The Incredible Shrinking New Papers

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

Oy, I've been lapse of late -- the curse of having tests and exercises to 
construct and grade, all while taking a class!  Thanks to SP and Colin 
McHenry and others for keeping me up to date on some of these journals that 
I don't check regularly...  Firstly, though, new dinosaur -- this one is 
available free on-line at 
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1096-3642.2007.00349.x 
(congrats, Bucky!!!):


Gates, T.A., and Sampson, S.D. 2007. A new species of Gryposaurus 
(Dinosauria: Hadrosauridae) from the late Campanian Kaiparowits Formation, 
southern Utah, USA. Zoological Journal of the Linnean Society 
151(2):351-376. doi: 10.1111/j.1096-3642.2007.00349.x.

ABSTRACT: A new species of the hadrosaurine hadrosaurid Gryposaurus was 
discovered in the late Campanian Kaiparowits Formation of southern Utah. 
Gryposaurus monumentensis, sp. nov. is distinguished from other Gryposaurus 
species by possessing a more robust skull, enlarged clover-shaped prongs on 
the predentary oral margin, an anteroposteriorly narrow infratemporal 
fenestra, and other autapomorphies plausibly associated with feeding 
adaptations. The derived morphology revealed in G. monumentensis 
necessitates revision of the generic diagnosis of Gryposaurus, including the 
addition of synapomorphies that further aid in distinguishing this taxon 
from Kritosaurus. A revised phylogenetic analysis places Gryposaurus within 
a monophyletic clade that includes Brachylophosaurus and Maiasaura. 
Gryposaurus monumentensis represents the most southern example of 
Gryposaurus, and underlines the remarkable diversification and long duration 
of this genus. Based on the phylogenetic, geographical, and stratigraphic 
evidence at hand, Gryposaurus was the most diverse genus within 
Hadrosaurinae; it also possessed one of the largest geographical and 
stratigraphic distributions, spanning more than five million years of the 
Campanian, and ranging from Alberta in the north to Utah (and possibly 
Texas) in the south.



Then a pterosaur paper:


Grellet-Tinner, G., Wroe, S., Thompson, M.B., and Ji, Q. 2007. A note on 
pterosaur nesting behavior. Historical Biology 19(4):273-277. doi: 
10.1080/08912960701189800.

ABSTRACT: Based on examination of eggshell structure and predicted vapor 
conductances in eggshells in recently described material from Argentina and 
China we conclude that pterosaurs buried their eggs. Egg-burying imposes 
theoretical restrictions on the distribution of pterosaurs, both 
geographically and spatially, raises the possibility of thermal sex 
determination and supports previous suggestions that they exhibited nesting 
fidelity. Some features associated with egg-burying, such as weight savings, 
are likely to have been fortuitous pre-adaptations for these flying 
reptiles, but others may have disadvantaged them relative to avian 
competitors or increased their vulnerability to extinction in a cooling 
climate.



...and stuff on general animal ecology and functional morphology that may be 
of interest for dinosaurian analogy:


Jeschke, J.M. 2007. When carnivores are 'full and lazy'. Oecologia 
152(2):357-364. doi: 10.1007/s00442-006-0654-2.

ABSTRACT: Are animals usually hungry and busily looking for food, or do they 
often meet their energetic and other needs in the 24 h of a day? Focusing on 
carnivores, I provide evidence for the latter scenario. I develop a model 
that predicts the minimum food abundance at which a carnivore reaches 
satiation and is released from time constraints. Literature data from five 
invertebrate and vertebrate species suggest that food abundances experienced 
in the field often exceed this threshold. A comparison of energetic demands 
to kill rates also suggests that carnivores often reach satiation: for the 
16 bird and mammal species analyzed, this frequency is 88% (average across 
species). Because pressure of time would likely lead to trade-offs in time 
allocation and thus to a nonsatiating food consumption, these results 
suggest that carnivores are often released from time constraints.




