Evolution of incisor enamel microstructure in lagomorpha
Evolution of incisor enamel microstructure in lagomorpha
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DOI：
10.1671/2513
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发表时间：
2004-06-11
影响因子：
1.4
通讯作者：
Martin, T
中科院分区：
文献类型：
--
作者：
Martin, T
门牙中的一层放射状牙釉质代表了Glires(兔形目和啮齿目)的茎系代表的拟态状态。在Zalambdalstid Barunlestes Butleri和拟拟人牙以及Eurymylid Eurymylus laticep的门牙上发现了单层放射状釉质。无脊椎动物Matutinia nitiulus表现出更多的派生性。双层Schmelzmuster带亨特-施莱格带(HSB)位于内门(PI)，放射状釉质位于外门(PE)。拟牙轮虫的特征是具有HSB的Schmelzmuster：Anatolimys rozhdestvenskii具有双层釉质(PI带有HSB，PE带有放射状牙釉质)，来自蒙古的两个未确定的拟牙轮虫显示单层牙釉质。吉尔吉斯斯坦始新世早期一种尚未确定的牙形动物(Strenulagus或Aktashmys)的门牙，是所研究的地质上最古老的门牙之一，其门牙具有双层釉质，PI中有HSB，PE中有放射状釉质，而所有其他Leporid都有单层HSB的釉质。这证明了单层的Leporid切牙Schmelzmuster是由双层条件产生的。改良径向牙釉质下切牙和上切牙中多层釉质的存在HSB和切向牙釉质得到证实。所有三种被认为是卵形类的Desmatolagus(D.gobiens、D.robostus和D.vetustus)都表现出带有HSB的单层Schmelzmuster，因此被转移到Leporidae。Ochotonid schmelzmuster是由不同于Leporid schmelzmuster的途径产生的，可能起源于尚不为人所知的古近纪早期的Gliriformes，如Decipomys mongoliensis。这表明Ochotonid-leporid的分化比之前认为的要古老得多。
A single layer of radial enamel in the incisors represents the plesiomorphic condition for stem-lineage representatives of Glires (Lagomorpha and Rodentia). A single layer of radial enamel is detected in the incisors of the zalambdalestid Barunlestes butleri and the pseudictopid Pseudictops lophiodon as well as the eurymylid Eurymylus laticeps. The eurymylid Matutinia nitidulus exhibits a more derived. double-layered schmelzmuster with Hunter-Schreger bands (HSB) in the portio interna (PI) and radial enamel in the portio externa (PE). Mimotonids are characterized by a schmelzmuster with HSB: Anatolimys rozhdestvenskii has double-layered enamel (PI with HSB, PE with radial enamel) and two undetermined mimotonids from Mongolia exhibit a single-layered enamel. An incisor of an undetermined leporid (Strenulagus or Aktashmys) from the early Eocene of Kyrgyzstan, one of the geologically oldest studied, has double-layered schmelzmuster with HSB in the PI and radial enamel in the PE, whereas all other leporids have single-layered enamel with HSB. This is evidence that the single-layered leporid incisor schmelzmuster is derived from a double-layered condition. The presence of multilayered schmelzmuster in upper and lower incisors of Ochotonidae with modified radial enamel. HSB, and tangential enamel is corroborated. All three species of the supposed ochotonid Desmatolagus (D. gobiensis, D. robustus, and D. vetustus) exhibit a single-layered schmelzmuster with HSB and therefore are transferred to the Leporidae. Ochotonid schmelzmuster was derived by a different pathway than leporid schmelzmuster and possibly originated from that of yet poorly known early Paleogene Gliriformes such as Decipomys mongoliensis. This indicates that the ochotonid-leporid divergence is much older than previously believed.