Difficulties with the Origin of Dinosaurs: a Short Comment on the Current Debate
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The Princeton Field Guide to Dinosaurs, Second Edition
MASS ESTIMATES - DINOSAURS ETC (largely based on models) taxon k model femur length* model volume ml x specific gravity = model mass g specimen (modeled 1st):kilograms:femur(or other long bone length)usually in decameters kg = femur(or other long bone)length(usually in decameters)3 x k k = model volume in ml x specific gravity(usually for whole model) then divided/model femur(or other long bone)length3 (in most models femur in decameters is 0.5253 = 0.145) In sauropods the neck is assigned a distinct specific gravity; in dinosaurs with large feathers their mass is added separately; in dinosaurs with flight ablity the mass of the fight muscles is calculated separately as a range of possiblities SAUROPODS k femur trunk neck tail total neck x 0.6 rest x0.9 & legs & head super titanosaur femur:~55000-60000:~25:00 Argentinosaurus ~4 PVPH-1:~55000:~24.00 Futalognkosaurus ~3.5-4 MUCPv-323:~25000:19.80 (note:downsize correction since 2nd edition) Dreadnoughtus ~3.8 “ ~520 ~75 50 ~645 0.45+.513=.558 MPM-PV 1156:~26000:19.10 Giraffatitan 3.45 .525 480 75 25 580 .045+.455=.500 HMN MB.R.2181:31500(neck 2800):~20.90 “XV2”:~45000:~23.50 Brachiosaurus ~4.15 " ~590 ~75 ~25 ~700 " +.554=~.600 FMNH P25107:~35000:20.30 Europasaurus ~3.2 “ ~465 ~39 ~23 ~527 .023+.440=~.463 composite:~760:~6.20 Camarasaurus 4.0 " 542 51 55 648 .041+.537=.578 CMNH 11393:14200(neck 1000):15.25 AMNH 5761:~23000:18.00 juv 3.5 " 486 40 55 581 .024+.487=.511 CMNH 11338:640:5.67 Chuanjiesaurus ~4.1 “ ~550 ~105 ~38 ~693 .063+.530=.593 Lfch 1001:~10700:13.75 2 M. -
A Re-Evaluation of the Enigmatic Dinosauriform Caseosaurus Crosbyensis from the Late Triassic of Texas, USA and Its Implications for Early Dinosaur Evolution
A re-evaluation of the enigmatic dinosauriform Caseosaurus crosbyensis from the Late Triassic of Texas, USA and its implications for early dinosaur evolution MATTHEW G. BARON and MEGAN E. WILLIAMS Baron, M.G. and Williams, M.E. 2018. A re-evaluation of the enigmatic dinosauriform Caseosaurus crosbyensis from the Late Triassic of Texas, USA and its implications for early dinosaur evolution. Acta Palaeontologica Polonica 63 (1): 129–145. The holotype specimen of the Late Triassic dinosauriform Caseosaurus crosbyensis is redescribed and evaluated phylogenetically for the first time, providing new anatomical information and data on the earliest dinosaurs and their evolution within the dinosauromorph lineage. Historically, Caseosaurus crosbyensis has been considered to represent an early saurischian dinosaur, and often a herrerasaur. More recent work on Triassic dinosaurs has cast doubt over its supposed dinosaurian affinities and uncertainty about particular features in the holotype and only known specimen has led to the species being regarded as a dinosauriform of indeterminate position. Here, we present a new diagnosis for Caseosaurus crosbyensis and refer additional material to the taxon—a partial right ilium from Snyder Quarry. Our com- parisons and phylogenetic analyses suggest that Caseosaurus crosbyensis belongs in a clade with herrerasaurs and that this clade is the sister taxon of Dinosauria, rather than positioned within it. This result, along with other recent analyses of early dinosaurs, pulls apart what remains of the “traditional” group of dinosaurs collectively termed saurischians into a polyphyletic assemblage and implies that Dinosauria should be regarded as composed exclusively of Ornithoscelida (Ornithischia + Theropoda) and Sauropodomorpha. In addition, our analysis recovers the enigmatic European taxon Saltopus elginensis among herrerasaurs for the first time. -
New Transitional Fossil from Late Jurassic of Chile Sheds Light on the Origin of Modern Crocodiles Fernando E