McHenry, C.R., Wroe, S., Clausen, P.D., Moreno, K., and Cunningham, E., S. 
2007. Supermodeled sabercat, predatory behavior in Smilodon fatalis revealed 
by high-resolution 3D computer simulation. Proceedings of the National 
Academy of Sciences 104(41):16010-16015. doi: 10.1073/pnas.0706086104.

ABSTRACT: The American sabercat Smilodon fatalis is among the most 
charismatic of fossil carnivores. Despite broad agreement that its 
extraordinary anatomy reflects unique hunting techniques, after >150 years 
of study, many questions remain concerning its predatory behavior. Were the 
"sabers" used to take down large prey? Were prey killed with an eviscerating 
bite to the abdomen? Was its bite powerful or weak compared with that of 
modern big cats? Here we quantitatively assess the sabercat's biomechanical 
performance using the most detailed computer reconstructions yet developed 
for the vertebrate skull. Our results demonstrate that bite force driven by 
jaw muscles was relatively weak in S. fatalis, one-third that of a lion 
(Panthera leo) of comparable size, and its skull was poorly optimized to 
resist the extrinsic loadings generated by struggling prey. Its skull is 
better optimized for bites on restrained prey where the bite is augmented by 
force from the cervical musculature. We conclude that prey were brought to 
ground and restrained before a killing bite, driven in large part by 
powerful cervical musculature. Because large prey is easier to restrain if 
its head is secured, the killing bite was most likely directed to the neck. 
We suggest that the more powerful jaw muscles of P. leo may be required for 
extended, asphyxiating bites and that the relatively low bite forces in S. 
fatalis might reflect its ability to kill large prey more quickly, avoiding 
the need for prolonged bites.



Another in the long list of "fossil vs. molecule" papers:


Benton, M.J., and Donoghue, P.C.J. 2007. Paleontological evidence to date 
the Tree of Life. Molecular Biology and Evolution 24(1):26-53. doi: 
10.1093/molbev/msl150.

ABSTRACT: The role of fossils in dating the tree of life has been 
misunderstood. Fossils can provide good "minimum" age estimates for branches 
in the tree, but "maximum" constraints on those ages are poorer. Current 
debates about which are the "best" fossil dates for calibration move to 
consideration of the most appropriate constraints on the ages of tree nodes. 
Because fossil-based dates are constraints, and because molecular evolution 
is not perfectly clock-like, analysts should use more rather than fewer 
dates, but there has to be a balance between many genes and few dates versus 
many dates and few genes. We provide "hard" minimum and "soft" maximum age 
constraints for 30 divergences among key genome model organisms; these 
should contribute to better understanding of the dating of the animal tree 
of life.



And here's a slightly older paper I only just came across...


Gheerbrant, E., and Rage, J.-C. 2006. Paleobiogeography of Africa: how 
distinct from Gondwana and Laurasia? Palaeogeography, Palaeoclimatology, 
Palaeoecology 241(2):224-246. doi: 10.1016/j.palaeo.2006.03.016.

