Anatomy of Amphioxus

What are the two clades of chordates that are invertebrates?

• urochordata

• hemichordata

• cephalochordata

• vertebrata

What clade does Amphioxus belong?

• urochordata

• hemichordata

• cephalochordata

• vertebrata

Amphioxus belongs to this genus.

• Branchiostoma

• Epigonichthyes

• cephalochordata

• Osteichtyes

Two genera of Cephalochordata

• Branchiostoma

• Epigonichthyes

• Enteropneusta

• Osteichtyes

Among the protochordate taxa, Urochordata is the most vertebrate-like.

• TRUE

• FALSE

Answer explanation

Cephalochordata is the most vertebrate-like

What does Amphioxus mean?

• fish-like

• ancestor chordate

• sharp at both ends

• free-swimming

1 extends anteriorly and overhangs the mouth and buccal cavity

1 extends anteriorly and overhangs the mouth and buccal cavity

2 extends around the dorsal and ventral margins of the tail.

3 ring of tentacle-like found on the ventrolateral side of the cranial region