DOCSLIB.ORG

Reptiles A. Cladistics 1. Many Groups of Organisms

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Reptiles A. Cladistics 1. Many Groups of Organisms Reptiles A. Cladistics 1. Many groups of organisms are “polyphyletic” a. This means that the group combines 2 or more lineages - example=fish 2. Cladistics follows only pure lineages going back in time - example Osteichthys B. Reptile Classifiecation - looks like a polyphyletic group 1. Dry skin - no loss of water through skin like amphibians 2. Aminotic egg - an egg that can survive on dry land - in contrast with the amphibian egg C. Mammals and Birds are derived from different lineages of reptiles (We will see below) D. Stem Reptiles 1. Different lineages based on the temporal region of their skulls - number of holes (or bars) a. These holes are necessary to accommodate large jaw muscles b. Anapsid Skull - no holes in temporal - jaws can move fast, but with little force 1. Muscles that move the jaw are small 2. There is no good paleotological evidence for the transition between amphibians and reptiles - no fossil intermediates a. Fossil amphibians have lots of dermal bones in skull b. Amphibians have no temporal openings in skull 1. (Aside) both fossil amphibians and primitive reptiles have a parietal “eye” that senses light and dark (“third” eye in middle of head) c. Reptile skull is higher than amphibian to accomodate larger jaw muscles d. Of the modern reptiles only turtles are anapsids 2. Diapsid Skull - has holes in the temporal region a. Diapsid reptiles gave rise to lizards and snakes - they have a diapsid skull 1. Also Tuatara, crocodiles, dinosaurs and pterydactyls Reptiles b. One group of diapsids also had a pre-orbital hole in the skull in front of eye - this hole is still preserved in the birds - this anatomy suggests strongly that the birds are derived from the diapsid reptiles 3. Diapsid lineage a. On the way to the dinosaurs b. Occipital condyl - where the skull attaches to the spinal column 1. Single in all reptiles including synapsids 2. 2 in mammals c. Modern reptiles 1. Snakes a. Highly modified jaw - really movable b. Allows snake to eat large prey 3. Synapsid Skull a. Only one hole in temporal region of head b. No synapsid reptiles survive today, all are fossils - mammals have modified the synapsid skull 1. Strong evidence that the mammals are derived from the synapsid reptiles c. Comparison with humans - Temporal opening still in same location as in synapsid reptiles 1. Still have a boney arch through which the temporalis muscle passes a. You can feel the boney arch, it is your cheek bone b. If you touch your temporal region on both sides of your head and clench your jaws you can feel the temporalis muscle tense up - that is right at the location of the temporal opening in the skull Reptiles d. Comparsions between humans and synapsids are tough because the synapsid reptiles had long muzzles like modern dogs 1. Humans have a face that is pushed in without a muzzle E. Amniote Egg 1. Amphibian egg is buried in jelly - absolutely needs to be in water 2. Poses a problem for a land-dwelling organism - “holds them back” 3. Fully adapted land-dweller needs an egg that will not dry out, will have enough food to carry the embryo to term, needs to be porous enough to let in air to breath a. Big engineering problem - solved by reptiles, birds and mammals b. Most of the egg is yolk (the food for the embryo) c. The embryo develops as a little disc on the surface of an enormous yolk d. Cleavage division on surface of yolk e. Blastopore on one side of this embryonic disk f. As it develops - the embryo grows around and envelops the enormous wad of yolk g. Amniotic folds grow over the embryo and form a water-filled amniotic sac 1. Substitute for the water in which the amphbian ancestor laid its egg 2. The amniotic sac is still present in mammals a. When a pregnant woman’s “water breaks”, the amniotic sac is breaking just before the baby is born - it releases the water in which the fetus developed h. Alantoic sac 1. Outside of amnionic sac - it is the location of gas exchange 1. O2 in CO2 out i. These membranes solve the problem of dessication j. Egg shell a. Placed around the egg before it is laid b. Needs to let gases through but not water F. Modern Reptile Types 1. Turtles Reptiles a. Drived directly from anapsids b. Ribs are incorporated into shell - they don’t move separately like they do in all other vertebrates 1. Different from all other tetrapods 2. Scapula is under shell and so are limbs - ribs are outside limbs! 1. Shell seems to grow over the scapula and limbs 2. Lizards a. High diversity b. Snake-like tongue in the Varanid (monitor) lizards 3. Snakes a. A few primitive snakes have limb remnants - male pythons have claws! 1. No front legs at all in snakes 4. Dinosaurs a. Brachiosaurs and Tyrannosaurs b. Pteradactyls 1. Membrane flight - no feathers 2. Related to dinosaur line 3. Many got pretty large - up to 25 ft 4. Tremendously modified head .
