You have a great style and attempted a very cool dynamic pose. The line work and shading is very simple, but subtle and effective, though I think maybe could have put some of the fur definition you have in some of the longer places throughout the body for consistency.
The biggest issue to correct would be the anatomy. His left arm is misproportioned and awkwardly posed. To help convey the action of the pose, it might help to lower the elbow and raise the forarm, which would require foreshortening. The right arm disappears behind the leg and then seems to bend like it's double jointed. Also the thumb almost appears to be coming from his foot at first. The angle of his left foot should be so that we can see the top of his paw a bit better, and also pointed a little more inward so that if continued, the lines of his feet would intersect insead of being parallel.
Some of the anatomy flaws are in species features. Fossa are feline-looking carnivores, their faces look sort of like a lion mixed with a weasel [link]. Here it looks more canine, almost wolfy. Their tails are also very long and thick.
One last consideration to make would be the motion of the character. He seems to be bouncing upward, so you can make the areas of longer fur have either some pull, like if he's still moving upwards, or sort of float loosely, like if he's reached the peak of his jump. It's a subtlety that can help make it look more alive and moving.
Yeah i think you are right, i tend to do not see these details a first but time after i get a crit and start looking at the drawing again; i know about the dead, the last time i looked at a picture of a fossa was like 4 years ago and i dont have internet, therefre no references because i wasnt at home either when drawing this i know it's not accurate.
And yeah i always fuck up the anatomy, i really suck -sig- mainly because i wasnt really paying attention since i didnt have proper references for the dynamics aswell and i was blocked, i never like what i do, hehe
The fur detail, yeah maybe you're right, i always draw fur if you take a look at my gallery, i love drawing it, but the purpose of this was to do not draw it with so much detail, but maybe i forgot something about it anyways heheh xD