12 
Donald Baird and John R. Horner 
Discussion. — This taxon was born in confusion and has persisted in the 
same state for more than a century. The bones from James King’s marl 
pits (note the plural) that Kerr submitted to Cope were so obviously 
water-tumbled and abraded that, even if they had been found in close 
proximity, their organic association should have been considered un- 
likely. Whether or not they were found together, the five bones that con- 
stituted the original syntypic series can now be shown to represent three 
suborders of dinosaurs. Cope, unfortunately, took their association for 
granted. In deducing a single species from these disparate elements he in- 
evitably created a monster incertae sedis for the confusion of subsequent 
students. 
Of the surviving syntypes illustrated in Fig. 4, A-A 1 is the caudal ver- 
tebra which inspired Cope’s specific name crassicauda (“thick-tailed”) and 
which we designate as lectotype; the other bones are removed from 
Hypsibema and described elsewhere in this paper. The fifth bone (now 
Fig. 5. Hypsibema crassicauda , caudal vertebrae in posterior and ventral views. A, 
USNM 7189, lectotype from James King’s marl pits; B, USNM 6136 from 
Phoebus Landing. Scale in cm. 
