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Gansus (Aves) locomotory abilities and habitat



From: Ben Creisler
bcreisler@gmail.com

A new article not yet mentioned on the DML. Note this came out online
in November (I somehow missed it), but it is now free.

R. L. Nudds, J. Atterholt, X. Wang, H.-L. You and G. J. Dyke (2013)
Locomotory abilities and habitat of the Cretaceous bird Gansus
yumenensis inferred from limb length proportions.
Journal of Evolutionary Biology 26(1):150–154
DOI: 10.1111/jeb.12036
http://onlinelibrary.wiley.com/doi/10.1111/jeb.12036/abstract
Free pdf:
http://onlinelibrary.wiley.com/doi/10.1111/jeb.12036/pdf



The relative length proportions of the three bony elements of the
pelvic (femur, tibiotarsus and tarsometatarsus) and pectoral (humerus,
ulna and manus) limbs of the early Cretaceous bird Gansus yumenensis,
a well-represented basal ornithuromorph from China, are investigated
and compared to those of extant taxa. Ternary plots show that the
pectoral limb length proportions of Gansus are most similar to
Apodiformes (swifts and hummingbirds), which plot away from all other
extant birds. In contrast, the pelvic limb length proportions of
Gansus fall within the extant bird cluster and show similarities with
the neornithine families Podicipedidae (grebes), Diomedeidae
(albatross) and Phalacrocoracidae (cormorants). Although it does have
some of the pelvic limb features of grebes and cormorants, the femur
of Gansus is more gracile and is thus more consistent with an
albatross-like shallow-diving mode of life than a strong
foot-propelled diving movement pattern. The position of Gansus in
pectoral limb ternary morphospace is largely due to its elongated
manus. In contrast to apodiformes, where the humerus and ulna are
short and robust, an adaptation, which provides a stiff wing for their
demanding fast agile and hovering flight (respectively), the
wing-bones of Gansus are slender, indicating a less vigorous flapping
flight style. The suite of characters exhibited by Gansus mean it is
difficult to completely interpret its likely ecology. Nevertheless,
our analyses suggest that it is probable that this bird was both
volant and capable of diving to some degree using either
foot-propelled or, perhaps, both its wings and its feet for underwater
locomotion.