ABSTRACT: Although Africa was south of the Tethys Sea and originally 
belonged to the Gondwana, its paleobiogeographical history appears to have 
been distinct from those of both Gondwana and Laurasia as early as the 
earliest Cretaceous, perhaps the Late Jurassic. This history has been more 
complex than the classical one reconstructed in the context of a dual world 
(Gondwana vs. Laurasia). Geological and paleobiogeographical data show that 
Africa was isolated from the Mid-Cretaceous (Albian-Aptian) to Early 
Miocene, i.e., for ca. 75 million years. The isolation of Africa was broken 
intermittently by discontinuous filter routes that linked it to some other 
Gondwanan continents (Madagascar, South America, and perhaps India), but 
mainly to Laurasia. Interchanges with Gondwana were rare and mainly 
"out-of-Africa" dispersals, whereas interchanges with Laurasia were numerous 
and bidirectional, although mainly from Laurasia to Africa. Despite these 
intermittent connections, isolation resulted in remarkable absences, poor 
diversity, and emergence of endemic taxa in Africa. Mammals suggest that an 
African faunal province might have appeared by Late Jurassic or earliest 
Cretaceous times, i.e., before the opening of the South Atlantic. During 
isolation, Africa was inhabited by vicariant West Gondwanan taxa (i.e., taxa 
inherited from the former South American-African block) that represent the 
African autochthonous forms, and by immigrants that entered Africa owing to 
filter routes. Nearly all, or all immigrants were of Laurasian origin. 
Trans-Tethyan dispersals between Africa and Laurasia were relatively 
frequent during the Cretaceous and Paleogene and are documented as early as 
the earliest Cretaceous or perhaps Late Jurassic, i.e., perhaps by the time 
of completion of the Tethys between Gondwana and Laurasia. They were 
permitted by the Mediterranean Tethyan Sill, a discontinuous route that 
connected Africa to Laurasia and was controlled by sea-level changes. 
Interchanges first took place between southwestern Europe and Africa, but by 
the Middle Eocene a second, eastern route - the Iranian route - involved 
southeastern Europe and southwestern Asia. The Iranian route was apparently 
the filtering precursor of the definitive connection between Africa and 
Eurasia. The relationships and successive immigrations of mammal (mostly 
placental) clades in Africa allow the recognition of five to seven phases of 
trans-Tethyan dispersals between Africa and Laurasia that range from the 
Late Cretaceous to the Eocene-Oligocene transition. These Dispersal Phases 
involve dispersals toward Laurasia and/or toward Africa (immigrations). The 
immigrations in Africa gave rise to faunal assemblages, the African Faunal 
Strata (AFSs). All successful and typical African radiations have arisen 
from these AFSs. We recognize four to six AFSs, each characterized by a 
faunal association. Even major, old African clades such as Paenungulata or 
the still controversial Afrotheria, which belong to the oldest known AFS 
involving placentals, ultimately originated from a Laurasian stem group. 
Africa was an important center of origin of various placental clades. Their 
success in Africa is probably related to peculiar African conditions 
(endemicity, weak competition). Although strongly marked by endemicity, the 
African placental fauna did not suffer extinctions of major clades when 
Africa contacted Eurasia. The present geographic configuration began to take 
shape as early as the Mid-Cretaceous. At that time, the last connections 
between Africa and other Gondwanan continents began to disappear, whereas 
Africa was already connected to Eurasia by a comparatively effective route 
of interchange.



A couple 'o things in _Palaeontology_'s online first section:

Kubo, T. and Benton, M.J. Evolution of hindlimb posture in archosaurs: limb 
stresses in extinct vertebrates. doi:10.1111/j.1475-4983.2007.00723.x

ABSTRACT: During the Triassic, some 250-200 million years ago, the basal 
archosaurs showed a transition from sprawling to erect posture. Past studies 
focused on changes in bone morphology, especially on the joints, as they 
reorientated from a sprawling to an erect posture. Here we introduce a 
biomechanical model to estimate the magnitude of femur stress in different 
postures, in order to determine the most reasonable postures for five basal 
archosaurs along the line to crocodiliforms (the rhynchosaur 
Stenaulorhynchus, the basal archosaur Erythrosuchus, the 'rauisuchian'Batrachotomus, 
the aetosaurs Desmatosuchus and Typothorax). The results confirm a sprawling 
posture in basal taxa and an erect posture in derived taxa. Erect posture 
may have evolved as a strategy to reduce large bending stresses on the limb 
bone caused by heavy body weights in larger forms.



Poinar, G., Jr., Voisin, C., and Voisin, J.-F. 2007. Bird eggshell in 
Dominican amber. doi:10.1111/j.1475-4983.2007.00713.x.