www.nature.com/scientificreports OPEN New transitional fossil from late Jurassic of Chile sheds light on the origin of modern crocodiles Fernando E. Novas1,2, Federico L. Agnolin1,2,3*, Gabriel L. Lio1, Sebastián Rozadilla1,2, Manuel Suárez4, Rita de la Cruz5, Ismar de Souza Carvalho6,8, David Rubilar‑Rogers7 & Marcelo P. Isasi1,2 We describe the basal mesoeucrocodylian Burkesuchus mallingrandensis nov. gen. et sp., from the Upper Jurassic (Tithonian) Toqui Formation of southern Chile. The new taxon constitutes one of the few records of non‑pelagic Jurassic crocodyliforms for the entire South American continent. Burkesuchus was found on the same levels that yielded titanosauriform and diplodocoid sauropods and the herbivore theropod Chilesaurus diegosuarezi, thus expanding the taxonomic composition of currently poorly known Jurassic reptilian faunas from Patagonia. Burkesuchus was a small‑sized crocodyliform (estimated length 70 cm), with a cranium that is dorsoventrally depressed and transversely wide posteriorly and distinguished by a posteroventrally fexed wing‑like squamosal. A well‑defned longitudinal groove runs along the lateral edge of the postorbital and squamosal, indicative of a anteroposteriorly extensive upper earlid. Phylogenetic analysis supports Burkesuchus as a basal member of Mesoeucrocodylia. This new discovery expands the meagre record of non‑pelagic representatives of this clade for the Jurassic Period, and together with Batrachomimus, from Upper Jurassic beds of Brazil, supports the idea that South America represented a cradle for the evolution of derived crocodyliforms during the Late Jurassic. In contrast to the Cretaceous Period and Cenozoic Era, crocodyliforms from the Jurassic Period are predomi- nantly known from marine forms (e.g., thalattosuchians)1. -
The Paleontograph______
__________The Paleontograph________ A newsletter for those interested in all aspects of Paleontology Volume 4 Issue 4 October, 2015 _________________________________________________________________ From Your Editor Welcome to our latest issue. This issue is one of the final things I do before shutting down my office for my move west. With all that is going on, I've only managed 4 issues so far this year. My field season has suffered also although I did manage a few days of collecting dinosaur material in SD thanks to a friend that brought me along on one of his trips. I met a bunch of nice people and had a good time playing in the dirt for a few days. I set my booth up at the Denver Coliseum show again this year and had an extremely successful show. For those of you that don't go to shows, I recommend it even if you are not a buyer. There are always cool things to see and cool people to meet. I went to shows for years before I started my business because I was always fascinated by what the commercial market brings to light that the scientific community just misses due to lack of funding, time, storage and just plain lack of interest. The shame of it is that as many in that community try to shut down the fossil marketplace, there are fossils out there just eroding away into dust. Anyone that spends time in the field as opposed to time at a desk can attest to this. The desk people also don't realize the chilling effect this will have on the pursuit of knowledge. -
SUPPLEMENTARY INFORMATION Doi:10.1038/Nature24011
SUPPLEMENTARY INFORMATION doi:10.1038/nature24011 1. Details of the new phylogenetic analysis 1.1. Modifications to Baron et al. (2017) data matrix The following list presents all character scoring modifications to the original taxon-character matrix of Baron et al. (2017). Unless explicitly mentioned, specimen numbers without asterisks have been scored from notes and photographs after their first-hand examination by at least one of the authors, specimens marked with † were coded based only on photographic material, and specimens marked with * were coded on direct observation of the specimens. Aardonyx celestae; score modifications based on the first-hand observation of all specimens mentioned in Yates et al. (2010). 19: 0 >1. 21 0 >1. 54: 0 >?. 57: 0 >?. 156: 1 >0. 202: 1 >0. 204: 1 >0. 266: 1 >0. 280: ? >0. Ch 286: 2 >1. 348: 0 >?. 365: ? >1. 376: ? >0. 382: 0 >?. 439: 0 >1. 450: 1 >0. Abrictosaurus consors; score modifications based on NHMUK RU B54†. Further bibliographic source: Sereno (2012). 7: 0>?; 26 0>?; 35. 2>0/1; 47: 0>?; 54 1>?; 369 0>?; 424 1>?. Agilisaurus louderbacki; score modifications based on Barrett et al. (2005) and scorings in Butler et al. (2008) and Barrett et al. (2016). 6: 0>?; 11: 0>1; 35: 1>0; 54: 1>0; 189: ?>0. Agnosphitys cromhallensis; score modifications based on cast of VMNH 1751. Further bibliographic source: Fraser et al. (2001). 15: ? >0; 16: ? >0; 21: ? >1; 24: ? >1; 30: 0 >?; 159: 0 >1; 160: - >0; 164: - >?; 165: ? >0; 167: ? >0; 172: 0 >?; 176: 0 >?; 177: 1 >0; 180: ? >0; 185: 0 >?; 221: 0 >?; 222: 0 >?; 252: 0 >1; 253: 0 >1; 254: 1 >?; 256: 0 >1; 258: 1 >?; 259: ? >0; 292: ? >1; 298: ? >0; 303: 1 >2; 305: 2 >1; 306: ? >2; 315: 1 >0; 317: ? >1; 318: ? >0; 409: ? >0; 411: 1 >0; 419: 1 >0; 421: ? >0. -
