Basal Paravian Functional Anatomy Illuminated by High-Detail Body Outline
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Anchiornis and Scansoriopterygidae
SpringerBriefs in Earth System Sciences SpringerBriefs South America and the Southern Hemisphere Series Editors Gerrit Lohmann Lawrence A. Mysak Justus Notholt Jorge Rabassa Vikram Unnithan For further volumes: http://www.springer.com/series/10032 Federico L. Agnolín · Fernando E. Novas Avian Ancestors A Review of the Phylogenetic Relationships of the Theropods Unenlagiidae, Microraptoria, Anchiornis and Scansoriopterygidae 1 3 Federico L. Agnolín “Félix de Azara”, Departamento de Ciencias Naturales Fundación de Historia Natural, CEBBAD, Universidad Maimónides Buenos Aires Argentina Fernando E. Novas CONICET, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” Buenos Aires Argentina ISSN 2191-589X ISSN 2191-5903 (electronic) ISBN 978-94-007-5636-6 ISBN 978-94-007-5637-3 (eBook) DOI 10.1007/978-94-007-5637-3 Springer Dordrecht Heidelberg New York London Library of Congress Control Number: 2012953463 © The Author(s) 2013 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. -
Northwestwildlife.Com Species Reports
A publication by: NORTHWEST WILDLIFE PRESERVATION SOCIETY Northern Flying Squirrel Glaucomys sabrinus Photo credit: US Fish and Wildlife By Renee Picard There are two species of flying squirrels that live in North America. The northern flying squirrel (with 25 sub-species) may be found in forests throughout most of Canada, except for the central prairies and the extreme North; also in the U.S. in Alaska and northern areas of the Rockies and Appalachians. The southern flying squirrel (with 10 sub-species) inhabits a broad range in the eastern and midwestern United States, but in Canada is only found in very small, scattered pockets of southeastern Ontario. The southern species is considered ‘vulnerable’ but the northern species is not at risk. It is the northern squirrel that you would be likely to encounter in the Pacific Northwest, so it is the focus of this article. Characteristics The scientific name for the northern flying squirrel is Glaucomys sabrinus. Glaucos means for silver or grey, mys means mouse, and sabrinus come from the Latin word for river-nymph. So you will notice them often in riparian areas, near streams and rivers. Their colours range from tan to cinnamon and they have greyish-white belly fur. They are about 30 cm (12 in.) long and weigh about 139 g (46 oz.) Flying squirrels have big black eyes and this characteristic helps their night vision for they are nocturnal animals. You might be surprised to find that, despite their name, flying squirrels do not really fly—they glide down from branch to branch. The front and back legs are connected with a thin fold of furry skin or membrane called a patagium. -
LETTER Doi:10.1038/Nature14423
LETTER doi:10.1038/nature14423 A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings Xing Xu1,2*, Xiaoting Zheng1,3*, Corwin Sullivan2, Xiaoli Wang1, Lida Xing4, Yan Wang1, Xiaomei Zhang3, Jingmai K. O’Connor2, Fucheng Zhang2 & Yanhong Pan5 The wings of birds and their closest theropod relatives share a ratios are 1.16 and 1.08, respectively, compared to 0.96 and 0.78 in uniform fundamental architecture, with pinnate flight feathers Epidendrosaurus and 0.79 and 0.66 in Epidexipteryx), an extremely as the key component1–3. Here we report a new scansoriopterygid short humeral deltopectoral crest, and a long rod-like bone articu- theropod, Yi qi gen. et sp. nov., based on a new specimen from the lating with the wrist. Middle–Upper Jurassic period Tiaojishan Formation of Hebei Key osteological features are as follows. STM 31-2 (Fig. 1) is inferred Province, China4. Yi is nested phylogenetically among winged ther- to be an adult on the basis of the closed neurocentral sutures of the opods but has large stiff filamentous feathers of an unusual type on visible vertebrae, although this is not a universal criterion for maturity both the forelimb and hindlimb. However, the filamentous feath- across archosaurian taxa12. Its body mass is estimated to be approxi- ers of Yi resemble pinnate feathers in bearing morphologically mately 380 g, using an empirical equation13. diverse melanosomes5. Most surprisingly, Yi has a long rod-like The skull and mandible are similar to those of other scansoriopter- bone extending from each wrist, and patches of membranous tissue ygids, and to a lesser degree to those of oviraptorosaurs and some basal preserved between the rod-like bones and the manual digits. -
