DOCSLIB.ORG

The Origin and Diversification of Osteichthyans and Sarcopterygians: Rare Chinese Fossil Findings Advance Research on Key Issues of Evolution

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Origin and Diversification of Osteichthyans and Sarcopterygians: Rare Chinese Fossil Findings Advance Research on Key Issues of Evolution Vol.24 No.2 2010 Paleoichthyology The Origin and Diversification of Osteichthyans and Sarcopterygians: Rare Chinese Fossil Findings Advance Research on Key Issues of Evolution YU Xiaobo1, 2 ZHU Min1* and ZHAO Wenjin1 1 Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), CAS, Beijing 100044, China 2 Department of Biological Sciences, Kean University, Union, New Jersey 07083, USA iving organisms represent into a hierarchical (or “set-within- chimaeras) with 970 living species, only 1% of all the biota that set”) pattern of groupings on the and the long-extinct placoderms and Lhas ever existed on earth. family tree, with members of each acanthodians. Within osteichthyans, All organisms, living or extinct, new group united by a common the actinopterygian lineage (with are related to each other by sharing ancestor and characterized by novel 26,981 living species) includes common ancestors at different levels, biological features. For instance, sturgeons, gars, teleosts and their like twigs and branches connected within vertebrates, gnathostomes (or relatives, while the sarcopterygian to each other at different nodes on jawed vertebrates) arose as a new lineage (with 26,742 living species) the great tree of life. One major task group when they acquired jaws as includes lungfishes, coelacanths for paleontologists and evolutionary novel features, which set them apart (Latimeria), their extinct relatives as biologists is to find out how the from jawless agnathans (lampreys, well as all land-dwelling tetrapods diverse groups of organisms arose hagfishes and their relatives). Within (amphibians, reptiles, birds, and and how they are related to each gnathostomes, four major groups mammals) (Fig.1). other, thereby reconstructing the developed: the bony osteichthyans The quest for their origins has history of life and understanding the (including all bony fishes and land- fascinated the human mind since pattern and process of evolution. dwelling tetrapods) with 53,633 the dawn of history. For many As organisms evolve and diverge living species, the cartilaginous years, scientists have puzzled over from common ancestors, they fall chondrichthyans (sharks, rays and questions such as: When and how did * To whom correspondence should be addressed at [email protected]. Bulletin of the Chinese Academy of Sciences 71 古脊椎专题.indd 71 2010-6-30 11:44:25 BCAS Vol.24 No.2 2010 (Zhu et al., 2009; Fig. 2). Guiyu (“ghost fish”) gets its name because of its ghostly or bazaar combination of morphological characters. Within gnathostomes, Guiyu sides with osteichthyans by bearing derived macromeric scales, yet it resembles non-osteichthyan chondrichthyans, placoderms and acanthodians by having a primitive pectoral girdle and median fin spine. Within osteichthyans, Guiyu sides with sarcopterygians by having a two part braincase with a movable joint in the middle (plus other cranial features), yet it resembles early actinopterygians by having ornamented ganoine surface covering and by the shape of its cheek and operculo-gular bones. Computerized analysis of morphological characters places Guiyu as an osteichthyan in the basal segment of the sarcopterygian Fig. 1 The family tree and geological time range of major vertebrate groups. Numbers of lineage (Zhu et al., 2009; Fig.3). living species (in brackets) indicate the relative abundance and diversity of the four living Three other fossil fishes from groups (Nelson, 2006). Yunnan (Meemannia, Psarolepis and gnathostomes arise? What would the common ancestor of all osteichthyans look like? How do osteichthyans relate to chondrichthyans, placoderms and acanthodians? How did osteichthyans diverge into the actinopterygian and sarcopterygian lineages? When and where did sarcopterygians arise and diverge? How did some sarcopterygian fishes eventually give rise to land-dwelling tetrapods, which include