Also new in Historical Biology

[Tim Williams <twilliams_alpha@hotmail.com>]

Yates, A.M. (2006).  Solving a dinosaurian puzzle: the identity of _Aliwalia 
rex_ Galton.  Historical Biology, iFirst article, 1-30.

Abstract: "_Eucnemesaurus fortis_ Van Hoepen 1920 from the Late Triassic of 
South Africa is demonstrated to be the senior synonym of the puzzling 
dinosaur taxon _Aliwalia rex_ Galton 1985. A new specimen of this 
poorly-known taxon is described. _Eucnemesaurus_ is clearly a sauropodomorph 
and increases the diversity of sauropodomorph taxa in the South African Late 
Triassic to six. It shares a number of femoral synapomorphies with 
_Riojasaurus_ from the Late Triassic of Argentina and Riojasauridae tax. 
nov. is erected to accommodate them. These conclusions are supported by a 
comprehensive cladistic analysis of 46 sauropodomorph and other basal 
dinosauriformtaxa using 353 osteological characters. This analysis also 
supports the paraphyletic nature of the traditional ?prosauropod? 
assemblage.?

Also erects the new taxon Massopoda (defined as _Saltasaurus_ but not 
_Plateosaurus_), and re-defines Sauropoda (_Saltasaurus_ but not 
_Melanorosaurus_).  Thus Sauropoda is a subset of Massopoda.  
_Plateosauravus_ and _Eucnemesaurus_ are both valid taxa (mentioned before). 
 The analysis shows _Ruehleia_ as the sister taxon to the 
Massopoda+Plateosauridae clade.  I guess this clade would be Plateosauria - 
Yates uses it as such, following Sereno (1998).  But Plateosauria was 
defined under the assumption that _Plateosaurus_ and _Massospondylus_ formed 
a clade to the exclusion of eusauropods, which no longer holds; so Sereno 
(2005) re-defined Plateosauria such that _Saltasaurus_ is a negative 
qualifier.


Bonaparte, J.F, Brea, G., Schultz, C.L., and Martinelli, A.G. (2006).  A new 
specimen of _Guaibasaurus candelariensis_ (basal Saurischia) from the Late 
Triassic Caturrita Formation of southern Brazil.  Historical Biology, iFirst 
article, 1-30.

Abstract: ?The comparison of the anatomy of a second incomplete skeleton of 
_Guaibasaurus candelariensis_ to that of basal Saurischia suggests that the 
origin of the ?Prosauropoda? was from unknown basal saurischians, after 
separating from theropods (except herrerasaurids). _Guaibasaurus_ and 
_Saturnalia_ are part of this early dichotomy, and they bear mixed 
characters-states of basal theropods and ?prosauropods? type. The Late 
Triassic age of both _Guaibasaurus_ and _Saturnalia_(the latter is older) 
predates the ?dominance? of basal sauropodomorphs as well as the appearance 
of the basal theropod _Zupaysaurus_, both recorded from the upper Los 
Colorados Formation of Argentina.?


Ferigolo, J. and Langer, M.C. (2006).  A Late Triassic dinosauriform from 
south Brazil and the origin
of the ornithischian predentary bone.   Historical Biology, iFirst article, 
1-11.

Abstract: ?The South American Late Triassic offers the most comprehensive 
window to the early radiation of dinosaurs. This is enhanced by the 
discovery of _Sacisaurus agudoensis_, a new dinosauriform from the Caturrita 
Formation of Brazil. Various morphological features suggest its close 
phylogenetic affinity to _Silesaurus_, and both may be basal ornithischian 
dinosaurs. __Sacisaurus_ has a pair of elements forming the tip of its lower 
jaw, hypothesized to be equivalent to the ornithischian predentary. This 
suggests that during an initial stage of their evolution, those dinosaurs 
had a paired predentary, which later fused into a single structure. As an 
originally paired bone, the predentary is comparable to elements that more 
often form the vertebrate mandible, such as the mentomeckelian bone. 
Although synapomorphic for ornithischians, the predentary does not seem 
neomorphic for the group, but primarily homologous to parts of the 
symphyseal region of the lower jaw of other vertebrates.?


