DINOFLAGELLATES: Unicellular aquatic organisms, motile and heterotrophic, parasitic, or photosynthetic. Generally with two flagella, one within an encircling sulcus, the second (longitudinal) oriented porteriorly. Life cycles various, but often with motile thecate stage having a cellulose cell wall, and a resting cyst (hypnozygote) with a chitinous or "dinosporinous" wall forming inside the theca. Form of the cyst ranges from similar to the theca (proximate) to bearing several trumpet-shaped processes (chorate). Theca and cyst often comprised of polygonal plates separated by sutures
Chorate cysts categorized based on relation of processes to theca sutures. Example: Spiniferate cysts have processes along the sutures. Cyst often with a polygonal opening (arceopyle) through which excystment occurs.

References:

• Fensome, R.A., Riding, J.B. & Taylor, F.J.R. 1996. Chapter 6. Dinoflagellates; in: Jansonius and McGregor (eds.) Palynology Principles and applications. AASP Foundation.
  
• Evitt, W.R. 1970 Dinoflagellates -- a selective review. Geoscience & Man 1: 29-69
  
• Taylor, F.J.R. (ed.) 1987. The Biology of Dinoflagellates. Blackwell Sci. Publ.
  
• Williams, Graham L., William A. S. Sarjeant, and Evan J. Kidson. 1978. A Glossary of the Terminology Applied to Dinoflagellate Amphiesmae and Cysts and Acritarchs. AASP Contrib 2.
  AASP References
  
• Modern Distribution
• Paleoenvironments
• Morphology & Systematics
• Paleopalynolgy & Stratigraphy
• AASP Foundation Contributions Series 2, 3, 5, 7, 9, 13, 17, 18, 20, 22, 23, 28 /
• W.R. Evitt (1985) Sporopollenin Dinoflagellate Cysts.
  Links:
  
• Mike Bidgood Dinoflagellates
• Fensome et al's Dinoflaj Database Comprehensive
• Michael Guiry Dino Definition
• Takeo Horiguchi Hokkaido Universtiy
• Andrew MacRea Comprehensive
• Red Tide Dinos
• Tropical Dinoflagellates Southern Illinois University
• U Berkeley Dino Intro
• U. Miami Dino Page
• Dinoflagellata: Fossil Record (K-12)