If I believed everything Hollywood told me I would accept that a paleontologist is someone who has a knack for finding numerous exceptionally-preserved, fully-articulated skeletons. The truth of the matter, however, is that most fossil creatures (at least as far as vertebrates are concerned) become known to science in bits and pieces. This was the case with the largest land mammal that ever lived, Paraceratherium.*
*[There is some controversy surrounding the name of this beast. At present paleontologists are still debating whether the bones of this mammal should be called Paraceratherium, Baluchitherium, Indrichotherium, or in what combination can these names might be synonymized. For now I will call the animal Paraceratherium as this name was published first and a solid case for two or three distinct genera of giant indrichothere that lived in the same place at the same time has yet to be made.]
For such a large animals, about 16-18 feet high at the shoulder, there seemed to be very little left of the Paraceratherium that once roamed much of Asia. When its remains first came to the notice of scientists at the beginning of the 20th century there was very little to go on. A note that appeared in a 1920 issue of Science, for instance, described how it was an enigmatic creature whose scant remains most resembled a rhinoceros but little else. This relationship was reinforced when a partially-complete skull of the animal was brought back to the American Museum of Natural History in 1922, but just how rhino-like was Paraceratherium?
There were two different models. The first was dashed off soon after the AMNH skull was restored and envisioned Paraceratherium as an enormous, hornless rhino. The body outline gave it a short, flabby neck and a pot belly, and this seemed appropriate enough if the animal truly was a giant rhinoceros. This illustration was quickly abandoned, however.
Although he does not state the reasons for his change of mind, in a Natural History article paleontologist H.F. Osborn noted that he drastically changed his ideas about the proportions of the animal in 1923. (I assume this is due to the incorporation of other evidence, such as huge neck vertebrae found from the same parts of Asia.) This new restoration gave Paraceratherium a giraffe-like neck and a taller stature, an increase of two to four feet at the shoulder over the previous restoration.
More fossil evidence would show this latter view to be the correct one, but it can be difficult to withdraw popular paleontological images once they have been popularized. A July 1923 issue of Popular Mechanics (published three months after Osborn’s revision), for instance, restored Paraceratherium in the short, squat rhino mode. This view eventually faded, especially since Paraceratherium was not a rhino per se but merely closely related to rhinos, and now the long-necked restoration graces museum halls and the paleontological books.