Ezcurra, M. (2006). The cranial anatomy of the coelophysoid theropod 
_Zupaysaurus rougieri_ from the Upper Triassic of Argentina.  Historical 
Biology, iFirst article, 1-18.

Abstract: ?_Zupaysaurus rougieri_ is a theropod dinosaur that is known from 
an almost complete skull and limited postcranial material (e.g., axial 
elements, scapulocoracoid, tibia, astragalocalcaneum), from the Los 
Colorados Formation (La Esquina Fauna, Norian), NW Argentina. This taxon was 
originally interpreted as a basal tetanuran, but is actually a member of the 
Coelophysoidea. _Zupaysaurus_ differs from other basal dinosaurs in the 
presence of the following cranial apomorphies: a maxillary-jugal ventral 
margin describing an obtuse angle in lateral view, a horizontal ramus of the 
maxilla with parallel dorsal and ventral margins, a notch at the base of the 
ascending process of the maxilla, and a sigmoid ventral process of the 
squamosal. Furthermore, the skull of this theropod reveals anatomical 
novelties (e.g., pneumatic lacrimal, maxillary fenestra, oval orbit, wide 
contact between squamosal and quadratojugal) absent in any other Triassic 
dinosaur hitherto described, including remaining coelophysoids. 
Interestingly, these features resemble morphological aspects of more derived 
theropods, approaching some traits of tetanuran and ceratosaurian 
neotheropods. In this regard, a redescription of the skull of _Zupaysaurus_ 
and comparisons with basal neotheropods, mainly coelophysoids, is presented 
here in order to provide a better cranial anatomical record for this 
Triassic theropod and insights to their early cranial evolution.?


Ezcurra, M.D. and Novas, F.E. (2006). Phylogenetic relationships of the 
Triassic theropod _Zupaysaurus rougieri_ from NW Argentina.  Historical 
Biology, iFirst article, 1-18.

Abstract: ?The anatomy and phylogenetic relationships of the Upper Triassic 
theropod _Zupaysaurus rougieri_ are reviewed. This taxon is represented by a 
nearly complete skull and fragmentary postcranial remains recovered from the 
Los Colorados Formation (Norian), NW Argentina. Originally, _Zupaysaurus 
rougieri_ was considered a basal member of the Tetanurae, but its anatomy 
closely resembles that of the Coelophysoidea, supporting its nesting within 
this theropodan subclade. Thus reinterpreted, _Zupaysaurus_ represents the 
first record of coelophysoids in South America. Phylogenetic analyses 
perfomed in this study depict _Zupaysaurus_ as a non-coelophysis 
[sic]coelophysoid. Autopomorphic traits of _Zupaysaurus_ include: 
maxillary-jugal ventral margin forming an obtuse angle in lateral view, 
tibia with a very deep and caudally open caudal fossa for the reception of 
an astragalar caudal process. Within the phylogenetic context outlined here, 
the derived features shared with Tetanurae (e.g. maxillary fenestra, 
caudally forked ascending ramus of the maxilla) are better interpreted as 
homoplasies rather than tetanuran derived features.?


And the one already mentioned?

Irmis, R.B., Parker, W.G, Nesbitt, S.J., Liu, J. (2006). Early ornithischian 
dinosaurs: the Triassic record.

The holotype of _Technosaurus_ is restricted to the premaxilla and dentary.  
 The premaxilla (at least) very closely resembles that of _Silesaurus_.  
The posterior mandibular fragment is referred to _Shuvosaurus_

_Azendohsaurus_ - probably non-dinosaurian, and related to a Madagasan taxon 
originally (and erroneously, based on more material) described as a 
prosauropod (Flynn et al., 1999).

_Galtonia_ and _Pekinosaurus_ - referred to _Revueltosaurus_ as 
_Revueltosaurus_ sp.

_Tecovasaurus_, _Lucianosaurus_, _Crosbysaurus_ and _Protecovasaurus_  - all 
valid taxa, but cannot be classified as anything other than Archosauriformes 
incertae sedis.

Cheers

Tim

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