Page 81 - Ultimate Visual Dictionary (DK)
P. 81

EARLY SIGNS OF LIFE

                                      Ambulacral groove
                                                            Row of                   Row of
                                                            ossicles                 ossicles
             Small
            ossicles
           of  upper                                                            Broad disk
            surface
            Central
              disk
                                                                                  Short
                                                                                   arm
              Iron
            pyrites
                          FOSSILIZED STARFISH               UPPER SURFACE OF           LOWER SURFACE OF
                                                            FOSSILIZED STARFISH        FOSSILIZED STARFISH






            Jointed                             Chelicera                                   Growing tip
               leg                              (jointed
                                                pincer)


          Jointed leg
           with oar-
            shaped
            paddle
                                                                                                 Disk-shaped
                                                                                                 sporangium
                                                                                                 (spore-case)
          Segmented
           abdomen








                   UNDERSIDE OF FOSSILIZED EURYPTERID


                                              Telson (tail
                                              spine)
                                                                                               Leaflike scale



                                                Abdominal
        Shell contains eight                    segments
          somites (thoracic
              segments)                                         Stem

                                               Hingeless,
                                               bivalved
                                               shell
                     FOSSIL OF AN EXTINCT SHRIMP             RECONSTRUCTION OF ASTEROXYLON


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