-
Helicoplacoidea is an
extinct class within the Echinodermata. All
known taxa were
discovered in
sediments dating back to the Cambrian.
Helicoplacoid skeletons...
-
Ophiuroidea Asteroidea Echinozoa Echinoidea Holothuroidea Ophiocistioidea †
Helicoplacoidea †
Blastozoa †
Blastoidea †
Cystoidea † von Buch, 1846
Eocrinoidea †Jaekel...
- Phylum:
Echinodermata Subphylum:
Echinozoa classes Echinoidea or sea
urchins Holothuroidea or sea cu****bers
Ophiocistioidea †
Helicoplacoidea † † = Extinct...
- 157-173. Durham, J.W., & Caster, K. E.; Caster, KE (17 May 1963). "
Helicoplacoidea: A New
class of Echinoderms". Science. 140 (3568): 820–822. Bibcode:1963Sci...
- This List of
echinoderm orders concerns the
various classes and
orders into
which taxonomists categorize the
roughly 7000
extant species as well as the...
- 30 (1): 9–14. JSTOR 1300370. Durham, J. W.; Caster, K. E. (1963). "
Helicoplacoidea: A New
class of Echinoderms". Science. 140 (3568): 820–822. Bibcode:1963Sci...
-
Helicocystis is a stalked,
spiralling pentaradial echinoderm known from the
Cambrian Jbel
Wawrmast Formation. Smith, A. B.; Zamora, S. (2013). "Cambrian...
- List of
echinodermata orders Calcichordate Theory Edrioasteroidea Helicoplacoidea Blastozoa Geggel,
Laura (22
February 2019). "480-Million-Year-Old Mystery...