humans? These and related questions not only lie at the center of evolutionary research but also have broad implications for science in general. Because of recent fossil fish findings from China, the global study on these key areas of vertebrate evolution has made significant progress and is now at the threshold of an exciting breakthrough in the near future. The most significant fossil fish finding from China is Guiyu, the oldest near-complete gnathostome Fig. 2 Reconstruction of “ghost fish” Guiyu as it may have lived in the Silurian waters 419 million years ago. Guiyu represents the earliest near-complete fossil gnathostome and fossil found from the 419-Myr-old fossil osteichthyan record. muddy limestone in eastern Yunnan Picture courtesy of Brian Choo (Victoria Museum, Australia). 72 Bulletin of the Chinese Academy of Sciences 古脊椎专题.indd 72 2010-6-30 11:44:27 Vol.24 No.2 2010 Paleoichthyology Late Silurian or earliest Devonian (Lochkovian) sarcopterygians, including four stem sarcopterygians (Guiyu, Meemannia, Psarolepis and Achoania) and four forms near the base of major subgroups of sarcopterygians (Styloichthys, Diabolepis, Youngolepis and an unnamed onychodont). During the Late Silurian–Lochkovian periods (about 411–422 million years ago), the South China region was a separate continent adjacent to eastern Gondwana, and its vertebrate fauna as a whole was highly endemic to the region, indicating little or no exchange between this region and other areas before the Middle Devonian period (397 million years ago). It was in this isolated or semi-isolated environment that major events in early sarcopterygian evolution unfolded and Fig. 3 The family tree and geological time range of “ghost fish” Guiyu and other important early osteichthyans from China. Of the nine Late Silurian or earliest Devonian two subgroups developed, one giving (Lochkovian) sarcopterygians, eight (framed in red) come from South China, suggesting rise to living lungfishes while the other that this region was once a center of origin and diversification for early sarcopterygians. giving rise to all tetrapods, including humans (Fig. 3). Achoania) cluster with Guiyu as basal calibrated by using fossils as specific Third, Guiyu provides the most or stem sarcopterygians, but they historical time markers. Guiyu as complete morphological information come from younger ages and consist a basal member of sarcopterygians for establishing the morphotype (or of less complete materials when has an accurate dating based on the primitive morphological model) of compared with Guiyu. The earliest Silurian conodont zonation (419 early gnathostomes, osteichthyans geologic time of appearance, a near- million years old), and this indicates and sarcopterygians. Based on complete preservation of whole body that the minimal estimated time for the morphotype for each major structures, and a unique combination the actinopterygian–sarcopterygian group, paleontologists can generate of gnathostome vs non-gnathostome split must be at least 419 million hypotheses about the sequential characters as well as sarcopterygian years ago (instead of the previously order of morphological changes vs actinopterygian characters―all 416-million-year-old estimate based from the origin of a group to specific these make Guiyu highly significant on Psarolepis―another important evolutionary events in history, such for the global study on the origin early sarcopterygian fossil from as the branching of lineages or the of gnathostomes, the origin and Yunnan). With this new calibration, conquering of new environments by diversification of osteichthyans, the molecular clock is now more new groups. and the origin and diversification of accurate than before in gauging the Gnathostomes may have first sarcopterygians. time dimension for accumulated appeared in the Late Ordovician First, Guiyu provides critical molecular changes between different (more than 444 million years fossil record to calibrate the molecular living groups. ago), but non-osteichthyan groups clock regarding the divergence time Second, Guiyu (together with (chondrichthyans, placoderms between two major osteichthyan seven other early sarcopterygians from and acanthodians) left