Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Any of various extinct jawed fishes of the group Placodermi of the Silurian and Devonian Periods, having bony plates of armor covering the head and thorax. Placoderms were among the first jawed vertebrates.

from The Century Dictionary.

  • Having the skin covered with broad flat plates, as a fish; belonging to the Placodermi.
  • noun A ganoid fish of the group Placodermi.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Paleon.) One of the Placodermi.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A member of an extinct group of fish with armored heads; the group lived during the Silurian and Devonian periods.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun fish-like vertebrate with bony plates on head and upper body; dominant in seas and rivers during the Devonian; considered the earliest vertebrate with jaws

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[New Latin Placodermī, class name : Greek plax, plak-, flat stone, plate; see plāk- in Indo-European roots + –derm.]

Examples

  • Scientists from Australia and Britain studying 380million-year-old fossils of placoderm fish were initially confused when they realized that the two fish were carrying embryos.

    Megite Technology News: What's Happening Right Now

  • Scientists from Australia and Britain studying 380million-year-old fossils of placoderm fish were initially confused when they realized that the two fish were carrying embryos.

    Megite Technology News: What's Happening Right Now

  • Nature that presents this missing piece of the puzzle and completes the picture of placoderm reproduction from mating to birth.

    EurekAlert! - Breaking News

  • The authors looked for a clasper in their placoderm fossils but couldn't find one, so they were forced to argue that it had been made of soft cartilage and had not been preserved.

    EurekAlert! - Breaking News

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