December, 1933 



FIELD MUSEUM NEWS 



Page 3 



MANDEL ZOOLOGICAL EXPEDITION 

 SAILS FOR GUATEMALA 



A zoological expedition, sponsored by 

 Leon Mandel of Chicago, to make extensive 

 collections of birds, mammals, reptiles and 

 amphibians of Guatemala for Field Museum, 

 sailed from New Orleans November 21, 

 aboard the steamship Tivives, for Puerto 

 Barrios. The official name of the expedition 

 is the Leon Mandel Guatemala Expedition 

 of Field Museum. 



A few weeks hence, after the party of 

 scientists has completed preliminary recon- 

 noitering and established camps, Mr. Mandel 

 is expected to join the expedition for a short 

 vacation. This is the second expedition 

 in which Mr. Mandel has participated as a 

 collector. His deep interest in zoology, and 

 enthusiasm as a collector of museum speci- 

 mens, was previously shown in 1932 when 

 he organized and led the Mandel-Field 

 Museum Zoological Expedition to Venezuela 

 which sailed aboard his yacht Buccaneer, 

 making a long sea voyage and penetrating 

 the innermost navigable reaches of the 

 Orinoco River. 



Karl P. Schmidt, Assistant Curator of 

 Reptiles at the Museum, is leader of the 

 present expedition. He is accompanied by 

 F. J. W. Schmidt, biologist, Emmet R. 

 Blake, ornithologist, and Daniel Clark, 

 general assistant. The expedition will 

 remain in Guatemala for about six months, 

 surveying various regions of the country, 

 which is remarkable for its diversification 

 of climate and altitude. This diversity of 

 habitat, which results in a wealth of species 

 of animal life, reaches its maximum for 

 Central America in Guatemala. The 

 country is of special interest zoologically 

 also because it is the meeting ground of 

 North and South American types of life. 



Field Museum has for years carried on 

 investigations of the fauna of the American 

 tropics, and the present expedition is for 

 the purpose of furthering these important 

 studies. While the expedition's primary 

 aim will be to collect specimens for addition 

 to the Museum's vast scientific reference 

 collections, it will also seek material for the 

 exhibits, including strikingly interesting 

 species of tropical reptiles, and a wide variety 

 of Central American birds to be used in a 

 series of groups reproducing the natural 

 habitats of the birds. One of the groups 

 for which specimens will be sought is that 

 of the giant oriole with its peculiar long 

 bag-like nests which hang in crowded 

 colonies on the trees. Various notable 

 game birds, and macaws, toucans, and other 

 exotic species, will also be hunted. 



Leader Karl Schmidt will concentrate his 

 efforts on his specialty, the reptiles, while 

 his brother, F. J. W. Schmidt, will specialize 

 on mammals, and Mr. Blake will have 

 charge of bird collecting. Karl Schmidt's 

 share in this expedition will be a continuation 

 of his work on the Central American fauna 

 for which he was awarded a fellowship in 

 1932 by the John Simon Guggenheim 

 Memorial Foundation. As far back as 1923 

 Mr. Schmidt made extensive collections in 

 the adjacent countries of Honduras and 

 British Honduras. Among the most interest- 

 ing creatures to be collected on the present 

 Guatemalan trip are arboreal salamanders 

 and frogs, many of which have extraordinary 

 breeding habits. 



Mr. Blake was one of the principal col- 

 lectors on the Mandel-Field Museum Zoo- 

 logical Expedition to Venezuela in 1932, 

 on which he made a remarkable record by 

 collecting and preparing more than 800 

 birdskins within a period of only five weeks 



in the mountain rain forests of the Mount 

 Turumiquiri region. 



F. J. W. Schmidt has for several years 

 experimented with special methods of col- 

 lecting mammals, and will apply his experi- 

 ence on the exceptionally rich mammalian 

 fauna of Guatemala in the hope of collecting 

 new and little-known forms. 



Additions to Library 



The Museum Library, which had several 

 volumes of the Memoirs of the Egyptian 

 Exploration Fund, recently received three 

 more volumes. Also the latest volume of 

 the Palaeontographical Society, volume 1 

 of Mizraim, and another volume of Obras 

 Completas de Ameghino, have been received. 



