vp-404b.jpg (44254 bytes)

The Skull of Dolichorhynchops osborni FHSM VP-404

Copyright 2007-2009 by Mike Everhart

Page created 12/24/2007

Last updated: 09/18/2009

The FHSM VP-404 specimen was presented to the Sternberg Museum on December 12, 1955 by the collector, M.C. Bonner and his son Orville, of Leoti, Kansas. At the time, it was only the third reasonably complete specimen known from the Smoky Hill Chalk (the other two being the type (KUVP 1400) and the specimen at Harvard (MCZ-1064), both of which were discovered by George F. Sternberg). It is probably the most complete specimen known.  The specimen was later described by Orville Bonner in his Masters Thesis:

Bonner, O. W., 1964. An osteological study of Nyctosaurus and Trinacromerum with a description of a new species of Nyctosaurus, Unpub. Masters Thesis, Fort Hays State University, 63 pages.

More information on this specimen here.

In November, 2007, we opened the glass case around our mounted Dolichorhynchops osborni specimen and removed the skull for a detailed examination. This was the first opportunity that I had had to really get a good look at the skull and to take quality photographs. As is obvious from the mounting (above) the skull is pretty much flattened dorso-ventrally, but is in excellent condition otherwise. There is a minor amount of reconstruction (darker brown) but most of the skull is as found. The following pictures provide the best look yet at the cranial details of this beautiful specimen.

VP-404A-a.jpg (27357 bytes) Dorsal view of the skull. Skull is 51.3 cm in length.
VP-404Aaa.jpg (15183 bytes) Detailed dorsal view of the skull
vp-404ba.jpg (24173 bytes) Ventral view of the skull. The single hole near the center and the two round holes at the back of the palate are for attachements used in mounting. There are 4 teeth in each premaxilla and 29 teeth in each maxilla.
VP-404Bba.jpg (16867 bytes) Detailed ventral view of the skull. The single, round hole near the center and the two round holes at the back of the palate are for attachements used in mounting.
vp-404ca.jpg (24065 bytes) Dorsal view of the lower jaws. The lower jaws are 56.4 cm in length. There are 38 teeth in the right dentary and 37 in the left.
vp-404da.jpg (21556 bytes) Ventral view of the lower jaws. The metal strap is used in mounting the skull (and not a very early orthodontic device)
vp-404fa.jpg (20039 bytes) Detail of the symphysis between the dentarys and other elements of the lower jaw in ventral view.
vp-404ea.jpg (18563 bytes) Braincase (detached) in dorsal view (left) and posterior view (right). These bones appartely became separarted from the rest of the skull during preservation. 

More information about polycotylids and pliosaurs here