Vertebrate evolutions/Jawless fishes

Subphylum Vertebrata’s evolution has been shaped by adaptations of

Living endoskeleton, grows with body, cartilage then bone

Subphylum Vertebrata has this that increased respiratory function and supports high metabolic rates

Pharynx

The nervous system of subphylum Vertebrata developed new cell types that promoted development of head and sensory organs

Neural Crest Cells

What are the five distinguishing traits of subphylum Vertebrates

Vertebral column, Cranium, Endoskeleton, Neural crest cells, Internal organs

Notochord is replaced by a column of interlocking vertebrae called

Vertebral Column

Anterior end of the nerve cord forms a brain that is encased in protective housing called

Cranium

Cranium and vertebral column are a part of this

Endoskelton

Embryonic cells that contribute to the development of the cranium are

Neural crest cells

This posses great diversity, are more complex than an analogous structures in invertebrate taxa

Internal organs

Garstang’s hypothesis

Tunicate larvae began to reproduce

Cephalochordates were once thought to be a vertebrate ancestors is now a

Sister Group

What were the earliest vertebrates

Ostracoderms

Jawless fishes are called

Agnatha

These are the extinct jawed vertebrate variants

Gnathostomata

What has bony anterior shield and tooth plates

Placoderms

What has most small and weakly armored species

Acanthodians

Acanthodians have this gill cover called

Operculum

What are modified cartilaginous gill arches

Jaws

What constitute half of all vertebrate species

Living Fishes

The paired fins in living fishes are precursors to

Tetrapod limbs

A hagfish is a

Living agnathans

What do living agnathans have along their bodies

Slime glands

What are living agnathans lacking

Jaws, scales, paired fins