Spinosaurus News ~

[Ngala]

The holotype collected and described by E. Stromer (1915) was incomplete, however it remains the most complete discovered. These is the plate of the bones discovered in Egypt by Stromer:

*This image is copyright of its original author

*This image is copyright of its original author

This is a photo with skeleton reconstruction of the original bones, in Munich (Germany), sadly destroyed in the world war II:

*This image is copyright of its original author

Now there aren't a complete skeleton of Spinosaurus. In this photo there is a reconstruction of skeleton proposed by Ibrahim et al. (2014), with the all known Spinosaurus bones (including the holotype) colored in red:

*This image is copyright of its original author

According to Ibrahim et al. (2014): 
"Center-of-mass estimates for several theropods have been expressed as a percentage of femoral length measured anteriorly from the hip joint. The center of mass in a biped must be located over the middle one-third of the pes to generate a plausible mid-stance pose. In our flesh rendering of Spinosaurus, the center of body mass is positioned in front of both the hip and knee joints at a distance greater than femur length, suggesting that forelimb support was required during terrestrial locomotion. Spinosaurus appears to have been poorly adapted to bipedal terrestrial locomotion. The forward position of the center of mass within the ribcage may have enhanced balance during foot-propelled locomotion in water. These adaptations suggest that Spinosaurus was primarily a piscivore....." 

"The locomotor adaptations outlined above, however, mark a profound departure in form an function from early spinosaurids. Prominent among these are the reduced pelvic girdle; short hindlimb; short femur; and long, low, flat-bottomed pedal unguals, all of which can be verified in the second partial skeleton described by Stromer as “Spinosaurus B”. We note here that Spinosaurus must have been an obligate quadruped on land, the first discovered among theropod dinosaurs, given the usual horizontal sacroiliac joint and the anterior location of the estimated center of body mass."

"In smaller-bodied bipedal dinosaurs, short femoral proportions indicate increased stride length and enhanced speed. In Spinosaurus this is clearly not the case, given the short hindlimb. The femur in Spinosaurus has an unusually robust attachment for the caudofemoral musculature, which is anchored along nearly one-third of the femoral shaft, suggesting powerful posterior flexion of the hindlimb. The articulation at the knee joint for vertical limb support, in contrast, is reduced. The distal condyles of the femur are narrow, and the cnemial crest of the tibia is only moderately expanded. Together these features recall the shortened condition of the femur in early cetaceans and in extant semiaquatic mammals that use their hindlimbs in foot-propelled paddling." 

PS: I saw the anterior portion of skull exposed at the Natural History Museum in Milan, and it's really impressive, look like an enormous Mecistops sp./Crocodylus sp. Really exciting! Reply