A New Raptorial Dinosaur with Exceptionally Long Feathering Provides Insights Into Dromaeosaurid flight Performance
ARTICLE Received 11 Apr 2014 | Accepted 11 Jun 2014 | Published 15 Jul 2014 DOI: 10.1038/ncomms5382 A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance Gang Han1, Luis M. Chiappe2, Shu-An Ji1,3, Michael Habib4, Alan H. Turner5, Anusuya Chinsamy6, Xueling Liu1 & Lizhuo Han1 Microraptorines are a group of predatory dromaeosaurid theropod dinosaurs with aero- dynamic capacity. These close relatives of birds are essential for testing hypotheses explaining the origin and early evolution of avian flight. Here we describe a new ‘four-winged’ microraptorine, Changyuraptor yangi, from the Early Cretaceous Jehol Biota of China. With tail feathers that are nearly 30 cm long, roughly 30% the length of the skeleton, the new fossil possesses the longest known feathers for any non-avian dinosaur. Furthermore, it is the largest theropod with long, pennaceous feathers attached to the lower hind limbs (that is, ‘hindwings’). The lengthy feathered tail of the new fossil provides insight into the flight performance of microraptorines and how they may have maintained aerial competency at larger body sizes. We demonstrate how the low-aspect-ratio tail of the new fossil would have acted as a pitch control structure reducing descent speed and thus playing a key role in landing. 1 Paleontological Center, Bohai University, 19 Keji Road, New Shongshan District, Jinzhou, Liaoning Province 121013, China. 2 Dinosaur Institute, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA. 3 Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, Beijing 100037, China. 4 University of Southern California, Health Sciences Campus, BMT 403, Mail Code 9112, Los Angeles, California 90089, USA. -
A Bird's Eye View of the Evolution of Avialan Flight
Chapter 12 Navigating Functional Landscapes: A Bird’s Eye View of the Evolution of Avialan Flight HANS C.E. LARSSON,1 T. ALEXANDER DECECCHI,2 MICHAEL B. HABIB3 ABSTRACT One of the major challenges in attempting to parse the ecological setting for the origin of flight in Pennaraptora is determining the minimal fluid and solid biomechanical limits of gliding and powered flight present in extant forms and how these minima can be inferred from the fossil record. This is most evident when we consider the fact that the flight apparatus in extant birds is a highly integrated system with redundancies and safety factors to permit robust performance even if one or more components of their flight system are outside their optimal range. These subsystem outliers may be due to other adaptive roles, ontogenetic trajectories, or injuries that are accommodated by a robust flight system. This means that many metrics commonly used to evaluate flight ability in extant birds are likely not going to be precise in delineating flight style, ability, and usage when applied to transitional taxa. Here we build upon existing work to create a functional landscape for flight behavior based on extant observations. The functional landscape is like an evolutionary adap- tive landscape in predicting where estimated biomechanically relevant values produce functional repertoires on the landscape. The landscape provides a quantitative evaluation of biomechanical optima, thus facilitating the testing of hypotheses for the origins of complex biomechanical func- tions. Here we develop this model to explore the functional capabilities of the earliest known avialans and their sister taxa. -
A Comparison of Flight Potential Among Small-Bodied Paravians
