The modern amphibians include frogs, salamanders, and ___. Amphibians in this last group look like earthworms and have dermal scales embedded in their skin. 

All chordate embryos have a skeletal rod named a ___. In adults, vertebrae replace this structure in most chordates.

In coralsnakes, ___ and ___ colored bands are in contact. Whereas these colors are separate in their mimics

The ___ were a group of agnathans with skin covered in bony plates.

Cartilagenous fishes have a pair of ___ used in copulation. These structures are part of the pelvic fins. 

The ratfish or ghost sharks (Holocephala) are sometimes called ___, because they resemble a monster from Greek mythology. 

Unlike other tetrapods, mammals have ___ (a number) inner ear bones.

___ skulls have two temporal fenestrae. Crocodiles have this type of skull.

Vertebrae consist of three main parts. A centrum, a neural arch, and a ___ arch.

How does the nerve cord of chordates differ from the nerve cord of protostomes?