Frogs and toads• No tail in adult• Webbed feet

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Order Apoda (Gymnophiona)

• Caecilian• No legs

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Class Reptilia

• Scales• Amniotic egg• One occipital condyle• Ectothermic• Three chambered

heart• Claws

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Amniotic Egg

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Reptile Skulls

• Anapsid– No opening

• Synapsid– One opening

• Diapsid– Two openings

• Euryapsid– One small opening

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Anapsids

• Turtles

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Diapsids

• Dinosaurs• Snakes• Lizards• Crocodilians• Birds

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Euryapsid

• Extinct• Ichythyosaurs

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Synapsids

• Pelycosaurs• Dimetrodon

– Mammal like reptile

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Order Testudines

• No teeth in adult• Shell• Anapsid• No teeth

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Turtle ShellCarapace

Plastron

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Lifespan 150 Years

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Leatherback Sea Turtle

• 6 feet long• 1,400 pounds

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Order Squamata

• Kinetic skull– Movable joints

• Lizards• Snakes• Dinosaurs

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Geckos

• Small lizards• Adhesive toe pads

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Texas Horned Lizard• Spines for protection• Eats ants• Endangered species

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Gila Monster

• Poisonous lizard• Not very aggressive

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Green Iguana

• Ornamental crest• Five feet long• Tropical rainforest

– Mexico– South America

• Omnivores

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Chameleons

• Arboreal• Africa and

Madagascar• Catch insects with

tongue

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Komodo Dragon

• Attack and eat humans

• 10 feet long• 300 pounds• Indonesia

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Snakes• No legs• No external ears• Jacobson’s organ

– Sense smell with aid of tongue

• Cornea of eye protected with a spectacle– transparent membrane

• Skull bones loose – Swallow large prey

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Oklahoma Snakes

Poisonous

Nonpoisonous

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Western Diamond Backed Rattlesnake

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Copperhead

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Cottonmouth or Water Moccasin

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Prairie Rattlesnake

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Timber Rattlesnake

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Black Rat Snake

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Diamond Backed Watersnake

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Green Snake

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Coral Snake

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Order Crocodilia

• Crocodiles• Caimans• Alligators• Gavials• Elongated skull• Four chambered

heart

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Alligator

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Caiman

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Gavial

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Alligator

Crocodile

Caiman

Gavial

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The End