Chapter 11 High Flyer or High Fashion? A Comparison of Flight Potential among Small-Bodied Paravians T. ALEXANDER DECECCHI,1 HANS C.E. LARSSON,2 MICHAEL PITTMAN,3 AND MICHAEL B. HABIB4 ABSTRACT The origin of flight in birds and its relationship to bird origins itself has achieved something of a renaissance in recent years, driven by the discovery of a suite of small-bodied taxa with large pen- naceous feathers. As some of these specimens date back to the Middle Jurassic and predate the earli- est known birds, understanding how these potential aerofoil surfaces were used is of great importance to answering the question: which came first, the bird or the wing? Here we seek to address this question by directly comparing key members of three of the major clades of paravians: anchiorni- thines, Microraptor and Archaeopteryx across their known size classes to see how they differ in terms of major flight-related parameters (wing loading; disc loading; specific lift; glide speed; takeoff poten- tial). Using specimens with snout to vent length (SVL) ranging from around 150 mm to 400 mm and mass ranging from approximately 130 g to 2 kg, we investigated patterns of inter- and intraspe- cific changes in flight potential. We find that anchiornithines show much higher wing- and disc- loading values and correspondingly high required minimum glide and takeoff speeds, along with lower specific lift and flapping running outputs suggesting little to no flight capability in this clade. In contrast, we see good support for flight potential, either gliding or powered flight, for all size classes of both Microraptor and Archaeopteryx, though there are differing patterns of how this shifts ontogenetically. -
The Evolution of Flight in Bats: a Novel Hypothesis Sophia C
bs_bs_banner Mammal Review ISSN 0305-1838 REVIEW The evolution of flight in bats: a novel hypothesis Sophia C. ANDERSON* School of Biology, University of St Andrews, Sir Harold Mitchell Building, Greenside Place, St Andrews, KY16 9TH, UK. Email: [email protected] Graeme D. RUXTON School of Biology, University of St Andrews, Sir Harold Mitchell Building, Greenside Place, St Andrews, KY16 9TH, UK. Email: [email protected] Keywords ABSTRACT bats, Chiroptera, echolocation, evolution of flight, interdigital webbing, pterosaurs, 1. Bats (order Chiroptera) are the only mammals capable of powered flight, Scansoriopterygidae and this may be an important factor behind their rapid diversification into *Correspondence author. the over 1400 species that exist today – around a quarter of all mammalian species. Though flight in bats has been extensively studied, the evolutionary Received: 10 October 2019 history of the ability to fly in the chiropterans remains unclear. Accepted: 13 May 2020 2. We provide an updated synthesis of current understanding of the mechanics Editor: DR of flight in bats (from skeleton to metabolism), its relation to echolocation, doi: 10.1111/mam.12211 and where previously articulated evolutionary hypotheses for the development of flight in bats stand following recent empirical advances. We consider the gliding model, and the echolocation-first, flight-first, tandem development, and diurnal frugivore hypotheses. In the light of the recently published de- scription of the web-winged dinosaur Ambopteryx longibrachium, we draw together all the current evidence into a novel hypothesis. 3. We present the interdigital webbing hypothesis: the ancestral bat exhibited interdigital webbing prior to powered flight ability, and the Yangochiroptera, Pteropodidae, and Rhinolophoidea evolved into their current forms along parallel trajectories from this common ancestor. -
Bat Wing Sensors Support Flight Control
Bat wing sensors support flight control Susanne Sterbing-D’Angeloa,1, Mohit Chadhab,c, Chen Chiuc, Ben Falkc, Wei Xianc, Janna Barceloc, John M. Zookd, and Cynthia F. Mossa,b,c bProgram in Neuroscience and Cognitive Science, cDepartment of Psychology, and aInstitute for Systems Research, University of Maryland, College Park, MD 20742; and dDepartment of Biological Sciences, Ohio University, Athens, OH 45701 Edited* by Jon H. Kaas, Vanderbilt University, Nashville, TN, and approved May 25, 2011 (received for review January 3, 2011) Bats are the only mammals capable of powered flight, and they hair is long (up to several millimeters), relatively thick (6–18 perform impressive aerial maneuvers like tight turns, hovering, μm), and found close to the ventral forearm, around the leg, and and perching upside down. The bat wing contains five