In rodents, incisor procumbency refers to the orientation of the upper incisor, defined by the position of the cutting edge of the incisor relative to the vertical plane of the incisors. Proodont (or procumbent) incisors have the cutting edge in front of the vertical plane, orthodont teeth have it perpendicular to the plane, opisthodont incisors have it behind the plane, and hyper-opisthodont teeth have the cutting edge even behind the back of the alveolus of the incisor.[2]
Phyllotini are mostly opisthodont, but Auliscomys and Galenomys are orthodont and have sometimes even been described as proodont, and Eligmodontia, Loxodontomys, and some species of Calomys are hyper-opisthodont. Irenomys, Reithrodon, and Neotomys, formerly classified as phyllotines, are also hyper-opisthodont.[3] Oryzomyini are also mostly opisthodont, but Amphinectomys savamis, Handleyomys fuscatus, Melanomys caliginosus, Mindomys hammondi, Scolomys melanops, and Sigmodontomys aphrastus are orthodont.[1]
References
[edit]Literature cited
[edit]- Steppan, S.J. 1995. Revision of the tribe Phyllotini (Rodentia: Sigmodontinae), with a phylogenetic hypothesis for the Sigmodontinae. Fieldiana Zoology 80:1–112.
- Weksler, M. 2006. Phylogenetic relationships of oryzomyine rodents (Muroidea: Sigmodontinae): separate and combined analyses of morphological and molecular data. Bulletin of the American Museum of Natural History 296:1–149.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction