"endoskeletons" meaning in English

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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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          "ref": "2009 January 15, Martin D. Brazeau, “The braincase and jaws of a Devonian 'acanthodian' and modern gnathostome origins”, Nature Volume 457 No. 7227, doi:10.1038/nature07436",
          "text": "Their relationships with modern gnathostomes have remained mysterious, partly because their un-mineralized endoskeletons rarely fossilized."
        }
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      "form_of": [
        {
          "word": "endoskeleton"
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      "glosses": [
        "plural of endoskeleton"
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      "id": "en-endoskeletons-en-noun-QgVpcB59",
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      "tags": [
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  "word": "endoskeletons"
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      "expansion": "endoskeletons",
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  "lang_code": "en",
  "pos": "noun",
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          "text": "Their relationships with modern gnathostomes have remained mysterious, partly because their un-mineralized endoskeletons rarely fossilized."
        }
      ],
      "form_of": [
        {
          "word": "endoskeleton"
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      "glosses": [
        "plural of endoskeleton"
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  "word": "endoskeletons"
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