Beavers (Castoridae, Rodentia) From The Late Miocene (Mn 9) Locality Grytsiv In Ukraine
Author
Rekovets, Leonid
Author
Stefen, Clara
Author
Demeshkant, Vitalii
text
Fossil Imprint
2020
2020-11-09
76
1
165
173
http://dx.doi.org/10.37520/fi.2020.010
journal article
10.37520/fi.2020.010
2533-4069
5382960
cf.
Euroxenomys minutus
(VON
MEYER, 1838
)
Pl. 1, Figs 10–11
2015
Trogontherium
(
Euroxenomys
)
minutum minutum
; Apoltsev and Rekovets, p. 521, fig. 1.
C o m m e n t s. Two teeth from Grytsiv belong to a small-sized beaver, and these specimens are tentatively assigned resembling those to
Euroxenomys minutus
following
Hugueney and Duranthon (2012)
. These authors accepted the genus as valid and not as a subgenus within
Trogontherium
.
D e s c r i p t i o n. The right P4 (NMNHU-P 22/218; Pl. 1, Fig. 11a, b) is broken at the base. The tooth is small and also appears more fragile than other beaver teeth from Grytsiv. The described specimen is slightly worn, its paraflexus has a tiny lateral opening. The metafossette is wide, appears to be just closed, and fills the distal part of the tooth. The mesoflexus has a wide buccal opening which shows some cement and is curved on the occlusal surface extending to the linguo-buccal side. The hypoflexus is straight, short, oriented diagonally, and ends in about the middle of the tooth width adjacent to the paraflexus. The hypostria extends lingually to the broken end of the tooth crown (Pl. 1, Fig. 11b). The specimen fits well into the size range of upper premolars of small beavers from Sansan assigned to
Euroxenomys minutus
(see
Hugueney and Duranthon 2012
for details).
The left М3 (NMNHU-P 22/217; Pl. 1, Fig. 10a, b) is not fully developed tooth germ. The tooth is small and slenderer than the other teeth assigned to
Chalicomys
. The tooth is unworn, without roots. The lingual hypostria is narrow and nearly reaches the crown base. The buccal mesostriia does not extend to the middle of the crown height. The ridges are visible on the occlusal surface. Anteriorly, at the protocone, there is a relatively wide fossette, interpreted herein as pre-parafossette. The narrow paraflexus shows a narrow lateral opening and extends to the hypoflexus on the occlusal surface. The hypoflexus appears as a pointed and wide triangle on the occlusal surface. Distal to the para- and hypoflexus, there is a narrow mesoflexid extending from side to side of the tooth. The metaflexus is open distally.