From the Late Cretaceous of Mon$Olia: Anatomy and Relationships
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CEPHALOPODS 688 Cephalopods
click for previous page CEPHALOPODS 688 Cephalopods Introduction and GeneralINTRODUCTION Remarks AND GENERAL REMARKS by M.C. Dunning, M.D. Norman, and A.L. Reid iving cephalopods include nautiluses, bobtail and bottle squids, pygmy cuttlefishes, cuttlefishes, Lsquids, and octopuses. While they may not be as diverse a group as other molluscs or as the bony fishes in terms of number of species (about 600 cephalopod species described worldwide), they are very abundant and some reach large sizes. Hence they are of considerable ecological and commercial fisheries importance globally and in the Western Central Pacific. Remarks on MajorREMARKS Groups of CommercialON MAJOR Importance GROUPS OF COMMERCIAL IMPORTANCE Nautiluses (Family Nautilidae) Nautiluses are the only living cephalopods with an external shell throughout their life cycle. This shell is divided into chambers by a large number of septae and provides buoyancy to the animal. The animal is housed in the newest chamber. A muscular hood on the dorsal side helps close the aperture when the animal is withdrawn into the shell. Nautiluses have primitive eyes filled with seawater and without lenses. They have arms that are whip-like tentacles arranged in a double crown surrounding the mouth. Although they have no suckers on these arms, mucus associated with them is adherent. Nautiluses are restricted to deeper continental shelf and slope waters of the Indo-West Pacific and are caught by artisanal fishers using baited traps set on the bottom. The flesh is used for food and the shell for the souvenir trade. Specimens are also caught for live export for use in home aquaria and for research purposes. -
8. Archosaur Phylogeny and the Relationships of the Crocodylia
8. Archosaur phylogeny and the relationships of the Crocodylia MICHAEL J. BENTON Department of Geology, The Queen's University of Belfast, Belfast, UK JAMES M. CLARK* Department of Anatomy, University of Chicago, Chicago, Illinois, USA Abstract The Archosauria include the living crocodilians and birds, as well as the fossil dinosaurs, pterosaurs, and basal 'thecodontians'. Cladograms of the basal archosaurs and of the crocodylomorphs are given in this paper. There are three primitive archosaur groups, the Proterosuchidae, the Erythrosuchidae, and the Proterochampsidae, which fall outside the crown-group (crocodilian line plus bird line), and these have been defined as plesions to a restricted Archosauria by Gauthier. The Early Triassic Euparkeria may also fall outside this crown-group, or it may lie on the bird line. The crown-group of archosaurs divides into the Ornithosuchia (the 'bird line': Orn- ithosuchidae, Lagosuchidae, Pterosauria, Dinosauria) and the Croco- dylotarsi nov. (the 'crocodilian line': Phytosauridae, Crocodylo- morpha, Stagonolepididae, Rauisuchidae, and Poposauridae). The latter three families may form a clade (Pseudosuchia s.str.), or the Poposauridae may pair off with Crocodylomorpha. The Crocodylomorpha includes all crocodilians, as well as crocodi- lian-like Triassic and Jurassic terrestrial forms. The Crocodyliformes include the traditional 'Protosuchia', 'Mesosuchia', and Eusuchia, and they are defined by a large number of synapomorphies, particularly of the braincase and occipital regions. The 'protosuchians' (mainly Early *Present address: Department of Zoology, Storer Hall, University of California, Davis, Cali- fornia, USA. The Phylogeny and Classification of the Tetrapods, Volume 1: Amphibians, Reptiles, Birds (ed. M.J. Benton), Systematics Association Special Volume 35A . pp. 295-338. Clarendon Press, Oxford, 1988. -
First Records and Descriptions of Early-Life Stages of Cephalopods from Rapa Nui (Easter Island) and the Nearby Apolo Seamount
First records and descriptions of early-life stages of cephalopods from Rapa Nui (Easter Island) and the nearby Apolo Seamount By Sergio A. Carrasco*, Erika Meerhoff, Beatriz Yannicelly, and Christian M. Ibáñez Abstract New records of early-life stages of cephalopods are presented based on planktonic collections carried out around Easter Island (Rapa Nui; 27°7′S; 109°21′W) and at the nearby Apolo Seamount (located at ∼7 nautical miles southwest from Easter Island) during March and September 2015 and March 2016. A total of thirteen individuals were collected, comprising four families (Octopodidae, Ommastrephidae, Chtenopterygidae, and Enoploteuthidae) and five potential genera/types (Octopus sp., Chtenopteryx sp., rhynchoteuthion paralarvae, and two undetermined Enoploteuthid paralarvae). Cephalopod mantle lengths (ML) ranged from 0.8 to 4.5 mm, with 65% of them (mainly Octopodidae) corresponding to newly hatched paralarvae of ~1 mm ML, and 35% to