of integrating into the Museum's fossil-mammal collection a great 

 number of Oligocene mammals received from the University of 

 Chicago. In preparation for the new exhibits of meteorites the last 

 of the meteorites was removed from Hall 35 (see page 66) and placed 

 in the study collection. Henry Horback, Assistant in Geology, who 

 reweighed every specimen in the collection, is to be credited for the 

 excellent manner in which he has arranged the entire collection. 



Exhibits— Geology 



The mount of the incomplete Brontosaurus skeleton, which had been 

 on exhibition in Ernest R. Graham Hall (Hall 38) since 1921, was 

 successfully completed during the year (see pages 21 and 95), a task 

 made possible by the acquisition of the missing parts, although from 

 a different individual, by a Museum expedition in Utah in 1942. 

 The preparation and assembling of the parts were accomplished pri- 

 marily by Orville L. Gilpin, Chief Preparator of Fossils, who was 

 ably assisted by Preparator Lambert, and both men are to be con- 

 gratulated for their skill in adding the new materials to the old 

 mount so perfectly that all parts of the skeleton seem to have been 

 mounted at the same time. The finished exhibit was displayed to 

 the public on Members' Night, April 18 (see page 36). Chief Pre- 

 parator Gilpin also remounted the damaged skelton of the giant Irish 

 deer that had been long on exhibition in Hall 38. 



First steps were taken during the year toward preparation of a 

 completely new series of fossil-fish exhibits to be arranged syste- 

 matically. A few large and spectacular fishes will be featured, one 

 of which is an exceptionally fine fourteen-foot specimen of the 

 teleost Portheus from the Walker Museum of the University of 

 Chicago. Also to be displayed are the fifteen-foot shark from 

 Indiana collected by Curators Zangerl and Richardson (see Annual 

 Report 1957, page 56) and one of the huge armored fishes, or placo- 

 derms, of the Devonian period, Dunkleosteus (Chief Preparator 

 Gilpin assembled and mounted a cast of one of the best specimens 

 of Dunkleosteus). Fossil fishes are generally not preserved well 

 enough to give a clear idea of how they might have looked in life. 

 To make visualization of the forms more distinct a number of 

 extremely lifelike restorations to be used in the planned exhibits 

 were completed by Miss Maidi Wiebe, Departmental Artist, who 

 is to be commended for the restorations in natural size of the jawless 

 fishes Pteraspis, Hemicyclaspis, and Pharyngolepis and of the placo- 

 derms Coccosteus and Gemundina. 



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