Manus, Sacrum, and Caudals of Sauropoda

Manus, Sacrum, and Caudals of Sauropoda is a scientific monograph by Henry Fairfield Osborn, the American paleontologist who lived from 1857 to 1935 and who served as president of the American Museum of Natural History in New York from 1908 to 1933. The paper belongs to the substantial body of dinosaur research that Osborn produced and supervised during his decades at the museum, when the Bone Wars of the late nineteenth century had given American institutions an enormous backlog of sauropod material to describe and classify.

The manus is the hand or forefoot. The sacrum is the fused vertebrae of the pelvic region. The caudals are the tail vertebrae. The paper presents detailed anatomical descriptions and measurements of these particular skeletal elements from sauropod dinosaurs, the long necked herbivorous group that included Diplodocus, Apatosaurus, Brontosaurus, Camarasaurus, and the other giant Jurassic and Cretaceous forms that were the most spectacular of all the dinosaur discoveries.

Osborn worked in the technical descriptive mode that vertebrate paleontology required at the turn of the twentieth century. The paper would have included plates with line drawings of the bones at known scale, measurements presented in tables, and detailed comparative analysis of how the same elements differed across the various sauropod genera that had been named in the previous decades. This kind of monograph was the basic building block on which the larger classifications and evolutionary interpretations rested.

The specific science of the paper is now substantially out of date. The classification of sauropods has been revised many times since Osborn’s day, with the Brontosaurus name famously being merged into Apatosaurus in the early twentieth century and then revived again in 2015 on the basis of new analysis. The fundamental descriptions of the bones themselves, however, remain part of the basic literature, and modern paleontologists still cite Osborn’s measurements when working with the museum specimens he originally described.

The paper is mostly of interest now to historians of paleontology and to serious students of sauropod anatomy. It pairs with the other Osborn monographs from the same period and with the later twentieth century revisionist literature.