rhynchoteuthion and early stages of oceanic squids of around 1.5 - 4.5 mm ML. These results provide the first records on composition and presence of early stages of cephalopods around a remote Chilean Pacific Island, while also providing a morphological and molecular basis to validate the identity of Octopus rapanui (but not Callistoctopus, as currently recorded), Ommastrephes bartramii and Chtenopteryx sp. around Rapa Nui waters. Despite adult Octopodidae and Ommastrephidae have been previously recorded at these latitudes, the current findings provide evidence to suggest that the northwest side of Easter Island, and one of the nearby seamounts, may provide a suitable spawning ground for benthic and pelagic species of cephalopods inhabiting these areas. For Chtenopterygidae and Enoploteuthidae, this is the first record for the Rapa Nui ecoregion. -
Examples from Dinosaur and Elephant Limb Imaging Studies John R
3 The Anatomical Foundation for Multidisciplinary Studies of Animal Limb Function: Examples from Dinosaur and Elephant Limb Imaging Studies John R. Hutchinson1, Charlotte Miller1, Guido Fritsch2, and Thomas Hildebrandt2 3.1 Introduction all we have to work with, at first. Yet that does not mean that behavior cannot be addressed by indi- What makes so many animals, living and extinct, rect scientifific means. so popular and distinct is anatomy; it is what leaps Here we use two intertwined case studies from out at a viewer fi rst whether they observe a muse- our research on animal limb biomechanics, one on um’s mounted Tyrannosaurus skeleton or an ele- extinct dinosaurs and another on extant elephants, phant placidly browsing on the savannah. Anatomy to illustrate how anatomical methods and evi- alone can make an animal fascinating – so many dence are used to solve basic questions. The dino- animals are so physically unlike human observers, saur study is used to show how biomechanical yet what do these anatomical differences mean for computer modeling can reveal how extinct animal the lives of animals? limbs functioned (with a substantial margin of The behavior of animals can be equally or more error that can be addressed explicitly in the stunning- how fast could a Tyrannosaurus move models). The elephant study is used to show (Coombs 1978; Alexander 1989; Paul 1998; Farlow how classical anatomical observation and three- et al. 2000; Hutchinson and Garcia 2002; Hutchin- dimensional (3D) imaging have powerful synergy son 2004a,b), or how does an elephant manage to for characterising extant animal morphology, momentarily support itself on one leg while without biomechanical modeling, but also as a first ‘running’ quickly (Gambaryan 1974; Alexander step toward such modeling. -
Allen-Etal-Calcium-2009.Pdf
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy Comparative Biochemistry and Physiology, Part A 154 (2009) 437–450 Contents lists available at ScienceDirect Comparative Biochemistry and Physiology, Part A journal homepage: www.elsevier.com/locate/cbpa Calcium regulation in wild populations of a freshwater cartilaginous fish, the lake sturgeon Acipenser fulvescens Peter J. Allen a,b,⁎, Molly A.H. Webb c, Eli Cureton c, Ronald M. Bruch d, Cameron C. Barth a,b, Stephan J. Peake b, W. Gary Anderson a a Department of Biological Sciences, University of Manitoba, Winnipeg, Canada, MB R3T 2N2 b Canadian Rivers Institute, University of New Brunswick, Fredericton, Canada, NB E3B 5A3 c USFWS Bozeman Fish Technology Center, Bozeman, MT, 59715, USA d Wisconsin Department of Natural Resources, 625 East County Road Y, Suite 700, Oshkosh, WI 54901, USA article info abstract Article history: Lake sturgeon, Acipenser fulvescens, are one of a few species of cartilaginous fishes that complete their life Received 27 May 2009 cycle entirely in freshwater. -
The Morphology and Sculpture of Ossicles in the Cyclopteridae and Liparidae (Teleostei) of the Baltic Sea
Estonian Journal of Earth Sciences, 2010, 59, 4, 263–276 doi: 10.3176/earth.2010.4.03 The morphology and sculpture of ossicles in the Cyclopteridae and Liparidae (Teleostei) of the Baltic Sea Tiiu Märssa, Janek Leesb, Mark V. H. Wilsonc, Toomas Saatb and Heli Špilevb a Institute of Geology at Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia; [email protected] b Estonian Marine Institute, University of Tartu, Mäealuse Street 14, 12618 Tallinn, Estonia; [email protected], [email protected], [email protected] c Department of Biological Sciences and Laboratory for Vertebrate Paleontology, University of Alberta, Edmonton, Alberta T6G 2E9 Canada; [email protected] Received 31 August 2009, accepted 28 June 2010 Abstract. Small to very small bones (ossicles) in one species each of the families Cyclopteridae and Liparidae (Cottiformes) of the Baltic Sea are described and for the first time illustrated with SEM images. These ossicles, mostly