From the Late Cretaceous of Patagonia
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Final Summary Report of the Research Project (ERB, 624732)
Final Summary Report of the Research Project (ERB, 624732): Introduction: Birds represent one of the most remarkable radiations in the history of life. The origin of flight and the diversification of birds have become classic ‘textbook’ examples for discussions about evolutionary models, biomechanics, the history of life, and phylogenetics. Much attention has focused on the discovery and description of new fossils, both derived theropods and basal birds: in particular, sediments of the Jehol Group in Liaoning and other provinces in China have doubled the number of Mesozoic bird taxa and have considerably expanded our knowledge of derived theropod dinosaurs. All this wealth of fossil data and new phylogenetic studies have established the relationships of basal bird groups, as well as their phylogenetic nesting among theropod dinosaurs, with dromaeosaurid and troodontid theropods as their closest sister groups. The mode and tempo of avian evolution have received much attention in recent years, thanks to the assembly of more complete datasets, the ongoing flow of new specimens and taxa, and the development of new techniques of macroevolutionary analysis. Recent studies revealed an avian radiation characterized by the gradual acquisition of apomorphies followed by accelerated (yet clade heterogeneous) rates of evolution. However, in the context of Coelurosauria (a diverse clade including T. rex and its kin, the ostrich-mimic ornithomimosaurs, and the sickle-clawed dromaeosaurids, among others), previous analyses have considered the skeleton as a whole, apart from studies focusing on single continuous traits. Here, I document the evolutionary dynamics of each anatomical region of the coelurosaurian skeleton. I aim at disentangling the relative role of each body part in the evolutionary dynamics of Coelurosauria. -
A New Caenagnathid Dinosaur from the Upper Cretaceous Wangshi
www.nature.com/scientificreports OPEN A new caenagnathid dinosaur from the Upper Cretaceous Wangshi Group of Shandong, China, with Received: 12 October 2017 Accepted: 7 March 2018 comments on size variation among Published: xx xx xxxx oviraptorosaurs Yilun Yu1, Kebai Wang2, Shuqing Chen2, Corwin Sullivan3,4, Shuo Wang 5,6, Peiye Wang2 & Xing Xu7 The bone-beds of the Upper Cretaceous Wangshi Group in Zhucheng, Shandong, China are rich in fossil remains of the gigantic hadrosaurid Shantungosaurus. Here we report a new oviraptorosaur, Anomalipes zhaoi gen. et sp. nov., based on a recently collected specimen comprising a partial left hindlimb from the Kugou Locality in Zhucheng. This specimen’s systematic position was assessed by three numerical cladistic analyses based on recently published theropod phylogenetic datasets, with the inclusion of several new characters. Anomalipes zhaoi difers from other known caenagnathids in having a unique combination of features: femoral head anteroposteriorly narrow and with signifcant posterior orientation; accessory trochanter low and confuent with lesser trochanter; lateral ridge present on femoral lateral surface; weak fourth trochanter present; metatarsal III with triangular proximal articular surface, prominent anterior fange near proximal end, highly asymmetrical hemicondyles, and longitudinal groove on distal articular surface; and ungual of pedal digit II with lateral collateral groove deeper and more dorsally located than medial groove. The holotype of Anomalipes zhaoi is smaller than is typical for Caenagnathidae but larger than is typical for the other major oviraptorosaurian subclade, Oviraptoridae. Size comparisons among oviraptorisaurians show that the Caenagnathidae vary much more widely in size than the Oviraptoridae. Oviraptorosauria is a clade of maniraptoran theropod dinosaurs characterized by a short, high skull, long neck and short tail. -
Upper Cretaceous), Brazil
Rev. Mus. Argentino Cienc. Nat., n.s. 7(1): 31-36, 2005 Buenos Aires, ISSN 1514-5158 Maniraptoran theropod ungual from the Marília Formation (Upper Cretaceous), Brazil Fernando E. NOVAS1, Luiz Carlos BORGES RIBEIRO2,3 & Ismar de SOUZA CARVALHO4 1CONICET - Museo Argentino de Ciencias Naturales «Bernardino Rivadavia», Av. Angel Gallardo 470, Buenos Aires (1405), Argentina, E-mail: [email protected]. 2Fundação Municipal de Ensino Superior de Uberaba- FUMESU/Centro de Pesquisas Paleontológicas L. I. Price. Av. Randolfo Borges Jr., n° 1.250. Universidade, 38.066-005, Uberaba- MG, Brazil, E-mail: [email protected]. 3Universidade de Uberaba-UNIUBE/Instituto de Formação de Educadores-Departamento de Biologia, Av. Nenê Sabino, n° 1.801. Universitário, Uberaba-MG, 38.055-500, Brazil, E-mail: [email protected]. 