enow.com Web Search

  1. Ad

    related to: primitive echinoderms group size comparison diagram worksheet template middle school
  2. teacherspayteachers.com has been visited by 100K+ users in the past month

    • Assessment

      Creative ways to see what students

      know & help them with new concepts.

    • Free Resources

      Download printables for any topic

      at no cost to you. See what's free!

    • Packets

      Perfect for independent work!

      Browse our fun activity packs.

    • Worksheets

      All the printables you need for

      math, ELA, science, and much more.

Search results

  1. Results from the WOW.Com Content Network
  2. Echinoderm - Wikipedia

    en.wikipedia.org/wiki/Echinoderm

    Diagram of water vascular system of a starfish, showing the ring canal, the radial canals, ampullae (small bulbs), and tube feet Echinoderms possess a unique water vascular system, a network of fluid-filled canals modified from the coelom (body cavity) that function in gas exchange, feeding, sensory reception and locomotion.

  3. Ctenocystoidea - Wikipedia

    en.wikipedia.org/wiki/Ctenocystoidea

    Ctenocystoidea is an extinct clade of echinoderms, which lived during the Cambrian and Ordovician periods. Unlike other echinoderms, ctenocystoids had bilateral symmetry, or were only very slightly asymmetrical. They are believed to be one of the earliest-diverging branches of echinoderms, with their bilateral symmetry a trait shared with other ...

  4. Hemichordate - Wikipedia

    en.wikipedia.org/wiki/Hemichordate

    Hemichordata (/ ˌhɛmɪkɔːrˈdeɪtə / HEM-ih-kor-DAY-tə) is a phylum which consists of triploblastic, eucoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and include two main classes: Enteropneusta (acorn worms), and ...

  5. Eocrinoidea - Wikipedia

    en.wikipedia.org/wiki/Eocrinoidea

    The Eocrinoidea are an extinct class of echinoderms that lived between the Early Cambrian and Late Silurian periods. They are the earliest known group of stalked, arm-bearing echinoderms, and were the most common echinoderms during the Cambrian. Eocrinoids were a paraphyletic group that may have been ancestral to six other classes: Rhombifera ...

  6. Nerve net - Wikipedia

    en.wikipedia.org/wiki/Nerve_net

    The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike central nervous systems, where neurons are typically grouped together, neurons found in nerve nets are spread apart. This nervous system allows cnidarians to respond to physical contact. They can detect food and other chemicals in a rudimentary way.

  7. Evolution of fish - Wikipedia

    en.wikipedia.org/wiki/Evolution_of_fish

    The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys.

  8. Acorn worm - Wikipedia

    en.wikipedia.org/wiki/Acorn_worm

    The acorn worms or Enteropneusta are a hemichordate class of invertebrates consisting of one order of the same name. [2] The closest non-hemichordate relatives of the Enteropneusta are the echinoderms. [3] There are 111 known species of acorn worm in the world, [4] the main species for research being Saccoglossus kowalevskii.

  9. Placoderm - Wikipedia

    en.wikipedia.org/wiki/Placoderm

    The diagram is based on Michael Benton, 2005. [17] Dunkleosteus, among the first of the vertebrate apex predators, was a giant armoured placoderm predator. Amazichthys, a pelagic arthrodire from the Middle Famennian of the Late Devonian. Fin spine of Eczematolepis, from the Middle Devonian of Wisconsin

  1. Ad

    related to: primitive echinoderms group size comparison diagram worksheet template middle school