Yaj tus incisor yog a hypsodont tooth, i.e. nws muaj lub kaus ntev uas txuas ntxiv mus (tawm) ntawm cov pos hniav tom qab txiav, teb rau kev loj hlob lossis hnub nyoog, thiab hnav.
Dab tsi tsiaj muaj hniav hypsodont?
Cov hniav ntawm nyuj thiab neesyog hypsodont. Cov kev mob sib txawv, cov hniav qis, yog hu ua brachydont. Tib neeg cov hniav yog brachydont. Hauv qee hom, hypsodont cov hniav txuas ntxiv mus thoob plaws tsiaj lub neej (piv txwv li, ntau hom nas subfamily Arvicolinae, tsev neeg Muridae).
Puas ruminants muaj hypsodont hniav?
Ruminants muaj hom hniav tshwj xeeb txawv los ntawm qhov siab dua (hypsodont)thiab txoj kab nkhaus nkhaus ntawm enamel (selenodont). Hypsodont cov hniav siv tau ntev heev vim lawv txhim kho qhov tob dua kom hnav.
yaj muaj hniav dab tsi?
Cov yaj ntawm cov hniav tau muab faib ua ob ntu, uas yog, yim qhov chaw ruaj khov nyob rau hauv lub puab tsaig sab hauv qabthiab nees nkaum plaub molars, tom kawg tau muab faib ua rau ntawm txhua sab ntawm lub puab tsaig sab sauv thiab sab qis. Yaj tsis muaj hniav nyob rau hauv pem hauv ntej ntawm lub puab tsaig sab sauv uas muaj ib tug tuab, tawv, fibrous pad.
Puas yog canines hypsodont?
… yog tias feem ntau ntawm cov tsiaj nyeg tsis ntev los no khaws cov poj koob yawm txwv brachydonty (Daim duab 1A), ob qho tib si marsu- pial thiab placental mammals tau tsim hypsodont cov hniav, hauv txhua hom hniav-incisors, canines, premolars, thiab molars (Daim duab 1A,2).
