Urantia During the Early Land-Life Era

60:2.1120,000,000 years ago a new phase of the rep­til­ian age be­gan. The great event of this pe­riod was the evo­lu­tion and de­cline of the di­no­saurs. Land-an­i­mal life reached its great­est de­vel­op­ment, in point of size, and had vir­tu­ally per­ished from the face of the earth by the end of this age. The di­no­saurs evolved in all sizes from a species less than two feet long up to the huge non­car­niv­o­rous di­no­saurs, sev­enty-five feet long, that have never since been equaled in bulk by any liv­ing crea­ture.

60:2.2The largest of the di­no­saurs orig­i­nated in west­ern North Amer­ica. These mon­strous rep­tiles are buried through­out the Rocky Moun­tain re­gions, along the whole of the At­lantic coast of North Amer­ica, over west­ern Eu­rope, South Africa, and In­dia, but not in Aus­tralia.

60:2.3These mas­sive crea­tures be­came less ac­tive and strong as they grew larger and larger; but they re­quired such an enor­mous amount of food and the land was so over­run by them that they lit­er­ally starved to death and be­came ex­tinct—they lacked the in­tel­li­gence to cope with the sit­u­a­tion.

60:2.4By this time most of the east­ern part of North Amer­ica, which had long been el­e­vated, had been lev­eled down and washed into the At­lantic Ocean so that the coast ex­tended sev­eral hun­dred miles far­ther out than now. The west­ern part of the con­ti­nent was still up, but even these re­gions were later in­vaded by both the north­ern sea and the Pa­cific, which ex­tended east­ward to the Dakota Black Hills re­gion.

60:2.5This was a fresh-wa­ter age char­ac­ter­ized by many in­land lakes, as is shown by the abun­dant fresh-wa­ter fos­sils of the so-called Mor­ri­son beds of Col­orado, Mon­tana, and Wyoming. The thick­ness of these com­bined salt- and fresh-wa­ter de­posits varies from 2,000 to 5,000 feet; but very lit­tle lime­stone is pres­ent in these lay­ers.

60:2.6The same po­lar sea that ex­tended so far down over North Amer­ica like­wise cov­ered all of South Amer­ica ex­cept the soon ap­pear­ing An­des Moun­tains. Most of China and Rus­sia was in­un­dated, but the wa­ter in­va­sion was great­est in Eu­rope. It was dur­ing this sub­mer­gence that the beau­ti­ful litho­graphic stone of south­ern Ger­many was laid down, those strata in which fos­sils, such as the most del­i­cate wings of olden in­sects, are pre­served as of but yes­ter­day.

60:2.7The flora of this age was much like that of the pre­ced­ing. Ferns per­sisted, while conifers and pines be­came more and more like the pres­ent-day va­ri­eties. Some coal was still be­ing formed along the north­ern Med­i­ter­ra­nean shores.

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.

60:2.9110,000,000 years ago the po­ten­tials of ma­rine life were con­tin­u­ing to un­fold. The sea urchin was one of the out­stand­ing mu­ta­tions of this epoch. Crabs, lob­sters, and the mod­ern types of crus­taceans ma­tured. Marked changes oc­curred in the fish fam­ily, a stur­geon type first ap­pear­ing, but the fe­ro­cious sea ser­pents, de­scended from the land rep­tiles, still in­fested all the seas, and they threat­ened the de­struc­tion of the en­tire fish fam­ily.

60:2.10This con­tin­ued to be, pre-em­i­nently, the age of the di­no­saurs. They so over­ran the land that two species had taken to the wa­ter for sus­te­nance dur­ing the pre­ced­ing pe­riod of sea en­croach­ment. These sea ser­pents rep­re­sent a back­ward step in evo­lu­tion. While some new species are pro­gress­ing, cer­tain strains re­main sta­tion­ary and oth­ers grav­i­tate back­ward, re­vert­ing to a for­mer state. And this is what hap­pened when these two types of rep­tiles for­sook the land.

60:2.11As time passed, the sea ser­pents grew to such size that they be­came very slug­gish and even­tu­ally per­ished be­cause they did not have brains large enough to af­ford pro­tec­tion for their im­mense bod­ies. Their brains weighed less than two ounces not­with­stand­ing the fact that these huge ichthyosaurs some­times grew to be fifty feet long, the ma­jor­ity be­ing over thirty-five feet in length. The ma­rine crocodil­ians were also a re­ver­sion from the land type of rep­tile, but un­like the sea ser­pents, these an­i­mals al­ways re­turned to the land to lay their eggs.

60:2.12Soon af­ter two species of di­no­saurs mi­grated to the wa­ter in a fu­tile at­tempt at self-preser­va­tion, two other types were driven to the air by the bit­ter com­pe­ti­tion of life on land. But these fly­ing pterosaurs were not the an­ces­tors of the true birds of sub­se­quent ages. They evolved from the hol­low-boned leap­ing di­no­saurs, and their wings were of bat­like for­ma­tion with a spread of twenty to twenty-five feet. These an­cient fly­ing rep­tiles grew to be ten feet long, and they had sep­a­ra­ble jaws much like those of mod­ern snakes. For a time these fly­ing rep­tiles ap­peared to be a suc­cess, but they failed to evolve along lines which would en­able them to sur­vive as air nav­i­ga­tors. They rep­re­sent the non­sur­viv­ing strains of bird an­ces­try.

60:2.13Tur­tles in­creased dur­ing this pe­riod, first ap­pear­ing in North Amer­ica. Their an­ces­tors came over from Asia by way of the north­ern land bridge.

60:2.14One hun­dred mil­lion years ago the rep­til­ian age was draw­ing to a close. The di­no­saurs, for all their enor­mous mass, were all but brain­less an­i­mals, lack­ing the in­tel­li­gence to pro­vide suf­fi­cient food to nour­ish such enor­mous bod­ies. And so did these slug­gish land rep­tiles per­ish in ever-in­creas­ing num­bers. Hence­forth, evo­lu­tion will fol­low the growth of brains, not phys­i­cal bulk, and the de­vel­op­ment of brains will char­ac­ter­ize each suc­ceed­ing epoch of an­i­mal evo­lu­tion and plan­e­tary prog­ress.

60:2.15This pe­riod, em­brac­ing the height and the be­gin­ning de­cline of the rep­tiles, ex­tended nearly twenty-five mil­lion years and is known as the Juras­sic.