A Theropod Dinosaur from the Late Jurassic Cañadón Calcáreo Formation of Central Patagonia, and the Evolution of the Theropod Tarsus
A THEROPOD DINOSAUR FROM THE LATE JURASSIC CAÑADÓN CALCÁREO FORMATION OF CENTRAL PATAGONIA, AND THE EVOLUTION OF THE THEROPOD TARSUS OLIVER W. M. RAUHUT 1 DIEGO POL 2 1SNSB, Bayerische Staatssammlung für Paläontologie und Geologie, Department of Earth and Environmental Sciences, GeoBioCenter, Ludwig-Maximilians- University, Richard-Wagner-Str. 10, 80333 München, Germany. 2CONICET, Museo Paleontológico Egidio Feruglio, Av. Fontana 140, U9100GYO Trelew, Argentina. Submitted: April 4 th , 2017 - Accepted: October 12 th , 2017 - Published online: November 1 st , 2017 To cite this article: Oliver W.M. Rauhut, and Diego Pol (2017). A theropod dinosaur from the Late Jurassic Cañadón Calcáreo Formation of central Patagonia, and the evolution of the theropod tarsus. Ameghiniana 54: 506–538. To link to this article: http://dx.doi.org/ 10.5710/AMGH.12.10.2017.3105 PLEASE SCROLL DOWN FOR ARTICLE Also appearing in this issue: Two new taxa unveil the A new ornithomimosaur taxon Murusraptor had a brain morphology previously unrecognized diversity from the Early Cretaceous of Niger similar to tyrannosaurids but of Coelophysidae in the Late Triassic and new anatomical data on neurosensorial capabilities of South America. Nqwebasaurus from South Africa. resembling that of allosauroids. ISSN 0002-7014 AMEGHINIANA - 2017 - Volume 54 (5): 539 – 566 GONDWANAN PERSPECTIVES A THEROPOD DINOSAUR FROM THE LATE JURASSIC CAÑADÓN CALCÁREO FORMATION OF CENTRAL PATAGONIA, AND THE EVOLUTION OF THE THEROPOD TARSUS OLIVER W. M. RAUHUT 1, AND DIEGO POL 2 1SNSB, Bayerische Staatssammlung für Paläontologie und Geologie, Department of Earth and Environmental Sciences, GeoBioCenter, Ludwig-Maximilians-University, Richard-Wagner-Str. 10, 80333 München, Germany. [email protected] 2CONICET, Museo Paleontológico Egidio Feruglio, Av. -
Reptile Family Tree - Peters 2017 1112 Taxa, 231 Characters
Reptile Family Tree - Peters 2017 1112 taxa, 231 characters Note: This tree does not support DNA topologies over 100 Eldeceeon 1990.7.1 67 Eldeceeon holotype long phylogenetic distances. 100 91 Romeriscus Diplovertebron Certain dental traits are convergent and do not define clades. 85 67 Solenodonsaurus 100 Chroniosaurus 94 Chroniosaurus PIN3585/124 Chroniosuchus 58 94 Westlothiana Casineria 84 Brouffia 93 77 Coelostegus Cheirolepis Paleothyris Eusthenopteron 91 Hylonomus Gogonasus 78 66 Anthracodromeus 99 Osteolepis 91 Protorothyris MCZ1532 85 Protorothyris CM 8617 81 Pholidogaster Protorothyris MCZ 2149 97 Colosteus 87 80 Vaughnictis Elliotsmithia Apsisaurus Panderichthys 51 Tiktaalik 86 Aerosaurus Varanops Greererpeton 67 90 94 Varanodon 76 97 Koilops <50 Spathicephalus Varanosaurus FMNH PR 1760 Trimerorhachis 62 84 Varanosaurus BSPHM 1901 XV20 Archaeothyris 91 Dvinosaurus 89 Ophiacodon 91 Acroplous 67 <50 82 99 Batrachosuchus Haptodus 93 Gerrothorax 97 82 Secodontosaurus Neldasaurus 85 76 100 Dimetrodon 84 95 Trematosaurus 97 Sphenacodon 78 Metoposaurus Ianthodon 55 Rhineceps 85 Edaphosaurus 85 96 99 Parotosuchus 80 82 Ianthasaurus 91 Wantzosaurus Glaucosaurus Trematosaurus long rostrum Cutleria 99 Pederpes Stenocybus 95 Whatcheeria 62 94 Ossinodus IVPP V18117 Crassigyrinus 87 62 71 Kenyasaurus 100 Acanthostega 94 52 Deltaherpeton 82 Galechirus 90 MGUH-VP-8160 63 Ventastega 52 Suminia 100 Baphetes Venjukovia 65 97 83 Ichthyostega Megalocephalus Eodicynodon 80 94 60 Proterogyrinus 99 Sclerocephalus smns90055 100 Dicynodon 74 Eoherpeton -
Skeletal Completeness of the Non‐Avian Theropod Dinosaur Fossil