digits, and on the tail membrane (IFM), resembling pelage hair. On the its specialized membrane is covered with stiff, microscopically other membranous parts of the wing, a second type of hair was small, domed hairs. We provide here unique empirical evidence found, which is invisible to the naked eye. Fig. 1 shows an ex- that the tactile receptors associated with these hairs are involved ample of these hairs collected from E.f. This type of hair is very in sensorimotor flight control by providing aerodynamic feedback. short (100–600 μm), with the shortest ones found along the We found that neurons in bat primary somatosensory cortex re- trailing edge of the wing. They are so thin that only one follicle spond with directional sensitivity to stimulation of the wing hairs cell builds each segment of the hair, resulting in a coronal scale with low-speed airflow. -
Saitta, ET, Gelernter, R., & Vinther, J
Saitta, E. T., Gelernter, R., & Vinther, J. (2018). Additional information on the primitive contour and wing feathering of paravian dinosaurs. Palaeontology, 61(2), 273-288. https://doi.org/10.1111/pala.12342 Peer reviewed version Link to published version (if available): 10.1111/pala.12342 Link to publication record in Explore Bristol Research PDF-document This is the author accepted manuscript (AAM). The final published version (version of record) is available online via Wiley at http://onlinelibrary.wiley.com/doi/10.1111/pala.12342/abstract . Please refer to any applicable terms of use of the publisher. University of Bristol - Explore Bristol Research General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/red/research-policy/pure/user-guides/ebr-terms/ Additional information on the primitive contour and wing feathering of paravian dinosaurs Evan T. Saitta1, Rebecca Gelernter2, & Jakob Vinther1,3 1School of Earth Sciences, University of Bristol, Bristol, United Kingdom; e-mails: [email protected] (ORCiD ID: orcid.org/0000-0002-9306-9060), [email protected] (ORCiD ID: orcid.org/0000-0002-3584-9616) 2Near Bird Studios, New Haven, Connecticut, USA; e-mail: [email protected] 3School of Biological Sciences, University of Bristol, Bristol, United Kingdom ABSTRACT: Identifying feather morphology in extinct dinosaurs is challenging due to dense overlapping of filaments within fossilized plumage and the fact that some extinct feather morphologies are unlike those seen in extant birds or those predicted from an ‘evo-devo’ model of feather evolution. -
Re-Evaluation of the Haarlem Archaeopteryx and the Radiation of Maniraptoran Theropod Dinosaurs Christian Foth1,3 and Oliver W
Foth and Rauhut BMC Evolutionary Biology (2017) 17:236 DOI 10.1186/s12862-017-1076-y RESEARCH ARTICLE Open Access Re-evaluation of the Haarlem Archaeopteryx and the radiation of maniraptoran theropod dinosaurs Christian Foth1,3 and Oliver W. M. Rauhut2* Abstract Background: Archaeopteryx is an iconic fossil that has long been pivotal for our understanding of the origin of birds. Remains of this important taxon have only been found in the Late Jurassic lithographic limestones of Bavaria, Germany. Twelve skeletal specimens are reported so far. Archaeopteryx was long the only pre-Cretaceous paravian theropod known, but recent discoveries from the Tiaojishan Formation, China, yielded a remarkable diversity of this clade, including the possibly oldest and most basal known clade of avialan, here named Anchiornithidae. However, Archaeopteryx remains the only Jurassic paravian theropod based on diagnostic material reported outside China. Results: Re-examination of the incomplete Haarlem Archaeopteryx specimen did not find any diagnostic features of this genus. In contrast, the specimen markedly differs in proportions from other Archaeopteryx specimens and shares two distinct characters with anchiornithids. Phylogenetic analysis confirms it as the first anchiornithid recorded outside the Tiaojushan Formation of China, for which the new generic name Ostromia is proposed here. Conclusions: In combination with a biogeographic analysis of coelurosaurian theropods and palaeogeographic and stratigraphic data, our results indicate an explosive radiation of maniraptoran coelurosaurs probably in isolation in eastern Asia in the late Middle Jurassic and a rapid, at least Laurasian dispersal of the different subclades in the Late Jurassic. Small body size and, possibly, a multiple origin of flight capabilities enhanced dispersal capabilities of paravian theropods and might thus have been crucial for their evolutionary success. -
