Identification: Head and body 24-31 inches; tail 9-11 inches; weight 20-60 pounds. If you see a stick and mud dam, or a large house of similar material at the edge of a lake and stumps of small tress i the vicinity showing tooth marks, then you are seeing the presence of beavers. A loud splash casued by the tail as the beaver dives below the surface of the water will also indicate beavers. Rich brown in color; tail naked, scaly, shapped like a paddle, flat, about 6 inches wide. Huge front teeth chestnut-colored on front faces; hind feet webbed, 2nd claw double.
Habitat: Streams and lakes with trees or alders on bank.
Skull: Long incisors, herbivour like teeth. Square, blocky, skull. Very square mandible.
- Beaver Castor canadensis
- Stage: Adult
- Area Collected: Trapper in North Dakota
- Collection Reference: 12A "Andy"
- Source: Sale
| Upper/Lower | Incisors | Canines | Premolars | Molars | U and L | Total |
| Upper | 1-1 | 0-0 | 1-1 | 3-3 | 10 | |
| Lower | 1-1 | 0-0 | 1-1 | 3-3 | 10 | =20 |