Load more

Recommended publications
  • Distributions of Extinction Times from Fossil Ages and Tree Topologies: the Example of Some Mid-Permian Synapsid Extinctions Gilles Didier, Michel Laurin
    Distributions of extinction times from fossil ages and tree topologies: the example of some mid-Permian synapsid extinctions Gilles Didier, Michel Laurin To cite this version: Gilles Didier, Michel Laurin. Distributions of extinction times from fossil ages and tree topologies: the example of some mid-Permian synapsid extinctions. 2021. hal-03258099v2 HAL Id: hal-03258099 https://hal.archives-ouvertes.fr/hal-03258099v2 Preprint submitted on 20 Sep 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributions of extinction times from fossil ages and tree topologies: the example of some mid-Permian synapsid extinctions Gilles Didier1 and Michel Laurin2 1 IMAG, Univ Montpellier, CNRS, Montpellier, France 2 CR2P (\Centre de Pal´eontologie { Paris"; UMR 7207), CNRS/MNHN/SU, Mus´eumNational d'Histoire Naturelle, Paris, France September 16, 2021 Abstract Given a phylogenetic tree that includes only extinct, or a mix of extinct and extant taxa, where at least some fossil data are available, we present a method to compute the distribution of the extinction time of a given set of taxa under the Fossilized-Birth-Death model. Our approach differs from the previous ones in that it takes into account (i) the possibility that the taxa or the clade considered may diversify before going extinct and (ii) the whole phylogenetic tree to estimate extinction times, whilst previous methods do not consider the diversification process and deal with each branch independently.
    [Show full text]
  • The Mammary Gland and Its Origin During Synapsid Evolution
    P1: GMX Journal of Mammary Gland Biology and Neoplasia (JMGBN) pp749-jmgbn-460568 January 9, 2003 17:51 Style file version Nov. 07, 2000 Journal of Mammary Gland Biology and Neoplasia, Vol. 7, No. 3, July 2002 (C 2002) The Mammary Gland and Its Origin During Synapsid Evolution Olav T. Oftedal1 Lactation appears to be an ancient reproductive trait that predates the origin of mammals. The synapsid branch of the amniote tree that separated from other taxa in the Pennsylva- nian (>310 million years ago) evolved a glandular rather than scaled integument. Repeated radiations of synapsids produced a gradual accrual of mammalian features. The mammary gland apparently derives from an ancestral apocrine-like gland that was associated with hair follicles. This association is retained by monotreme mammary glands and is evident as ves- tigial mammary hair during early ontogenetic development of marsupials. The dense cluster of mammo-pilo-sebaceous units that open onto a nipple-less mammary patch in monotremes may reflect a structure that evolved to provide moisture and other constituents to permeable eggs. Mammary patch secretions were coopted to provide nutrients to hatchlings, but some constituents including lactose may have been secreted by ancestral apocrine-like glands in early synapsids. Advanced Triassic therapsids, such as cynodonts, almost certainly secreted complex, nutrient-rich milk, allowing a progressive decline in egg size and an increasingly altricial state of the young at hatching. This is indicated by the very small body size, presence of epipubic bones, and limited tooth replacement in advanced cynodonts and early mammali- aforms. Nipples that arose from the mammary patch rendered mammary hairs obsolete, while placental structures have allowed lactation to be truncated in living eutherians.
    [Show full text]
  • The Conservation Biology of Tortoises
    The Conservation Biology of Tortoises Edited by Ian R. Swingland and Michael W. Klemens IUCN/SSC Tortoise and Freshwater Turtle Specialist Group and The Durrell Institute of Conservation and Ecology Occasional Papers of the IUCN Species Survival Commission (SSC) No. 5 IUCN—The World Conservation Union IUCN Species Survival Commission Role of the SSC 3. To cooperate with the World Conservation Monitoring Centre (WCMC) The Species Survival Commission (SSC) is IUCN's primary source of the in developing and evaluating a data base on the status of and trade in wild scientific and technical information required for the maintenance of biological flora and fauna, and to provide policy guidance to WCMC. diversity through the conservation of endangered and vulnerable species of 4. To provide advice, information, and expertise to the Secretariat of the fauna and flora, whilst recommending and promoting measures for their con- Convention on International Trade in Endangered Species of Wild Fauna servation, and for the management of other species of conservation concern. and Flora (CITES) and other international agreements affecting conser- Its objective is to mobilize action to prevent the extinction of species, sub- vation of species or biological diversity. species, and discrete populations of fauna and flora, thereby not only maintain- 5. To carry out specific tasks on behalf of the Union, including: ing biological diversity but improving the status of endangered and vulnerable species. • coordination of a programme of activities for the conservation of biological diversity within the framework of the IUCN Conserva- tion Programme. Objectives of the SSC • promotion of the maintenance of biological diversity by monitor- 1.
    [Show full text]
  • 2018 NMGS Spring Meeting: Abstract-748
    FIRST DISCOVERY OF A TETRAPOD BODY FOSSIL IN THE LOWER PERMIAN YESO GROUP, CENTRAL NEW MEXICO Emily D. Thorpe1, Spencer G. Lucas2, David S. Berman3, Larry F. Rinehart2, Vincent Santucci4 and Amy C. Henrici3 1 POBox 147, Morrisonville, WI, 53571, [email protected] 2New Mexico Museum of Natural History and Science, 1801 Mountain Road N. W., Albuquerque, NM, 87104 3Carnegie Museum of Natural History, 4400 Forbes Ave, Pittsburgh, PA, 15213 4National Parks Service, 1849 C Street, NW, Washington, DC, 20240, United States The lower Permian Yeso Group records arid coastal plain, shallow marine, and evaporitic deposition across much of central New Mexico. Generally considered to have few fossils, recent study of Yeso Group strata has discovered a diverse fossil record of marine micro-organisms (mostly algae and foraminiferans), terrestrial plants, and tetrapod footprints. We report here the first discovery of a tetrapod body fossil in the Yeso Group—a partial skeleton of a basal synapsid, varanopidae eupelycosaur. The fossil is the natural casts of bones in two pieces, part and counterpart, that were preserved in a sandstone bed of the lower part of the Arroyo de Alamillo Formation in the southern Manzano Mountains. The fossil-bearing sandstone is fine-grained, quartz rich, and pale reddish brown to grayish red unweathered, weathers to blackish red, and is in part encrusted by white caliche. The casts preserve part of the pelvis(?), 18 caudal vertebral centra, both femora and tibia-fibulae, and most of the pedes, largely in close articulation, of a single individual. The skeleton is of a relatively small (femur length = 62 mm, total length of the preserved cast from the pelvis to tip of the incomplete tail = 325 mm) and gracile eupelycosaur most similar to Varanops.
