Palechinoidea or Paleechinoidea: How To spell?
The word Palechinoidea is misspelled against Paleechinoidea, a noun meaning "An extinct order of sea urchins found in the Paleozoic rocks. They had more than twenty vertical rows of plates. Called also Palaeechini."
Paleechinoidea has double "ee" is mispronounced as "e"Remember double 'EE' in between the strings Pal & chinoidea which should not be misspelled with single 'E'
Wrong Spelling:  Pal-e-chinoidea  Correct Spelling:  Pal-ee-chinoidea 
Find more incorrect spellings of Paleechinoidea to spell right way.