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Beverly Hills New Papers



Sorry for yet another prolonged absence, but here's a few that I don't think
have been mentioned on the list before -- thanks to DF for some of them!
Apologies if any are duplicates...



Zelenitsky, D.K., Therrien, F., and Kobayashi, Y. 2008. Olfactory acuity in
theropods: palaeobiological and evolutionary implications. Proceedings of
the Royal Society of London B. doi: 10.1098/rspb.2008.1075.

ABSTRACT: This research presents the first quantitative evaluation of the
olfactory acuity in extinct theropod dinosaurs. Olfactory ratios (i.e. the
ratio of the greatest diameter of the olfactory bulb to the greatest
diameter of the cerebral hemisphere) are analysed in order to infer the
olfactory acuity and behavioural traits in theropods, as well as to identify
phylogenetic trends in olfaction within Theropoda. A phylogenetically
corrected regression of olfactory ratio to body mass reveals that, relative
to predicted values, the olfactory bulbs of (i) tyrannosaurids and
dromaeosaurids are significantly larger, (ii) ornithomimosaurs and
oviraptorids are significantly smaller, and (iii) ceratosaurians,
allosauroids, basal tyrannosauroids, troodontids and basal birds are within
the 95% CI. Relative to other theropods, olfactory acuity was high in
tyrannosaurids and dromaeosaurids and therefore olfaction would have played
an important role in their ecology, possibly for activities in low-light
conditions, locating food, or for navigation within large home ranges.
Olfactory acuity was the lowest in ornithomimosaurs and oviraptorids,
suggesting a reduced reliance on olfaction and perhaps an omnivorous diet in
these theropods. Phylogenetic trends in olfaction among theropods reveal
that olfactory acuity did not decrease in the ancestry of birds, as
troodontids, dromaeosaurids and primitive birds possessed typical or high
olfactory acuity. Thus, the sense of smell must have remained important in
primitive birds and its presumed decrease associated with the increased
importance of sight did not occur until later among more derived birds.



Gierlinski, G.D., and Sabath, K. 2008. Stegosaurian footprints from the
Morrison Formation of Utah and their implications for interpreting other
ornithischian tracks. Oryctos 8:29-46.

ABSTRACT: The supposed stegosaurian track Deltapodus Whyte & Romano, 1994
(Middle Jurassic of England) is sauropod-like, elongate and plantigrade, but
many blunt-toed, digitigrade, large ornithopod-like footprints (including
pedal print cast associated with the manus of Stegopodus Lockley & Hunt,
1998) from the Upper Jurassic of Utah, better fit the stegosaurian foot
pattern. The Morrison Formation of Utah yielded other tracks fitting the
dryomorph (camptosaur) foot pattern (Dinehichnus Lockley et al., 1998) much
better than Stegopodus. If the Stegopodus pedal specimen (we propose to
shift the emphasis from the manus to the pes in the revised diagnosis of
this ichnotaxon) and similar ichnites are proper stegosaur footprints,
Deltapodus must have been left by another thyreophoran trackmaker. Other
Deltapodus-like (possibly ankylosaurian) tracks include Navahopus Baird,1980
and Apulosauripus Nicosia et al., 1999. Heel-dominated, short-toed forms
within the Navahopus-Deltapodus-Apulosauripus plexus differ from the
gracile, relatively long-toed Tetrapodosaurus Sternberg, 1932, traditionally
regarded as an ankylosaurian track. Thus, the original interpretation of the
latter as a ceratopsian track might be correct, supporting early (Aptian)
appearance of ceratopsians in North America.
     Isolated pedal ichnites from the Morrison Formation (with a single
tentatively associated manus print, and another one from Poland) and the
only known trackways with similar footprints (Upper Jurassic of Asturias,
Spain) imply bipedal gait of their trackmakers. Thus, problems with
stegosaur tracks possibly stem from the expectation of their quadrupedality.
Massive but short stegosaur forelimbs suggest primarily bipedal locomotion,
and quadrupedal defense posture.




Gierlinski, G.D., Ploch, I., Gawor-Biedowa, E., and Niedzwiedzki, G. 2008.
The first evidence of dinosaur tracks in the Upper Cretaceous of Poland.
Oryctos 8:107-113.

