Bulletin of the Michigan Ornithological Club. 



Fossil Birds— A Brief Review of 

 Present Knowledoe. 



IN onr study of ornithology it may be 

 well for us to look a few moments into 

 the past and learn something, if pos- 

 sible, of the former existence of biid-life. 

 When did birds make their first appearance? 

 What other animals came into existence 

 with them? Which of the grand divisions 

 of earth-history saw their coming? Did 

 they advance from a lower order, or did 

 they suddenly mount upon the wing in their 

 full-fledged glory? These are but a few of 

 the questions which geology tries to an- 

 swer. 



I assume that you are familiar with the 

 latter subject, and know that the science of 

 geology treats of the history of the earth as 

 recorded in the rocks, and tries to explain 

 the causes of tlie many kinds of rock-form- 

 ation we see around us. You know that 



Peop. C. a. Whittemoee. 



students have carefully examined such rec- 

 ords, and have constructed a chart of geo- 

 logical history. The inconceivable geons of 

 time indicated can not be measured in 

 years, but they can be measured relatively. 

 One period may be seen to be much shorter 

 or longer than the one just before or fol- 

 lowing. Certain features of the rocks occur 

 in such regular succession that a science 

 may be built around them, and the facts so 

 observed may be announced as the laws of 

 the world. The succession of life is regular 

 from the earliest times. Some life-forms 

 may be omitted in different localities, but 

 the order of succession is never reversed. 

 By examination and comparison of fossils, 

 chiefly, this history already referred to has 



been divided into five principal eras, name- 

 ly, Eozoic or Dawn Life, Palaeozoic or 

 Ancient Life, Mesozoic or Middle Life,, 

 Cenozoic or Ltecent Life,, and Psychozoic 

 or Age of Mind. They are again sub- 

 divided into seven ages, namely, Archaean 

 or Age of Eozoon^ Silurian or Age of 

 Livertehrates, Devonian or Age of Fishes^ 

 Carboniferous or Age of Coal-plants^ 

 Secondary Rocks or Age of Reptiles, the 

 Age of Mammals and the Age of Man. 

 Invertebrates and fishes first appeared, be- 

 cause the earth could not support any 

 higher forms. Then the coal-plants came, 

 and it is believed that there was a super- 

 abundance of carbonic acid in the air. The 

 air being partly cleared of its carbon by the 

 formation of coal, was rendered purer, and 

 reptiles appeared. Then came the disputed 

 ice-age, and drove all life before its frigid 

 front. Then came the present mammalian 

 fauna, and man came in with it. The first 

 plants were sea-weeds ; the first animals 

 were invertebrates. Before speaking of the 

 appearance of birds, let us spend a few 

 moments with the first reptiles. The car- 

 boniferous was followed by a period of great 

 changes both in life-forms and in noncon- 

 formity of strata. This period was called 

 Permian, and was followed by the Meso- 

 zoic era or Age of Reptiles. In tliis age 

 reptiles reached their culmination both in 

 numbers and size of individuals. In this 

 age also, was the first appearance of mam- 

 mals and birds. The reptiles were large 

 and beast-like ; the mammals in the begin- 

 ning were small and few in numbers, and 

 were most all marsupials. Mammals ap- 

 peared before the birds. One would think 

 that the birds came first, but we must con- 

 sider them a branch of the reptilian family 

 of vertebrates. Many of the reptiles had 

 chai'acters which connected them with 

 fishes ; others had characters we now see in 

 birds. The latter class had long and strong 

 hind legs and short fore legs, thus indicat- 

 ing that they walked on their hind feet. 

 Many of them had three toes on their hind 

 feet, and made bird-like tracks. Many 

 more had bird-like ankle-joints. 



The Pterosaurs or Winged Saurians were 

 among the most I'emarkable aninuils that 

 have been found. They had the stout body, 

 the keeled breast-bone, the long, flexible 



