What is the main difference between the Maine Coon, Siberian Forest cat, and Norwegian Forest cat? I only know of small differences and I can't distinguish them easily.
Here's a nice comparison table I found (taken from here ):
There's also this interesting drawing (taken from here ):

Reference | Norwegian Forest Cat | Maine Coon Cat | Siberian |
Head | Equilateral triangle | Wedge shaped with a square muzzle | Broad, modified wedge with gentle rounded contours |
Nose Profile | Straight, no break | Gentle curve | Nose has a slight curvature and the lower portion to the tip of the nose is concave. |
Eyes | Almond shaped | Large with open expression | Large, almost round. |
Ears | Outer edge of ear follows the line of the head down to the chin completing the triangle. | Set high on the top of the head with not more than a ears width apart. | Set high on the top of the head with 1 to 1 1/2 ear width apart. |
Body | Medium in length, square in the appearance. | Long and rectangular. | |
Legs | Hind legs are higher than front legs. | Medium in length | Moderately long, slightly rear legs longer than the front legs |
Tail | Long and flowing, as long as the body, circumference can reach 12" plus in circumference. | Long and flowing, as long as body, not as bushy. | Wide at base, blunt at tip. Even and thick long hairs drape down from the top side of the tail. |
Coat | Distinctive double coat, long guard hairs covering a thick wooly undercoat. | Silky, shaggy, uneven coat with a slight undercoat. | Moderately long to longhaired. |
Ruff | When cat matures, a profuse ruff develops around the neck. | Moderate frontal ruff around the neck. | Abundant |
Mature Size/Age | Up to 15 pounds, Females age 3 (7-10 lbs.) Males age 4. (10-15 lbs.) | Up to 20 pounds, Females smaller, Males larger. | Not given |
There's also this interesting drawing (taken from here ):

Comments
Hi, I would like to adopt this cat and would like to know what is his closest breed (it was found in the streets so it might be either a pure breed who escaped and never found/ or was left on the road, or a mixed breed). Thanks!
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