DGS finds Adriosaurus hand

Adriosaurus is a snake ancestor sister with a long sinuous body and tiny limbs. We looked at it earlier here, here and here. Today we’ll take a look at a new specimen SMNH 2158 (Caldwell and Palci 2010), one which evidently did not preserve the manus, but indeed it did. The bones were recovered using DGS, digital graphic segregation.

Figure 1. Adriosaurus manus recovered by DGS. Colorized digits are reconstructed here with continuous parallel interphalangeal lines.

Figure 1. Adriosaurus manus recovered by DGS. Colorized digits are reconstructed here with continuous parallel interphalangeal lines.

That the reconstruction of this tracing produces continuous parallel interphalangeal lines (PILs) and matches other Adriosaurus specimens appears to validate the method, again.

The DGS method 
has been disputed. While I agree that DGS should not be trusted, I think you all will agree, that a central tenet of Science is that nothing should be trusted. Trust is a hallmark of religion and politics. In Science everything should be tested. If an observation is scientifically valid it can be replicated by others using the same method. In this case I did not trust Caldwell and Palci that the manus was unossified or not visible and so tested their observations myself. Another test is whether the method delvers the same results as in other methods using other specimens. An interclavicle was also recovered mixed in with and largely beneath the other bones.

Figure 2. Adriosaurus, a snake ancestor sister.

Figure 2. Adriosaurus, a snake ancestor sister.

References
Caldwell MW and Palci A 2010. A new species of marine ophidiomorph lizard, Adriosaurus skrbinensis, from the upper Cretaceous of Slovenia. Journal of Vertebrate Paleontology 30:747-755.

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