Sophisticated Digestive Systems in Early Arthropods
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Flatworms Phylum Platyhelminthes
Flatworms Phylum Platyhelminthes The flatworms include more than 13,000 species of free-living and parasitic species.There are 3 classes of flat- worms, the planarians, flukes and tapeworms. General Physical Traits (Anatomy): Flatworms are bilaterally symmetrical. This means that they can only be cut them length-wise to produce two mirror-image halves. They have a distinct right and left half. This is differ- ent from radially symmetrical animals, like the anemones, which can be cut anywhere top to bottom to get two similar halves. Flatworms have 3 tissue layers, compared to the 2 layers in sponges and cnidarians (jellyfishes, anemones and corals). They also have only one opening for food to enter and waste to leave, like the sponges and cnidarians. This is called a “sac” body plan. Planarian (class Tubellaria) Habitat: They live mostly in saltwater (marine) habitats, but are also found in freshwater. Habits: They are free-living flatworms (not parasites). Physical Traits (Anatomy): Planarians are small - less than a centimeter long. They have a head, brain and sense organs. This is called “cephalization.” The sense organs – called eyespots – look like eyes and are sensitive to light changes, but are not like human eyes. They are made up of simple nerve cells that respond to stimuli, like light. When many nerve cells are gathered in one place, they are called a “ganglion,” so the two eyespots are actually ganglia. They also have points on either side of the head that look a bit like ears, called “sensory lobes” or auricles. They do not hear, but can sense food. -
Argulus Ambystoma, a New Species Parasitic on the Salamander Ambystoma Dumerilii from Mexico (Crustacea: Branchiura: Argulidae)1
Argulus ambystoma, a New Species Parasitic on the Salamander Ambystoma dumerilii from Mexico (Crustacea: Branchiura: Argulidae)1 WILLIAM J. POLY2, Department of Zoology, Southern Illinois University, Carbondale, IL 62901-6501 ABSTRACT. A new species of Argulus is described based on 18 specimens taken from the salamander ("achoque" or "ajolote") Ambystoma dumerilii Duges, collected in Lake Patzcuaro, Michoacan, Mexico. Diagnostic characters include the shape of the respiratory areas, number of sclerites in suction cup rods, and structures on the legs of males. Females are heavily stippled, whereas males have a very distinctive pigment pattern consisting of abundant melanophores covering the testes dors ally and two dark, inverted triangular patches on the carapace dorsally. The new species is similar to the North American species, A versicolor,A. americanus, A. maculosus, and A diversus. A single, dorsal pore was observed on each caudal ramus using scanning electron microscopy; these pores have not been reported previously in the Branchiura. OHIO J SCI 103 (3>52-6l, 2003 INTRODUCTION 1991; Osorio-Sarabia and others 1986; Perez-Ponce de Ten species of Argulus Miiller have been collected in Leon and others 1994; Peresbarbosa-Rojas and others Mexico, Central America, and the West Indies. The wide- 1994; Espinosa-Huerta and others 1996; Peresbarbosa- spread exotic, Argulus japonicus Thiele, was found on Rojas and others 1997). A number of endemic taxa exist aquarium fishes, Carassius auratus (Linne) and Astro- in Lake Patzcuaro including several fishes (Cbirostoma notus ocellatus (Agassiz), in Puerto Rico (Bunkley-Williams patzcuaro Meek, C. e. estor Jordan, C. a. attenuatum and Williams 1994), and Vargas and Fallas (1976) found Meek), a crayfish (Cambarellus patzcuarensis Villa- A. -
Articulo Agnostida (Trilobita)
Dies, M.E. y Gozalo, R. 2004. Agnostida (Trilobita) de la Formación Valdemiedes (Leoniense: Cámbrico Medio basal) de las Cadenas Ibéricas (NE de España). Boletín Geológico y Minero, 115 (4): 683-698 ISSN: 0366-0176 Agnostida (Trilobita) de la Formación Valdemiedes (Leoniense: Cámbrico Medio basal) de las Cadenas Ibéricas (NE de España) M.E. Dies(1) y R. Gozalo(2) (1) Área y Museo de Paleontología. Facultad de Ciencias. Universidad de Zaragoza. E-50009 Zaragoza, España. E-mail: [email protected] (2) Departamento de Geología. Universitat de València. Dr. Moliner, 50. E-46100 Burjassot, España. E-mail: [email protected] RESUMEN El hallazgo de trilobites del Orden Agnostida del Leoniense Medio en las Cadenas Ibéricas (NE de España), así como material nuevo pro- cedente del Leoniense Inferior, han permitido