ammonites

• ammonites

60:1.12The ma­rine life of this pe­riod was mea­ger but im­proved rapidly with the new in­va­sion of the sea, which again pro­duced ex­ten­sive coast lines of shal­low wa­ters. Since there was more shal­low wa­ter around Eu­rope and Asia, the rich­est fos­sil beds are to be found about these con­ti­nents. To­day, if you would study the life of this age, ex­am­ine the Hi­malayan, Siberian, and Med­i­ter­ra­nean re­gions, as well as In­dia and the is­lands of the south­ern Pa­cific basin. A promi­nent fea­ture of the ma­rine life was the pres­ence of hosts of the beau­ti­ful am­monites, whose fos­sil re­mains are found all over the world.

60:1.13130,000,000 years ago the seas had changed very lit­tle. Siberia and North Amer­ica were con­nected by the Bering Strait land bridge. A rich and unique ma­rine life ap­peared on the Cal­i­for­nian Pa­cific coast, where over one thou­sand species of am­monites de­vel­oped from the higher types of ceph­a­lop­ods. The life changes of this pe­riod were in­deed rev­o­lu­tion­ary not­with­stand­ing that they were tran­si­tional and grad­ual.

• ammonites

60:2.8The re­turn of the seas im­proved the weather. Corals spread to Eu­ro­pean wa­ters, tes­ti­fy­ing that the cli­mate was still mild and even, but they never again ap­peared in the slowly cool­ing po­lar seas. The ma­rine life of these times im­proved and de­vel­oped greatly, es­pe­cially in Eu­ro­pean wa­ters. Both corals and crinoids tem­porar­ily ap­peared in larger num­bers than here­to­fore, but the am­monites dom­i­nated the in­ver­te­brate life of the oceans, their av­er­age size rang­ing from three to four inches, though one species at­tained a di­am­e­ter of eight feet. Sponges were ev­ery­where, and both cut­tle­fish and oys­ters con­tin­ued to evolve.

• ammonites

60:4.5Bi­o­log­i­cally as well as ge­o­log­i­cally this was an event­ful and ac­tive age on land and un­der wa­ter. Sea urchins in­creased while corals and crinoids de­creased. The am­monites, of pre­pon­der­ant in­flu­ence dur­ing a pre­vi­ous age, also rapidly de­clined. On land the fern forests were largely re­placed by pine and other mod­ern trees, in­clud­ing the gi­gan­tic red­woods. By the end of this pe­riod, while the pla­cen­tal mam­mal has not yet evolved, the bi­o­logic stage is fully set for the ap­pear­ance, in a sub­se­quent age, of the early an­ces­tors of the fu­ture mam­malian types.