Shifts in stability and control effectiveness during evolution of Paraves support aerial maneuvering hypotheses for flight origins

Evangelista, Dennis; Cam, Sharlene; Huynh, Tony L.; Kwong, Austin; Mehrabani, Homayun; Tse, Kyle; Dudley, Robert

doi:10.7717/peerj.632

Cited by 21 publications

(17 citation statements)

References 71 publications

(205 reference statements)

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“…The supplementary stereo lithography [STL] file is available online (palaeo-electronica.org/content/ 2015/1073-blastoid-hydrospire-fluid-flow). Blender was used for ease in modeling curved biological shapes (Munk, 2011;Evangelista, 2013;Zeng, 2013;Evangelista et al, 2014).…”

Section: Construction Of the Physical Modelmentioning

confidence: 99%

Visualizing the fluid flow through the complex skeletonized respiratory structures of a blastoid echinoderm

Huynh

Evangelista

Marshall

2015

Palaeontologia Electronica

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Spiraculate blastoids have extraordinary internal skeletonized respiratory structures, the hydrospires. However, the detailed pattern of seawater flow within them is unknown, making it difficult to assess their respiratory effectiveness. Using a scaled-up (72x) 3D printed physical model to visualize the flow of water through the most distal (aboral) part of the hydrospire of Pentremites rusticus, we show that flow was consistent with effective respiratory exchange in the hydrospire folds-the flow continued horizontally within the hydrospire folds after passing through the hydrospire pore canals and only developed an adoral component to its velocity once it had entered the hydrospire canals. The observed orderly laminar flow is consistent with the Reynolds numbers we estimate for a living blastoid (Re = 0.0008-0.05). While most functional analyses of spiraculate hydrospires focus on their respiratory function, it is also possible that they played a role in feeding, helping to draw water past the brachioles, which is a hypothesis that is amenable to future testing.

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Section: Construction Of the Physical Modelmentioning

confidence: 99%

Visualizing the fluid flow through the complex skeletonized respiratory structures of a blastoid echinoderm

Huynh

Evangelista

Marshall

2015

Palaeontologia Electronica

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“…Powered flight differs from gliding flight in that it uses active flapping to generate thrust. Some models of the origin of avian flight propose antecedents living in trees and deriving the flight stroke from a parachuting or gliding stage ( Chatterjee & Templin, 2004 ; Alexander et al, 2010 ; Dyke et al, 2013 ) based primarily on the observation that many modern arboreal tetrapods perform similar behaviors ( Dudley et al, 2007 ; Evangelista et al, 2014 ). Yet nearly all stem avians have hindlimb morphologies that compare most closely to extant cursorial tetrapods ( Dececchi & Larsson, 2011 ) and a multivariate analysis of limb element lengths recovered the earliest birds as most similar to extant terrestrial foragers ( Bell & Chiappe, 2011 ; Mitchell & Makovicky, 2014 ).…”

Section: Introductionmentioning

confidence: 99%

The wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents

Dececchi

Larsson

Habib

2016

PeerJ

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Background: Powered flight is implicated as a major driver for the success of birds. Here we examine the effectiveness of three hypothesized pathways for the evolution of the flight stroke, the forelimb motion that powers aerial locomotion, in a terrestrial setting across a range of stem and basal avians: flap running, Wing Assisted Incline Running (WAIR), and wing-assisted leaping.Methods: Using biomechanical mathematical models based on known aerodynamic principals and in vivo experiments and ground truthed using extant avians we seek to test if an incipient flight stroke may have contributed sufficient force to permit flap running, WAIR, or leaping takeoff along the phylogenetic lineage from Coelurosauria to birds.Results: None of these behaviours were found to meet the biomechanical threshold requirements before Paraves. Neither was there a continuous trend of refinement for any of these biomechanical performances across phylogeny nor a signal of universal applicability near the origin of birds. None of these flap-based locomotory models appear to have been a major influence on pre-flight character acquisition such as pennaceous feathers, suggesting non-locomotory behaviours, and less stringent locomotory behaviours such as balancing and braking, played a role in the evolution of the maniraptoran wing and nascent flight stroke. We find no support for widespread prevalence of WAIR in non-avian theropods, but can’t reject its presence in large winged, small-bodied taxa like Microraptor and Archaeopteryx.Discussion: Using our first principles approach we find that “near flight” locomotor behaviors are most sensitive to wing area, and that non-locomotory related selection regimes likely expanded wing area well before WAIR and other such behaviors were possible in derived avians. These results suggest that investigations of the drivers for wing expansion and feather elongation in theropods need not be intrinsically linked to locomotory adaptations, and this separation is critical for our understanding of the origin of powered flight and avian evolution.