4Universidade Federal do Rio de Janeiro, Departamento de Geologia, CCMN/IGEO. 21.949-900 Cidade Universitária-Ilha do Fundão, Rio de Janeiro-RJ, Brazil, E-mail: [email protected] Abstract: A new theropod record from the Marília Formation (Late Cretaceous, Minas Gerais, Brazil) is here described. It consists of an isolated manual ungual which exhibits derived maniraptoran features (e.g., presence of proximodorsal lip). The ungual distinguishes by a set of unique features (e.g., dorsoventrally low and proximodistally elongate profile in side view; block-like flexor tuberosity; proximal articular surface more dorsally oriented than in other theropods; cutting «keel» located distally on ventral surface) suggesting that the animal that produced it was a member of an unknown group of derived maniraptoran theropods, other than alvarezsaurids, deinonychosaurians and oviraptorosaurians already recorded in South America. -
The Oldest Record of Alvarezsauridae (Dinosauria: Theropoda) in the Northern Hemisphere
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Kazan Federal University Digital Repository PLoS ONE, 2017, vol.12, N10 The oldest record of Alvarezsauridae (Dinosauria: Theropoda) in the Northern Hemisphere Averianov A., Sues H. Kazan Federal University, 420008, Kremlevskaya 18, Kazan, Russia Abstract © 2017, Public Library of Science. All rights reserved. This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. Procoelous caudal vertebrae, a carpometacarpus with a hypertrophied metacarpal II, and robust proximal and ungual phalanges of manual digit II of a small theropod dinosaur from the Upper Cretaceous (Turonian) Bissekty Formation at Dzharakuduk, Uzbekistan, show unequivocal synapomorphies of the clade Alvarezsauridae and thus are referred to it. The caudal vertebrae have a unique longitudinal canal within the neural arch. The carpometacarpus, with metacarpal III occupying about one third of the width of the carpometacarpus, shows the most plesiomorphic stage of the evolution of the forelimb among known alvarezsaurids. The proximal phalanx of manual digit II differs from the corresponding bone in Parvicursorinae in having a less asymmetrical proximal articular surface without a dorsal process and short ventral ridges. The ungual phalanx of manual digit II has laterally open ventral foramina. The Bissekty alvarezsaurid possibly represents a basal parvicursorine and is the stratigraphically oldest known alvarezsaurid in Asia known to date. http://dx.doi.org/10.1371/journal.pone.0186254 References [1] Chiappe LM, Norell MA, Clark JM. -
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. -
Smaller Than You Think Bird-Brained? Need for Speed
An Introduction The clade Alvarezsauria is a group of small-bodied Ancient Aardvarks: [10] maniraptoran dinosaurs. The first known alvarezsaurid, Alvarezsaurus calvoi, was discovered in partial remains in the late 20th century, and named by Jose F. Bonaparte. A. calvoi was uncovered in Argentina, but today alvarezsaurs are known to have ranged across the Americas, Asia, and Meet the Alvarezsaurs Europe.[10] It is currently estimated that members of this Eggs and Bones clade existed between the Late Jurassic and the Cretaceous. This feather covered bird-like dinosaur is known for its insect based diet and especially its unique hooked The recently discovered Bonapartenykus forelimbs. These highly derived and powerful arms evolved ultimus represents a new genus of of throughout the clade Alvarezsauridae, giving these Alvarezsaurs. A 70 million year old pocket [12] Stunted But Strong dinosaurs a predatory advantage. of fossilized bones and two eggs of this Bird-Brained? species have been discovered in Argentina. This is the first time Alvarezsaurs have strangely powerful Using a cast of a skull from the species Alvarezsaurus bones and egg remains forearms, with one large thumb claw and the Ceratonykus oculatus, researchers have been found in close proximity. other two digits highly reduced. They are reconstructed an alvarezsaurian brain. Prehistoric Delicacies Though evidence of brooding behavior radically transformed from the typical Their analysis revealed that this has been found for other theropod theropod forelimb, which is longer, with three dinosaur had acute hearing and dinosaurs, no conclusion can yet be [10] functional digits and grasping ability. Given excellent eyesight, with intelligence drawn for Alvareszsaurs as no indication their highly specialized nature, it has been comparable to living birds. -
Lyons SCIENCE 2021 the Influence of Juvenile Dinosaurs SUPPL.Pdf
