Sailing the skies: the improbable aeronautical success of the pterosaurs

Wilkinson, Matthew T.

doi:10.1242/jeb.000307

Cited by 13 publications

(10 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…After a long period of debate concerning the role of the hindlimb in pterosaur wing structure, it now appears that evidence strongly supports the inclusion of much or all of the hindlimb in the wing membrane [Unwin and Bakhurina, 1994;Unwin, 1999]. Models of pterosaur aerodynamics [Wilkinson et al, 2006;Wilkinson, 2007] could be readily modified to account for potential effects of active hindlimb positioning and membrane stiffness modulation.…”

Section: Allometric Patterning In the Bat Hindlimbmentioning

confidence: 99%

Biomechanics of the Bat Limb Skeleton: Scaling, Material Properties and Mechanics

Swartz¹,

Middleton²

2007

Cells Tissues Organs

View full text Add to dashboard Cite

Background/Aims: Wing skeletons of bats are uniquely specialized for flight, reflecting both evolutionary history and the need to maintain structural integrity while generating aerodynamic forces. Methods: We analyzed the anatomical structure of bat wing skeletons in the context of scaling patterns relative to other mammals, material properties and the mechanical function of the wing bones during flight. Results: Compared with nonvolant mammals, the bones of the bat forelimb are elongated, even after correcting for shared phylogenetic history. Bats have consistently larger-diameter bones in the forelimb than do nonvolant mammals but significantly narrower hindlimb bones. Mineralization in the cortical bone of wings is lower than in the long bones of other adult mammals, with a proximodistal gradient of decreasing mineralization. The distal phalanges have only a small amount of mineralized tissue underlying the articular cartilage. Loads required to elicit a 10% length deflection in the wing bones of Glossophaga soricina varied approximately 50-fold along the wing and flexural stiffness nearly 200-fold. Commensurate with low mineralization and flexural stiffness, bat bones experience extraordinarily high bending strains during flight. Conclusion: Bat limb skeletons share features with other mammals and possess specialized characteristics, mostly related to the mechanical demands of flight.

show abstract

Section: Allometric Patterning In the Bat Hindlimbmentioning

confidence: 99%

Biomechanics of the Bat Limb Skeleton: Scaling, Material Properties and Mechanics

Swartz¹,

Middleton²

2007

Cells Tissues Organs

View full text Add to dashboard Cite

show abstract

“…By applying the assumed locomotory muscle forces to a 3D reconstruction of the limb of a tetrapod that is placed in a variety of possible orientations relative to the ground, it will be possible to discover which posture and gait minimises the stresses generated in the bones, with the implication that these reflect the animal's normal mode of locomotion in life. Again, as with dinosaur cranial mechanics, the technique will illuminate the functional significance of transitions to radically new modes of locomotion, for example the origin the bipedality of dinosaurs (Hutchinson 2004), parasagittal gait of mammals (Kemp 1978), and the flight of birds (Garner et al 1999;Clarke et al 2006) and pterosaurs (Wilkinson 2007). …”

Section: Computed Tomography and Finite Element Analysismentioning

confidence: 99%

New Perspectives on the Evolution of Late Palaeozoic and Mesozoic Terrestrial Tetrapods

Kemp

2010

New Aspects of Mesozoic Biodiversity

View full text Add to dashboard Cite

Palaeobiology, like all sciences, progresses by a combination of the discovery of new fossils, the application of new techniques, and the development of new concepts with which to generate novel kinds of hypotheses. Research in the field of Late Palaeozoic and Mesozoic terrestrial tetrapods has involved major advances in all three of these over the last decade or so. Several new discoveries fill in gaps in the evolution of higher tetrapod taxa such as Tetrapoda, Dicynodontia, and birds, while others add significantly to the understanding of patterns of faunal turnover and palaeo-community structure.The molecular revolution in biology is having a profound effect on several aspects of palaeobiology, in particular the use of large amounts of sequence data for phylogenetic studies and estimating branching dates. In some cases, notably placental mammals, this has produced results that highlight the limitations of purely morphological evidence in this, and probably other cases, and points to the desirability of seeking other kinds of evidence of relationships. Molecular developmental biology is starting to suggest new evolutionary hypotheses about the molecular genetic basis of the evolutionary transitions that can be inferred from the fossil record, such as how the tetrapod limb arose. In the field of functional analysis of fossils, CT scanning has opened the way to the application of such methods as finite element analysis for studying the mechanical design of fossil tetrapod skulls and skeletons. Geochemistry has also introduced new methods, notably stable isotope analysis, that have a direct bearing on the interpretation of the palaeoenvironmental background of major evolutionary events such as mass extinctions.The principal new concept in palaeobiology arises from a shift towards the systems view that it is the interactions of the parts of a complex system, rather than the nature of the parts themselves, that provide the main key to understanding how the system works. Correlated progression is a model based on this concept which offers a more realistic view of major evolutionary transitions such as the origins of tetrapods, mammals, and potentially all the higher taxa of tetrapods. Earth sciences are also moving more towards a systems way of thinking, such as when seeking explanations for mass extinctions.