little or no lineages (i.e., actinopterygians and the Silurian and earliest Devonian complete fossil specimens before the sarcopterygians). While modern strata of southern China) establishes Early Devonian period. Similarly, biologists can determine the the paleobiogeographic importance previously known osteichthyan amount of molecular differences of ancient South China region as a fossils from the Late Silurian are separating different living groups, center of origin and diversification fragmentary and their lineage this information can serve as a useful for sarcopterygians. So far, Yunnan assignment is uncertain. Thus, molecular clock only when it is has yielded eight out of the nine Guiyu represents the earliest near- Bulletin of the Chinese Academy of Sciences 73 古脊椎专题.indd 73 2010-6-30 11:44:30 BCAS Vol.24 No.2 2010 complete gnathostome and the to exist only in non-osteichthyan “superstars” among paleontologists earliest near-complete osteichthyan groups. Consequently, many pre- for many other reasons. For instance, fossil known to science. Although Devonian spine-like materials can Youngolepis (named after late Prof. other important osteichthyan fossils now be reexamined (and possibly Young Chungchien, pioneer of (Meemannia and Psarolepis from reinterpreted) in the light of Guiyu vertebrate paleontology in China) is Yunnan, Ligulalepis from Australia, and Psarolepis. an early occurring
Load more

Recommended publications
  • Osteichthyes: Sarcopterygii) Apex Predator from the Eifelian-Aged Dundee Formation of Ontario, Canada
    Canadian Journal of Earth Sciences A large onychodontiform (Osteichthyes: Sarcopterygii) apex predator from the Eifelian-aged Dundee Formation of Ontario, Canada. Journal: Canadian Journal of Earth Sciences Manuscript ID cjes-2016-0119.R3 Manuscript Type: Article Date Submitted by the Author: 04-Dec-2016 Complete List of Authors: Mann, Arjan; Carleton University, Earth Sciences; University of Toronto Faculty of ArtsDraft and Science, Earth Sciences Rudkin, David; Royal Ontario Museum Evans, David C.; Royal Ontario Museum, Natural History; University of Toronto, Ecology and Evolutionary Biology Laflamme, Marc; University of Toronto - Mississauga, Chemical and Physical Sciences Keyword: Sarcopterygii, Onychodontiformes, Body size, Middle Devonian, Eifelian https://mc06.manuscriptcentral.com/cjes-pubs Page 1 of 34 Canadian Journal of Earth Sciences A large onychodontiform (Osteichthyes: Sarcopterygii) apex predator from the Eifelian- aged Dundee Formation of Ontario, Canada. Arjan Mann 1,2*, David Rudkin 1,2 , David C. Evans 2,3 , and Marc Laflamme 1 1, Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, Ontario, M5S 3B1, Canada, [email protected], [email protected] 2, Department of Palaeobiology, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario, Canada M5S 2C6 3, Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada M5S 3B2 *Corresponding author (e-mail: [email protected] ca). https://mc06.manuscriptcentral.com/cjes-pubs Canadian Journal of Earth Sciences Page 2 of 34 Abstract The Devonian marine strata of southwestern Ontario, Canada have been well documented geologically, but their vertebrate fossils are poorly studied. Here we report a new onychodontiform (Osteichthyes, Sarcopterygii) Onychodus eriensis n.
    [Show full text]
  • Cambridge University Press 978-1-107-17944-8 — Evolution And
    Cambridge University Press 978-1-107-17944-8 — Evolution and Development of Fishes Edited by Zerina Johanson , Charlie Underwood , Martha Richter Index More Information Index abaxial muscle,33 Alizarin red, 110 arandaspids, 5, 61–62 abdominal muscles, 212 Alizarin red S whole mount staining, 127 Arandaspis, 5, 61, 69, 147 ability to repair fractures, 129 Allenypterus, 253 arcocentra, 192 Acanthodes, 14, 79, 83, 89–90, 104, 105–107, allometric growth, 129 Arctic char, 130 123, 152, 152, 156, 213, 221, 226 alveolar bone, 134 arcualia, 4, 49, 115, 146, 191, 206 Acanthodians, 3, 7, 13–15, 18, 23, 29, 63–65, Alx, 36, 47 areolar calcification, 114 68–69, 75, 79, 82, 84, 87–89, 91, 99, 102, Amdeh Formation, 61 areolar cartilage, 192 104–106, 114, 123, 148–149, 152–153, ameloblasts, 134 areolar mineralisation, 113 156, 160, 189, 