The grinding teeth are of the tritubercular pattern; there are three of each kind in the upper jaw, but in the lower jaw only two premolars on each side.
We may regard as family-characters the pentadactyle limbs, the existence of three pairs of incisors in the lower and four in the upper jaw; and the tritubercular nature of the upper molars.
The upper molars are triconodont, being either of the typical or a modified form of what is known as the tritubercular sectorial type.
In the remaining groups the upper molars form narrow V's of the true tritubercular type.
Dorsetshire Purbeck; the latter having the three cusps of the cheek-teeth rotated so as to assume a tritubercular type.
In the advance of their molar teeth from a tritubercular to a grinding type, the author traces a curious parallelism between marsupials and placentals.
Osborn, "Palaeontological Evidence for the Original Tritubercular Theory," in vol.
Molar teeth of the simple tritubercular type persist in the golden moles (Chrysochloris) among the Insectivora and also in the marsupial mole (Notoryctes) among the marsupials.
The type is, moreover, common among the mammals of the early Eocene, and still more so in those of the Jurassic epoch; this forming one of the strongest arguments in favour of the tritubercular theory.
The tritubercular nomenclature was abandoned because of overwhelming difficulties; more research on the Hystricomorpha is certainly needed before the tritubercular nomenclature can be applied with confidence.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "tritubercular" in a variety of sentences. We hope that you will now be able to make sentences using this word.