EXHIBIT SHOWS FOSSIL SKELETON AS FOUND IN THE EARTH 



By Elmbk S. Riggs 

 Associate Curator of Paleontology 



A new exhibit in Ernest R. Graham Hall 

 (Hall 38) shows a fossil skeleton in the earth 

 just as it was discovered by the Marshall 

 Field Paleontological Expedition to Argen- 

 tina and Bolivia. The animal is one of the 

 great sloths abundant in South America 

 ten thousand years ago. The exhibit shows 

 how such fossils are preserved through long 

 periods, and how they are sometimes 

 revealed when erosion by rain and stream 

 attacks their burial places. 



These sloths, great beasts which originated 

 many millions of years ago, played an im- 

 portant part in the animal history of South 



adjacent grasslands. Year after year this 

 work of wind and stream is repeated and 

 layer after layer is built up, covering plants 

 and bodies of animals. 



The skeletons of the great sloths were 

 left among the reeds or by the shores of 

 streams. The sediments, gathering through 

 thousands of years, covered and preserved 

 many of them. Ages later, when these 

 lands had been raised higher than the shore 

 to southward, streams cut their channels 

 through the older sediments underlying the 

 plain. When men came to graze their 

 cattle and horses over these lands and to 

 grow wheat and other grains, they found, 

 from time to time, the bones of strange 



Fossil Sloth Skeleton as Paleont<>l>>t>is[s Kiiuiul It 

 New exhibit in Ernest R. Graham Hall shows how the remains of an extinct animal were preserved in the 

 pampas formation of Argentina and there discovered by members of a Museum expedition. 



America. They had long narrow heads, 

 clumsy bodies, short stout hind legs, long 

 forelegs, and massive tails. They are dis- 

 tantly related to the little tree sloths which 

 still live along the Amazon. They lumbered 

 about the low, wet pampas lands overgrown 

 with reedy grasses and tall, plumed pampas 

 grass. With the great claws of their forefeet 

 they tore up the ground in search of roots 

 and tubers upon which they fed. In autumn 

 they wandered northward to sparsely wooded 

 lands. Rearing upon their hind legs, they 

 pulled down the branches of the abundant 

 algaroba trees and, with long slender 

 tongue, gathered in and fed upon the 

 sweet seed pods. 



Laymen often ask, "How do you know 

 where to dig to find fossil skeletons?" This 

 skeleton, half revealed in the earth, answers 

 that question. The scene represents a 

 stretch of pampas land, as level and as 

 fertile as the plains of Illinois. In winter 

 rains are frequent on the pampas. Shallow 

 streams often overflow their banks. The 

 fiood waters are heavy with mud and fine 

 sand. Flowing out upon the reedy meadows 

 the current of the stream is checked and 

 the sediment settles in layers over the 

 ground. In the dry weather of late summer, 

 sands are scattered by winds over the 



animals washed out on the banks of streams. 

 Reports of these became subjects of scientific 

 study in many countries. 



Such reports led the Marshall Field 

 Paleontological Expedition to the region 

 where this skeleton was discovered. One 

 of the members followed up a dry wash 

 near the River Quequen Grande. The 

 banks of this wash, cut through wheat and 

 pasture lands, were steep and bare of vegeta- 

 tion. Winter rains and summer winds were 

 steadily wearing them away. Thus it 

 happened that the skeleton of this great 

 sloth, buried some ten thousand years ago, 

 was being laid bare. On the face of the 

 bank, four or five feet below the soil, an 

 irregular line of dark brown spots caught 

 the attention of the collector. Hasty 

 examination showed that these were the 

 broken ends of fossil bones. 



At the left the point of the nose was just 

 appearing. To the right, were the bones of 

 the foreleg. Farther to the right, the point 

 of the hip appeared and beyond that the 

 extended hind leg. With pick and shovel 

 workmen removed the soil and underlying 

 sandy clay until the skeleton was revealed 

 as now shown in the Museum group, the 

 preparation of which is the work of Phil C. 

 Orr of the staff of the Department of Geology. 



