Skip to main content
Select Source:

Spatangoida

Spatangoida (heart urchins; subphylum Echinozoa, class Echinoidea) An order of irregular echinoids which have a compact apical system and a plastron in which the labrum is followed by a pair of large plates. Most spatangoids have narrow bands of densely ciliated spines, which can be recognized in fossils as areas of very small tubercles on denuded fascioles. The Spatangoida first appeared in the lowermost Cretaceous.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Spatangoida." A Dictionary of Zoology. . Encyclopedia.com. 18 Sep. 2018 <http://www.encyclopedia.com>.

"Spatangoida." A Dictionary of Zoology. . Encyclopedia.com. (September 18, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/spatangoida

"Spatangoida." A Dictionary of Zoology. . Retrieved September 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/spatangoida

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.

heart urchins

heart urchins See ECHINOIDEA; SPATANGOIDA.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"heart urchins." A Dictionary of Zoology. . Encyclopedia.com. 18 Sep. 2018 <http://www.encyclopedia.com>.

"heart urchins." A Dictionary of Zoology. . Encyclopedia.com. (September 18, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heart-urchins

"heart urchins." A Dictionary of Zoology. . Retrieved September 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/heart-urchins

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.