Date of this Version
NGS Volume 4 Part 18
Comparisons of the acetabula of various mastodons and mammoths common to Nebraska show conclusively that absence of the round ligament is not a characteristic of the proboscidea, as generally accepted. From the specimens in our collections, there is evidence that the ligament was not on! y present, but was uncommonly large and well developed in the earlier Nebraska proboscideans. Examination of material collected since 1891, and preserved in the cabinets of the Nebraska State Museum. and the Morrill Geological Collections, makes it apparent that all Nebraska proboscideans had round ligaments, though perhaps the latest survivors did not.