192, 195, 198–199, 207, Amia, 154, 185, 190, 193, 258 Areyongalepis,7,64–65 213, 217–218, 220 ammocoete, 30, 40, 51, 56–57, 176, 206, 208, Argentina, 60–61, 67 Acanthodiformes, 14, 68 218 armoured agnathans, 150 Acanthodii, 152 amphiaspids, 5, 27 Arthrodira, 12, 24, 26, 28, 74, 82–84, 86, 194, Acanthomorpha, 20 amphibians, 1, 20, 150, 172, 180–182, 245, 248, 209, 222 Acanthostega, 22, 155–156, 255–258, 260 255–256 arthrodires, 7, 11–13, 22, 28, 71–72, 74–75, Acanthothoraci, 24, 74, 83 amphioxus, 49, 54–55, 124, 145, 155, 157, 159, 80–84, 152, 192, 207, 209, 212–213, 215, Acanthothoracida, 11 206, 224, 243–244, 249–250 219–220 acanthothoracids, 7, 12, 74, 81–82, 211, 215, Amphioxus, 120 Ascl,36 219 Amphystylic, 148 Asiaceratodus,21
    [Show full text]
  • Paleontological Research
    Paleontological Research Vol. 6 No.3 September 2002 The Palaeontological Society 0 pan Co-Editors Kazushige Tanabe and Tomoki Kase Language Editor Martin Janal (New York, USA) Associate Editors Alan G. Beu (Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand), Satoshi Chiba (Tohoku University, Sendai, Japan), Yoichi Ezaki (Osaka City University, Osaka, Japan), James C. Ingle, Jr. (Stanford University, Stanford, USA), Kunio Kaiho (Tohoku University, Sendai, Japan), Susan M. Kidwell (University of Chicago, Chicago, USA), Hiroshi Kitazato (Shizuoka University, Shizuoka, Japan), Naoki Kohno (National Science Museum, Tokyo, Japan), Neil H. Landman (Amemican Museum of Natural History, New York, USA), Haruyoshi Maeda (Kyoto University, Kyoto, Japan), Atsushi Matsuoka (Niigata University, Niigata, Japan), Rihito Morita (Natural History Museum and Institute, Chiba, Japan), Harufumi Nishida (Chuo University, Tokyo, Japan), Kenshiro Ogasawara (University of Tsukuba, Tsukuba, Japan), Tatsuo Oji (University of Tokyo, Tokyo, Japan), Andrew B. Smith (Natural History Museum, London, Great Britain), Roger D. K. Thomas (Franklin and Marshall College, Lancaster, USA), Katsumi Ueno (Fukuoka University, Fukuoka, Japan), Wang Hongzhen (China University of Geosciences, Beijing, China), Yang Seong Young (Kyungpook National University, Taegu, Korea) Officers for 2001-2002 Honorary President: Tatsuro Matsumoto President: Hiromichi Hirano Councillors: Shuko Adachi, Kazutaka Amano, Yoshio Ando, Masatoshi Goto, Hiromichi Hirano, Yasuo Kondo, Noriyuki
    [Show full text]
  • Lecture 6 – Integument ‐ Scale • a Scale Is a Small Rigid Plate That Grows out of an Animal’ S Skin to Provide Protection
    Lecture 6 – Integument ‐ Scale • A scale is a small rigid plate that grows out of an animal’s skin to provide protection. • Scales are quite common and have evolved multiple times with varying structure and function. • Scales are generally classified as part of an organism's integumentary system. • There are various types of scales according to shape and to class of animal. • Although the meat and organs of some species of fish are edible by humans, the scales are usually not eaten. Scale structure • Fish scales Fish scales are dermally derived, specifically in the mesoderm. This fact distinguishes them from reptile scales paleontologically. Genetically, the same genes involved in tooth and hair development in mammals are also involved in scale development. Earliest scales – heavily armoured thought to be like Chondrichthyans • Fossil fishes • ion reservoir • osmotic control • protection • Weighting Scale function • Primary function is protection (armor plating) • Hydrodynamics Scales are composed of four basic compounds: ((gmoving from inside to outside in that order) • Lamellar bone • Vascular or spongy bone • Dentine (dermis) and is always associated with enamel. • Acellular enamel (epidermis) • The scales of fish lie in pockets in the dermis and are embeded in connective tissue. • Scales do not stick out of a fish but are covered by the Epithelial layer. • The scales overlap and so form a protective flexible armor capable of withstanding blows and bumping. • In some catfishes and seahorses, scales are replaced by bony plates. • In some other species there are no scales at all. Evolution of scales Placoid scale – (Chondricthyes – cartilagenous fishes) develop in dermis but protrude through epidermis.