    [Show full text]
  • Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha)
    Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) by Richard Kissel A thesis submitted in conformity with the requirements for the degree of doctor of philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto © Copyright by Richard Kissel 2010 Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) Richard Kissel Doctor of Philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto 2010 Abstract Based on dental, cranial, and postcranial anatomy, members of the Permo-Carboniferous clade Diadectidae are generally regarded as the earliest tetrapods capable of processing high-fiber plant material; presented here is a review of diadectid morphology, phylogeny, taxonomy, and paleozoogeography. Phylogenetic analyses support the monophyly of Diadectidae within Diadectomorpha, the sister-group to Amniota, with Limnoscelis as the sister-taxon to Tseajaia + Diadectidae. Analysis of diadectid interrelationships of all known taxa for which adequate specimens and information are known—the first of its kind conducted—positions Ambedus pusillus as the sister-taxon to all other forms, with Diadectes sanmiguelensis, Orobates pabsti, Desmatodon hesperis, Diadectes absitus, and (Diadectes sideropelicus + Diadectes tenuitectes + Diasparactus zenos) representing progressively more derived taxa in a series of nested clades. In light of these results, it is recommended herein that the species Diadectes sanmiguelensis be referred to the new genus
    [Show full text]
  • Distributions of Extinction Times from Fossil Ages and Tree Topologies: the Example of Some Mid-Permian Synapsid Extinctions
    bioRxiv preprint doi: https://doi.org/10.1101/2021.06.11.448028; this version posted June 11, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Distributions of extinction times from fossil ages and tree topologies: the example of some mid-Permian synapsid extinctions Gilles Didier1 and Michel Laurin2 1IMAG, Univ Montpellier, CNRS, Montpellier, France 2CR2P (“Centre de Recherches sur la Paléobiodiversité et les Paléoenvironnements”; UMR 7207), CNRS/MNHN/UPMC, Sorbonne Université, Muséum National d’Histoire Naturelle, Paris, France June 11, 2021 Abstract Given a phylogenetic tree of extinct and extant taxa with fossils where the only temporal infor- mation stands in the fossil ages, we devise a method to compute the distribution of the extinction time of a given set of taxa under the Fossilized-Birth-Death model. Our approach differs from the previous ones in that it takes into account the possibility that the taxa or the clade considered may diversify before going extinct, whilst previous methods just rely on the fossil recovery rate to estimate confidence intervals. We assess and compare our new approach with a standard previous one using simulated data. Results show that our method provides more accurate confidence intervals. This new approach is applied to the study of the extinction time of three Permo-Carboniferous synapsid taxa (Ophiacodontidae, Edaphosauridae, and Sphenacodontidae) that are thought to have disappeared toward the end of the Cisuralian, or possibly shortly thereafter. The timing of extinctions of these three taxa and of their component lineages supports the idea that a biological crisis occurred in the late Kungurian/early Roadian.
    [Show full text]
  • The Global Distribution of Tetrapods Reveals a Need for Targeted Reptile
    1 The global distribution of tetrapods reveals a need for targeted reptile 2 conservation 3 4 Uri Roll#1,2, Anat Feldman#3, Maria Novosolov#3, Allen Allison4, Aaron M. Bauer5, Rodolphe 5 Bernard6, Monika Böhm7, Fernando Castro-Herrera8, Laurent Chirio9, Ben Collen10, Guarino R. 6 Colli11, Lital Dabool12 Indraneil Das13, Tiffany M. Doan14, Lee L. Grismer15, Marinus 7 Hoogmoed16, Yuval Itescu3, Fred Kraus17, Matthew LeBreton18, Amir Lewin3, Marcio Martins19, 8 Erez Maza3, Danny Meirte20, Zoltán T. Nagy21, Cristiano de C. Nogueira19, Olivier S.G. 9 Pauwels22, Daniel Pincheira-Donoso23, Gary Powney24, Roberto Sindaco25, Oliver Tallowin3, 10 Omar Torres-Carvajal26, Jean-François Trape27, Enav Vidan3, Peter Uetz28, Philipp Wagner5,29, 11 Yuezhao Wang30, C David L Orme6, Richard Grenyer✝1 and Shai Meiri✝*3 12 13 # Contributed equally to the paper 14 ✝ Contributed equally to the paper 15 * Corresponding author 16 17 Affiliations: 18 1 School of Geography and the Environment, University of Oxford, Oxford, OX13QY, UK. 19 2 Mitrani Department of Desert Ecology, The Jacob Blaustein Institutes for Desert Research, 20 Ben-Gurion University, Midreshet Ben-Gurion 8499000, Israel. (Current address) 21 3 Department of Zoology, Tel-Aviv University, Tel-Aviv 6997801, Israel. 22 4 Hawaii Biological Survey, 4 Bishop Museum, Honolulu, HI 96817, USA. 23 5 Department of Biology, Villanova University, Villanova, PA 19085, USA. 24 6 Department of Life Sciences, Imperial College London, Silwood Park Campus Silwood Park, 25 Ascot, Berkshire, SL5 7PY, UK 26 7 Institute of Zoology, Zoological Society of London, London NW1 4RY, UK. 27 8 School of Basic Sciences, Physiology Sciences Department, Universidad del Valle, Colombia.
