Ischyromys Typus (Leidy) Rodent jaw

Ischyromys  Typus  (Leidy)
From the Oligocene ,Brule formation.
Collected from Pennington county ,South Dakota USA.
What a beauty, this is the right side of the jaw  with,three erupted ,this really looks good ,and has come seriously close to going in my own collection.
This species was a roughly two foot long (when fully grown) and was an early rodent like animal ,in fact one of the earliest rodents known,called a Sqiuromorph which includes members of the squirrel and Beaver family.
The specimen is loose from matrix and measures 16.8mm x 12mm.

Please Be advised, the specimen has been attached onto the white tray of the display box, with Blu-tac,removing it from the display case may cause damage the back of the specimen as it may be fragile!
This has been done to ensure the specimen is safe and secure for display and during transport.