What are hard parts?

Some articles on hard parts, parts:

How Microbial Mats Help Paleontologists
... Most fossils preserve only the hard parts of organisms, e.g ... fossils are preserved (the remains of soft-bodied organisms and also of the soft parts of organisms for which only hard parts such as shells are usually found) are extremely valuable because they ...
Permian–Triassic Extinction Event - Extinction Patterns - Possible Explanations of These Patterns
... marine organisms were those that produced calcareous hard parts (i.e ... Close relatives without calcareous hard parts suffered only minor losses, for example sea anemones, from which modern corals evolved ... respiratory systems, and non-calcareous hard parts had negligible losses—except for conodonts, in which 33% of genera died out ...

Famous quotes containing the words parts and/or hard:

    When the coherence of the parts of a stone, or even that composition of parts which renders it extended; when these familiar objects, I say, are so inexplicable, and contain circumstances so repugnant and contradictory; with what assurance can we decide concerning the origin of worlds, or trace their history from eternity to eternity?
    David Hume (1711–1776)

    Go, grieving rimes of mine, to that hard stone
    Whereunder lies my darling, lies my dear,
    And cry to her to speak from heaven’s sphere.
    Petrarch (1304–1374)