    [Show full text]
  • (Diapsida: Saurosphargidae), with Implications for the Morphological Diversity and Phylogeny of the Group
    Geol. Mag.: page 1 of 21. c Cambridge University Press 2013 1 doi:10.1017/S001675681300023X A new species of Largocephalosaurus (Diapsida: Saurosphargidae), with implications for the morphological diversity and phylogeny of the group ∗ CHUN LI †, DA-YONG JIANG‡, LONG CHENG§, XIAO-CHUN WU†¶ & OLIVIER RIEPPEL ∗ Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, China ‡Department of Geology and Geological Museum, Peking University, Beijing 100871, PR China §Wuhan Institute of Geology and Mineral Resources, Wuhan, 430223, PR China ¶Canadian Museum of Nature, PO Box 3443, STN ‘D’, Ottawa, ON K1P 6P4, Canada Department of Geology, The Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605-2496, USA (Received 31 July 2012; accepted 25 February 2013) Abstract – Largocephalosaurus polycarpon Cheng et al. 2012a was erected after the study of the skull and some parts of a skeleton and considered to be an eosauropterygian. Here we describe a new species of the genus, Largocephalosaurus qianensis, based on three specimens. The new species provides many anatomical details which were described only briefly or not at all in the type species, and clearly indicates that Largocephalosaurus is a saurosphargid. It differs from the type species mainly in having three premaxillary teeth, a very short retroarticular process, a large pineal foramen, two sacral vertebrae, and elongated small granular osteoderms mixed with some large ones along the lateral most side of the body. With additional information from the new species, we revise the diagnosis and the phylogenetic relationships of Largocephalosaurus and clarify a set of diagnostic features for the Saurosphargidae Li et al.
    [Show full text]
  • A Small Lepidosauromorph Reptile from the Early Triassic of Poland
    A SMALL LEPIDOSAUROMORPH REPTILE FROM THE EARLY TRIASSIC OF POLAND SUSAN E. EVANS and MAGDALENA BORSUK−BIAŁYNICKA Evans, S.E. and Borsuk−Białynicka, M. 2009. A small lepidosauromorph reptile from the Early Triassic of Poland. Palaeontologia Polonica 65, 179–202. The Early Triassic karst deposits of Czatkowice quarry near Kraków, southern Poland, has yielded a diversity of fish, amphibians and small reptiles. Two of these reptiles are lepido− sauromorphs, a group otherwise very poorly represented in the Triassic record. The smaller of them, Sophineta cracoviensis gen. et sp. n., is described here. In Sophineta the unspecial− ised vertebral column is associated with the fairly derived skull structure, including the tall facial process of the maxilla, reduced lacrimal, and pleurodonty, that all resemble those of early crown−group lepidosaurs rather then stem−taxa. Cladistic analysis places this new ge− nus as the sister group of Lepidosauria, displacing the relictual Middle Jurassic genus Marmoretta and bringing the origins of Lepidosauria closer to a realistic time frame. Key words: Reptilia, Lepidosauria, Triassic, phylogeny, Czatkowice, Poland. Susan E. Evans [[email protected]], Department of Cell and Developmental Biology, Uni− versity College London, Gower Street, London, WC1E 6BT, UK. Magdalena Borsuk−Białynicka [[email protected]], Institut Paleobiologii PAN, Twarda 51/55, PL−00−818 Warszawa, Poland. Received 8 March 2006, accepted 9 January 2007 180 SUSAN E. EVANS and MAGDALENA BORSUK−BIAŁYNICKA INTRODUCTION Amongst living reptiles, lepidosaurs (snakes, lizards, amphisbaenians, and tuatara) form the largest and most successful group with more than 7 000 widely distributed species. The two main lepidosaurian clades are Rhynchocephalia (the living Sphenodon and its extinct relatives) and Squamata (lizards, snakes and amphisbaenians).
