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Hello, I have some bonebed material from: Gr. Gröningen Crailsheim, Germany Triassic, Ipper Muschelkalk. its a Nothosaur bone sticking out, but a small part is in another stone (piece broke before I acquired it). I tried to scratch it out, but that will takes ages and doesnt seem to look too good. I heard about acid prepping, would that be a good idea with this? Its similar stuff as: http://www.thefossilforum.com/topic/111818-lets-talk-blezingeria/ if so, how to go at this? Anyone has experience with this?

First off: happy new year, everyone! Blezingeria ichthyospondylus is an enigmatic marine reptile from the Ladinian-stage Triassic, Upper Muschelkalk of Baden-Württemberg in southwestern Germany, first discovered in Crailsheim. Although various material has been referred to the species through time, its affiliation remains unclear. Initially described as nothosaurian and later as cymbospondylid ichthyosaurian, it has most recently been classed as thalattosaurian. Fossilworks, however, still defines it as cymbospondylid, whereas Muschelkalk.eu classifies it as an Eosuchian. Below is an overview of some of the material that has been attributed to the species: Source: Wikipedia Vertebrae & humerus. Source: Wikimedia Commons Source: Muschelkalkmuseum Ingelfingen Vertebrae & scapula. Source: Muschelkalk.eu As you can see, the vertebrae are amphicoelous, just like those of ichthyosaurians. Though, contrary to in ichthyosaurs, the neural arch in B. ichthyospondylus is attached to the vertebral body. Scapulae and pubis bones are also highly reminiscent of those found in ichthyosaurs. All this, of course, is not to say that there were no other early marine reptiles with amphicoelous vertebrae - such as those of Placodus gigas figured below, for example: Sources: online vendor & figure 13 from Diedrich, 2013. Review of the Middle Jurassic "sea cow" Placodus gigas (Reptilia) in Pangea's shallow marine macroalgae meadows of Europe At the same time, and in the same area, true ichthyosaurs were also already around, and already had characteristic their amphicoelous vertebrae free of neural arch, including such species as Cymbospondylus sp., Phantomosaurus sp. - which, according to Fossilworks, are sister taxa to B. ichthyospondylus - and, possibly, Pessosaurus sp., to which the below Middle Triassic vertebra has tentatively been ascribed: Source: Muschelkalkmuseum Ingelfingen The most comprehensive overview of Blezingeria ichthyospondylus material, however, comes from Diedrich, 2015. The vertebrates from the Lower Ladinian (Middle Triassic) bonebed of Lamerden (Germany) as palaeoenvironment indicators in the Germanic Basin (figure 9): Looking at the above image, the similarities with ichthyosaur skeletal material is indeed no longer obvious, which is reflected in the reconstruction, though there are still similarities to be found in the bone morphology of B. ichthyospondylus' fibula (no. 11 in the image above) and the Utatsusaurus sp. (primitive ichthyosaur) paddle in the diagram below: Figure 4 from Motani, 2005. Evolution of Fish-Shaped Reptiles (reptilia: Ichthyopterygia) in Their Physical Environments and Constraints The only cladistic data I can find on the interrelationships between thalattosauria, ichthyopterygia and sauropterygia, however, comes from the Pterosaur Heresies and Reptile Evolution - and, therefore, doesn't derive from the most reliable sources - lacks documented source references, and seems, at least in part, internally contradictory: Not having read Diedrich 2015 yet, my first question is, is there any more information on Blezingeria ichthyospondylus out there on easily accessible media (i.e., the internet, preferably open access)? Does anyone on TFF know about this species, and what is there to know about this species? Where does it fit in phylogenetically, and how does this relate to the other clades of marine reptile? Is there any merit to the above cladograms? Thanks for your help!