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Dinosaur Genera List corrections #143

No new genera to report this time, just an upgrade of a genus previously 
listed as preoccupied, and a couple of new species for Mesozoic Meanderings 
#3. What follows is heavily italicized and boldfaced, but these typographical 
features may be lost for non-AOL email addresses.

[1] After a number of searches through the literature at various times during 
the past several years, Ben Creisler and I have come to the opinion that the 
name Centrosaurus Lambe, 1904 is after all not preoccupied by the name Centros
aurus Fitzinger, 1843. Centrosaurus Fitzinger, 1843 was originally published 
as a junior synonym of the genus Phrynosoma (a "horned toad"), and according 
to the rules in effect when Chure & McIntosh (1989) proposed Eucentrosaurus 
as a replacement name for Centrosaurus Lambe, 1904, in order for it to 
preoccupy Centrosaurus Lambe, 1904, it must have been used as an available 
generic name, not just as a junior synonym, at some time prior to 1961. This 
is what we looked for, and so far we have come up with no such usage. 
Overwhelmingly, indeed as far as we can tell entirely, throughout the 20th 
century the prevailing usage of the name Centrosaurus has been for the 
dinosaur described by Lambe, not for the lizard. Furthermore, the new 2000 
ICZN code strongly supports maintaining prevailing usage and suppressing 
forgotten senior homonyms that threaten nomenclatural stability in this 
manner. So I have reinstated Centrosaurus to availability and removed its 
preoccupied notation in the Dinosaur Genera List. It now simply reads as 

Centrosaurus Lambe, 1904

Fitzinger's 1843 genus Centrosaurus should be considered a nomen oblitum, or 
forgotten name, and Chure & McIntosh's 1989 name Eucentrosaurus becomes a 
junior objective synonym of Centrosaurus Lambe, 1904 (sorry, guys!). The 
entry for Eucentrosaurus in Mesozoic Meanderings #3 changes to Centrosaurus, 
and the listed species and annotation now read as follows:

Centrosaurus Lambe, 1904
    = Eucentrosaurus Chure & McIntosh, 1989
    = Kentrosaurus Romer, 1927/Hennig, 1915 [sic]
    C. apertus Lambe, 1904?
        = Eucentrosaurus apertus (Lambe, 1904) Olshevsky, 1991?
        = Monoclonius apertus (Lambe, 1904) Kuhn, 1964
    C. flexus Brown, 1914
        = Eucentrosaurus flexus (Brown, 1914) Olshevsky, 1991
        = Monoclonius (Centrosaurus) flexus (Brown, 1914) Lull, 1933
        = Monoclonius flexus (Brown, 1914)
        = Monoclonius inflexus Kuhn, 1936 [sic]
    C. cutleri (Brown, 1917) L. S. Russell, 1930
        = Monoclonius cutleri Brown, 1917
        = Centrosaurus (Monoclonius) cutleri (Brown, 1917) C. M. Sternberg, 
        = Eucentrosaurus cutleri (Brown, 1917) Olshevsky, 1991
        = Monoclonius (Centrosaurus) cutleri (Brown, 1917) Lull, 1933
    C. nasicornus (Brown, 1917) Lull, 1933
        = Monoclonius nasicornus Brown, 1917
        = Eucentrosaurus nasicornus (Brown, 1917) Olshevsky, 1991
        = Monoclonius (Centrosaurus) nasicornus (Brown, 1917) Lull, 1933
    ?C. longirostris C. M. Sternberg, 1940
        = Eucentrosaurus longirostris (C. M. Sternberg, 1940) Olshevsky, 1991
        = Monoclonius longirostris (C. M. Sternberg, 1940) Kuhn, 1964
NOTE: Fitzinger's 1843 initial use of the generic name Centrosaurus (with 
type species Centrosaurus horridus, by monotypy) was as a junior synonym of 
the lizard genus Phrynosoma. The Zoological Code (ICZN 1985: Article 11e) 
requires that for a scientific name initially proposed as a junior synonym to 
be considered a senior homonym of a later name, it must at some time before 
1961 have been used as an available generic name or as a senior homonym 
suppressing a junior homonym. Kuhn (1964), in a footnote, cited Centrosaurus 
Fitzinger, 1843 as a senior homonym of Centrosaurus Lambe, 1904, thereby 
almost fulfilling the ICZN requirement of senior homonymy to render Centrosaur
us Lambe, 1904 preoccupied. Romer (1956) used Centrosaurus Fitzinger, 1843 as 
a synonym of a different genus, Heloderma, but this could well be a 
typographical or inadvertent manuscript error. A search of the literature 
prior to 1961 for more unequivocal usages of Centrosaurus Fitzinger, 1843 has 
yielded none (B. Creisler, pers. comm.), so the name Centrosaurus for the 
ceratopian, not for the lizard of Fitzinger, 1843, must prevail. Centrosaurus 
Fitzinger, 1843 is thus a nomen oblitum and does not preoccupy Centrosaurus 
Lambe, 1904. The name Eucentrosaurus proposed by Chure & McIntosh (1989) as a 
replacement name for Centrosaurus Lambe, 1904 is therefore unnecessary and 
becomes a junior objective synonym of Centrosaurus.
    Most species of Centrosaurus are likely junior subjective synonyms of the 
type species Centrosaurus apertus.

