blastoid

blastoid

▪ fossil class
      any member of an extinct class (Blastoidea) of echinoderms, animals related to the modern starfish and sea lilies, that existed from the Middle Ordovician to the Late Permian periods (from 472 million to 251 million years ago). Blastoids were sedentary animals anchored to the seafloor by a stemlike column of circular plates. Unlike other echinoderms, blastoids were characterized by a regularity of structure; the blastoid body region consisted of 13 plates of calcium carbonate, an external framework, or skeleton, arranged in 3 circles about the body.

      Some blastoids are useful as index, or guide, fossils that allow the correlation of rock units; the genus Pentremites is especially well known and common.

* * *


Universalium. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Blastoid — Blas toid, n. (Zo[ o]l.) One of the Blastoidea. [1913 Webster] || …   The Collaborative International Dictionary of English

  • blastoid — BLASTOÍD, Ă I. adj. în formă de mugur. II. s. n. pl. clasă de echinoderme fosile cu înfăţişare de muguri calcaroşi. (< fr. blastoïde/s/) Trimis de raduborza, 15.09.2007. Sursa: MDN …   Dicționar Român

  • Blastoid — Taxobox name = Blastoids fossil range = Ordovician Permian image caption = Blastoid fossils ( thecae ) attached to matrix. regnum = Animalia phylum = Echinodermata subphylum = Blastozoa classis = Blastoidea classis authority = Say, 1825… …   Wikipedia

  • blastoid — blas·toid …   English syllables

  • blastoid — I. ˈblaˌstȯid noun ( s) Etymology: New Latin Blastoidea, from blast + oidea : an echinoderm or fossil of the class Blastoidea II. adjective : of, relating to, or like the Blastoidea …   Useful english dictionary

  • Eocrinoidea — Paraphyletic group name = Eocrinoidea fossil range = Cambrian Silurian image2 caption = Colourful reconstruction of Gogia ojenai image caption=Eocrinoid holdfasts (Middle Ordovician, Utah) regnum = Animalia phylum = Echinodermata subphylum =… …   Wikipedia

  • Gogia — Taxobox name = Gogia fossil range = Mid Cambrian image caption = Gogia ojenai status = Fossil regnum = Animalia phylum = Echinodermata subphylum = Blastozoa classis = Eocrinoidea classis authority = Miller, 1821 ordo = genus = Gogia subdivision… …   Wikipedia

  • Aggressive NK-cell leukemia — Infobox Disease Name = PAGENAME Caption = DiseasesDB = ICD10 = ICD9 = ICDO = ICDO|9948|3 OMIM = MedlinePlus = eMedicineSubj = ent eMedicineTopic = 776 MeshID = Aggressive NK cell leukemia is a disease with an aggressive, systemic proliferation of …   Wikipedia

  • Taxonomy of commonly fossilised invertebrates — Although the phylogenetic classification of sub vertebrate animals (both extinct and extant) remains a work in progress, the following taxonomy attempts to be useful by combining both traditional (old) and new (21st century) paleozoological… …   Wikipedia

  • Mantle cell lymphoma — Classification and external resources Micrograph showing mantle cell lymphoma (bottom of image) in a biopsy of the terminal ileum. H E stain …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”