Lampreys are a group of jawless fish composing the order Petromyzontiformes, sole order in the class Petromyzontida. The adult lamprey is characterized by a toothed, funnel-like, sucking mouth. The co
Mouth of a sea lamprey, Petromyzon marinus
Median section of lamprey demonstrating internal anatomy
The cartilaginous skeleton of a lamprey washed up on a beach in North Carolina.
A chordate is a bilaterian animal belonging to the phylum Chordata. All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics that distinguish
The glass catfish (Kryptopterus vitreolus) is one of the few chordates with a visible backbone. The spinal cord is housed within its backbone.
Cephalochordate: lancelet. Pictured species: Branchiostoma lanceolatum
A skeleton of the blue whale, the largest animal, extant or extinct, ever discovered. Mounted outside the Long Marine Laboratory at the University of California, Santa Cruz. The largest blue whale ever reliably recorded measured 98ft (30m) long.