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New Mesozoic bird papers
From: Ben Creisler
bh480@scn.org
In case these new papers concerning Mesozoic birds have
not been mentioned yet:
Alyssa Bell and Luis M. Chiappe (2011)
Statistical approach for inferring ecology of Mesozoic
birds.
Journal of Systematic Palaeontology (advance online
publication)
DOI: 10.1080/14772019.2010.525536
http://www.informaworld.com/smpp/content~db=all~content=a9
32842339~frm=titlelink
The ability to identify the ecological role an organism
plays is fundamental to modern ecology and is an
important goal of palaeontological studies. Morphometrics
has the potential to be a statistically robust means of
furthering this goal, identifying ecomorphological trends
within a group of organisms. The dramatic morphological
and ecological diversity of modern and fossil birds makes
them ideal for ecomorphological studies, and the vast
increase in known Mesozoic avian diversity opens numerous
possibilities for applying modern ecomorphology to
enhance our understanding of avian diversification in the
Mesozoic. This study presents a large morphometric
database of modern birds analysed using a multivariate
statistical approach, in order to identify correlations
between ecology and morphology. These relationships were
also examined in a number of Mesozoic birds in order to
investigate both the ecological diversification of early
birds as a whole and the specific ecological roles
individual taxa may have played.
Amanda R. Falk, Larry D. Martin and Stephen T. Hasiotis
(2011)
A morphologic criterion to distinguish bird tracks.
Journal of Ornithology (advance online publication)
DOI: 10.1007/s10336-011-0645-x
http://www.springerlink.com/content/p3837x1780868j43/
Few anatomical criteria have been proposed to distinguish
bird tracks from dinosaur tracks. The most commonly used
criterion is the angle of divarication between toes II
and IV, which is usually greater in birds than dinosaurs.
The angle of divarication as related to some skeletal
feature in modern birds may provide additional
information about the trackmaker and its evolutionary
relationships. A total of 186 bird tarsometatarsi (11
orders, 21 families, 39 genera, 41 species) from 8
morphotypes?shorebirds, wading birds, perching birds,
zygodactyl birds, birds of prey, ground foragers, webbed-
footed birds, and syndactyl birds?were sampled to test
the hypothesis that the morphology of the distal end of
the tarsometatarsus is the primary influence on the angle
of divarication of the toes. Skeletal limb anatomy was
also studied for correlations with stride length in an
effort to predict pivot point height in birds from their
trackways. Analysis shows a pronounced correlation
between a large trochlea arc angle, and a small angle of
divarication. Distinct differences in the trochlear arc
angle and the angle of divarication could be correlated
to such avian morphotypes as shorebirds, waders, ground
foragers, and perching birds. No correlations between
limb length and stride length could be established, and
the equations commonly used for most vertebrate trackways
did not hold for birds, most likely due to their unique
hindlimb anatomy.