Abstract
Two large rodents from the Middle Miocene (13.0–12.4 Ma) were discovered at the Chiang Muan Coal Mine, northern Thailand. One, a beaver (Anchitheriomys, Castoridae), has large cheek teeth with a high crown, the crown base wider buccolingually, basically six fossettes/sinuses, enamel foldings strongly complicated, and hypoflexus/flexid shallow dorsoventrally. Based on dental morphology, this form is more similar to Anchitheriomys suevicus from Europe than to Anchitheriomys tungurensis from northern China. The other species is considerably larger than Anchitheriomys, based on incisor measurements, and lacks longitudinal grooves or deep ridges on the enamel surface, which are diagnostic of Anchitheriomys. Furthermore, the inner enamel observed by scanning electron microscope has uniserial Hunter-Schreger bands, similar to castorids rather than hystricids. This species is indeterminate taxonomically, but differs from any rodents known from Asia. The distribution of Anchitheriomys was previously restricted between the latitudes 30°N and 50°N, but this occurrence in northern Thailand at low latitude (ca. 19°N) suggests that it had wider distribution on the Eurasian continent.
| Original language | English |
|---|---|
| Pages (from-to) | 151-158 |
| Number of pages | 8 |
| Journal | Historical Biology |
| Volume | 28 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - 2016 Feb 17 |
| Externally published | Yes |
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Keywords
- beaver
- Castoridae
- Neogene
- Rodentia
- Southeast Asia
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
Cite this
Two large rodents from the Middle Miocene of Chiang Muan, northern Thailand. / Nishioka, Yuichiro; Nakaya, Hideo; Suzuki, Kunihiro; Ratanasthien, Benjavun; Jintasakul, Pratueng; Hanta, Rattanaphorn; Kunimatsu, Yutaka.
In: Historical Biology, Vol. 28, No. 1-2, 17.02.2016, p. 151-158.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Two large rodents from the Middle Miocene of Chiang Muan, northern Thailand
AU - Nishioka, Yuichiro
AU - Nakaya, Hideo
AU - Suzuki, Kunihiro
AU - Ratanasthien, Benjavun
AU - Jintasakul, Pratueng
AU - Hanta, Rattanaphorn
AU - Kunimatsu, Yutaka
PY - 2016/2/17
Y1 - 2016/2/17
N2 - Two large rodents from the Middle Miocene (13.0–12.4 Ma) were discovered at the Chiang Muan Coal Mine, northern Thailand. One, a beaver (Anchitheriomys, Castoridae), has large cheek teeth with a high crown, the crown base wider buccolingually, basically six fossettes/sinuses, enamel foldings strongly complicated, and hypoflexus/flexid shallow dorsoventrally. Based on dental morphology, this form is more similar to Anchitheriomys suevicus from Europe than to Anchitheriomys tungurensis from northern China. The other species is considerably larger than Anchitheriomys, based on incisor measurements, and lacks longitudinal grooves or deep ridges on the enamel surface, which are diagnostic of Anchitheriomys. Furthermore, the inner enamel observed by scanning electron microscope has uniserial Hunter-Schreger bands, similar to castorids rather than hystricids. This species is indeterminate taxonomically, but differs from any rodents known from Asia. The distribution of Anchitheriomys was previously restricted between the latitudes 30°N and 50°N, but this occurrence in northern Thailand at low latitude (ca. 19°N) suggests that it had wider distribution on the Eurasian continent.
AB - Two large rodents from the Middle Miocene (13.0–12.4 Ma) were discovered at the Chiang Muan Coal Mine, northern Thailand. One, a beaver (Anchitheriomys, Castoridae), has large cheek teeth with a high crown, the crown base wider buccolingually, basically six fossettes/sinuses, enamel foldings strongly complicated, and hypoflexus/flexid shallow dorsoventrally. Based on dental morphology, this form is more similar to Anchitheriomys suevicus from Europe than to Anchitheriomys tungurensis from northern China. The other species is considerably larger than Anchitheriomys, based on incisor measurements, and lacks longitudinal grooves or deep ridges on the enamel surface, which are diagnostic of Anchitheriomys. Furthermore, the inner enamel observed by scanning electron microscope has uniserial Hunter-Schreger bands, similar to castorids rather than hystricids. This species is indeterminate taxonomically, but differs from any rodents known from Asia. The distribution of Anchitheriomys was previously restricted between the latitudes 30°N and 50°N, but this occurrence in northern Thailand at low latitude (ca. 19°N) suggests that it had wider distribution on the Eurasian continent.
KW - beaver
KW - Castoridae
KW - Neogene
KW - Rodentia
KW - Southeast Asia
UR - http://www.scopus.com/inward/record.url?scp=84942865904&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84942865904&partnerID=8YFLogxK
U2 - 10.1080/08912963.2015.1007971
DO - 10.1080/08912963.2015.1007971
M3 - Article
VL - 28
SP - 151
EP - 158
JO - Historical Biology
JF - Historical Biology
SN - 0891-2963
IS - 1-2
ER -