Paravian Phylogeny and the Dinosaur-Bird Transition: an Overview
feart-06-00252 February 11, 2019 Time: 17:42 # 1 REVIEW published: 12 February 2019 doi: 10.3389/feart.2018.00252 Paravian Phylogeny and the Dinosaur-Bird Transition: An Overview Federico L. Agnolin1,2,3*, Matias J. Motta1,3, Federico Brissón Egli1,3, Gastón Lo Coco1,3 and Fernando E. Novas1,3 1 Laboratorio de Anatomía Comparada y Evolución de los Vertebrados, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Buenos Aires, Argentina, 2 Fundación de Historia Natural Félix de Azara, Universidad Maimónides, Buenos Aires, Argentina, 3 Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina Recent years witnessed the discovery of a great diversity of early birds as well as closely related non-avian theropods, which modified previous conceptions about the origin of birds and their flight. We here present a review of the taxonomic composition and main anatomical characteristics of those theropod families closely related with early birds, with the aim of analyzing and discussing the main competing hypotheses pertaining to avian origins. We reject the postulated troodontid affinities of anchiornithines, and the Edited by: dromaeosaurid affinities of microraptorians and unenlagiids, and instead place these Corwin Sullivan, University of Alberta, Canada groups as successive sister taxa to Avialae. Aiming to evaluate previous phylogenetic Reviewed by: analyses, we recoded unenlagiids in the traditional TWiG data matrix, which resulted Thomas Alexander Dececchi, in a large polytomy at the base of Pennaraptora. This indicates that the TWiG University of Pittsburgh, United States phylogenetic scheme needs a deep revision. Regarding character evolution, we found Spencer G. Lucas, New Mexico Museum of Natural that: (1) the presence of an ossified sternum goes hand in hand with that of ossified History & Science, United States uncinate processes; (2) the presence of foldable forelimbs in basal archosaurs indicates *Correspondence: widespread distribution of this trait among reptiles, contradicting previous proposals Federico L. -
Written in Stone
112 W RITTENIN S TONE had yet been undertaken (the fossil had only come to the attention of Canadian paleontologist Phil Currie and paleo-artist Michael Skrepnick two weeks earlier), the specimen confirmed the connection between dino- saurs and birds that had been proposed on bones alone. The new dino- saur was dubbed Sinosauropteryx, and it had come from Cretaceous deposits in China that exhibited a quality of preservation that exceeded that of the Solnhofen limestone. Sinosauropteryx was only the first feathered dinosaur to be an- nounced. A panoply of feathered fossils started to turn up in the Jurassic and Cretaceous strata of China, each just as magnificent as the one be- fore. There were early birds that still retained clawed hands (Confuciu- sornis) and teeth (Sapeornis, Jibeinia), while non-flying coelurosaurs such as Caudipteryx, Sinornithosaurus, Jinfengopteryx, Dilong, and Beipiaosaurus wore an array of body coverings from wispy fuzz to full flight feathers. The fossil feathers of the strange, stubby-armed dinosaur Shuvuuia even preserved the biochemical signature of beta-keratin, a protein present in the feathers of living birds, and quill knobs on the forearm of Velociraptor reported in 2007 confirmed that the famous predator was covered in feathers, too. As new discoveries continued to accumulate it became apparent that almost every group of coelurosaurs had feathered representatives, from the weird secondarily herbivorous forms such as Beipiaosaurus to Dilong, an early relative of Tyrannosaurus. It is even possible that, FIGURE 37 - A Velociraptor attempts to catch the early bird Confuciusornis. Both were feathered dinosaurs. 113 Footprints and Feathers during its early life, the most famous of the flesh-tearing dinosaurs may have been covered in a coat of dino-fuzz.