ABSTRACT: Here we report an eggshell in Dominican amber, representing the 
first vertebrate egg in any amber deposit. The eggshell is compared with 
present-day eggs of lizards, snails and birds. Based on the surface 
structure and type of shell breakage, it appears that the most likely 
candidate is a bird, and with that consideration, an avian group that 
produces eggs similar to the fossil in shape, size and colouration is the 
Trochilidae (hummingbirds). Several possible explanations of how the fossil 
could be preserved in amber are provided. If indeed a hummingbird was 
involved, this discovery would represent the first New World record of a 
fossil trochilid.




Lastly, lots of new stuff also in _Naturwissenschaften's_ online first 
section:


Fernandez, M. and Gasparini, Z. 2007. Salt glands in the Jurassic 
metriorhynchid Geosaurus: implications for the evolution of osmoregulation 
in Mesozoic marine crocodyliforms. doi: 10.1007/s00114-007-0296-1

ABSTRACT: The presence of salt-excreting glands in extinct marine sauropsids 
has been long suspected based on skull morphology. Previously, we described 
for the first time the natural casts of salt-excreting glands in the head of 
the Jurassic metriorhynchid crocodyliform Geosaurus araucanensis from the 
Tithonian of the Vaca Muerta Formation in the Neuquén Basin (Argentina). In 
the present study, salt-excreting glands are identified in three new 
individuals (adult, a sub-adult and a juvenile) referable to the same 
species. New material provides significant information on the salt glands 
form and function and permit integration of evolutionary scenarios proposed 
on a physiological basis in extant taxa with evidence from the fossil 
record. G. araucanensis represents an advanced stage of the basic 
physiological model to marine adaptations in reptiles. G. araucanensis salt 
glands were hypertrophied. On this basis, it can be hypothesized that these 
glands had a high excretory capability. This stage implies that G. 
araucanensis (like extant pelagic reptiles, e.g. cheloniids) could have 
maintained constant plasma osmolality even when seawater or osmoconforming 
prey were ingested. A gradual model of marine adaptation in crocodyliforms 
based on physiology (freshwater to coastal/estuarine to estuarine /marine to 
pelagic life) is congruent with the phylogeny of crocodyliforms based on 
skeletal morphology. The fossil record suggests that the stage of marine 
pelagic adaptation was achieved by the Early Middle Jurassic. Salt gland 
size in the juvenile suggests that juveniles were, like adults, pelagic.



Louchart, A., Tourment, N. Carrier, J., Roux, T., and Mourer-Chauvire, C. 
2007. Hummingbird with modern feathering: an exceptionally well-preserved 
Oligocene fossil from southern France. doi: 10.1007/s00114-007-0309-0.

ABSTRACT: Hummingbirds (Trochilidae) today have an exclusively New World 
distribution, but their pre-Pleistocene fossil record comes from Europe 
only. In this study, we describe an exceptionally preserved fossil 
hummingbird from the early Oligocene of southeastern France. The specimen is 
articulated, with a completely preserved beak and feathering. Osteological 
characters allow to identify it as Eurotrochilus sp. This genus is a stem 
group representative of Trochilidae and was recently described from the 
early Oligocene of southern Germany. The new fossil reveals that these 
European Trochilidae were remarkably modern in size, skeletal proportions 
and the shape of the wing, tail and beak and hyoid bones. These features 
confirm the early acquisition of the abilities of hovering and nectarivory 
in hummingbirds, probably before the Oligocene. In several morphological 
characteristics, they resemble members of the 'true hummingbirds' (subfamily 
Trochilinae) and differ from hermits (Phaethornithinae). These features, 
which include a short and square tail and a moderately long, almost straight 
beak, appear to be primitive within the family Trochilidae.


...and two papers concerning Cretaceous fossil ants, which I'll mention but 
not post since they're only of tangential relevance to a dinosaur list 
server...

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

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