    [Show full text]
  • Constraints on the Timescale of Animal Evolutionary History
    Palaeontologia Electronica palaeo-electronica.org Constraints on the timescale of animal evolutionary history Michael J. Benton, Philip C.J. Donoghue, Robert J. Asher, Matt Friedman, Thomas J. Near, and Jakob Vinther ABSTRACT Dating the tree of life is a core endeavor in evolutionary biology. Rates of evolution are fundamental to nearly every evolutionary model and process. Rates need dates. There is much debate on the most appropriate and reasonable ways in which to date the tree of life, and recent work has highlighted some confusions and complexities that can be avoided. Whether phylogenetic trees are dated after they have been estab- lished, or as part of the process of tree finding, practitioners need to know which cali- brations to use. We emphasize the importance of identifying crown (not stem) fossils, levels of confidence in their attribution to the crown, current chronostratigraphic preci- sion, the primacy of the host geological formation and asymmetric confidence intervals. Here we present calibrations for 88 key nodes across the phylogeny of animals, rang- ing from the root of Metazoa to the last common ancestor of Homo sapiens. Close attention to detail is constantly required: for example, the classic bird-mammal date (base of crown Amniota) has often been given as 310-315 Ma; the 2014 international time scale indicates a minimum age of 318 Ma. Michael J. Benton. School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, U.K. [email protected] Philip C.J. Donoghue. School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, U.K. [email protected] Robert J.
    [Show full text]
  • Spiracular Air Breathing in Polypterid Fishes and Its Implications for Aerial
    ARTICLE Received 1 May 2013 | Accepted 27 Nov 2013 | Published 23 Jan 2014 DOI: 10.1038/ncomms4022 Spiracular air breathing in polypterid fishes and its implications for aerial respiration in stem tetrapods Jeffrey B. Graham1, Nicholas C. Wegner1,2, Lauren A. Miller1, Corey J. Jew1, N Chin Lai1,3, Rachel M. Berquist4, Lawrence R. Frank4 & John A. Long5,6 The polypterids (bichirs and ropefish) are extant basal actinopterygian (ray-finned) fishes that breathe air and share similarities with extant lobe-finned sarcopterygians (lungfishes and tetrapods) in lung structure. They are also similar to some fossil sarcopterygians, including stem tetrapods, in having large paired openings (spiracles) on top of their head. The role of spiracles in polypterid respiration has been unclear, with early reports suggesting that polypterids could inhale air through the spiracles, while later reports have largely dismissed such observations. Here we resolve the 100-year-old mystery by presenting structural, behavioural, video, kinematic and pressure data that show spiracle-mediated aspiration accounts for up to 93% of all air breaths in four species of Polypterus. Similarity in the size and position of polypterid spiracles with those of some stem tetrapods suggests that spiracular air breathing may have been an important respiratory strategy during the fish-tetrapod transition from water to land. 1 Marine Biology Research Division, Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, USA. 2 Fisheries Resource Division, Southwest Fisheries Science Center, NOAA Fisheries, La Jolla, California 92037, USA. 3 VA San Diego Healthcare System, San Diego, California 92161, USA.
