Crocodile Specialist Group Newsletter
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I What Is a Crocodilian?
I WHAT IS A CROCODILIAN? Crocodilians are the only living representatives of the Archosauria group (dinosaurs, pterosaurs, and thecodontians), which first appeared in the Mesozoic era. At present, crocodiliams are the most advanced of all reptiles because they have a four-chambered heart, diaphragm, and cerebral cortex. The extent morphology reflects their aquatic habits. Crocodilians are elongated and armored with a muscular, laterally shaped tail used in swimming. The snout is elongated, with the nostrils set at the end to allow breathing while most of the body remains submerged. Crocodilians have two pairs of short legs with five toes on the front and four tows on the hind feet; the toes on all feet are partially webbed. The success of this body design is evidenced by the relatively few changes that have occurred since crocodilians first appeared in the late Triassic period, about 200 million years ago. Crocodilians are divided into three subfamilies. Alligatorinae includes two species of alligators and five caiman. Crocodylinae is divided into thirteen species of crocodiles and on species of false gharial. Gavialinae contains one species of gharial. Another way to tell the three groups of crocodilians apart is to look at their teeth. II PHYSICAL CHARACTERISTICS A Locomotion Crocodilians spend time on land primarily to bask in the sun, to move from one body of water to another, to escape from disturbances, or to reproduce. They use three distinct styles of movement on land. A stately high walk is used when moving unhurried on land. When frightened, crocodilians plunge down an embankment in an inelegant belly crawl. -
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. -
Specialized Stem Cell Niche Enables Repetitive Renewal of Alligator Teeth
Specialized stem cell niche enables repetitive renewal PNAS PLUS of alligator teeth Ping Wua, Xiaoshan Wua,b, Ting-Xin Jianga, Ruth M. Elseyc, Bradley L. Templed, Stephen J. Diverse, Travis C. Glennd, Kuo Yuanf, Min-Huey Cheng,h, Randall B. Widelitza, and Cheng-Ming Chuonga,h,i,1 aDepartment of Pathology, University of Southern California, Los Angeles, CA 90033; bDepartment of Oral and Maxillofacial Surgery, Xiangya Hospital, Central South University, Hunan 410008, China; cLouisiana Department of Wildlife and Fisheries, Rockefeller Wildlife Refuge, Grand Chenier, LA 70643; dEnvironmental Health Science and eDepartment of Small Animal Medicine and Surgery, University of Georgia, Athens, GA 30602; fDepartment of Dentistry and iResearch Center for Wound Repair and Regeneration, National Cheng Kung University, Tainan City 70101, Taiwan; and gSchool of Dentistry and hResearch Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei 10617, Taiwan Edited by Edward M. De Robertis, Howard Hughes Medical Institute/University of California, Los Angeles, CA, and accepted by the Editorial Board March 28, 2013 (received for review July 31, 2012) Reptiles and fish have robust regenerative powers for tooth renewal. replaced from the dental lamina connected to the lingual side of However, extant mammals can either renew their teeth one time the deciduous tooth (15). Human teeth are only replaced one time; (diphyodont dentition) or not at all (monophyodont dentition). however, a remnant of the dental lamina still exists (16) and may Humans replace their milk teeth with permanent teeth and then become activated later in life to form odontogenic tumors (17). lose their ability for tooth renewal. -
Cardiovascular Function in Ectotherm Sauropsids
Cardiovascular Function in Ectotherm Sauropsids Dissertation der Fakultät für Biologie de Ludig‐Maiilias‐Uiesität Mühe Ulrike Campen München, September 2017 Cardiovascular Function in Ectotherm Sauropsids Diese Dissertation wurde angefertigt unter der Leitung von Prof. Dr. J. Matthias Starck/ Prof. Dr. Gerhard Haszprunar im Bereich von Biologie: Systematische Zoologie/ Zoologie a de Ludig‐Maiilias‐Uiesität Mühe Erstgutachter/in: Prof. Dr. Gerhard Haszprunar Zweitgutachter/in: Prof. Dr. Dirk Metzler Tag der Abgabe: 21. September 2017 Tag der mündlichen Prüfung: 28. Mai 2018 ERKLÄRUNG Ich versichere hiermit an Eides statt, dass meine Dissertation selbständig und ohne unerlaubte Hilfsmittel angefertigt worden ist. Die vorliegende Dissertation wurde weder ganz, noch teilweise bei einer anderen Prüfungskommission vorgelegt. Ich habe noch zu keinem früheren Zeitpunkt versucht, eine Dissertation einzureichen oder an einer Doktorprüfung teilzunehmen. München, den 09. Juni 2018 Ulrike Campen 2 Cardiovascular Function in Ectotherm Sauropsids Coduted ithi the faeok of the Gaduate Shool Life Siee Muih. Supported by a Graduiertenstipendium nach dem Bayerischen Eliteförderungsgesetz (BayEFG) des Bayerischen Staatsministeriums für Wissenschaft, Forschung und Kunst. 