Bunch o' New Refs

["Jerry D. Harris" <jharris@dixie.edu>]

Hi All -

    Lots of new things out, only a few of which pertain directly to 
dinosaurs but some of which at least have direct dinosaurian implications...

Jalil, N.-E., and Peyer, K. 2007. A new rauisuchian (Archosauria, Suchia) 
from the Upper Triassic of the Argana Basin, Morocco. Palaeontology 
50(2):417-430. doi: 10.1111/j.1475-4983.2007.00640.x.

ABSTRACT: In the 1970s the Upper Triassic strata of the Argana Basin yielded 
archosaurian remains that were tentatively attributed to the rauisuchian 
Ticinosuchus. Restudy of this material together with new remains reveal new 
anatomical data and show that it in fact belongs to a new taxon, 
Arganasuchus dutuiti gen. et sp. nov. The systematics of the Rauisuchia are 
still unresolved; nevertheless, a monophyletic suprageneric group can be 
defined within the probable non-monophyletic rauisuchians. Arganasuchus 
dutuiti differs from all adequately known rauisuchians in three 
autapomorphies: acetabular rim on pubis runs anteroventrally parallel to 
pubic shift rather than being terminal and perpendicular to it; large 
contribution of pubis to acetabular depression; palatal process of maxillary 
low and confluent with interdental crest, rather than separated from it by a 
large area. The maxilla of Arganasuchus resembles those of Batrachotomus and 
Fasolasuchus in having a Y-shaped rather than a U-shaped form. As in 
rauisuchids, Arganasuchus dutuiti has short cervical vertebrae and a dorsal 
border of the proximal extremity of the pubis that is convex in lateral 
view. It shares one derived character state with Batrachotomus and 
Postosuchus (a tear-shaped and anteriorly orientated rugosity on the lateral 
side of the pubis, lying on a deep, longitudinal depression) and one more 
derived character state with Batrachotomus (narrow ante-acetabular part of 
the pubis; hence, the anterior border of the proximal extremity of the pubis 
is almost contiguous with the actabular rim).


Danilov, I.G., and Parham, J.F. 2007. The type series of 'Sinemys' 
wuerhoensis, a problematic turtle from the Lower Cretaceous of China, 
includes at least three taxa. Palaeontology 50(2):431-444. doi: 
10.1111/j.1475-4983.2006.00632.x.

ABSTRACT: We re-examine the type series of 'Sinemys' wuerhoensis Yeh (at 
least 20 specimens, including several shells and skulls on three slabs of 
matrix and one isolated skull) from the Early Cretaceous Tugulu Group of 
China. Our study shows that the type series of 'S.'wuerhoensis is actually a 
chimera made up of at least three distinct taxa. The holotype of this taxon 
should be assigned to the basal eucryptodire genus Xinjiangchelys Yeh. As 
there are no characters that distinguish 'S.'wuerhoensis from Xinjiangchelys 
species, we consider it to be a nomen dubium. This new assignment of 'S.'wuerhoensis 
expands the temporal range of Xinjiangchelys from the Late Jurassic into the 
Early Cretaceous in Asia. The majority of the paratypes of 'S.'wuerhoensis 
(several shells in dorsal and ventral aspect and skulls) are referred to the 
basal eucryptodire genus Ordosemys Brinkman and Peng. We establish a new 
name for these specimens, Ordosemys brinkmania sp. nov. One additional 
specimen in the type series of 'S.'wuerhoensis, a skull, is referred to cf. 
Pantrionychia Joyce, Parham and Gauthier indet.


Christiansen, P. 2007. Long-bone geometry in columnar-limbed animals: 
allometry of the proboscidean appendicular skeleton. Zoological Journal of 
the Linnean Society 149(3):423-438. doi: 10.1111/j.1096-3642.2007.00249.x.

ABSTRACT: Limb-bone allometry was investigated for 19 species of 
proboscideans, spanning almost the entire phylogenetic spectrum. More 
archaic proboscideans ('gompthotheres') have substantially thicker long-bone 
diaphyses relative to length than elephantids, as has been suggested 
previously, but contrary to previous suggestions it could not be confirmed 
that Mammuthus had more massive long-bone diaphyses on average than extant 
Elephas and Loxodonta. When correcting for phylogeny, the circumference of 
the limb bones to their length in proboscideans as a group generally scale 
with negative allometry, becoming stouter with increased length, as would be 
expected from limb mechanics. Few slopes were, however, statistically 
significantly negatively allometric. Correcting for phylogeny produced 
better correlations than traditional regression analyses, in contrast to 
most other studies where the reverse is the case. Intraspecific analyses of 
extant Elephas and Loxodonta, in addition to Mammuthus primigenius, Mammut 
americanum, and Gomphotherium productum, also resulted in negatively 
allometric regression slopes, frequently conforming to the theory of elastic 
similarity, as could be expected from the columnar posture of proboscideans. 
At present the reasons for the more massive limbs of gomphotheres s.l. are 
not fully understood.


Pol, D., and Norell, M.A. 2007. Uncertainty in the age of fossils and the 
stratigraphic fit to phylogenies. Systematic Biology 55(3):512-521. doi: 
10.1080/10635150600755446.