ABSTRACT: A new theropod and ornithischian dinosaur track (Irenesauripus sp.
and cf. Hadrosauropodus sp.) are reported from the Polish Cretaceous
carbonate facies. The reported finds came from the Maastrichtian limestones,
informal unit called Gaizes, exposed in the vicinity of the Roztocze
National Park and represents isolated theropod pedal print and manus-pes set
left by hadrosaurid dinosaur. These are the first dinosaur track record in
the Cretaceous of Poland.






Rayfield, E.J., and Milner, A.C. 2008. Establishing a framework for
archosaur cranial mechanics. Paleobiology 34(4):494-515. doi:
10.1666/07006.1.

ABSTRACT: The aim of this analysis was to establish the basic mechanical
principles of simple archosaur cranial form. In particular we estimated the
influence of two key archosaur innovations, the secondary palate and the
antorbital fenestra, on the optimal resistance of biting-induced loads.
Although such simplified models cannot substitute for more complex cranial
geometries, they can act as a clearly derived benchmark that can serve as a
reference point for future studies incorporating more complex geometry. We
created finite element (FE) models comprising either a tall, domed
(oreinirostral) snout or a broad, flat (platyrostral) archosaur snout. Peak
von Mises stress was recorded in models with and without a secondary palate
and/or antorbital fenestra after the application of bite loads to the tooth
row. We examined bilateral bending and unilateral torsion-inducing bites for
a series of bite positions along the jaw, and conducted a sensitivity
analysis of material properties. Pairwise comparison between different FE
morphotypes revealed that oreinirostral models are stronger than their
platyrostral counterparts. Oreinirostral models are also stronger in bending
than in torsion, whereas platyrostral models are equally susceptible to
either load type. As expected, we found that models with a fenestra always
have greatest peak stresses and by inference are "weaker," significantly so
in oreinirostral forms and anterior biting platyrostral forms. Surprisingly,
although adding a palate always lowers peak stress, this is rarely by large
magnitudes and is not significant in bilateral bending bites. The palate is
more important in unilateral torsion-inducing biting. Two basic principles
of archosaur cranial construction can be derived from these simple models:
(1) forms with a fenestra are suboptimally constructed with respect to
biting, and (2) the presence or absence of a palate is significant to
cranial integrity in unilaterally biting animals. Extrapolating these
results to archosaur cranial evolution, it appears that if mechanical
optimization were the only criterion on which skull form is based, then most
archosaurs could in theory strengthen their skulls to increase resistance to
biting forces. These strengthened morphotypes are generally not observed in
the fossil record, however, and therefore archosaurs appear subject to
various non-mechanical morphological constraints. Carnivorous theropod
dinosaurs, for example, may retain large suboptimal fenestra despite
generating large bite forces, owing to an interplay between craniofacial
ossification and pneumatization. Furthermore, living crocodylians appear to
strengthen their skull with a palate and filled fenestral opening in the
most efficient way possible, despite being constrained perhaps by
hydrodynamic factors to the weaker platyrostral morphotype. The future
challenge is to ascertain whether these simple predictions are maintained
when the biomechanics of complex cranial geometries are explored in more
detail.





Fricke, H.C., and Pearson, D.A. 2008. Stable isotope evidence for changes in
dietary niche partitioning among hadrosaurian and ceratopsian dinosaurs of
the Hell Creek Formation, North Dakota. Paleobiology 34(4):534-552. doi:
10.1666/08020.1.