3 Cardiovascular Function in Ectotherm Sauropsids Previous publications of parts of this thesis Parts of this thesis have already been published in Campen R. and Starck J.M. 2012. Cardiovascular circuits and digestive function of intermittent-feeding sauropsids. Pp. 133-154. Chapter 09 in: -
The Herpetofauna of the Cubango, Cuito, and Lower Cuando River Catchments of South-Eastern Angola
Official journal website: Amphibian & Reptile Conservation amphibian-reptile-conservation.org 10(2) [Special Section]: 6–36 (e126). The herpetofauna of the Cubango, Cuito, and lower Cuando river catchments of south-eastern Angola 1,2,*Werner Conradie, 2Roger Bills, and 1,3William R. Branch 1Port Elizabeth Museum (Bayworld), P.O. Box 13147, Humewood 6013, SOUTH AFRICA 2South African Institute for Aquatic Bio- diversity, P/Bag 1015, Grahamstown 6140, SOUTH AFRICA 3Research Associate, Department of Zoology, P O Box 77000, Nelson Mandela Metropolitan University, Port Elizabeth 6031, SOUTH AFRICA Abstract.—Angola’s herpetofauna has been neglected for many years, but recent surveys have revealed unknown diversity and a consequent increase in the number of species recorded for the country. Most historical Angola surveys focused on the north-eastern and south-western parts of the country, with the south-east, now comprising the Kuando-Kubango Province, neglected. To address this gap a series of rapid biodiversity surveys of the upper Cubango-Okavango basin were conducted from 2012‒2015. This report presents the results of these surveys, together with a herpetological checklist of current and historical records for the Angolan drainage of the Cubango, Cuito, and Cuando Rivers. In summary 111 species are known from the region, comprising 38 snakes, 32 lizards, five chelonians, a single crocodile and 34 amphibians. The Cubango is the most western catchment and has the greatest herpetofaunal diversity (54 species). This is a reflection of both its easier access, and thus greatest number of historical records, and also the greater habitat and topographical diversity associated with the rocky headwaters. -
Nyika and Vwaza Reptiles & Amphibians Checklist
LIST OF REPTILES AND AMPHIBIANS OF NYIKA NATIONAL PARK AND VWAZA MARSH WILDLIFE RESERVE This checklist of all reptile and amphibian species recorded from the Nyika National Park and immediate surrounds (both in Malawi and Zambia) and from the Vwaza Marsh Wildlife Reserve was compiled by Dr Donald Broadley of the Natural History Museum of Zimbabwe in Bulawayo, Zimbabwe, in November 2013. It is arranged in zoological order by scientific name; common names are given in brackets. The notes indicate where are the records are from. Endemic species (that is species only known from this area) are indicated by an E before the scientific name. Further details of names and the sources of the records are available on request from the Nyika Vwaza Trust Secretariat. REPTILES TORTOISES & TERRAPINS Family Pelomedusidae Pelusios rhodesianus (Variable Hinged Terrapin) Vwaza LIZARDS Family Agamidae Acanthocercus branchi (Branch's Tree Agama) Nyika Agama kirkii kirkii (Kirk's Rock Agama) Vwaza Agama armata (Eastern Spiny Agama) Nyika Family Chamaeleonidae Rhampholeon nchisiensis (Nchisi Pygmy Chameleon) Nyika Chamaeleo dilepis (Common Flap-necked Chameleon) Nyika(Nchenachena), Vwaza Trioceros goetzei nyikae (Nyika Whistling Chameleon) Nyika(Nchenachena) Trioceros incornutus (Ukinga Hornless Chameleon) Nyika Family Gekkonidae Lygodactylus angularis (Angle-throated Dwarf Gecko) Nyika Lygodactylus capensis (Cape Dwarf Gecko) Nyika(Nchenachena), Vwaza Hemidactylus mabouia (Tropical House Gecko) Nyika Family Scincidae Trachylepis varia (Variable Skink) Nyika, -
Caiman Crocodilus Crocodilus) Revista De La Facultad De Ciencias Veterinarias, UCV, Vol