of dermal origin, include dermal platelets, scutes, tubercles, prickles and sensory line segments. This work was undertaken to reveal characteristics of the morphology, sculpture and ultrasculpture of these small ossicles that could be useful as additional features in taxonomy and systematics, in a manner similar to their use in fossil material. The scutes and tubercles of the cyclopterid Cyclopterus lumpus Linnaeus are built of small denticles, each having its own cavity viscerally. The thumbtack prickles of the liparid Liparis liparis (Linnaeus) have a tiny spinule on a porous basal plate; the small size of the prickles seems to be related to their occurrence in the exceptionally thin skin, to an adaptation for minimizing weight and/or metabolic cost and possibly to their evolution from isolated ctenii no longer attached to the scale plates of ctenoid scales. -
The Integumental Appendages of the Turtle Shell: an Evo-Devo Perspective JACQUELINE E
COMMENTARY AND PERSPECTIVE The Integumental Appendages of the Turtle Shell: An Evo-Devo Perspective JACQUELINE E. MOUSTAKAS-VERHO1* 2 AND GENNADII O. CHEREPANOV 1Institute of Biotechnology, University of Helsinki, Helsinki, Finland 2Department of Vertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia ABSTRACT The turtle shell is composed of dorsal armor (carapace) and ventral armor (plastron) covered by a keratinized epithelium. There are two epithelial appendages of the turtle shell: scutes (large epidermal shields separated by furrows and forming a unique mosaic) and tubercles (numerous small epidermal bumps located on the carapaces of some species). In our perspective, we take a synthetic, comparative approach to consider the homology and evolution of these integumental appendages. Scutes have been more intensively studied, as they are autapomorphic for turtles and can be diagnostic taxonomically. Their pattern of tessellation is stable phylogenetically, but labile in the individual. We discuss the history of developmental investigations of these structures and hypotheses of evolutionary and anomalous variation. In our estimation, the scutes of the turtle shell are an evolutionary novelty, whereas the tubercles found on the shells of some turtles are homologous to reptilian scales. J. Exp. Zool. (Mol. Dev. Evol.) 324B:221–229, 2015. © 2015 Wiley Periodicals, Inc. J. Exp. Zool. (Mol. Dev. Evol.) How to cite this article: Moustakas-Verho JE, Cherepanov GO. 2015. The integumental 324B:221–229, appendages of the turtle shell: An evo-devo perspective. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 2015 221–229. EVOLUTIONARY ORIGIN AND DEVELOPMENT OF TURTLE Turtles can often be recognized by the pattern of scutes, or lack SCUTES thereof, on their shell. -
The Role of Collagen in the Dermal Armor of the Boxfish
j m a t e r r e s t e c h n o l . 2 0 2 0;9(xx):13825–13841 Available online at www.sciencedirect.com https://www.journals.elsevier.com/journal-of-materials-research-and-technology Original Article The role of collagen in the dermal armor of the boxfish a,∗ b c b Sean N. Garner , Steven E. Naleway , Maryam S. Hosseini , Claire Acevedo , d e a e c Bernd Gludovatz , Eric Schaible , Jae-Young Jung , Robert O. Ritchie , Pablo Zavattieri , f Joanna McKittrick a Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093–0411, USA b Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112, USA c Lyles School of Civil Engineering, Purdue University, West Lafayette, IN 47907, USA d School of Mechanical & Manufacturing Engineering, UNSW Sydney, NSW 2052, Australia e Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA f Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093–0411, USA a r t i c l e i n f o a b s t r a c t Article history: This research aims to further the understanding of the structure and mechanical properties Received 1 June 2020 of the dermal armor of the boxfish (Lactoria cornuta). Structural differences between colla- Accepted 24 September 2020 gen regions underlying the hexagonal scutes were observed with confocal microscopy and Available online 5 October 2020 microcomputed tomography (-CT). -CT revealed a tapering of the mineral plate from the center of the scute to the interface between scutes, suggesting the structure allows for more Keywords: flexibility at the interface. -
Carapacial Scute Anomalies of Star Tortoise (Geochelone Elegans) In