University of Birmingham Skeletal completeness of the non-avian theropod dinosaur fossil record Cashmore, Daniel; Butler, Richard DOI: 10.1111/pala.12436 License: Creative Commons: Attribution (CC BY) Document Version Publisher's PDF, also known as Version of record Citation for published version (Harvard): Cashmore, D & Butler, R 2019, 'Skeletal completeness of the non-avian theropod dinosaur fossil record', Palaeontology, vol. 62, no. 6, pp. 951-981. https://doi.org/10.1111/pala.12436 Link to publication on Research at Birmingham portal Publisher Rights Statement: Cashmore, D & Butler, R (2019), 'Skeletal completeness of the non-avian theropod dinosaur fossil record', Palaeontology, vol. 62, no. 6, pp. 951-981. © 2019 The Authors 2019. https://doi.org/10.1111/pala.12436 General rights Unless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law. •Users may freely distribute the URL that is used to identify this publication. •Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research. •User may use extracts from the document in line with the concept of ‘fair dealing’ under the Copyright, Designs and Patents Act 1988 (?) •Users may not further distribute the material nor use it for the purposes of commercial gain. Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. -
Pterosaur Integumentary Structures with Complex Feather-Like Branching
ARTICLES https://doi.org/10.1038/s41559-018-0728-7 Pterosaur integumentary structures with complex feather-like branching Zixiao Yang1, Baoyu Jiang 1*, Maria E. McNamara 2, Stuart L. Kearns3, Michael Pittman 4, Thomas G. Kaye 5, Patrick J. Orr6, Xing Xu7 and Michael J. Benton 3* Pterosaurs were the first vertebrates to achieve true flapping flight, but in the absence of living representatives, many ques- tions concerning their biology and lifestyle remain unresolved. Pycnofibres—the integumentary coverings of pterosaurs—are particularly enigmatic: although many reconstructions depict fur-like coverings composed of pycnofibres, their affinities and function are not fully understood. Here, we report the preservation in two anurognathid pterosaur specimens of morpholog- ically diverse pycnofibres that show diagnostic features of feathers, including non-vaned grouped filaments and bilaterally branched filaments, hitherto considered unique to maniraptoran dinosaurs, and preserved melanosomes with diverse geom- etries. These findings could imply that feathers had deep evolutionary origins in ancestral archosaurs, or that these structures arose independently in pterosaurs. The presence of feather-like structures suggests that anurognathids, and potentially other pterosaurs, possessed a dense filamentous covering that probably functioned in thermoregulation, tactile sensing, signalling and aerodynamics. eathers are the most complex integumentary appendages in uropatagium in CAGS–Z070 (Fig. 1o,p). As reported elsewhere, vertebrates1. Most feathers in modern birds possess an axial they are parallel to subparallel and closely packed. Individual fibres Fshaft from which lateral barbs and barbules branch. Much is are 0.08–0.11 mm wide (around 5 fibres per mm) and at least 1.9 mm known about the anatomy, developmental biology and genomic long. -
Supplementary Information 1.0 Further Discussion of the Main
Supplementary Information 1.0 Further discussion of the main phylogenetic analyses Trees were produced and analysed in TNT 1.5-beta (Goloboff et al. 2008). In total 74 taxa were scored for 457 characters. Using the new technology search function, with ratchet and drift set to their defaults (10 iterations and 10 cycles respectively) and with 100 random additional sequences, our data produced 93 MPTs of length 1734. Bremer supports were also calculated using TNT 1.5- beta. The following characters were treated as ordered: 24, 35, 39, 60, 68, 71, 117, 145, 167, 169, 174, 180, 197, 199, 206, 214, 215, 222, 251, 269, 272, 286, 289, 303, 305, 307, 313, 322, 333, 334, 338, 353, 360, 376, 378, 387, 393, 442, 446 Our characters were drawn and modified from a number of previous studies and supplemented with an additional 63 novel characters. The main sources of our characters were Gauthier (1986), Sereno (1991), Langer and Benton (2006), Yates (2007), Butler et al. (2008), Ezcurra (2010), Nesbitt (2011) and Pol et al. (2011). Our investigations and analyses showed that a number of characters previously thought only to appear in theropods or sauropodomorphs (or both) can also found in a several ornithischian taxa and, conversely, a number of features traditionally associated with basal ornithischian taxa are also present in basal theropods and, in some instances, sauropodomorphs. Furthermore, many other characters that are more traditionally associated with only one or two dinosauriform groups were found to have a wider and/or more complex distribution than other studies have previously proposed, e.g. -