completar el estudio taxonómico de este grupo en el Cámbrico Medio basal de este área. La presencia de dos poblaciones de la especie Condylopyge cruzensis Liñán y Gozalo, 1986 ha posibilitado realizar un estudio morfomé- trico y poblacional de la misma. Por otro lado, se ha identificado por primera vez el taxón Peronopsis aff. longinqua Öpik, 1979, lo que puede ser considerado como una herramienta más que apoye la correlación propuesta para el piso Leoniense y el Ordian/early Templentonian de Australia. Palabras clave: Agnostida, Cadenas Ibéricas, Cámbrico Medio, Formación Valdemiedes, Leoniense, trilobites Agnostida (Trilobita) from the Valdemiedes Formation (Leonian: low Middle Cambrian) of the Iberian Chains (NE Spain) ABSTRACT The discovery of Middle Leonian trilobites of the Agnostida Order in the Iberian Chains (NE Spain) together with new Lower Leonian mate- rial make possible to complete the taxonomic study of this group in the low Middle Cambrian of this area. -
A New Middle Cambrian Trilobite with a Specialized Cephalon from Shandong Province, North China
Editors' choice A new middle Cambrian trilobite with a specialized cephalon from Shandong Province, North China ZHIXIN SUN, HAN ZENG, and FANGCHEN ZHAO Sun, Z., Zeng, H., and Zhao, F. 2020. A new middle Cambrian trilobite with a specialized cephalon from Shandong Province, North China. Acta Palaeontologica Polonica 65 (4): 709–718. Trilobites achieved their maximum generic diversity in the Cambrian, but the peak of morphological disparity of their cranidia occurred in the Middle to Late Ordovician. Early to middle Cambrian trilobites with a specialized cephalon are rare, especially among the ptychoparioids, a group of libristomates featuring the so-called “generalized” bauplan. Here we describe an unusual ptychopariid trilobite Phantaspis auritus gen. et sp. nov. from the middle Cambrian (Miaolingian, Wuliuan) Mantou Formation in the Shandong Province, North China. This new taxon is characterized by a cephalon with an extended anterior area of double-lobate shape resembling a pair of rabbit ears in later ontogenetic stages; a unique type of cephalic specialization that has not been reported from other trilobites. Such a peculiar cephalon as in Phantaspis provides new insights into the variations of cephalic morphology in middle Cambrian trilobites, and may represent a heuristic example of ecological specialization to predation or an improved discoidal enrollment. Key words: Trilobita, Ptychopariida, ontogeny, specialization, Miaolingian, Paleozoic, Longgang, Asia. Zhixin Sun [[email protected]], Han Zeng [[email protected]], and Fangchen Zhao [[email protected]] (cor responding author), State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palae ontology and Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China. -
Biochemical Divergence Between Cavernicolous and Marine
The position of crustaceans within Arthropoda - Evidence from nine molecular loci and morphology GONZALO GIRIBET', STEFAN RICHTER2, GREGORY D. EDGECOMBE3 & WARD C. WHEELER4 Department of Organismic and Evolutionary- Biology, Museum of Comparative Zoology; Harvard University, Cambridge, Massachusetts, U.S.A. ' Friedrich-Schiller-UniversitdtJena, Instituifiir Spezielte Zoologie und Evolutionsbiologie, Jena, Germany 3Australian Museum, Sydney, NSW, Australia Division of Invertebrate Zoology, American Museum of Natural History, New York, U.S.A. ABSTRACT The monophyly of Crustacea, relationships of crustaceans to other arthropods, and internal phylogeny of Crustacea are appraised via parsimony analysis in a total evidence frame work. Data include sequences from three nuclear ribosomal genes, four nuclear coding genes, and two mitochondrial genes, together with 352 characters from external morphol ogy, internal anatomy, development, and mitochondrial gene order. Subjecting the com bined data set to 20 different parameter sets for variable gap and transversion costs, crusta ceans group with hexapods in Tetraconata across nearly all explored parameter space, and are members of a monophyletic Mandibulata across much of the parameter space. Crustacea is non-monophyletic at low indel costs, but monophyly is favored at higher indel costs, at which morphology exerts a greater influence. The most stable higher-level crusta cean groupings are Malacostraca, Branchiopoda, Branchiura + Pentastomida, and an ostracod-cirripede group. For combined data, the Thoracopoda and Maxillopoda concepts are unsupported, and Entomostraca is only retrieved under parameter sets of low congruence. Most of the current disagreement over deep divisions in Arthropoda (e.g., Mandibulata versus Paradoxopoda or Cormogonida versus Chelicerata) can be viewed as uncertainty regarding the position of the root in the arthropod cladogram rather than as fundamental topological disagreement as supported in earlier studies (e.g., Schizoramia versus Mandibulata or Atelocerata versus Tetraconata). -