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“…The model, however, suffers from any number of insurmountable problems and has been refuted numerous times, most prominently by Senter [63], Feduccia [8], and Chatterjee and Templin [28] , on a number of points, primarily the fact that avian ancestors, either theropodan or archosaurian, lacked the appropriate pectoral architecture and musculature to enact WAIR. Most recently Bock [64] argued on anatomy that urvogels like Archaeopteryx (even more true of putative archosaurian or theropodan ancestors of birds), were specialized gliders and not active flapping fliers, and Evangelista et al [16] showed that even the ontogenetic evidence cited by Dial was critically flawed. In reality, by observing fledging ducks such as the Wood Duck (Aix sponsa) or Common Goldeneye (Bucephala clangula) jumping out of their tree nests to the ground, with wings spread out and feet laterally splayed, one could just as easily conclude that birds evolved from gliding ancestors, the most probable scenario.…”

Section: Fig (3)mentioning

confidence: 99%

FANTASY VS REALITY: A Critique of Smith et al.'s Bird Origins

Feduccia¹

2016

TOOENIJ

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Adherents of the current orthodoxy of a derivation of birds from theropod dinosaurs, criticize the commentary by Feduccia (2013, Auk, 130) [1 -12] entitled "Bird Origins Anew" as well as numerous papers by Lingham-Soliar on theropod dermal fibers, using numerous mischaracterizations and misstatements of content, and illustrate their own misconceptions of the nature of the debate, which are here clarified. While there is general agreement with the affinity of birds and maniraptorans, the widely accepted phylogeny, advocating derived earth-bound maniraptorans giving rise to more primitive avians (i.e. Archaeopteryx), may be "topsyturvy." The current primary debate concerns whether maniraptorans are ancestral or derived within the phylogeny, and whether many maniraptorans and birds form a clade distinct from true theropods. Corollaries of the current scheme show largely terrestrial maniraptoran theropods similar to the Late Cretaceous Velociraptor giving rise to avians, and flight originating via a terrestrial (cursorial) "gravity-resisted," as opposed to an arboreal "gravity-assisted" model. The current dogma posits pennaceous flight remiges in earth-bound theropods having evolved in terrestrial theropods that never flew. As part of the orthodoxy, fully feathered maniraptorans such as the tetrapteryx gliders Microraptor and allies, are incorrectly reconstructed as terrestrial cursors, when in reality their anatomy and elongate hindlimb feathers would be a hindrance to terrestrial locomotion.The same is true of many early birds, exemplified by reconstruction of the arboreally adapted Confuciusornis as a terrestrial predator, part of the overall theropodan scheme of birds evolving from terrestrial dinosaurs, and flight from the ground up. Both sides of this contentious debate must be constantly aware that new fossil or even molecular discoveries on birds may change current conclusions.

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Shifts in stability and control effectiveness during evolution of Paraves support aerial maneuvering hypotheses for flight origins

Cited by 21 publications

References 71 publications

Visualizing the fluid flow through the complex skeletonized respiratory structures of a blastoid echinoderm

Visualizing the fluid flow through the complex skeletonized respiratory structures of a blastoid echinoderm

The wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents

FANTASY VS REALITY: A Critique of Smith et al.'s Bird Origins

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