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Living theropod (Buteo) digital anatomy (free pdfs) + other non-dino papers



From: Ben Creisler
bcreisler@gmail.com


A number of recent non-dino papers that may be of interest:

Stephan Lautenschlager, Jen A. Bright & Emily J. Rayfield (2013)
Digital dissection – using contrast-enhanced computed tomography
scanning to elucidate hard- and soft-tissue anatomy in the Common
Buzzard Buteo buteo.
Journal of Anatomy (advance online publication)
DOI: 10.1111/joa.12153
http://onlinelibrary.wiley.com/doi/10.1111/joa.12153/abstract

pdf is open access, also supp. materials:
http://onlinelibrary.wiley.com/doi/10.1111/joa.12153/pdf

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joa12153-sup-0001-FigS1.pdf application/PDF 17322K Fig. S1 Interactive
3D pdf showing the digitally segmented hard- and soft-tissue
structures of the Common Buzzard Buteo buteo. [.pdf]


joa12153-sup-0002-MovieS1.mpg video/mpg 30033K Video S1 Movie file of
the CT dataset showing the stained specimen in coronal section in
rostrocaudal direction. [.mpeg]

http://onlinelibrary.wiley.com/doi/10.1111/joa.12153/suppinfo


**
Gross dissection has a long history as a tool for the study of human
or animal soft- and hard-tissue anatomy. However, apart from being a
time-consuming and invasive method, dissection is often unsuitable for
very small specimens and often cannot capture spatial relationships of
the individual soft-tissue structures. The handful of comprehensive
studies on avian anatomy using traditional dissection techniques focus
nearly exclusively on domestic birds, whereas raptorial birds, and in
particular their cranial soft tissues, are essentially absent from the
literature. Here, we digitally dissect, identify, and document the
soft-tissue anatomy of the Common Buzzard (Buteo buteo) in detail,
using the new approach of contrast-enhanced computed tomography using
Lugol's iodine. The architecture of different muscle systems
(adductor, depressor, ocular, hyoid, neck musculature), neurovascular,
and other soft-tissue structures is three-dimensionally visualised and
described in unprecedented detail. The three-dimensional model is
further presented as an interactive PDF to facilitate the
dissemination and accessibility of anatomical data. Due to the digital
nature of the data derived from the computed tomography scanning and
segmentation processes, these methods hold the potential for further
computational analyses beyond descriptive and illustrative proposes.

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An article that likely applies to extinct aquatic reptiles:

Vladimir Dinets (2013)
Underwater Sound Locating Capability in the American Alligator
(Alligator mississippiensis).
Journal of Herpetology 47(4):521-523
doi: http://dx.doi.org/10.1670/12-110
http://www.bioone.org/doi/abs/10.1670/12-110



It is known that crocodilians are able to locate the source of
air-borne sound. However, locating the source of water-borne sound is
difficult for physical reasons. I tested the ability of American
Alligators (Alligator mississippiensis) to determine the direction
toward the source of underwater sound by using their tendency to be
attracted to slaps on the water surface. To produce surface slapping
sounds with no air-borne component, I slapped the surface of the water
inside a submerged diving bell and recorded the direction of alligator
movements after the sound. The results show that alligators have a
directionally biased response to water-borne sounds, indicating that
they are capable of locating the source of a sound signal transmitted
through the water. It would be physically difficult for the animal to
do so by using the differences in time of sound arrival or in
amplitude between left and right sides of the animal's head, so it is
likely that alligators use other methods such as a sound pressure
gradient system.

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Ruchira Somaweera, Matthew Brien, and Richard Shine (2013)
The Role of Predation in Shaping Crocodilian Natural History.
Herpetological Monographs 27(1): 23-51
doi: http://dx.doi.org/10.1655/HERPMONOGRAPHS-D-11-00001
http://www.bioone.org/doi/abs/10.1655/HERPMONOGRAPHS-D-11-00001?prevSearch=reptile&searchHistoryKey=&queryHash=b7ece5385b8c5b4502afd84e75e3c866



Although adult crocodilians have few predators (mostly humans and
other crocodilians), hatchlings and eggs are killed and consumed by a
diverse array of invertebrates, fishes, anurans, reptiles, birds, and
mammals. We review published literature to evaluate the incidence of
predation in crocodilian populations, and the implications of that
mortality for crocodilian life-history evolution. Presumably because
predation is size-dependent, small-bodied crocodilian taxa appear to
be more vulnerable to predation (across a range of life stages) than
are larger-bodied species. Several features of crocodilian biology
likely reflect adaptations to reducing vulnerability to predation. For
example, the threat of predation may have influenced the evolution of
traits such as nest-site selection, maternal care of eggs and
hatchlings, crèche behavior in hatchlings, and cryptic coloration and
patterning. Even for such large and superficially invulnerable taxa
such as crocodilians, the avoidance of predation appears to have been
a significant selective force on behavior, morphology, and ecology.

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Guangping Xu, Judith L. Hannah, Holly J. Stein, Atle Mørk, Jorunn Os
Vigran, Bernard Bingen, Derek Schutt, Bjørn A. Lundschien (2013)
Cause of Upper Triassic climate crisis revealed by Re-Os geochemistry
of Boreal black shales.
Palaeogeography, Palaeoclimatology, Palaeoecology  (advance online publication)
doi: http://dx.doi.org/10.1016/j.palaeo.2013.12.027
http://www.sciencedirect.com/science/article/pii/S0031018213005646



The Triassic Period is bracketed by two of the ‘big five’ Phanerozoic
mass extinctions. Though long viewed as a period of climatic
stability, emerging data suggest multiple climatic swings and at least
one severe ecological crisis. Linking these climatic instabilities
with probable causes is hampered by poor age control within the
Triassic time scale. Here we present new Re-Os ages for shale sections
straddling Middle-Upper Triassic stage boundaries. Nominal Re-Os
isochron ages of 236.6 and 239.3 Ma for the top and base of the
Ladinian (upper Middle Triassic) bring absolute time into the
contentious Triassic time scale, and place the beginning of the Late
Triassic about 12 m.y. earlier than previously assigned. A marked
decrease in initial 187Os/188Os in Upper Ladinian shale records input
from Wrangellian flood basalts – an instigator in the Carnian (Late
Triassic) Pluvial Event and accompanying radiation of key fossil
groups (e.g., dinosaurs and calcareous nanoplankton). An absolute time
scale is proposed for the Anisian – Ladinian – Carnian boundaries
based on Re-Os geochronology.


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