    [Show full text]
  • Fishes Scales & Tails Scale Types 1
    Phylum Chordata SUBPHYLUM VERTEBRATA Metameric chordates Linear series of cartilaginous or boney support (vertebrae) surrounding or replacing the notochord Expanded anterior portion of nervous system THE FISHES SCALES & TAILS SCALE TYPES 1. COSMOID (most primitive) First found on ostracaderm agnathans, thick & boney - composed of: Ganoine (enamel outer layer) Cosmine (thick under layer) Spongy bone Lamellar bone Perhaps selected for protection against eurypterids, but decreased flexibility 2. GANOID (primitive, still found on some living fish like gar) 3. PLACOID (old scale type found on the chondrichthyes) Dentine, tooth-like 4. CYCLOID (more recent scale type, found in modern osteichthyes) 5. CTENOID (most modern scale type, found in modern osteichthyes) TAILS HETEROCERCAL (primitive, still found on chondrichthyes) ABBREVIATED HETEROCERCAL (found on some primitive living fish like gar) DIPHYCERCAL (primitive, found on sarcopterygii) HOMOCERCAL (most modern, found on most modern osteichthyes) Agnatha (class) [connect the taxa] Cyclostomata (order) Placodermi Acanthodii (class) (class) Chondrichthyes (class) Osteichthyes (class) Actinopterygii (subclass) Sarcopterygii (subclass) Dipnoi (order) Crossopterygii (order) Ripidistia (suborder) Coelacanthiformes (suborder) Chondrostei (infra class) Holostei (infra class) Teleostei (infra class) CLASS AGNATHA ("without jaws") Most primitive - first fossils in Ordovician Bottom feeders, dorsal/ventral flattened Cosmoid scales (Ostracoderms) Pair of eyes + pineal eye - present in a few living fish and reptiles - regulates circadian rhythms Nine - seven gill pouches No paired appendages, medial nosril ORDER CYCLOSTOMATA (60 spp) Last living representatives - lampreys & hagfish Notochord not replaced by vertebrae Cartilaginous cranium, scaleless body Sea lamprey predaceous - horny teeth in buccal cavity & on tongue - secretes anti-coaggulant Lateral Line System No stomach or spleen 5 - 7 year life span - adults move into freshwater streams, spawn, & die.
    [Show full text]
  • Phylogeny of Basal Tetrapoda
    Stuart S. Sumida Biology 342 Phylogeny of Basal Tetrapoda The group of bony fishes that gave rise to land-dwelling vertebrates and their descendants (Tetrapoda, or colloquially, “tetrapods”) was the lobe-finned fishes, or Sarcopterygii. Sarcoptrygii includes coelacanths (which retain one living form, Latimeria), lungfish, and crossopterygians. The transition from sarcopterygian fishes to stem tetrapods proceeded through a series of groups – not all of which are included here. There was no sharp and distinct transition, rather it was a continuum from very tetrapod-like fishes to very fish-like tetrapods. SARCOPTERYGII – THE LOBE-FINNED FISHES Includes •Actinista (including Coelacanths) •Dipnoi (lungfishes) •Crossopterygii Crossopterygians include “tetrapods” – 4- legged land-dwelling vertebrates. The Actinista date back to the Devonian. They have very well developed lobed-fins. There remains one livnig representative of the group, the coelacanth, Latimeria chalumnae. A lungfish The Crossopterygii include numerous representatives, the best known of which include Eusthenopteron (pictured here) and Panderichthyes. Panderichthyids were the most tetrapod-like of the sarcopterygian fishes. Panderichthyes – note the lack of dorsal fine, but retention of tail fin. Coelacanths Lungfish Rhizodontids Eusthenopteron Panderichthyes Tiktaalik Ventastega Acanthostega Ichthyostega Tulerpeton Whatcheeria Pederpes More advanced amphibians Tiktaalik roseae – a lobe-finned fish intermediate between typical sarcopterygians and basal tetrapods. Mid to Late Devonian; 375 million years old. The back end of Tiktaalik’s skull is intermediate between fishes and tetrapods. Tiktaalik is a fish with wrist bones, yet still retaining fin rays. The posture of Tiktaalik’s fin/limb is intermediate between that of fishes an tetrapods. Coelacanths Lungfish Rhizodontids Eusthenopteron Panderichthyes Tiktaalik Ventastega Acanthostega Ichthyostega Tulerpeton Whatcheeria Pederpes More advanced amphibians Reconstructions of the basal tetrapod Ventastega.
