Lancelet
- Photograph of Branchiostoma lanceolatum and information from Wikipedia on the genus, traditionally known as amphioxus, its physical features and taxonomy.
- http://en.wikipedia.org/wiki/Lancelet

Amphioxus: A Peaceful Anchovy Fillet to Illuminate Chordate Evolution
- Illustrated article on amphioxus, a species which occupies a central place in evolutionary thoughts when considering the origin of vertebrates.
- http://www.biolsci.org/v02p0030.htm

The Amphioxus Song
- A song, set to the tune of “It’s a long way to Tipperary”, that explains in verse the evolutionary development of vertebrates from invertebrates.
- http://www.molecularevolution.org/resources/amphioxus/

Subphylum Cephalochordata
- Information on this group and the three characteristic chordate features, the notochord, the dorsal nerve cord and the pharyngeal slits.
- http://orion1.paisley.ac.uk/courses/Tatner/biomedia/units/chor3.htm

Introduction to the Cephalochordata
- Illustrated description of these primitive chordates, which are small, eel-like, unprepossessing animals that spend much of their time buried in sand.
- http://www.ucmp.berkeley.edu/chordata/cephalo.html

Amphioxus Embryonic Development
- A fascinating short movie from YouTube showing the early cell divisions in the egg and its subsequent development.
- http://www.youtube.com/watch?v=ycHJMXUT2o0

Animalia: Cephalochordata
- Illustration of Branchiostoma.
- http://biodidac.bio.uottawa.ca/thumbnails/filedet.htm?File_name=CEPL030P&File_type=GIF

Branchiostoma in coarse sand
- Information on several species that live in sand at moderate depths off the coast of Devon, UK, and photographs of the lancelet (Branchiostoma lanceolatum) and the pea urchin (Echinocyamus pusillus).
- http://www.devonwildlifetrust.org/index.php?section=champions:baywatch:biotope_7

Invertebrate Anatomy OnLine: Branchiostoma
- Detailed illustrated anatomical description of amphioxus and the lancelets.
- http://webs.lander.edu/rsfox/invertebrates/branchiostoma.html