Urchin Greek root is incorrectly written and should be written as "erythro - Greek root" being its meaning:
Also eritr-, widely used in medicine Greek prefixes derived from the adjective erythros erythra erythron which means red. So the red blood cells called erythrocytes ( 41 red cells; or red blood cells. It can be also used as infix. Form words as erythrocytosis eritremia, eritroblasto, eritrocianosis, eritrofobia, eritrolisis, pseudoeritrocitosis