science.sciencemag.org/content/371/6532/941/suppl/DC1 Supplementary Materials for The influence of juvenile dinosaurs on community structure and diversity Katlin Schroeder*, S. Kathleen Lyons, Felisa A. Smith *Corresponding author. Email: [email protected] Published 26 February 2021, Science 371, 941 (2021) DOI: 10.1126/science.abd9220 This PDF file includes: Materials and Methods Supplementary Text Figs. S1 and S2 Tables S1 to S7 References Other Supplementary Material for this manuscript includes the following: (available at science.sciencemag.org/content/371/6532/941/suppl/DC1) MDAR Reproducibility Checklist (PDF) Materials and Methods Data Dinosaur assemblages were identified by downloading all vertebrate occurrences known to species or genus level between 200Ma and 65MA from the Paleobiology Database (PaleoDB 30 https://paleobiodb.org/#/ download 6 August, 2018). Using associated depositional environment and taxonomic information, the vertebrate database was limited to only terrestrial organisms, excluding amphibians, pseudosuchians, champsosaurs and ichnotaxa. Taxa present in formations were confirmed against the most recent available literature, as of November, 2020. Synonymous taxa or otherwise duplicated taxa were removed. Taxa that could not be identified to genus level 35 were included as “Taxon X”. GPS locality data for all formations between 200MA and 65MA was downloaded from PaleoDB to create a minimally convex polygon for each possible formation. Any attempt to recreate local assemblages must include all potentially interacting species, while excluding those that would have been separated by either space or time. We argue it is 40 acceptable to substitute formation for home range in the case of non-avian dinosaurs, as range increases with body size. -
Full Text (1005.6
Osteology of the Late Cretaceous alvarezsauroid Linhenykus monodactylus from China and comments on alvarezsauroid biogeography XING XU, PAUL UPCHURCH, QINGYU MA, MICHAEL PITTMAN, JONAH CHOINIERE, CORWIN SULLIVAN, DAVID W.E. HONE, QINGWEI TAN, LIN TAN, DONG XIAO, and FENGLU HAN Xu, X., Upchurch, P., Ma, Q., Pittman, M., Choiniere, J., Sullivan, C., Hone, D.W.E., Tan, Q., Tan, L., Xiao, D., and Han, F. 2013. Osteology of the Late Cretaceous alvarezsauroid Linhenykus monodactylus from China and comments on alvarez− sauroid biogeography. Acta Palaeontologica Polonica 58 (1): 25–46. The alvarezsauroid theropod Linhenykus monodactylus from the Upper Cretaceous of Inner Mongolia, China is the first known monodactyl non−avian dinosaur, providing important information on the complex patterns of manual evolution seen in alvarezsauroids. Here we provide a detailed description of the osteology of this taxon. Linhenykus shows a number of fea− tures that are transitional between parvicursorine and non−parvicursorine alvarezsauroids, but detailed comparisons also re− veal that some characters had a more complex distribution. We also use event−based tree−fitting to perform a quantitative analysis of alvarezsauroid biogeography incorporating several recently discovered taxa. The results suggest that there is no statistical support for previous biogeographic hypotheses that favour pure vicariance or pure dispersal scenarios as explana− tions for the distributions of alvarezsauroids across South America, North America and Asia. Instead, statistically significant biogeographic reconstructions suggest a dominant role for sympatric (or “within area”) events, combined with a mix of vicariance, dispersal and regional extinction. At present the alvarezsauroid data set is too small to completely resolve the biogeographic history of this group: future studies will need to create larger data sets that encompass additional clades. -
A Fast-Growing Basal Troodontid (Dinosauria: Theropoda) from The
www.nature.com/scientificreports OPEN A fast‑growing basal troodontid (Dinosauria: Theropoda) from the latest Cretaceous of Europe Albert G. Sellés1,2*, Bernat Vila1,2, Stephen L. Brusatte3, Philip J. Currie4 & Àngel Galobart1,2 A characteristic fauna of dinosaurs and other vertebrates inhabited the end‑Cretaceous European archipelago, some of which were dwarves or had other unusual features likely related to their insular habitats. Little is known, however, about the contemporary theropod dinosaurs, as they are represented mostly by teeth or other fragmentary fossils. A new isolated theropod metatarsal II, from the latest Maastrichtian of Spain (within 200,000 years of the mass extinction) may represent a jinfengopterygine troodontid, the frst reported from Europe. Comparisons with other theropods and phylogenetic analyses reveal an autapomorphic foramen that distinguishes it from all other troodontids, supporting its identifcation as a new genus and species, Tamarro insperatus. Bone histology shows that it was an actively growing subadult when it died but may have had a growth pattern in which it grew rapidly in early ontogeny and attained a subadult size quickly. We hypothesize that it could have migrated from Asia to reach the Ibero‑Armorican island no later than Cenomanian or during the Maastrichtian dispersal events. During the latest Cretaceous (ca. 77–66 million years ago) in the run-up to the end-Cretaceous mass extinc- tion, Europe was a series of islands populated by diverse and distinctive communities of dinosaurs and other vertebrates. Many of these animals exhibited peculiar features that may have been generated by lack of space and resources in their insular habitats. -
