Review Animal Evolution Non-molting vs. Molting Embryonic Mouth Formation Body Symmetry Non-organs vs. Organs Review

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Embryo Formation Deuterostomia Protostomia

Embryo Formation Deuterostomia Protostomia

Review Animal Evolution Non-molting vs. Molting Embryonic Mouth Formation Body Symmetry Non-organs vs. Organs Review

Deuterostome Phylogeny Echinoderms 1 BYA Tunicates Cephalochordates Phylum Chordata Vertebrates

Phylum Chordata Subphylum: Urochordata Subphylum: Cephalochordata Subphylum: Vertebrata

What are the specific characteristics of the Chordata? 1) Pharyngeal gills 2) Dorsal hollow nerve cord 3) Notochord 4) Postanal tail

Phylum Chordata Specific Characteristics:

Phylum Chordata Specific Characteristics:

Phylum Chordata Specific Characteristics:

Internal Skeleton = Endoskeleton Phylum Chordata Subphylum: Vertebrata (Vertebrates) Sk Internal Skeleton = Endoskeleton

or nails Legs Endoskeleton Kidney

But before there was a skeleton Pikaia But before there was a skeleton there was a notochord Zebra fish

VERTEBRATE ORIGINS Pikaia

Vertebrate Evolution Sea  Fresh Water Body surface covered with scales and armor to reduce water influx Kidney evolved to pump out water that did enter via gills Notochord  backbone and skeletal system for calcium storage and improved locomotion Gills  Gills + Lungs to deal with water with low O2 levels in marshes