Trogontherium (Euroxenomys) minutum Meyer, 1838

Apoltsev, D. A. & Rekovets, L. I., 2015, Beavers Of The Genus Trogontherium (Castoridae, Rodentia) From The Late Miocene Of Ukraine, Vestnik Zoologii 49 (6), pp. 419-528 : 520-521

Trogontherium (Euroxenomys) minutum Meyer, 1838

Monosaulax sp. : Topachevsky et al., 1987; Trogontherium minutum: Rekovets et al., 2009 ; Kovalchuk, Apoltsev, 2013; Euroxenomys minutus: Hugueney, Duranthon, 2012 .

T y p e l o c a l i t y: Elgg (Braunkohle), Switzerland.

G e o l o g i c a l a g e: middle Miocene.

S p e c i e s c o m p o s i t i o n: Trogontherium minutum minutum Meyer, 1938 , Trogontherium minutum rhenanum Franzen, Storch, 1975 , Trogontherium minutum ozansoyi ( Ünay, 1975) and Euroxenomys minutus minutus from Sansan ( Hugueney, Duranthon, 2012) described earlier as a separate genus.

Remains of the nominative subspecies are known from the early Late Miocene (MN 9) of the Grytsev locality in Western Ukraine. Remains of Trogontherium (Euroxenomys) minutum rhenanum have been collected from the Late Miocene in the range of MN 10 (late Vallesian) — MN 13 (Turolian), i. e. during the time of existence of the Sarmatian- Pontian sea basins in the south of Eastern Europe. The subspecies Trogontherium minutum ozansoyi (= Steneofiber minutus ozanzoyi ) was found in the Late Miocene (MN 12) strata of Catakbayaka, Turkey ( Ünay, 1975).

Morphometric parameters, separating these three subspecies of the genus Trogontherium based mainly on differences in the length of dentition, although they are also based on some other features. E. g., the length of the lower P 4 –M 3 dentition in Trogontherium (Euroxenomys) minutum minutum from Petersbuch is in the range of 11.0–13.0 mm, while it averages 13.0 mm (restored) in the subspecies Trogontherium (Euroxenomys) minutum rhenanum ( Franzen, Storch, 1975) . The restored length of the lower dentition P 4 –M 3 in Trogontherium minutum ozansoyi may be in the range of 10.0– 11.0 mm. Special morphology of the P 4 also is a hallmark for this subspecies ( Ünay, 1975).