Tuesday, July 8, 2014

[PaleoOrnithology • 2014] Pelagornis sandersi • Flight Performance of The Largest Volant Bird

A reconstruction of the world's largest-ever flying bird, Pelagornis sandersi
 identified by Daniel Ksepka | illustration: Liz Bradford 

Pelagornithidae is an extinct clade of birds characterized by bizarre tooth-like bony projections of the jaws. Here, the flight capabilities of pelagornithids are explored based on data from a species with the largest reported wingspan among birds. Pelagornis sandersi sp. nov. is represented by a skull and substantial postcranial material. Conservative wingspan estimates (∼6.4 m) exceed theoretical maximums based on extant soaring birds. Modeled flight properties indicate that lift:drag ratios and glide ratios for P. sandersi were near the upper limit observed in extant birds and suggest that pelagornithids were highly efficient gliders, exploiting a long-range soaring ecology.

Keywords: Aves, fossil, Oligocene, paleontology, pseudotooth

A line drawing of the world's largest-ever flying bird, Pelagornis sandersi, showing comparative wingspan. left, a California condor Gymnogyps californianus, right, a Wandering albatross Diomedea exulans.
by Liz Bradford

Systematic Paleontology

Aves Linnaeus, 1758. 
Pelagornithidae Fürbringer, 1888. 

Pelagornis Lartet, 1857. 
Pelagornis sandersi sp. nov.

Etymology. sandersi honors retired Charleston Museum curator Albert Sanders, collector of the holotype.

Locality and Age. The holotype was collected from Bed 2 of the Chandler Bridge Formation near Charleston Airport (Charleston, SC). It is late Oligocene (lower Chattian, ~25–28 Ma) in age based on calcareous nannoplankton biostratigraphy.

Fig. 1. (Upper) Reconstruction of Pelagornis sandersi (elements preserved in the holotype are shown in white) with D. exulans (Wandering Albatross; 3-m average wingspan) for scale.
(Lower) P. sandersi holotype (ChM PV4768) skull in (a) dorsal, (b) ventral, (c ) left lateral (mandible in medial view), and (d) right lateral views (mandible in lateral view). Right humerus in (e ) caudal and (f ) cranial views. Scapula in (g) lateral and (h) medial views. (i) Partial furcula femur in (j ) cranial and (k) caudal views. Tibiotarsus in (l ) cranial and (m ) caudal views. Fibula in (n) lateral view. Tarsometatarsus in (o) dorsal view (distal portion exposed in the medial view because of deformation) and (p) rotated to show the distal portion in dorsal view. (q) Pedal phalanx.
cc, Lateral cnemial crest; fac, fossa aditus canalis neurovascularis; fc, facet; haf, humeral articular facet; ie, intercotylar eminence; j, jugal; lf, lateral furrow; mtII, metatarsal trochlea II; nfh, nasofrontal hinge; pf, pneumatic foramen; pp, paroccipital process; sf, subcondylar fossa; sup, supra-angulare; sw, swelling on crista deltopectoralis; syn, synovial joint; tb, tubercle; trf, transverse furrow.


Daniel T. Ksepka. 2014. Flight Performance of The Largest Volant Bird. PNAS

A fossil species of pelagornithid bird exhibits the largest known avian wingspan. Pelagornithids are an extinct group of birds known for bony tooth-like beak projections, large size, and highly modified wing bones that raise many questions about their ecology. At 6.4 m, the wingspan of this species was approximately two times that of the living Royal Albatross. Modeling of flight parameters in this species indicates that it was capable of highly efficient gliding and suggests that pelagornithids exploited a long-range marine soaring strategy similar, in some ways, to that of extant albatrosses.

World's largest-ever flying bird identified http://phy.so/323962726 via @physorg_com