The Tiger Beetles (Coleoptera, Cicindelidae) of the Southern Levant and Adjacent Territories: from Cybertaxonomy to Conservation Biology
A peer-reviewed open-access journal ZooKeys 734: 43–103 The(2018) tiger beetles( Coleoptera, Cicindelidae) of the southern Levant... 43 doi: 10.3897/zookeys.734.21989 MONOGRAPH http://zookeys.pensoft.net Launched to accelerate biodiversity research The tiger beetles (Coleoptera, Cicindelidae) of the southern Levant and adjacent territories: from cybertaxonomy to conservation biology Thorsten Assmann1, Estève Boutaud1, Jörn Buse2, Jörg Gebert3, Claudia Drees4,5, Ariel-Leib-Leonid Friedman4, Fares Khoury6, Tamar Marcus1, Eylon Orbach7, Ittai Renan4, Constantin Schmidt8, Pascale Zumstein1 1 Institute of Ecology, Leuphana University Lüneburg, Universitätsallee 1, D-21335 Lüneburg, Germany 2 Ecosystem Monitoring, Research and Wildlife Conservation (SB 23 Invertebrates and Biodiversity), Black Forest National Park, Kniebisstraße 67, D-72250 Freudenstadt, Germany 3 Karl-Liebknecht-Straße 73, D-01109 Dresden. Germany 4 Steinhardt Museum of Natural History, Tel Aviv University, Ramat-Aviv, Tel Aviv, IL-69978, Israel 5 Biocentre Grindel, Universität Hamburg, Martin-Luther-King-Platz 3, D-20146 Hamburg, Germany 6 Department of Biology and Biotechnology, American University of Madaba, P.O.Box 2882, Amman, JO-11821, Jordan 7 Remez St. 49, IL-36044 Qiryat Tiv’on, Israel 8 Deichstr. 13, D-21354 Bleckede, Germany Corresponding author: Thorsten Assmann ([email protected]) Academic editor: B. Guéorguiev | Received 1 November 2017 | Accepted 15 January 2018 | Published 5 February 2018 http://zoobank.org/7C3C687B-64BB-42A5-B9E4-EC588BCD52D5 Citation: Assmann T, Boutaud E, Buse J, Gebert J, Drees C, Friedman A-L-L, Khoury F, Marcus T, Orbach E, Renan I, Schmidt C, Zumstein P (2018) The tiger beetles (Coleoptera, Cicindelidae) of the southern Levant and adjacent territories: from cybertaxonomy to conservation biology. -
Old Woman Creek National Estuarine Research Reserve Management Plan 2011-2016
Old Woman Creek National Estuarine Research Reserve Management Plan 2011-2016 April 1981 Revised, May 1982 2nd revision, April 1983 3rd revision, December 1999 4th revision, May 2011 Prepared for U.S. Department of Commerce Ohio Department of Natural Resources National Oceanic and Atmospheric Administration Division of Wildlife Office of Ocean and Coastal Resource Management 2045 Morse Road, Bldg. G Estuarine Reserves Division Columbus, Ohio 1305 East West Highway 43229-6693 Silver Spring, MD 20910 This management plan has been developed in accordance with NOAA regulations, including all provisions for public involvement. It is consistent with the congressional intent of Section 315 of the Coastal Zone Management Act of 1972, as amended, and the provisions of the Ohio Coastal Management Program. OWC NERR Management Plan, 2011 - 2016 Acknowledgements This management plan was prepared by the staff and Advisory Council of the Old Woman Creek National Estuarine Research Reserve (OWC NERR), in collaboration with the Ohio Department of Natural Resources-Division of Wildlife. Participants in the planning process included: Manager, Frank Lopez; Research Coordinator, Dr. David Klarer; Coastal Training Program Coordinator, Heather Elmer; Education Coordinator, Ann Keefe; Education Specialist Phoebe Van Zoest; and Office Assistant, Gloria Pasterak. Other Reserve staff including Dick Boyer and Marje Bernhardt contributed their expertise to numerous planning meetings. The Reserve is grateful for the input and recommendations provided by members of the Old Woman Creek NERR Advisory Council. The Reserve is appreciative of the review, guidance, and council of Division of Wildlife Executive Administrator Dave Scott and the mapping expertise of Keith Lott and the late Steve Barry. -
Soft−Part Preservation in Two Species of the Arthropod Isoxys from the Middle Cambrian Burgess Shale of British Columbia, Canada
