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New sauropod limb paper



From: Ben Creisler bh480@scn.org

In case this paper has not been mentioned yet:

Bonnan, M.F. 2004. Morphometric analysis of humerus and 
femur shape in Morrison sauropods: implications for 
functional morphology and paleobiology. Paleobiology 30 
(3): 444-470.
Morphometric analyses of sauropod limbs have the potential 
to illuminate functional aspects of sauropod locomotion 
and paleobiology. However, analyses of sauropod limb 
dimensions typically show few discernible morphological 
trends because of large size differences among the 
individuals in a sample. For sauropods, combined analyses 
of both limb dimension and shape may be more desirable. 
Numerous humeri and femora from Apatosaurus , Diplodocus , 
and Camarasaurus  provide an opportunity to explore and 
compare limb morphology in contemporaneous, sympatric 
sauropods. Thin-plate splines were used to analyze 
landmark-based shape differences in combination with 
traditional morphometrics. The aims of the analysis were 
(1) to determine if humerus and femur shape were 
significantly different among the genera; (2) to determine 
where shape changes occurred; and (3) to infer the basic 
functional implications of the shape differences using an 
Extant Phylogenetic Bracket approach. Few differences were 
detected among the genera using traditional morphometric 
analyses, and linear regression revealed a predominantly 
isometric relationship between most measurement variables 
and element size. Thin-plate splines revealed significant 
shape differences among the taxa. Apatosaurus > humeri and 
femora were the most robust, with expanded regions for 
muscle insertion and more distally placed deltopectoral 
and caudofemoral landmarks. Diplodocus  humeri and femora 
were gracile, with more proximally located landmarks of 
muscular insertion. Camarasaurus  humeri were surprisingly 
gracile, with a less extensive deltopectoral crest, but 
had more robust femora similar to those of Apatosaurus . 
Few differences distinguished juvenile from adult 
specimens. These data suggest some locomotor differences 
were present among the three genera.