Revista de la Facultad de Ciencias Veterinarias, UCV ISSN: 0258-6576 [email protected] Universidad Central de Venezuela Venezuela Alvarado-Rico, Sonia; García, Gisela; Céspedes, Raquel; Casañas, Martha; Rodríguez, Albert Carecterización Morfológica e Histoquímica del Hígado de la Baba (Caiman crocodilus crocodilus) Revista de la Facultad de Ciencias Veterinarias, UCV, vol. 53, núm. 1, enero-junio, 2012, pp. 13-19 Universidad Central de Venezuela Maracay, Venezuela Disponible en: http://www.redalyc.org/articulo.oa?id=373139079002 Cómo citar el artículo Número completo Sistema de Información Científica Más información del artículo Red de Revistas Científicas de América Latina, el Caribe, España y Portugal Página de la revista en redalyc.org Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Rev. Fac. Cs. Vets. HISTOLOGÍA UCV. 53(1):13-19. 2012 CARACTERIZACIÓN MORFOLÓGICA E HISTOQUÍMICA DEL HÍGADO DE LA BABA (Caiman crocodilus crocodilus) Morphological and Histochemical Characterization of the Liver of the Spectacled Cayman (Caiman crocodilus crocodilus) Sonia Alvarado-Rico*,1, Gisela García*, Raquel Céspedes**, Martha Casañas*** y Albert Rodríguez**** *Cátedra de Histología y **Cátedra de Anatomía Facultad de Ciencias Veterinarias. ***Postgrado de la Facultad de Ciencias Veterinarias. ****Pregrado de la Facultad de Ciencias Veterinarias. Universidad Central de Venezuela. Apartado 4563, Maracay, 2101A, estado Aragua, Venezuela Correo-E:[email protected] Recibido: 28/11/11 - Aprobado: 13/07/12 RESUMEN ABSTraCT La morfología, organización y los componentes The morphology, organization and intracytoplasmic intracitoplasmáticos del hepatocito de la baba components of the liver of the spectacled cayman (Caiman crocodilus crocodilus) son aspectos que se (Caiman crocodilus crocodilus) are aspects that have han estudiado parcialmente hasta el momento. -
Fauna of Australia 2A
FAUNA of AUSTRALIA 39. GENERAL DESCRIPTION AND DEFINITION OF THE ORDER CROCODYLIA Harold G. Cogger 39. GENERAL DESCRIPTION AND DEFINITION OF THE ORDER CROCODYLIA Pl. 9.1. Crocodylus porosus (Crocodylidae): the salt water crocodile shows pronounced sexual dimorphism, as seen in this male (left) and female resting on the shore; this species occurs from the Kimberleys to the central east coast of Australia; see also Pls 9.2 & 9.3. [G. Grigg] Pl. 9.2. Crocodylus porosus (Crocodylidae): when feeding in the water, this species lifts the tail to counter balance the head; see also Pls 9.1 & 9.3. [G. Grigg] 2 39. GENERAL DESCRIPTION AND DEFINITION OF THE ORDER CROCODYLIA Pl. 9.3. Crocodylus porosus (Crocodylidae): the snout is broad and rounded, the teeth (well-worn in this old animal) are set in an irregular row, and a palatal flap closes the entrance to the throat; see also Pls 9.1 & 9.2. [G. Grigg] 3 39. GENERAL DESCRIPTION AND DEFINITION OF THE ORDER CROCODYLIA Pl. 9.4. Crocodylus johnstoni (Crocodylidae): the freshwater crocodile is found in rivers and billabongs from the Kimberleys to eastern Cape York; see also Pls 9.5–9.7. [G.J.W. Webb] Pl. 9.5. Crocodylus johnstoni (Crocodylidae): the freshwater crocodile inceases its apparent size by inflating its body when in a threat display; see also Pls 9.4, 9.6 & 9.7. [G.J.W. Webb] 4 39. GENERAL DESCRIPTION AND DEFINITION OF THE ORDER CROCODYLIA Pl. 9.6. Crocodylus johnstoni (Crocodylidae): the freshwater crocodile has a long, slender snout, with a regular row of nearly equal sized teeth; the eyes and slit-like ears, set high on the head, can be closed during diving; see also Pls 9.4, 9.5 & 9.7. -
Longitudinal Studies on Tooth Replacement in the Leopard
LONGITUDINAL STUDIES ON TOOTH REPLACEMENT IN THE LEOPARD GECKO by Andrew Carlton Edward Wong BMSc, DDS, The University of Alberta, 2011 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Craniofacial Science) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) July 2015 © Andrew Carlton Edward Wong, 2015 Abstract The leopard gecko is an emerging reptilian model for the molecular basis of indefinite tooth replacement. Here we characterize the tooth replacement frequency and pattern of tooth loss in the normal adult gecko. We chose to perturb the system of tooth replacement by activating the Wingless signaling pathway (Wnt). Misregulation of Wnt leads to supernumerary teeth in mice and humans. We hypothesized by activating Wnt signaling with LiCl, tooth replacement frequency would increase. To measure the rate of tooth loss and replacement, weekly dental wax bites of 3 leopard geckos were taken over a 35-week period. The present/absent tooth positions were recorded. During the experimental period, the palate was injected bilaterally with NaCl (control) and then with LiCl. The geckos were to be biological replicates. Symmetry was analyzed with parametric tests (repeated measures ANOVA, Tukey’s post-hoc), while time for emergence and total absent teeth per week were analyzed with non- parametric tests (Kruskal-Wallis ANOVA, Mann-Whitney U post-hoc and Bonferroni Correction). The average replacement frequency was 6-7 weeks and posterior-to-anterior waves of replacement were formed. Right to left symmetry between individual tooth positions was high (>80%) when all teeth were included but dropped to 50% when only absent teeth were included. -