Coelophysis, the New Mexico State Fossil
summer 2017 COELOPHYSIS, THE NEW MEXICO STATE FOSSIL any of us are aware that the State of credited with jump-starting American He sent the sack, along with some MNew Mexico has a state gemstone science in the late 19th century. additional specimens from near Gallina, to (Turquoise), a state flower (Yucca), a state In February 1881, while living in Cope in Philadelphia. Cope named them bird (Roadrunner), and even a state ques- Abiquiu, Baldwin explored the Upper two species of a genus of small meat-eating tion (Red or Green?). But how many know Triassic deposits of what is called the dinosaur (theropod) previously named by that New Mexico also has an official state Chinle Formation a few miles north of Marsh; Coelurus longicollis and Coelurus fossil? And that this particular fossil is one town, in exposures along the Chama bauri, writing that Coelurus bauri was of the scientifically best-known and most River at a locality he knew as Arroyo Seco. “… about the size of a greyhound.” After important dinosaurs in the world? New Baldwin often collected in winter, when further consideration, Cope moved Mexico has an incredibly rich fossil record a steady source of water was available as both species to a different genus, first and many remarkable fossil organisms have snow. He found a small concentration Tanystrophaeus and then the new genus been recovered here. But one in particular, of delicate bones, which he picked up Coelophysis. The name Coelophysis is a relatively small, and at first glance, and placed in a sack. He included a note derived from two Greek roots meaning unassuming, animal was chosen by the written in flowing black script,“Contains “hollow form,” referring to the hollow New Mexico state legislature on March 17, Triassic or Jurassic bones all small and bones of the small animal. -
Untangling the Dinosaur Family Tree
BRIEF COMMUNICATIONS ARISING Untangling the dinosaur family tree ARISING FROM M. G. Baron, D. B. Norman & P. M. Barrett Nature 543, 501–506 (2017); doi:10.1038/nature21700 For over a century, the standard classification scheme has split dino- and Templeton tests show no significant differences between the two saurs into two fundamental groups1: ‘lizard-hipped’ saurischians hypotheses (see Supplementary Information). (including meat-eating theropods and long-necked sauropodomorphs) Character scoring changes explain our different results. They also and ‘bird-hipped’ ornithischians (including a variety of herbivorous alter the optimisation of the 21 putative ornithoscelidan synapomor- species)2–4. In a recent paper, Baron et al.5 challenged this paradigm phies proposed by Baron et al.5 (see Supplementary Information), with a new phylogenetic analysis that places theropods and ornithis- revealing that many have a complex distribution among early dino- chians together in a group called Ornithoscelida, to the exclusion of saurs. Some are not only present in ornithoscelidans, but can also be sauropodomorphs, and used their phylogeny to argue that dinosaurs found more broadly among early dinosaurs, including herrerasaurids may have originated in northern Pangaea, not in the southern part of and sauropodomorphs. Others are absent in many early diverging the supercontinent, as has more commonly been considered6,7. Here ornithoscelidans and probably evolved independently in later ornith- we evaluate and reanalyse the morphological dataset underpinning ischians and theropods. Several of the characters used by Baron et al.5 the proposal by Baron et al.5 and provide quantitative biogeographic have uninformative distributions, are poorly defined and/or completely analyses, which challenge the key results of their study by recovering a or partially duplicate one another (see Supplementary Information).