Marine Vertebrate Zoology

Vertebrate AncestryHow did it all begin?

Vertebrate Ancestry 2

Invertebrate Origin

A great division in the invertebrate world occurred creating two distinct evolutionary lines:

Early Invertebrate

First Branch- Annelids- Molluscs- Arthropods

Second Branch- Bryozoans- Brachiopods- Echinoderms- Chordates

(hydra? sea anenome?)

Vertebrate Ancestry 3

Invertebrate Origin

Deutrostome

Protostome

Vertebrate Ancestry 4

Vertebrate Ancestry 5

Chordates

Characteristics of all chordates:1. Notochord2. Hollow nerve cord3. Pharyngeal gill slits4. Post anal tail

Vertebrate Ancestry 6

Phylum Chordata

Subphylum Hemichordata• Acorn worms

Subphylum Urochordata• Tunicates

Subphylum Cephalochordata• Amphioxus (Lancelets)

Subphylum Vertebrata• Fishes, amphibians, reptiles,

birds, and mammals

Vertebrate Ancestry 7

Geological Record

Our understanding of taxonomy and systematics and the appearance of life on earth is based upon fossil remains.

To grasp the magnitude of the geological record it is divided into Eras, which are divided into periods, and divided further into epochs• Paleozoic 600 - 280 million years

• Mesozoic 225 - 136 million years

• Cenozoic 65 million years - to the present

Vertebrate Family Tree *

Amphibians

Reptiles & Birds

Mammals