TAPROBANICA, ISSN 1800-427X. October, 2012. Vol. 04, No. 02: pp. 105-107, 1 pl. © Taprobanica Private Limited, 146, Kendalanda, Homagama, Sri Lanka. Carapacial scute anomalies of star tortoise arrangement and the carapace drawings are (Geochelone elegans) in Western India from the sources of Deraniyagala (1939). But the ‘Figure 5’ (on page 13) shows something The basic taxonomy and classification of reptile else, an illustration which is not a typical scale species and genera often use pholidotic drawing of the species. This figure of a tortoise characters. Despite that each species has a shows abnormal scales and scutes, especially standard pattern, there are always deviant vertebral, costal and marginal scutes, which are individuals in terms of scale number, shape, in higher numbers than the provided description size, or color. Turtles are excellent models for of the species by Schoepff (1795). the study of developmental instability because anomalies are easily detected in the form of Observations (see plate 1 for figures) malformations, additions, or reductions in the During the last eleven years (1990-2011), I number of scutes or scales (Velo-Antón et al., have come across many star tortoises in the 2011). The normal number of carapacial scutes wild (n=65) and in captivity (n=135), belonging in turtles is five vertebrals, four pairs of costals, to different ages and sizes (from hatchlings to a and 12 pairs of marginals, a pattern known as 55 year old, which was the largest one) (Vyas, “typical chelonian carapacial scutation” 2011). All specimens were bred under natural (Deraniyagala, 1939). Any deviation of conditions (although 5 of the 6 specimens with vertebral, costal, or marginal scute numbers or anomalies were later kept in captivity). -
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. -
CROCODYLIFORMES, MESOEUCROCODYLIA) from the EARLY CRETACEOUS of NORTH-EAST BRAZIL by DANIEL C
[Palaeontology, Vol. 52, Part 5, 2009, pp. 991–1007] A NEW NEOSUCHIAN CROCODYLOMORPH (CROCODYLIFORMES, MESOEUCROCODYLIA) FROM THE EARLY CRETACEOUS OF NORTH-EAST BRAZIL by DANIEL C. FORTIER and CESAR L. SCHULTZ Departamento de Paleontologia e Estratigrafia, UFRGS, Avenida Bento Gonc¸alves 9500, 91501-970 Porto Alegre, C.P. 15001 RS, Brazil; e-mails: [email protected]; [email protected] Typescript received 27 March 2008; accepted in revised form 3 November 2008 Abstract: A new neosuchian crocodylomorph, Susisuchus we recovered the family name Susisuchidae, but with a new jaguaribensis sp. nov., is described based on fragmentary but definition, being node-based group including the last com- diagnostic material. It was found in fluvial-braided sedi- mon ancestor of Susisuchus anatoceps and Susisuchus jagua- ments of the Lima Campos Basin, north-eastern Brazil, ribensis and all of its descendents. This new species 115 km from where Susisuchus anatoceps was found, in corroborates the idea that the origin of eusuchians was a rocks of the Crato Formation, Araripe Basin. S. jaguaribensis complex evolutionary event and that the fossil record is still and S. anatoceps share a squamosal–parietal contact in the very incomplete. posterior wall of the supratemporal fenestra. A phylogenetic analysis places the genus Susisuchus as the sister group to Key words: Crocodyliformes, Mesoeucrocodylia, Neosuchia, Eusuchia, confirming earlier studies. Because of its position, Susisuchus, new species, Early Cretaceous, north-east Brazil. B razilian crocodylomorphs form a very expressive Turonian–Maastrichtian of Bauru basin: Adamantinasu- record of Mesozoic vertebrates, with more than twenty chus navae (Nobre and Carvalho, 2006), Baurusuchus species described up to now. -
From the Late Cretaceous of Minas Gerais, Brazil: New Insights on Sphagesaurid Anatomy and Taxonomy
The first Caipirasuchus (Mesoeucrocodylia, Notosuchia) from the Late Cretaceous of Minas Gerais, Brazil: new insights on sphagesaurid anatomy and taxonomy Agustín G. Martinelli1,2,3, Thiago S. Marinho2,4, Fabiano V. Iori5 and Luiz Carlos B. Ribeiro2 1 Instituto de Geociencias, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil 2 Centro de Pesquisas Paleontológicas L. I. Price, Complexo Cultural e Científico Peirópolis, Pró-Reitoria de Extensão Universitária, Universidade Federal do Triangulo Mineiro, Uberaba, Minas Gerais, Brazil 3 CONICET-Sección Paleontologia de Vertebrados, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Argentina 4 Departamento de Ciências Biológicas, Universidade Federal do Triângulo Mineiro, Instituto de Ciências Exatas, Naturais e Educação, Uberaba, Minas Gerais, Brazil 5 Museu de Paleontologia “Prof. Antonio Celso de Arruda Campos”, Monte Alto, Sao Paulo, Brazil ABSTRACT Field work conducted by the staff of the Centro de Pesquisas Paleontológicas Llewellyn Ivor Price of the Universidade Federal do Triângulo Mineiro since 2009 at Campina Verde municipality (MG) have resulted in the discovery of a diverse vertebrate fauna from the Adamantina Formation (Bauru Basin). The baurusuchid Campinasuchus dinizi was described in 2011 from Fazenda Três Antas site and after that, preliminary descriptions of a partial crocodyliform egg, abelisaurid teeth, and fish remains have been done. Recently, the fossil sample has been considerably increased including the discovery