Soft−part preservation in two species of the arthropod Isoxys from the middle Cambrian Burgess Shale of British Columbia, Canada DIEGO C. GARCÍA−BELLIDO, JEAN VANNIER, and DESMOND COLLINS García−Bellido, D.C., Vannier, J., and Collins, D. 2009. Soft−part preservation in two species of the arthropod Isoxys from the middle Cambrian Burgess Shale of British Columbia, Canada. Acta Palaeontologica Polonica 54 (4): 699–712. doi:10.4202/app.2009.0024 More than forty specimens from the middle Cambrian Burgess Shale reveal the detailed anatomy of Isoxys, a worldwide distributed bivalved arthropod represented here by two species, namely Isoxys acutangulus and Isoxys longissimus. I. acutangulus had a non−mineralized headshield with lateral pleural folds (= “valves” of previous authors) that covered the animal’s body almost entirely, large frontal spherical eyes and a pair of uniramous prehensile appendages bearing stout spiny outgrowths along their anterior margins. The 13 following appendages had a uniform biramous design—i.e., a short endopod and a paddle−like exopod fringed with marginal setae with a probable natatory function. The trunk ended with a flap−like telson that protruded beyond the posterior margin of the headshield. The gut of I. acutangulus was tube−like, running from mouth to telson, and was flanked with numerous 3D−preserved bulbous, paired features inter− preted as digestive glands. The appendage design of I. acutangulus indicates that the animal was a swimmer and a visual predator living off−bottom. The general anatomy of Isoxys longissimus was similar to that of I. acutangulus although less information is available on the exact shape of its appendages and visual organs. -
Phylum Chordata
Phylum Chordata 48,000 species very diverse phylum but still more unity in major characteristics than in most other phyla most advanced phylum of animal kingdom one to which we belong along with fish, amphibians reptiles, birds and other mammals some of the largest or most massive animals true coelom 4 major identifying characteristics: 1. Notochord flexible rodlike structure enclosed by a fibrous sheath extends the length of the body in larva and/or adult provides basic support and serves as main axis for muscle attachments to permit “fishlike” undulatory movements first part of skeleton to form in embryo in primitive chordates the notochord persists through life Animals: Chordates & Introduction to Vertebrates; Ziser Lecture Notes, 2006 1 in most chordates the notochord is replaced by a vertebral column of bone remnants of the notochord remain as “intervertebral discs” 2. Dorsal tubular nerve cord in most invert groups; nerve cord is ventral & paired in chordates the nerve cord is a single dorsal hollow nerve cord front end usually enlarged to form brain 3. Pharyngeal (gill) slits slit-like opening sleading from throat to outside first evolved as a filter feeding apparatus still used by some to filter water for food in others as gills in some groups they are only found in embryo and lost as adults 4. endostyle or thyroid gland specific kind of tissue found only in chordates was originally part of the feeding apparatus endostyle secretes mucus and traps food inside the pharyngeal cavity eg. lamprey larva in most chordates the same tissue has become an endocrine Animals: Chordates & Introduction to Vertebrates; Ziser Lecture Notes, 2006 2 gland in the neck region that helps control metabolism 5. -
Morphology and Function in the Cambrian Burgess Shale
Haug et al. BMC Evolutionary Biology 2012, 12:162 http://www.biomedcentral.com/1471-2148/12/162 RESEARCH ARTICLE Open Access Morphology and function in the Cambrian Burgess Shale megacheiran arthropod Leanchoilia superlata and the application of a descriptive matrix Joachim T Haug1*, Derek EG Briggs2,3 and Carolin Haug1 Abstract Background: Leanchoilia superlata is one of the best known arthropods from the middle Cambrian Burgess Shale of British Columbia. Here we re-describe the morphology of L. superlata and discuss its possible autecology. The re-description follows a standardized scheme, the descriptive matrix approach, designed to provide a template for descriptions of other megacheiran species. Results: Our findings differ in several respects from previous interpretations. Examples include a more slender body; a possible hypostome; a small specialised second appendage, bringing the number of pairs of head appendages to four; a further sub-division of the great appendage, making it more similar to that of other megacheirans; and a complex joint of the exopod reflecting the arthropod’s