... by their extreme morphological variation. The covariation with skull shape suggests strong functional relationships within the masticatory system despite strong artificial selection. Skull Mandible Jaw muscles Masticatory system Canis familiaris Lever model The constituents of the masticatory...

.... ( 1944 ). Speed in Animals. Chicago: University of Chicago Press. Jayes, A. S. and Alexander, R. McN. ( 1978 ). Mechanics of locomotion of dogs ( Canis familiaris ) and sheep( Ovis aries ). J. Zool. Lond. 185 , 289 -308. Lee, C. R. and Farley, C. T. ( 1998 ). Determinants of the center...

.... * e-mail: [email protected] 16 4 2002 © The Company of Biologists Limited 2002 2002 hypaxial muscle ventilation locomotion locomotor—respiratory coupling mammal dog Canis familiaris The hypaxial muscles of terrestrial vertebrates are known to function in both lung...

... hypothesized that bipeds recruit a larger volume of muscle to support their weight, eliminating the potential economy of longer legs and slower steps. To test our hypothesis, we calculated the relative volume of muscle needed to support body weight over a stride in small dogs ( Canis familiaris ) and wild...