ABSTRACT: Questions related to dinosaur behavior can be difficult to answer
conclusively by using morphological studies alone. As a complement to these
approaches, carbon and oxygen isotope ratios of tooth enamel can provide
insight into habitat and dietary preferences of herbivorous dinosaurs. This
approach is based on the isotopic variability in plant material and in
surface waters of the past, which is in turn reflected by carbon and oxygen
isotope ratios of animals that ingested the organic matter or drank the
water. Thus, it has the potential to identify and characterize dietary and
habitat preferences for coexisting taxa.
     In this study, stable isotope ratios from coexisting hadrosaurian and
ceratopsian dinosaurs of the Hell Creek Formation of North Dakota are
compared for four different stratigraphic levels. Isotopic offsets between
tooth enamel and tooth dentine, as well as taxonomic differences in means
and in patterns of isotopic data among taxa, indicate that primary
paleoecological information is preserved. The existence of taxonomic offsets
also provides the first direct evidence for dietary niche partitioning among
these herbivorous dinosaur taxa. Of particular interest is the observation
that the nature of this partitioning changes over time: for some localities
ceratopsian dinosaurs have higher carbon and oxygen isotope ratios than
hadrosaurs, indicating a preference for plants living in open settings near
the coast, whereas for other localities isotope ratios are lower, indicating
a preference for plants in the understory of forests. In most cases the
isotope ratios among hadrosaurs are similar and are interpreted to represent
a dietary preference for plants of the forest canopy. The inferred
differences in ceratopsian behavior are suggested to represent a change in
vegetation cover and hence habitat availability in response to sea level
change or to the position of river distributaries. Given our current lack of
taxonomic resolution, it is not possible to determine if dietary and habitat
preferences inferred from stable isotope data are associated with single, or
multiple, species of hadrosaurian/ceratopsian dinosaurs.





Benton, M.J. 2008. How to find a dinosaurs, and the role of synonymy in
biodiversity studies. Paleobiology 34(4):516-533. doi: 10.1666/06077.1.

ABSTRACT: Taxon discovery underlies many studies in evolutionary biology,
including biodiversity and conservation biology. Synonymy has been
recognized as an issue, and as many as 30-60% of named species later turn
out to be invalid as a result of synonymy or other errors in taxonomic
practice. This error level cannot be ignored, because users of taxon lists
do not know whether their data sets are clean or riddled with erroneous
taxa. A year-by-year study of a large clade, Dinosauria, comprising over
1000 taxa, reveals how systematists have worked. The group has been subject
to heavy review and revision over the decades, and the error rate is about
40% at generic level and 50% at species level. The naming of new species and
genera of dinosaurs is proportional to the number of people at work in the
field. But the number of valid new dinosaurian taxa depends mainly on the
discovery of new territory, particularly new sedimentary basins, as well as
the number of paleontologists. Error rates are highest (>50%) for dinosaurs
from Europe; less well studied continents show lower totals of taxa,
exponential discovery curves, and lower synonymy rates. The most prolific
author of new dinosaur names was Othniel Marsh, who named 80 species,
closely followed by Friedrich von Huene (71) and Edward Cope (64), but the
"success rate" (proportion of dinosaurs named that are still regarded as
valid) was low (0.14-0.29) for these earlier authors, and it appears to
improve through time, partly a reflection of reduction in revision time, but
mainly because modern workers base their new taxa on more complete
specimens. If only 50% of species are valid, evolutionary biologists and
conservationists must exercise care in their use of unrevised taxon lists.





Buffetaut, E. 2008. Spinosaurid teeth from the Late Jurassic of Tendaguru,
Tanzania, with remarks on the evolutionary and biogeographical history of
the Spinosauridae; pp. 26-28, Mid-Mesozoic Life and Environments, Cognac.  




Sacchi, E., Conti, M.A., D'Orazi Porchetti, S., Logoluso, A., Nicosia, U.,
Perugini, G., and Petti, F.M. 2008. Aptian dinosaur footprints from the
Apulian platform (Bisceglie, southern Italy) in the framework of
periadriatic ichnosites. Palaeogeography, Palaeoclimatology, Palaeoecology.
doi: 10.1016/j.palaeo.2008.09.018.