[2] A copy of Madsen & Welles, 2000, on Ceratosaurus, has reached me (thanks 
to James Madsen), and besides adding the two new species described therein, 
there are some minor changes to the Ceratosaurus listings for some of the 
other continents besides North America.

For Asia, the listing for Szechuanosaurus changes to:

Szechuanosaurus Young, 1942 [nomen dubium]
    S. campi Young, 1942?
        = Labrosaurus huene Huene, 1956 vide Madsen & Welles, 2000 [nomen 
        = Metriacanthosaurus carpenteri Paul, 1988 [sic, probably for Metriaca
    ?S. yandonensis Dong, Chang, Li & Zhou, 1978 [nomen nudum]
    ?S. zigongensis Gao, 1993
NOTE: This questionable genus is based on a few teeth. More complete skeletal 
remains that have been referred to it may be redescribed in different genera. 
The undescribed species Labrosaurus huene was stated (Madsen & Welles, 2000) 
to be based on a theropod tooth from Szechuan, and pending further 
information it is provisionally referred to Szechuanosaurus campi.

For Africa, the listing for Ceratosaurus changes to:

Ceratosaurus Marsh, 1884
    ?C. ingens (Janensch, 1920) Paul, 1988 [nomen dubium]
        = Megalosaurus ingens Janensch, 1920 [nomen dubium]
    ?C. stechowi (Janensch, 1920) n. comb. [nomen dubium]
        = Labrosaurus stechowi Janensch, 1920 [nomen dubium]
        = Antrodemus stechowi (Janensch, 1920) Steel, 1970 [nomen dubium]
        = Antrodemus steschowi Chabli, 1986 [sic]
        = Labrosaurus steschowi Chabli, 1986 [sic]
        = Ceratosaurus roechlingi Janensch, 1925 [nomen dubium]
        = Ceratosaurus roechlinqi Chabli, 1986 [sic]
NOTE: Madsen & Welles, 2000 synonymized the species Labrosaurus stechowi and C
eratosaurus roechlingi, noting that Labrosaurus stechowi is the junior 
synonym. It is, however, Ceratosaurus roechlingi that is the junior synonym, 
and the referral of both species (though doubtfully) to the genus Ceratosaurus
 necessitates creation of the new combination Ceratosaurus stechowi for this 

For North America, the listing for Ceratosaurus changes to:

Ceratosaurus Marsh, 1884
    C. nasicornis Marsh, 1884?
        = Megalosaurus nasicornis (Marsh, 1884) Cope, 1892
        = Megalosaurus nasecornis Cope, 1892 [sic]
        = Labrosaurus sulcatus Marsh, 1896 [nomen dubium]
        = Antrodemus sulcatus (Marsh, 1896) Hay, 1902 [nomen dubium]
        = Ceratosaurus nasicornus Chabli, 1986 [sic]
NOTE: Madsen & Welles, 2000 considered Labrosaurus sulcatus referable to Cerat
osaurus but indeterminate to species level. When Madsen originally made this 
referral, there was only one species of Ceratosaurus, and to avoid creating a 
spurious new combination, Labrosaurus sulcatus was provisionally referred to C
eratosaurus nasicornis. It can remain referred to this species on this basis.
    C. dentisulcatus Madsen & Welles, 2000
        = Ceratosaurus dentisulcatus [Anonymous] 1995 [nomen nudum; appears 
on a price list
            of specimens available from Dinolab, Salt Lake City, Utah]
    C. magnicornis Madsen & Welles, 2000
        = Ceratosaurus willisobrienorum Welles, H. P. Powell & Pickering vide 
Pickering, 1995
            [nomen nudum]

For Europe, the listing for Ceratosaurus changes to:

Ceratosaurus Marsh, 1884
    ?C. meriani (Greppin, 1870) Olshevsky, 2000 [nomen dubium]
        = Megalosaurus meriani Greppin, 1870 [nomen dubium]
        = Allosaurus meriani (Greppin, 1870) Olshevsky, 1978 [nomen dubium]
        = Antrodemus meriani (Greppin, 1870) Steel, 1970 [nomen dubium]
        = Labrosaurus meriani (Greppin, 1870) von Huene, 1926 [nomen dubium]
NOTE: This species is based on a single tooth resembling the type of Labrosaur
us sulcatus. Inasmuch as the type tooth of Labrosaurus sulcatus is here 
considered a Ceratosaurus nasicornis specimen, referral of Megalosaurus 
meriani Greppin, 1870 to the genus Ceratosaurus follows. Steel (1970) 
referred this species to the genus Antrodemus but did not actually employ the 
binomen Antrodemus meriani.

All these changes will appear in the second printing of Mesozoic Meanderings 
#3, which will be published shortly after the first printing sells out. To 
order a copy of the first printing (still available), please visit my website 


Ordering instructions are at the top of the page; the current Dinosaur Genera 
List forms approximately the lower 2/3 of the page.