Dinosaur Genera List update #189

[Dinogeorge@aol.com]

Ralph Molnar and I have managed to track down enough references to understand 
some of the taxonomic history of the preoccupied Fitzinger genus Palaeosaurus 
(which isn't dinosaurian; see DGL update #186; different from the Riley & 
Stutchbury genus Palaeosaurus). This resulted in the addition of name #950 to 
the Dinosaur Genera List:

Sphenosaurus von Meyer, 1847* [procolophonid]

I also updated the Palaeosaurus entry to:

Palaeosaurus Fitzinger, 1840/Geoffroy Saint-Hilaire, 1833* -> Sphenosaurus 
[procolophonid]

The reason this Permian form appears in the Dinosaur Genera List is that 
Huxley (1870) considered the possibility it was dinosaurian, and also that I 
had referred it (in error), as Palaeosaurus, to the Riley & Stutchbury genus 
(which is also non-dinosaurian but much more dinosaurian than Fitzinger's 
genus). Under the name Palaeosaurus, it had been described some two years 
before the concept of a dinosaur was articulated by Owen (1842), so it could 
not originally have been described as a dinosaur. Von Meyer (1847) noted that 
the name Palaeosaurus was preoccupied by Geoffroy Saint-Hilaire's 1833 name 
Palaeosaurus and renamed it Sphenosaurus. Two years later, Agassiz (1849) 
used the name Sphenosaurus for a crocodylian (type species Crocodilus 
clavirostris Morton, 1844), evidently not knowing it was preoccupied. This 
species was eventually (Nopcsa, 1926) referred to the crocodylian genus 
Thoracosaurus, so a replacement name for the crocodylian genus Sphenosaurus 
is unnecessary. When it became clear that the Fitzinger/von Meyer Sphenosaurus
 could not be dinosaurian, von Huene (1902) referred its type species to von 
Meyer's procolophonid genus Sclerosaurus. According to a Google search, 
however, Sphenosaurus remains an available genus.

Here is how the entry looks for the forthcoming second printing of Mesozoic 
Meanderings #3:

Sphenosaurus von Meyer, 1847*
    = Palaeosaurus Fitzinger, 1840/Geoffroy Saint-Hilaire, 1833*
    S. sternbergii (Fitzinger, 1840) von Meyer, 1847â
        = Palaeosaurus sternbergii Fitzinger, 1840â*
        = Palaeosauriscus sternbergii (Fitzinger, 1840) Olshevsky, 1991*
        = Paleosaurus sternbergii (Fitzinger, 1840) Olshevsky, 2000*
        = Sclerosaurus sternbergii (Fitzinger, 1840) von Huene, 1902*
NOTE: The genus Palaeosaurus Fitzinger, 1840 is probably a procolophonid (R. 
E. Molnar, pers. comm.). It was referred to the archosaurian genera 
Palaeosaurus Riley & Stutchbury, 1836, Palaeosauriscus, and Paleosaurus by 
Olshevsky, 2000 in error. As a preoccupied name, it was given the new generic 
name Sphenosaurus by von Meyer, 1847 and later was referred to the 
procolophonid genus Sclerosaurus von Meyer, 1859 by von Huene in 1902. Huxley 
(1870) considered the possibility that Sphenosaurus was dinosaurian. 
Sphenosaurus is also the name of a crocodylian genus (Agassiz, 1849) that is 
presently considered a (preoccupied) synonym of Thoracosaurus Leidy, 1852 
(Nopcsa, 1926).