Some of my Dinosaur poses

I wanted to share some of my Dinosaur poses. I would like some feedback so I can improve. Please excuse the watermarks for I upload these on DeviantArt and usually people like to steal art.

http://fc03.deviantart.net/fs71/i/2010/098/7/7/The_hunters_become_the_hunted_by_Tirann0.jpg

http://fc05.deviantart.net/fs71/i/2010/098/a/d/Stop_right_there_criminal_scum_by_Tirann0.jpg

http://fc08.deviantart.net/fs70/f/2010/103/d/f/One_with_nature_by_Tirann0.jpg

http://fc06.deviantart.net/fs70/f/2010/126/e/1/Romantic_Embrase_by_Tirann0.png

As a bonus, here is a tribute to Back to the Future the Ride to celebrate the new Delorean model:

http://fc08.deviantart.net/fs71/i/2011/058/7/2/great_scott_it__s_a_dinosaur_by_tirann0-d3akgw0.png

Criticism is more then welcome as long as it is constructive.

The 1st and 5th ones are great! The 4th one’s good too.

2-3 are meh, especially 2.

The geometry of the ground ruins it.

[editline]15th March 2011[/editline]

Using 1 as a background now.

1 and 5 are great, 3 is pretty good. 2 and 4 not so much, 2’s lacking in anything really eye-catching and 4 just doesn’t get my attention as well as the others.