BULLETIN FLORIDA STATE MUSEUM


The Florida N. phlegon dentitions have a thinner covering of cement
than do the AMNH specimens from Crawfish Draw, Mt. Blanco,
although this difference may be related to diagenetic phenomena.
Nevertheless, both these samples of N. phlegon have a relatively thick
covering of cement above the alveolar border in contrast to those of
many other late Cenozoic horses.
 No complete upper dentition is known from the Florida sample, and
the following description is based on isolated teeth. The upper molars
are moderately curved in the anteroposterior plane and slightly curved
in the transverse plane. In cross-section, P2 is triangular and P3-M3 are
rectangular, with the anteroposterior length being greater than the
transverse width (Fig. 3, Table 1). P2 has a moderately developed
pseudoparastyle posterior to the true parastyle on the ectoloph. The
protoloph connects directly to the true parastyle on P2. The anterior
part of P2, including the parastyle, is often expanded in many Cenozoic


M1 or M2


 0 1 2 3 4 5cm

FIGURE 3.-Isolated upper cheek teeth of Nannippus phlegon from Florida. (A) occlusal
view, M3, UF 11888b, Santa Fe River 1B, M' or M2, UF 22611, Santa Fe River 4A, P2,
UF 22617, Santa Fe River 4A; (B) medial (internal) view, UF 11888b, UF 22611, UF
22617.


Vol. 25, No. 1