Abstract
We describe the tooth of a fossil beaver (Castoridae, Rodentia) discovered in the lower Miocene Koura Formation of Shimane Prefecture, western Japan. The specimen is an isolated, unworn left lower third molar that can be assigned to a large castorid, Youngofiber. To determine the taxonomic classification based on the internal enamel patterns of the tooth, we reconstructed those patterns using a three-dimensional image by X-ray peripheral quantitative computed tomography (pQCT). The obtained enamel patterns indicate that the M3 of Youngofiber is characterized by a transversely elongated proparafossettid and simple synclinids running obliquely and parallel. Moreover, the present specimen retains a well developed mesostriid extending up to half the lingual height of the crown. This characteristic is shared with another castorid specimen from the lower Miocene Nojima Group in Nagasaki Prefecture, suggesting a close relationship between Koura and Nojima beavers.
| Original language | English |
|---|---|
| Pages (from-to) | 43-50 |
| Number of pages | 8 |
| Journal | Paleontological Research |
| Volume | 15 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2011 Apr |
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Keywords
- Castoridae
- Koura Formation
- Matsue
- Miocene
- pQCT
- Youngofiber
ASJC Scopus subject areas
- Palaeontology
- Ecology, Evolution, Behavior and Systematics
Cite this
X-Ray Computed Tomography Examination of a Fossil Beaver Tooth from the Lower Miocene Koura Formation of Western Japan. / Nishioka, Yuichiro; Hirayama, Ren; Kawano, Shigenori; Tomida, Yukimitsu; Takai, Masanaru.
In: Paleontological Research, Vol. 15, No. 1, 04.2011, p. 43-50.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - X-Ray Computed Tomography Examination of a Fossil Beaver Tooth from the Lower Miocene Koura Formation of Western Japan
AU - Nishioka, Yuichiro
AU - Hirayama, Ren
AU - Kawano, Shigenori
AU - Tomida, Yukimitsu
AU - Takai, Masanaru
PY - 2011/4
Y1 - 2011/4
N2 - We describe the tooth of a fossil beaver (Castoridae, Rodentia) discovered in the lower Miocene Koura Formation of Shimane Prefecture, western Japan. The specimen is an isolated, unworn left lower third molar that can be assigned to a large castorid, Youngofiber. To determine the taxonomic classification based on the internal enamel patterns of the tooth, we reconstructed those patterns using a three-dimensional image by X-ray peripheral quantitative computed tomography (pQCT). The obtained enamel patterns indicate that the M3 of Youngofiber is characterized by a transversely elongated proparafossettid and simple synclinids running obliquely and parallel. Moreover, the present specimen retains a well developed mesostriid extending up to half the lingual height of the crown. This characteristic is shared with another castorid specimen from the lower Miocene Nojima Group in Nagasaki Prefecture, suggesting a close relationship between Koura and Nojima beavers.
AB - We describe the tooth of a fossil beaver (Castoridae, Rodentia) discovered in the lower Miocene Koura Formation of Shimane Prefecture, western Japan. The specimen is an isolated, unworn left lower third molar that can be assigned to a large castorid, Youngofiber. To determine the taxonomic classification based on the internal enamel patterns of the tooth, we reconstructed those patterns using a three-dimensional image by X-ray peripheral quantitative computed tomography (pQCT). The obtained enamel patterns indicate that the M3 of Youngofiber is characterized by a transversely elongated proparafossettid and simple synclinids running obliquely and parallel. Moreover, the present specimen retains a well developed mesostriid extending up to half the lingual height of the crown. This characteristic is shared with another castorid specimen from the lower Miocene Nojima Group in Nagasaki Prefecture, suggesting a close relationship between Koura and Nojima beavers.
KW - Castoridae
KW - Koura Formation
KW - Matsue
KW - Miocene
KW - pQCT
KW - Youngofiber
UR - http://www.scopus.com/inward/record.url?scp=79955964966&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79955964966&partnerID=8YFLogxK
U2 - 10.2517/1342-8144-15.1.043
DO - 10.2517/1342-8144-15.1.043
M3 - Article
AN - SCOPUS:79955964966
VL - 15
SP - 43
EP - 50
JO - Paleontological Research
JF - Paleontological Research
SN - 1342-8144
IS - 1
ER -