swimming capabilities. Conclusions: Different aspects of the morphology, for example, the morphology of the great appendage and the presence of a basipod with strong median armature on the biramous appendages indicate that L. superlata was an active and agile necto-benthic predator (not a scavenger or deposit feeder as previously interpreted). Keywords: Megacheira, Great-appendage arthropods, Chelicerata sensu lato, Descriptive matrix, Active predator Background shared with other species. As a consequence, morpho- The description of species is fundamental to the science logical details in many phylogenetic matrices have to be of zoology, including taxonomy, phylogenetic systema- (re-)interpreted, often without the benefit of a compre- tics, functional morphology and ultimately evolutionary hensive description. -
The Cambrian Explosion: a Big Bang in the Evolution of Animals
The Cambrian Explosion A Big Bang in the Evolution of Animals Very suddenly, and at about the same horizon the world over, life showed up in the rocks with a bang. For most of Earth’s early history, there simply was no fossil record. Only recently have we come to discover otherwise: Life is virtually as old as the planet itself, and even the most ancient sedimentary rocks have yielded fossilized remains of primitive forms of life. NILES ELDREDGE, LIFE PULSE, EPISODES FROM THE STORY OF THE FOSSIL RECORD The Cambrian Explosion: A Big Bang in the Evolution of Animals Our home planet coalesced into a sphere about four-and-a-half-billion years ago, acquired water and carbon about four billion years ago, and less than a billion years later, according to microscopic fossils, organic cells began to show up in that inert matter. Single-celled life had begun. Single cells dominated life on the planet for billions of years before multicellular animals appeared. Fossils from 635,000 million years ago reveal fats that today are only produced by sponges. These biomarkers may be the earliest evidence of multi-cellular animals. Soon after we can see the shadowy impressions of more complex fans and jellies and things with no names that show that animal life was in an experimental phase (called the Ediacran period). Then suddenly, in the relatively short span of about twenty million years (given the usual pace of geologic time), life exploded in a radiation of abundance and diversity that contained the body plans of almost all the animals we know today. -
The Origin and Evolution of Arthropods Graham E
INSIGHT REVIEW NATURE|Vol 457|12 February 2009|doi:10.1038/nature07890 The origin and evolution of arthropods Graham E. Budd1 & Maximilian J. Telford2 The past two decades have witnessed profound changes in our understanding of the evolution of arthropods. Many of these insights derive from the adoption of molecular methods by systematists and developmental biologists, prompting a radical reordering of the relationships among extant arthropod classes and their closest non-arthropod relatives, and shedding light on the developmental basis for the origins of key characteristics. A complementary source of data is the discovery of fossils from several spectacular Cambrian faunas. These fossils form well-characterized groupings, making the broad pattern of Cambrian arthropod systematics increasingly consensual. The arthropods are one of the most familiar and ubiquitous of all ani- Arthropods are monophyletic mal groups. They have far more species than any other phylum, yet Arthropods encompass a great diversity of animal taxa known from the living species are merely the surviving branches of a much greater the Cambrian to the present day. The four living groups — myriapods, diversity of extinct forms. One group of crustacean arthropods, the chelicerates, insects and crustaceans — are known collectively as the barnacles, was studied extensively by Charles Darwin. But the origins Euarthropoda. They are united by a set of distinctive features, most and the evolution of arthropods in general, embedded in what is now notably the clear segmentation of their bodies, a sclerotized cuticle and known as the Cambrian explosion, were a source of considerable con- jointed appendages. Even so, their great diversity has led to consider- cern to him, and he devoted a substantial and anxious section of On able debate over whether they had single (monophyletic) or multiple the Origin of Species1 to discussing this subject: “For instance, I cannot (polyphyletic) origins from a soft-bodied, legless ancestor.