Follow-up comparisons.--Most of the comparisons thus far have been to hypsodont
One of these is the evolution of high-crowned (hypsodont
) teeth in association with "the great transformation" from a browsing to a grazing diet (Simpson 1951).
The lower molars are hypsodont
and narrow crowned (Fig.
A comprehensive revision was made by Hussain (1971), and noted that a single migration of a Hipparion primitive species, Hipparion nagriensis during Lower Nagri time led to the local diversity of two Hipparion taxa in the Middle Siwalik horizons: Hipparion antelopinum, a small form with slender elongate third metapodials and more hypsodont
teeth, and Hipparion theobaldi, a large form with more massive metapodials and more hypsodont
teeth than Hipparion nagriensis.
For example, arid conditions are reflected in the presence of Hispanotherium matritense or Anchitherium cursor, two perissodactyls with hypsodont
dentition and relatively gracile limbs that are adapted to open and arid conditions (Cerdeno and Nieto, 1995; Soria et al., 2000; Salesa et al., 2001; Hernandez Fernandez et al., 2003), or several members of the order Rodentia, such as Armantomys, Microdyromys, Democricetodon or Cricetodon (Weerd and Daams, 1978; Meulen and de Bruijn, 1982; Daams and Meulen, 1984; Mein, 1983; Sese et al., 1985).
Pronghorns have strongly hypsodont
molars early in life, but in advanced age roots develop.
The most familiar character representing a grazing diet is the presence of high-crowned, or hypsodont
Comments: Crown enamel portion from hypsodont
molariform tooth that includes one fossette.
As indicated by measurements (Table I), the specimens are extremely hypsodont
and show less complicated plications.
The second upper molar (PC-GCUF 12/48) is hypsodont
with deepened furchen (Fig.
teeth in rodents were firstly interpreted by several authors as associated to abrasive diets dominated by grass (Kay and Madden, 1997; Vianey-Liaud, 1991; Williams and Kay, 2001).