Echinoidea
Harrison Cassidy, Lauren Bower, Renée Carew, Tosin Fashoranti
Introduction
 Phylum Echinodermata
 Regular and Irregular
 Found in all intertidal zones
 ~1000 known species
Evolutionary History
 Regular echinoids
• 450 million years ago during the Ordovician
Period
 Irregular echinoids
 Ancestral
deuterostome
 Believed to evolve
from the edioasteriods
Edrioasteroids
Regular Echiniods
 Water vascular system
 Locomotion
 Respiration
 Food an waste transportation
 Aristotle’s lantern
 Bilateral symmetry
 Test (aka the shell)
 Movable spines
 Inhabit the ocean floor
 Omnivores
Irregular
 Not formally a group
 Penta-radial & bilateral symmetry
 Anus on the side rather than apex
Heart Urchin
 About 2 inches in diameter
 Muddy areas, burrowing up to 6 inches
 Most common in depths under 160ft
Sand Dollar
 Shallow, sandy areas
 Flattened
 Miniature spines (felt like)
 Aristotle’s Lantern (mouth)
more flat & grinds sand
 Bury themselves for defense
Life Cycle
 There are two types of life cycles:
 Planktotrophy
 Lecithotrophy
Planktotrophy
 Several eggs are externally fertilized in the
water column
 Larval phase
 Echinopluteus
Echinopluteus
Lecithotrophy
 Fewer eggs that are larger
 The eggs are externally fertilized in the mother’s
pouch
 No larval phase
Fun facts
 The red sea urchin can live up to 200 years or longer.
 Sea urchin eggs are commonly eaten in sushi.
 Sea urchins are also called “sea heghogs”.
 They have a large fossil record due to the high calcium content
in their shells.
Bibliography
 "The Echinoid Directory." - Natural History Museum. N.p., n.d. Web. 26 Mar. 2014.
http://www.nhm.ac.uk/research-curation/research/projects/echinoiddirectory/intro/introduction.html
 "Animal Diversity Web." Animal Diversity Web. N.p., n.d. Web. 26 Mar. 2014.
<http://animaldiversity.ummz.umich.edu/accounts/Echinoidea/>.
 "Introduction to the Echinoidea." The Echinoidea. N.p., n.d. Web. 26 Mar. 2014.
http://www.ucmp.berkeley.edu/echinodermata/echinoidea.html
 Follo, Judy. "Animal Diversity Web." Animal Diversity Web. University of Michigan, n.d. Web. 24
Mar. 2014. http://animaldiversity.ummz.umich.edu/accounts/Echinoidea/
 "Investigation." Sea Urchin. N.p., n.d. Web. 25 Mar. 2014.
<http://tolweb.org/treehouses/?treehouse_id=4881>.
 "Class Echinoidea." Class Echinoidea. N.p., n.d. Web. 30 Mar. 2014.
<http://encina.pntic.mec.es/~nmeb0000/invertebrates/equinodermos/gruposequinodermos/eq
uinoideos.html>.

Heart Urchin. Digital image. Heart Urchin. N.p., n.d. Web. 24 Mar. 2014.
<http://www.afsc.noaa.gov/race/media/photo_gallery/invert_files/Heart_urchin.htm>.

Kroh, A. & Mooi, R. (2011). World Echinoidea Database. Available online
at http://www.marinespecies.org/echinoidea[accessed 2014-03-30].

Living Sand Dollar. Digital image. Panoramio. N.p., n.d. Web. 24 Mar. 2014.
<http://www.panoramio.com/photo/20966104>.

Long Post Central. Digital image. (Sand Dollars! Actually a Sort of Sea Urchin! For...). N.p., n.d.
Web. 24 Mar. 2014. <http://stuckinabucket.tumblr.com/post/53620165374/sand-dollars-actuallya-sort-of-sea-urchin-for>.

"The Echinoid Directory." - Natural History Museum. N.p., n.d. Web. 24 Mar. 2014.
<http://www.nhm.ac.uk/research-curation/research/projects/echinoiddirectory/intro/introduction.html>.

"Major Phyla Of Animals." Animal Phyla. N.p., n.d. Web. 29 Mar. 2014.
<http://waynesword.palomar.edu/trnov01.htm>.

"The Heart Urchin." Smithsonian Marine Station at Fort Pierce. N.p., n.d. Web. 25 Mar. 2014.
<http://www.sms.si.edu/IRLFieldGuide/Moira_atropo.htm>.