A Second Record of Scolecomorphus Kirkii Boulenger, 1883 (Gymnophiona: Scolecomorphidae) for Mozambique
Herpetology Notes, volume 8: 59-62 (2015) (published online on 10 March 2015) A second record of Scolecomorphus kirkii Boulenger, 1883 (Gymnophiona: Scolecomorphidae) for Mozambique Harith Omar Morgadinho Farooq1 and Werner Conradie2,* The herpetofauna of northern Mozambique (Nampula, Branch et al., 2014), crustaceans (Daniels and Bayliss, Niassa, and Cabo Degabo Provinces) remains one of the 2012) and bats (Taylor et al., 2012). While Portik et al. most poorly-known in Africa. This is a consequence of (2013a) summarised the herpetofauna of the inselbergs the physical inaccessibility of the region as well as the of northern Mozambique, they overlooked the valuable protracted civil war, which affected the study of many amphibian collections in the technical report by Branch areas. Mozambique is expected to have a large diversity (2004) from Niassa Game Reserve and the herpetofaunal of herpetofauna due to the variety of different habitat collections from Mount Mabu (Timberlake et al., 2012), types available and the large size (area) of the country. which led to underestimation and incorrect accounts of The lack of scientific studies of northern Mozambique the herpetofaunal diversity of the montane inselbergs of has led to widely disparate and inaccurate summaries northern Mozambique. of the herpetofaunal diversity of the country. While In November 2011 and May 2014 a team of scientists, there are no formal publications that explicitly deal mountain climbers, and conservationists had the with this topic, reputable internet sources indicate that opportunity to survey Mount Namuli, which resulted 221 reptile (Uetz, 2015) and 69 amphibian species in some additions to the herpetofauna of that area. (AmphibiaWeb, 2015) are expected to occur in the whole of Mozambique. -
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. -
New Insights Into the Biology of Theropod Dinosaurs
AN ABSTRACT OF THE DISSERTATION OF Devon E. Quick for the degree of Doctor of Philosophy in Zoology presented on December 1, 2008. Title: New Insights into the Biology of Theropod Dinosaurs. Abstract approved: __________________________________________________________ John A. Ruben There is little, if any, direct fossil evidence of the cardiovascular, respiratory, reproductive or digestive biology of dinosaurs. However, a variety of data can be used to draw reasonable inferences about the physiology of the carnivorous theropod dinosaurs (Archosauria: Theropoda). Extant archosaurs, birds and crocodilians, possess regionally differentiated, vascularized and avascular lungs, although the crocodilian lung is less specialized than the avian lung air-sac system. Essential components of avian lungs include the voluminous, thin-walled abdominal air-sacs which are ventilated by an expansive sternum and specialized ribs. Inhalatory, paradoxical collapse of these air-sacs in birds is prevented by the synsacrum, pubes and femoral-thigh complex. The present work examines the theropod abdomen and reveals that it lacked sufficient space to have housed similarly enlarged abdominal air-sacs as well as the skeleto-muscular modifications requisite to have ventilated them. There is little evidence to indicate that theropod dinosaurs possessed a specialized bird-like, air-sac lung and, by extension, that theropod cardiovascular function was any more sophisticated than that of crocodilians. Conventional wisdom holds that theropod visceral anatomy was similar to that in birds. However, exceptional soft tissue preservation in Scipionyx samnitcus (Theropoda) offers rare evidence of in situ theropod visceral anatomy. Using computed tomography, close comparison of Scipionyx with gastrointestinal morphology in crocodilians, birds and lizards indicates that theropod visceral structure and “geography” was strikingly similar only to that in Alligator.