    [Show full text]
  • Tiago Rodrigues Simões
    Diapsid Phylogeny and the Origin and Early Evolution of Squamates by Tiago Rodrigues Simões A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in SYSTEMATICS AND EVOLUTION Department of Biological Sciences University of Alberta © Tiago Rodrigues Simões, 2018 ABSTRACT Squamate reptiles comprise over 10,000 living species and hundreds of fossil species of lizards, snakes and amphisbaenians, with their origins dating back at least as far back as the Middle Jurassic. Despite this enormous diversity and a long evolutionary history, numerous fundamental questions remain to be answered regarding the early evolution and origin of this major clade of tetrapods. Such long-standing issues include identifying the oldest fossil squamate, when exactly did squamates originate, and why morphological and molecular analyses of squamate evolution have strong disagreements on fundamental aspects of the squamate tree of life. Additionally, despite much debate, there is no existing consensus over the composition of the Lepidosauromorpha (the clade that includes squamates and their sister taxon, the Rhynchocephalia), making the squamate origin problem part of a broader and more complex reptile phylogeny issue. In this thesis, I provide a series of taxonomic, phylogenetic, biogeographic and morpho-functional contributions to shed light on these problems. I describe a new taxon that overwhelms previous hypothesis of iguanian biogeography and evolution in Gondwana (Gueragama sulamericana). I re-describe and assess the functional morphology of some of the oldest known articulated lizards in the world (Eichstaettisaurus schroederi and Ardeosaurus digitatellus), providing clues to the ancestry of geckoes, and the early evolution of their scansorial behaviour.
    [Show full text]
  • Marine Reptiles Arne R
    Virginia Commonwealth University VCU Scholars Compass Study of Biological Complexity Publications Center for the Study of Biological Complexity 2011 Marine Reptiles Arne R. Rasmessen The Royal Danish Academy of Fine Arts John D. Murphy Field Museum of Natural History Medy Ompi Sam Ratulangi University J. Whitfield iG bbons University of Georgia Peter Uetz Virginia Commonwealth University, [email protected] Follow this and additional works at: http://scholarscompass.vcu.edu/csbc_pubs Part of the Life Sciences Commons Copyright: © 2011 Rasmussen et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Downloaded from http://scholarscompass.vcu.edu/csbc_pubs/20 This Article is brought to you for free and open access by the Center for the Study of Biological Complexity at VCU Scholars Compass. It has been accepted for inclusion in Study of Biological Complexity Publications by an authorized administrator of VCU Scholars Compass. For more information, please contact [email protected]. Review Marine Reptiles Arne Redsted Rasmussen1, John C. Murphy2, Medy Ompi3, J. Whitfield Gibbons4, Peter Uetz5* 1 School of Conservation, The Royal Danish Academy of Fine Arts, Copenhagen, Denmark, 2 Division of Amphibians and Reptiles, Field Museum of Natural History, Chicago, Illinois, United States of America, 3 Marine Biology Laboratory, Faculty of Fisheries and Marine Sciences, Sam Ratulangi University, Manado, North Sulawesi, Indonesia, 4 Savannah River Ecology Lab, University of Georgia, Aiken, South Carolina, United States of America, 5 Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia, United States of America Of the more than 12,000 species and subspecies of extant Caribbean, although some species occasionally travel as far north reptiles, about 100 have re-entered the ocean.
    [Show full text]
  • Meet the Herps!
    Science Standards Correlation SC06-S2C2-03, SC04-S4C1-04, SC05-S4C1-01, SC04-S4C1-06, SC07-S4C3-02, SC08- S4C4-01, 02&06 MEET THE HERPS! Some can go without a meal for more than a year. Others can live for a century, but not really reach a ripe old age for another couple of decades. One species is able to squirt blood from its eyes. What kinds of animals are these? They’re herps – the collective name given to reptiles and amphibians. What Is Herpetology? The word “herp” comes from the word “herpeton,” the Greek word for “crawling things.” Herpetology is the branch of science focusing on reptiles and amphibians. The reptiles are divided into four major groups: lizards, snakes, turtles, and crocodilians. Three major groups – frogs (including toads), salamanders and caecilians – make up the amphibians. A herpetologist studies animals from all seven of these groups. Even though reptiles and amphibians are grouped together for study, they are two very different kinds of animals. They are related in the sense that early reptiles evolved from amphibians – just as birds, and later mammals, evolved from reptiles. But reptiles and amphibians are each in a scientific class of their own, just as mammals are in their own separate class. One of the reasons reptiles and amphibians are lumped together under the heading of “herps” is that, at one time, naturalists thought the two kinds of animals were much more closely related than they really are, and the practice of studying them together just persisted through the years. Reptiles vs. Amphibians: How Are They Different? Many of the differences between reptiles and amphibians are internal (inside the body).
    [Show full text]