Zöology; a textbook for colleges and universities . or perhaps the mammals learned to eattheir eggs, which they did not know how to protect. 9. While the dinosaurs were rulers of the earth, manyimportant events were taking place. Warm-bloodedcreatures evolved from reptilian types, one series devel-oping wings and becoming birds, the other retainingthe four walking legs and giving rise to the early birds, like their reptilian ancestors, weretoothed. Of the first mammals we know little; butthey were small, and are believed to have laid eggs,like the Australian duckbill of the present
Zöology; a textbook for colleges and universities . or perhaps the mammals learned to eattheir eggs, which they did not know how to protect. 9. While the dinosaurs were rulers of the earth, manyimportant events were taking place. Warm-bloodedcreatures evolved from reptilian types, one series devel-oping wings and becoming birds, the other retainingthe four walking legs and giving rise to the early birds, like their reptilian ancestors, weretoothed. Of the first mammals we know little; butthey were small, and are believed to have laid eggs,like the Australian duckbill of the present time. Another event of scarcely less importance was theappearance of flowering plants, and with them of typesof insects adapted for visiting flowers. The latterappear to have come in principally with the developmentof herbaceous vegetation at the end of the Mesozoic andduring the Cenozoic. The first flowering plants werewoody, and were mostly, if not wholly, pollinatedthrough the agency of the wind, or at any rate without THE HISTORY OF LIFE 153. Photograph from Am. Mus. Natural HistoryFIG. 27. Bronljsaurus (or Apatosaurus), one of the dinosaurs, a gigantic Mesozoicreptile, as restored by C. R. Knight under the direction of Professor Osborn at theAmerican Museum of Natural History, New York. the assistance of bees or butterflies. Owing to thechange in the flora, the landscape during the Cretaceous
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1920
