Mack

Mar 28 2012, 09:08 AM

The mousasaur is way out of proportain. Firstly the werent that long and secondly they were much thinner then that. Thery skeleton shows that they were much thinner then that

http://upload.wikimedia.org/wikipedia/commons/f/f7/Mosasaurs.jpg

coherentsheaf

Mar 28 2012, 07:50 PM

I tookthe length for Mosasaurus hoffmanni from Lingham-Solair:

"...an enormous almost complete dentary of
Mosasaurus hoffmanni, NHMM 009002 (Meijer 1983,
figure 3) measuring 900 mm (complete estimate =
1000 mm), suggests an even greater total size. The
entire lower jaw is reliably estimated at 1600 mm.
Using a 1: 10 head to body ratio (see Russell 1967, p.
210 for M. maximus) the length of the whole animal is
estimated at 17.6 m, making it the largest marine
reptile known. Huge size in M. hoffmanni is also
indicated by isolated specimens of an enormous
quadrate NHMM 603092 and humerus TSMHN
11252 (figure 9i,j)."

If you have grounds to contest this estimate, please post them.

It is true that until very recently Mosasaurs have been reconstructed as very elongated anguilliform swimmers,however recent discoveries have called this conception into question:

"The preserved body outline, placement of internal organs and anterior migration of the rib-cage suggest a grossly whale/shark-like body."
(Lindgren in a comment to Henry, on PlosOne)

The plosone article also containe this reconstruction:


It depicts the more primitive Platecarpus, but I do not see any grounds to think that the more advanced Mosasaurus would differ very much in body shape especially since its vertebrae show functional adaptations similar to platecarpus.

Sources:
Lingham-Soliar, (1995). "Mosasaurus hoffmanni (Mosasauridae),
Anatomy and Functional Morphology of the Largest Marine Reptile known"

Lindgren et al. (2010). "Convergent Evolution in Aquatic Tetrapods: Insights from an Exceptional Fossil Mosasaur"