The Marine-Life Era on Urantia

59:6.1This pe­riod marks the end of piv­otal evo­lu­tion­ary de­vel­op­ment in ma­rine life and the open­ing of the tran­si­tion pe­riod lead­ing to the sub­se­quent ages of land an­i­mals.

59:6.2This age was one of great life im­pov­er­ish­ment. Thou­sands of ma­rine species per­ished, and life was hardly yet es­tab­lished on land. This was a time of bi­o­logic tribu­la­tion, the age when life nearly van­ished from the face of the earth and from the depths of the oceans. To­ward the close of the long ma­rine-life era there were more than one hun­dred thou­sand species of liv­ing things on earth. At the close of this pe­riod of tran­si­tion less than five hun­dred had sur­vived.

59:6.3The pe­cu­liar­i­ties of this new pe­riod were not due so much to the cool­ing of the earth’s crust or to the long ab­sence of vol­canic ac­tion as to an un­usual com­bi­na­tion of com­mon­place and pre-ex­ist­ing in­flu­ences—re­stric­tions of the seas and in­creas­ing el­e­va­tion of enor­mous land masses. The mild ma­rine cli­mate of for­mer times was dis­ap­pear­ing, and the harsher con­ti­nen­tal type of weather was fast de­vel­op­ing.

59:6.4170,000,000 years ago great evo­lu­tion­ary changes and ad­just­ments were tak­ing place over the en­tire face of the earth. Land was ris­ing all over the world as the ocean beds were sink­ing. Iso­lated moun­tain ridges ap­peared. The east­ern part of North Amer­ica was high above the sea; the west was slowly ris­ing. The con­ti­nents were cov­ered by great and small salt lakes and nu­mer­ous in­land seas which were con­nected with the oceans by nar­row straits. The strata of this tran­si­tion pe­riod vary in thick­ness from 1,000 to 7,000 feet.

59:6.5The earth’s crust folded ex­ten­sively dur­ing these land el­e­va­tions. This was a time of con­ti­nen­tal emer­gence ex­cept for the dis­ap­pear­ance of cer­tain land bridges, in­clud­ing the con­ti­nents which had so long con­nected South Amer­ica with Africa and North Amer­ica with Eu­rope.

59:6.6Grad­u­ally the in­land lakes and seas were dry­ing up all over the world. Iso­lated moun­tain and re­gional glaciers be­gan to ap­pear, es­pe­cially over the South­ern Hemi­sphere, and in many re­gions the glacial de­posit of these lo­cal ice for­ma­tions may be found even among some of the up­per and later coal de­posits. Two new cli­matic fac­tors ap­peared—glacia­tion and arid­ity. Many of the earth’s higher re­gions had be­come arid and bar­ren.

59:6.7Through­out these times of cli­matic change, great vari­a­tions also oc­curred in the land plants. The seed plants first ap­peared, and they af­forded a bet­ter food sup­ply for the sub­se­quently in­creased land-an­i­mal life. The in­sects un­der­went a rad­i­cal change. The rest­ing stages evolved to meet the de­mands of sus­pended an­i­ma­tion dur­ing win­ter and drought.

59:6.8Among the land an­i­mals the frogs reached their cli­max in the pre­ced­ing age and rapidly de­clined, but they sur­vived be­cause they could long live even in the dry­ing-up pools and ponds of these far-dis­tant and ex­tremely try­ing times. Dur­ing this de­clin­ing frog age, in Africa, the first step in the evo­lu­tion of the frog into the rep­tile oc­curred. And since the land masses were still con­nected, this pre­rep­til­ian crea­ture, an air breather, spread over all the world. By this time the at­mo­sphere had been so changed that it served ad­mirably to sup­port an­i­mal res­pi­ra­tion. It was soon af­ter the ar­rival of these pre­rep­til­ian frogs that North Amer­ica was tem­porar­ily iso­lated, cut off from Eu­rope, Asia, and South Amer­ica.

59:6.9The grad­ual cool­ing of the ocean wa­ters con­tributed much to the de­struc­tion of oceanic life. The ma­rine an­i­mals of those ages took tem­po­rary refuge in three fa­vor­able re­treats: the pres­ent Gulf of Mex­ico re­gion, the Ganges Bay of In­dia, and the Si­cil­ian Bay of the Med­i­ter­ra­nean basin. And it was from these three re­gions that the new ma­rine species, born to ad­ver­sity, later went forth to re­plen­ish the seas.

59:6.10160,000,000 years ago the land was largely cov­ered with veg­e­ta­tion adapted to sup­port land-an­i­mal life, and the at­mo­sphere had be­come ideal for an­i­mal res­pi­ra­tion. Thus ends the pe­riod of ma­rine-life cur­tail­ment and those test­ing times of bi­o­logic ad­ver­sity which elim­i­nated all forms of life ex­cept such as had sur­vival value, and which were there­fore en­ti­tled to func­tion as the an­ces­tors of the more rapidly de­vel­op­ing and highly dif­fer­en­ti­ated life of the en­su­ing ages of plan­e­tary evo­lu­tion.

59:6.11The end­ing of this pe­riod of bi­o­logic tribu­la­tion, known to your stu­dents as the Per­mian, also marks the end of the long Pa­le­o­zoic era, which cov­ers one quar­ter of the plan­e­tary his­tory, two hun­dred and fifty mil­lion years.

59:6.12The vast oceanic nurs­ery of life on Uran­tia has served its pur­pose. Dur­ing the long ages when the land was un­suited to sup­port life, be­fore the at­mo­sphere con­tained suf­fi­cient oxy­gen to sus­tain the higher land an­i­mals, the sea moth­ered and nur­tured the early life of the realm. Now the bi­o­logic im­por­tance of the sea pro­gres­sively di­min­ishes as the sec­ond stage of evo­lu­tion be­gins to un­fold on the land.

59:6.13[Pre­sented by a Life Car­rier of Neb­a­don, one of the orig­i­nal corps as­signed to Uran­tia.]