ABSTRACT: The ages of first appearance of fossil taxa in the stratigraphic 
record are inherently associated to an interval of error or uncertainty, 
rather than being precise point estimates. Contrasting this temporal 
information with topologies of phylogenetic relationships is relevant to 
many aspects of evolutionary studies. Several indices have been proposed to 
compare the ages of first appearance of fossil taxa and phylogenies. For 
computing most of these indices, the ages of first appearance of fossil taxa 
are currently used as point estimates, ignoring their associated errors or 
uncertainties. The effect of age uncertainty on measures of stratigraphic 
fit to phylogenies is explored here for two indices based on the extension 
of ghost lineages (MSM* and GER). A solution based on randomization of the 
ages of terminal taxa is implemented, resulting in a range of possible 
values for measures of stratigraphic fit to phylogenies, rather than in a 
precise but arbitrary stratigraphic fit value. Sample cases show that 
ignoring the age uncertainty of fossil taxa can produce misleading results 
when comparing the stratigraphic fit of competing phylogenetic hypotheses. 
Empirical test cases of alternative phylogenies of two dinosaur groups are 
analyzed through the randomization procedure proposed here.


These aren't technically OUT yet (= not in paper) -- available in on-line 
first format, though:

Kundrát, M. 2007. Avian-like attributes of a virtual brain model of the 
oviraptorid theropod Conchoraptor gracilis. Naturwissenschaften. doi: 
10.1007/s00114-007-0219-1.

ABSTRACT: An almost complete adult endoneurocranium of Conchoraptor gracilis 
Barsbold 1986 (Oviraptoridae; ZPAL MgD-I/95), discovered at the Hermiin Tsav 
locality (the Upper Cretaceous) in Mongolia, is analyzed. A virtual model of 
the endoneurocranial cavity was derived from CT scans and represents the 
most complete maniraptoran endocast to date. It displays reduced olfactory 
bulbs, large cerebral hemispheres in contact with the expanded cerebellum, 
an epiphysial projection, optic lobes displaced latero-ventrally, 
presumptive cerebellar folia, enlarged cerebellar auricles, and a deep 
medulla oblongata with a prominent ventral flexure. Contrary to 
Archaeopteryx, the shortened olfactory tract and cerebellum overtopping 
cerebral hemispheres of Conchoraptor resemble conditions in modern birds. 
Calculating brain mass relative to body mass indicates that Conchoraptor 
falls within the range of extant birds, whereas Archaeopteryx occupies a 
marginal position. Most of the endoneurocranial attributes, however, have a 
less birdlike appearance in Conchoraptor than do corresponding structures in 
Archaeopteryx and modern birds in which 1) postero-laterally expanded 
hemispheral domains broadly overlap the optic lobes, 2) the epiphysis 
projects to the posterior cerebrum, 3) lateral extension of the optic lobes 
substantially decreases a brain length-to-width ratio, 4) optic lobe and 
anterior hindbrain are superposed in lateral view, and 5) cerebellar and 
midbrain compartments are in distinct superposition. The endoneurocranial 
characteristics of Conchoraptor, taken together, suggest that the animal had 
a keen sense of vision, balance, and coordination. The data presented in 
this study do not allow an unambiguous assessment whether the avian-like 
endoneurocranial characteristics of the flightless Conchoraptor evolved 
convergently to those of avian theropods, or indicate a derivation of 
oviraptorosaurs from volant ancestors.


Evans, S.E., and Wang, Y. 2007. A juvenile lizard specimen with 
well-preserved skin impressions from the Upper Jurassic/Lower Cretaceous of 
Daohugou, Inner Mongolia, China. Naturwissenschaften. doi: 
10.1007/s00114-006-0214-y.

ABSTRACT: Lizards are now relatively well known from the Yixian Formation of 
northeastern China. In this study, we describe a juvenile lizard from a 
fossil horizon at Daohugou, Inner Mongolia. These beds predate the Yixian 
Formation, and are probably Late Jurassic or earliest Cretaceous in age. The 
new specimen thus documents the first lizard material from the Daohugou 
locality and is the earliest lizard skeleton from China. Comparisons with 
developmental stages of modern lizards suggest the Daohugou lizard is a 
hatchling. Although tiny, the specimen is notable in preserving exquisite 
skin impressions showing the variation in scalation across the body, the 
shape and position of the cloacal outlet, and details of the manus and pes. 
These are the earliest recorded lepidosaurian skin traces. In its general 
proportions and the possession of paired frontals, the small Daohugou lizard 
resembles both the Yixian taxon Yabeinosaurus tenuis and the questionable 
Jeholacerta formosa, but it differs from the latter in scalation and, based 
on other characters, may be distinct from both.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
and     dinogami@gmail.com
http://cactus.dixie.edu/jharris/

"Trying to estimate the divergence times
of fungal, algal or prokaryotic groups on
the basis of a partial reptilian fossil and
protein sequences from mice and humans
is like trying to decipher Demotic Egyptian with
the help of an odometer and the Oxford
English Dictionary."
              -- D. Graur & W. Martin (_Trends
                  in Genetics_ 20[2], 2004)