ABSTRACT: New dinosaur tracks have been found near Bisceglie (Bari, Apulia),
on loose blocks ascribed to the Corato Member (late Bedoulian to early
Gargasian) of the Calcare di Bari Fm. The material consists of isolated
footprints as well as of short trackways of quadrupedal and bipedal
dinosaurs. The new tracksite has yielded a quite differentiated dinosaur
ichnocoenosis, including theropod, sauropod, thyreophoran and ornithopod
footprints.
     The discovery of early Aptian dinosaur footprints in the limestone of
the carbonate platform of southern Italy gives new insights on dinosaur
distribution, and new palaeontological constraints for the palaeogeographic
reconstruction of the Mediterranean Tethys during the Cretaceous. The
analysis of this and others ichnosites of the periadriatic carbonate
platforms, gives evidence of repeated emersions and of widespread
land-vertebrates dwelling. The characteristics of the associations suggest
that the trackmakers did not constitute a real coevolved association but the
occasional co-occurrence of taxa after migration.
     The results emphasize the need of both structural and environmental
continuity and walking ways between a southern continent and the
periadriatic carbonate platforms during the Early Cretaceous.




Zhang, G., Wang, Y., Jones, M.E.H., and Evans, S.E. 2008. A new Early
Cretaceous salamander (Regalerpeton weichangensis gen. et sp. nov.) from the
Huajiying Formation of northeastern China. Cretaceous Research. doi:
10.1016/j.cretres.2008.10.004.

ABSTRACT: Recent discoveries of well-preserved Late Jurassic and Early
Cretaceous salamander fossils from China are helping to resolve highly
controversial aspects of caudate phylogeny. Here we report on a new Early
Cretaceous salamander, Regalerpeton weichangensis gen. et sp. nov., from the
Huajiying Formation in Hebei Province, China. This specimen is characterized
by long, arched vomerine tooth rows running parallel to the maxillary
arcade; a long and tapered anterior ramus of the pterygoid that curves
anteromedially; an ossified hyobranchium with one pair of hypobranchials and
two pairs of ceratobranchials; and  scapulocoracoids with greatly expanded,
approximately rectangular coracoid components. Phylogenic analysis places
Regalerpeton as the sister group to a Cryptobranchidae clade including
Chunerpeton, with Jeholotriton and Pangerpeton as successive sister taxa.





Dalton, R. 2008. School of rock. Nature 455:858-860. doi: 10.1038/455858a.

ABSTRACT: In the heart of America's dinosaur country, the relationship
between Native Americans and outside palaeontologists has always been tense.
In the 1890s, the battle between white settlers and Native Americans was
barely over when legendary fossil-hunter Edward Cope arrived to prospect for
bones in the grassy hills that make up the Standing Rock Sioux Reservation
in North and South Dakota.





Claessens, L.P.A.M. 2008. The skeletal kinematics of lung ventilation in
three basal bird taxa (emu, tinamou, and guinea fowl). Journal of
Experimental Zoology. doi: 10.1002/jez.501. 

ABSTRACT: In vivo visceral and skeletal kinematics of lung ventilation was
examined using cineradiography in two palaeognaths, the emu (Dromaius
novaehollandiae) and the Chilean tinamou (Nothoprocta perdicaria), and a
basal neognath, the helmeted guinea fowl (Numida meleagris). Upon
inspiration, the thorax expands in all dimensions. The vertebral ribs swing
forward and upward, thereby increasing the transverse diameter of the trunk.
The consistent location of the parapophysis throughout the dorsal vertebral
series, ventral and cranial to the diapophysis, ensures a relatively uniform
lateral expansion. An increase in the angle between the vertebral and the
sternal ribs causes the sternal ribs to push the sternum ventrally. Owing to
the greater length of the caudal sternal ribs, the caudal sternal margin is
displaced further ventrally than the cranial sternal margin. When observed
in lateral view, sternal movement is not linear, but elliptical.
     The avian thorax is highly constrained in its movement when compared
with crocodylians, the other extant archosaur clade. Birds lack a lumbar
region and intermediate ribs. Sternal ribs are completely ossified, and have
a bicondylar articulation with the sternum. Considering the importance of
pressure differences between cranial and caudal air sac complexes for the
generation of unidirectional air flow in the avian lung, it is hypothesized
that a decrease in the degrees of freedom of movement of the avian trunk
skeleton, greater expansion of the ventrocaudal trunk region, and elliptical
sternal movement may represent specific adaptations for fine-tuned control
over air flow within the complex avian pulmonary system.




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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/

"I have made this letter longer
than usual because I lack the
time to make it shorter."
                      -- Blaise Pascal