RE: Atlasaurus

[bh480@scn.org]

From: Ben Creisler bh480@scn.org
RE: Atlasaurus

Atlasaurus is NOT the same as "Cetiosaurus" mogrebiensis. 
I quote from the description of Atlasaurus (pgs. 521-522):

Atlasaurus can be distinguished from each of the three 
incomplete skeletons from the Middle Atlas of Morocco 
considered by Lapparent (1955) as the cotypes 
of "Cetiosaurus" mogrebiensis: the neural arch bases and 
pleurocentra are situated in a mid-length position on 
dorsal vertebrae (El Mers n. 1) whereas they are more 
anterior in position in Atlasaurus; the length of the 
humerus is shorter relative to that of the femur (the 
ratio is 0.86 in El Mers n. 3) whereas they are equal in 
length in Atlasaurus; and the lengths of the ulna and 
metacarpals are longer relative to the length of the 
humerus (the ratios are respectively 0.77 and 0.28 in El 
Mers n. 8) than in Atlasaurus where the ratios are 0.65 
and 0.24. It should be noted that the huge lunate manus 
imprints from the Bathonian of the High Atlas 
(Breviparopus taghbaloutensis Ishigaki 1989) are 
inconsistent with the smaller size of the manus and non-
reflexed position of the first metacarpal in Atlasaurus. 
At least three different sauropods were present in the 
Middle Jurassic of Morocco.