A Giant Eocene Bird 



By W. D. MATTHEW and WALTKK (J RANGER 



IT is not often that a really important fos- 

 sil discovery is clue to sheer good luck. 

 Generally speaking it is the result of a 

 prolonged and arduous search in a formation 

 which earlier reconnoissances had shown to 

 promise good results. Sometimes it is found 

 early in the campaign, more often after a 

 long series of disappointments or partial 

 successes that try the patience of the collec- 

 tor. Time and again he discovers fragments 

 — teeth or jaws or parts of the skeleton — that 

 buoy up his hopes and give warrant for his 

 expectation that sooner or later a complete 

 specimen will come to light if the exposures 

 hold out and he sticks stubbornly to his 

 search. Sometimes in the end his persist- 

 ence remains unrewarded; at the close of 

 the campaign he finds himself Avith but a 

 poor return for diligent Avork, and must seek 

 to retrieve his reputation in some other fossil 

 field. Once in a while fortune befriends him, 

 and he can place to his credit some new and 

 splendid find which had, so to speak, no right 

 to be there. 



Such a discovery, to speak frankly, Avas 

 the giant bird skeleton i found by Mr. Wil- 

 liam Stein last summer in the Bighorn Bad 

 Lands of Wyoming. But let no one suppose 

 that it Avas a find that anybody might have 

 made. Only a trained fossil hunter Avould 

 recognize such a find if he came across it, or 

 having recognized Avould knoAv hoAv to ex- 

 plore and collect it properly. Mr. Stein is 

 an able and expert fossil collector of many 

 years' experience. 



The Bighorn basin has been a Avell-knoAvn 

 fossil region since 1881 Avhen its riches Avere 

 first discovered by Dr. J. L. Wortman, at 

 that time collecting for the late Professor 

 Cope. In 1891 Doctor Wortman headed a 

 fossil hunting expedition to the basin for 

 the American Museum, and again in 1896. 



^ The principal parts of the Diatryma skeleton 

 have been temporarily arranged for exhibition in 

 the case in front of the elevator on the fourth 

 floor. It is intended later to exhibit the original 

 specimen as a panel mount in the dinosaur hall, 

 next the skeletons of Hesperornis and moa and 

 other fossil birds. The skeleton was mostly dis- 

 articulated and scattered when found, and the 

 bones are considerably distorted by crushing. It 

 does not appear advisable to articulate the original 

 specimen as an "open mount," but the bones can 

 be cast and remodeled for this purpose. 



In 1904 it Avas explored by the Amherst 

 party under direction of Dr. F. B. Loomis. 

 In 1910 Mr. Granger began a thorough and 

 systematic exploration of the basin for the 

 American Museum, and continued it for sev- 

 eral successive seasons. Practically every 

 exposure of the Eocene formations had 

 been thoroughly gone over in this search, 

 except for tAvo or three small areas, and the 

 Museum collections Avere enriched by over 

 one thousand specimens important enough to 

 catalogue and record individually, besides 

 innumerable teeth and other fragments not 

 catalogued. Practically all these fossils 

 were mammals, the best of them being skulls 

 and partial skeletons. By far the most 

 abundant fossil is the Eohippus or four-toed 

 horse, and of this the best specimen is the 

 skeleton secured by Mr. Stein, which was 

 fairly complete. Doctor Wortman in his 

 early explorations secured tAvo skeletons of 

 the Phenacodus Avhich are still the finest 

 mammal skeletons that have ever been found 

 there; and incomplete skeletons of several 

 other interesting animals, Oxjicena, Corypho- 

 don, Fachywna, Vassacyon, etc., have been 

 found. But on the AA-hole, skeletons are 

 rarities in the Bighorn fauna, more so than 

 they are in the later Eocene formations, 

 where fossils are usually better preserved. 



Fossil birds moreover are exceedingly rare 

 in our Eocene formations. Among the thou- 

 sands of specimens secured by Mr. Granger's 

 parties only a half dozen or so belonged to 

 birds of any kind, and of these only two 

 represented birds of gigantic size. One con- 

 sisted of tAvo toe bones, the other a frag- 

 ment from the end of the metatarsus or 

 "cannon bone." These Avere duly described 

 by Dr. Robert W. Shufeldt and referred to 

 the same genus as a couple of equally frag- 

 mentary remnants found in 1874 by Profes- 

 sor Cope in New Mexico, and named by 

 him Diatryma gigantca. 



In order to finish the Avork in the Bighorn 

 basin, Mr. Stein Avas directed to search the 

 small areas left unvisited, and spent about 

 tAvo months last summer in completing their 

 exploration. He secured, as Ave expected, a 

 fair collection of fossil mammals, AA^hich 

 added something to our knoAA'ledge of certain 



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