show abstract

“…Irrespective of its articulation point, however, debates have centred on whether, or not, the pteroid supported the propatagial region of the pterosaur wing in flight by projecting forward in an anterior orientation (e.g. Hankin 1912;Frey & Riess 1981;Unwin et al 1996;Wilkinson et al 2006;Wilkinson 2007Wilkinson , 2008Unwin 2006) (figure 1a), or was orientated more parallel to the edge of the wing in a medial orientation (e.g. Wagner 1858; Hankin & Watson 1914;Padian 1984;Wellnhofer 1991a;Padian & Rayner 1993;Bennett 2007;Prondvai & Hone 2008) (figure 1b).…”

Section: Introductionmentioning

confidence: 99%

“…Hypotheses for pteroid function have been based on anatomical interpretations of well-preserved fossils (Pennycuick 1988;Unwin et al 1996;Frey et al 2003;Bennett 2007), theoretical consideration of aerodynamic performance advantages (Frey & Riess 1981) and on aerodynamic experiments using models (Wilkinson et al 2006). An anteriorly orientated reconstruction for the pteroid (Wilkinson 2007(Wilkinson , 2008 means that the propatagium must have extended distally from the pteroid to form, in dorsal profile, an elongate triangle to an attachment at the distal end of the wing metacarpal (figure 1c). Proximal to the pteroid, the anterior edge of the propatagium is reconstructed subparallel to the radius/ulna, terminating in the region where the shoulder joins the body (Wilkinson 2007) (figure 1c).…”

Section: Introductionmentioning

confidence: 99%

Biomechanics of the unique pterosaur pteroid

Palmer

Dyke

2009

Proc. R. Soc. B.

View full text Add to dashboard Cite

Pterosaurs, flying reptiles from the Mesozoic, had wing membranes that were supported by their arm bones and a super-elongate fourth finger. Associated with the wing, pterosaurs also possessed a unique wrist bone-the pteroid-that functioned to support the forward part of the membrane in front of the leading edge, the propatagium. Pteroid shape varies across pterosaurs and reconstructions of its orientation vary (projecting anteriorly to the wing leading edge or medially, lying alongside it) and imply differences in the way that pterosaurs controlled their wings. Here we show, using biomechanical analysis and considerations of aerodynamic efficiency of a representative ornithocheirid pterosaur, that an anteriorly orientated pteroid is highly unlikely. Unless these pterosaurs only flew steadily and had very low body masses, their pteroids would have been likely to break if orientated anteriorly; the degree of movement required for a forward orientation would have introduced extreme membrane strains and required impractical tensioning in the propatagium membrane. This result can be generalized for other pterodactyloid pterosaurs because the resultant geometry of an anteriorly orientated pteroid would have reduced the aerodynamic performance of all wings and required the same impractical properties in the propatagium membrane. We demonstrate quantitatively that the more traditional reconstruction of a medially orientated pteroid was much more stable both structurally and aerodynamically, reflecting likely life position.

show abstract

Sailing the skies: the improbable aeronautical success of the pterosaurs

Cited by 13 publications

References 34 publications

Biomechanics of the Bat Limb Skeleton: Scaling, Material Properties and Mechanics

Biomechanics of the Bat Limb Skeleton: Scaling, Material Properties and Mechanics

New Perspectives on the Evolution of Late Palaeozoic and Mesozoic Terrestrial Tetrapods

Biomechanics of the unique pterosaur pteroid

Contact Info

Product

Resources

About