A New Tiny Dromaeosaurid Dinosaur from the Lower Cretaceous Jehol
第55卷 第2期 古 脊 椎 动 物 学 报 pp. 129-144 - 2017年4月 VERTEBRATA PALASIATICA figs. 1 4 A new tiny dromaeosaurid dinosaur from the Lower Cretaceous Jehol Group of western Liaoning and niche differentiation among the Jehol dromaeosaurids XU Xing1* QIN Zi-Chuan1,2 (1 Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Beijing 100044 * Corresponding author: [email protected]) (2 University of Chinese Academy of Sciences Beijing 100049) Abstract The Early Cretaceous Jehol dromaeosaurids are taxonomically and morphologically diverse, and one of them, Microraptor zhaoianus, has been suggested to be among the smallest known non-avialan theropods. However, this idea is based on specimens of relatively early ontogenetic stages, and the lower limit of the mature body mass of Jehol dromaeosaurids thus remains unknown. Here we describe a new dromaeosaurid, Zhongjianosaurus yangi gen. et sp. nov., based on a specimen from the Lower Cretaceous Yixian Formation (the middle section of the Jehol Group) from Sihedang, Lingyuan County, Liaoning in Northeast China. While this new taxon is referable to the Microraptorinae, it differs from other microraptorine dromaeosaurids in numerous features, most notably the fusion of proportionally long uncinate processes to dorsal ribs, a humerus with a strongly medially offset proximal end and a large fenestra within the deltopectoral crest, an ulna slightly longer than the humerus, and an arctometatarsalian pes. Most significantly, the estimated 0.31 kg mass of the Z. yangi holotype of an adult individual confirms that some Jehol dromaeosaurids are among the smallest known non-avialan theropods. -
The Dinosaur Field Guide Supplement
The Dinosaur Field Guide Supplement September 2010 – December 2014 By, Zachary Perry (ZoPteryx) Page 1 Disclaimer: This supplement is intended to be a companion for Gregory S. Paul’s impressive work The Princeton Field Guide to Dinosaurs, and as such, exhibits some similarities in format, text, and taxonomy. This was done solely for reasons of aesthetics and consistency between his book and this supplement. The text and art are not necessarily reflections of the ideals and/or theories of Gregory S. Paul. The author of this supplement was limited to using information that was freely available from public sources, and so more information may be known about a given species then is written or illustrated here. Should this information become freely available, it will be included in future supplements. For genera that have been split from preexisting genera, or when new information about a genus has been discovered, only minimal text is included along with the page number of the corresponding entry in The Princeton Field Guide to Dinosaurs. Genera described solely from inadequate remains (teeth, claws, bone fragments, etc.) are not included, unless the remains are highly distinct and cannot clearly be placed into any other known genera; this includes some genera that were not included in Gregory S. Paul’s work, despite being discovered prior to its publication. All artists are given full credit for their work in the form of their last name, or lacking this, their username, below their work. Modifications have been made to some skeletal restorations for aesthetic reasons, but none affecting the skeleton itself. -
Redalyc.Unenlagiinae Revisited: Dromaeosaurid Theropods From
Anais da Academia Brasileira de Ciências ISSN: 0001-3765 [email protected] Academia Brasileira de Ciências Brasil GIANECHINI, FEDERICO A.; APESTEGUÍA, SEBASTIÁN Unenlagiinae revisited: dromaeosaurid theropods from South America Anais da Academia Brasileira de Ciências, vol. 83, núm. 1, marzo, 2011, pp. 163-195 Academia Brasileira de Ciências Rio de Janeiro, Brasil Available in: http://www.redalyc.org/articulo.oa?id=32717681008 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative “main” — 2011/2/10 — 14:11 — page 163 — #1 Anais da Academia Brasileira de Ciências (2011) 83(1): 163-195 (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 www.scielo.br/aabc Unenlagiinae revisited: dromaeosaurid theropods from South America FEDERICO A. GIANECHINI and SEBASTIÁN APESTEGUÍA CONICET – Área de Paleontología, Fundación de Historia Natural ‘Félix de Azara’ Departamento de Ciencias Naturales y Antropología CEBBAD, Universidad Maimónides, Hidalgo 775 (1405BDB), Ciudad Autónoma de Buenos Aires, Argentina Manuscript received on October 30, 2009; accepted for publication on June 21, 2010 ABSTRACT Over the past two decades, the record of South American unenlagiine dromaeosaurids was substantially increased both in quantity as well as in quality of specimens. Here is presented a summary review of the South American record for these theropods. Unenlagia comahuensis, Unenlagia paynemili, and Neuquenraptor argentinus come from the Portezuelo Formation, the former genus being the most complete and with putative avian features.