    [Show full text]
  • The Big Picture Book
    BOOK PUBLISHERS Teachers Notes (Middle Years) by Dr John Long The Big Picture Book by Dr John Long, illustrated by Brian Choo ISBN 9781741143287 Recommended for ages 8-14 These notes may be reproduced free of charge for use and study within schools but they may not be reproduced (either in whole or in part) and offered for commercial sale. Introduction ............................................ 2 Science studies........................................ 2 Time........................................... 2 Astronomy .................................. 3 Geology ...................................... 3 Biology ....................................... 4 Science and the future .................. 6 Cultural studies ....................................... 6 Language................................................ 7 Meanings of some of the names featured in the book ........... 7 About the writer and illustrator .................. 7 Appendix: A ‘Bestiary’ of living things featured in the illustrations........................ 10 83 Alexander Street PO Box 8500 Crows Nest, Sydney St Leonards NSW 2065 NSW 1590 ph: (61 2) 8425 0100 [email protected] Allen & Unwin PTY LTD Australia Australia fax: (61 2) 9906 2218 www.allenandunwin.com ABN 79 003 994 278 INTRODUCTION This book was written to introduce to upper primary and lower secondary level children an outline of the three main themes that contribute towards our understanding of evolution: time, physical processes, and biological change. The book can be used to augment studies in general science (astronomy, geology, biology), but also to contribute to an understanding of the birth of human culture and to promote discussion of environmental issues confronting the world today. The writing is a simple, almost lyrical style to facilitate an easy level of reading, with pronunciation guide and glossary at the back of the book to help children say and understand the meaning of most of the technical words used in the text.
    [Show full text]
  • Hans-Peter Schultze, a Great Paleoichthyologist for Whom Work Is Synonymous with Enjoyment
    Mitt. Mus. Nat.kd. Berl., Geowiss. Reihe 5 (2002) 5-17 10.11.2002 Hans-Peter Schultze, a great paleoichthyologist for whom work is synonymous with enjoyment Richard Cloutierl With 4 figures and 2 tables In the summer of 1982, Hans-Peter Schultze and above all by his simplicity and friendliness. Two Gloria Arratia were invited to a small museum years later I started my PbD. at The University located on a fossiliferous site of the Devonian of Kansas, under the supervision of Hans-Peter. Escuminac Formation in Miguasha, Quebec, Compared to his long career, these two weeks eastern Canada. Hans-Peter was to work with that Hans-Peter spent in Miguasha represent an Marius Arsenault, the director of the Miguasha extremely short period of time. Some might say Museum, on the skull of the elpistostegalid EZ- that this little anecdote is insignificant when in- pistostege watsoni, a species closely related to ba- troducing a vertebrate paleontologist (Fig. ZA) sal tetrapods. In addition, he went through the who published 132 papers and books (a total of collections to describe and measure numerous 2977 published pages) in addition to more than juvenile specimens of the osteolepiform Eusthe- 80 abstracts, book reviews and obituaries. How- nopteron foordi. As expected, these two projects ever, this brief story is representative of Hans- turned out to be important contributions in low- Peter’s personality and contributions. He is a er vertebrate paleontology and systematics: one great scientist with numerous interests in science, on the origin of tetrapods (1985), and the second art, and history. Hans-Peter enjoys digging for one on growth patterns of a Late Devonian fish fossils, looking at fossils and describing fossils, (1984).
    [Show full text]
  • A Comparative Study of Piscine Defense the Scales of Arapaima
    Journal of the mechanical behavior of biomedical materials xx (xxxx) xxxx–xxxx Contents lists available at ScienceDirect Journal of the Mechanical Behavior of Biomedical Materials journal homepage: www.elsevier.com/locate/jmbbm A comparative study of piscine defense: The scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula ⁎ Vincent R. Shermana, Haocheng Quana, Wen Yangb, Robert O. Ritchiec, Marc A. Meyersa,d, a Department of Mechanical and Aerospace Engineering, Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA b Department of Materials, ETH Zurich, 8093 Zurich, Switzerland c Department of Materials Science and Engineering, University of California Berkeley, CA 94720, USA d Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA ARTICLE INFO ABSTRACT Keywords: We compare the characteristics of the armored scales of three large fish, namely the Arapaima gigas Scales (arapaima), Latimeria chalumnae (coelacanth), and Atractosteus spatula (alligator gar), with specific focus on Bioinspiration their unique structure-mechanical property relationships and their specialized ability to provide protection from Bouligand predatory pressures, with the ultimate goal of providing bio-inspiration for manmade materials. The arapaima Alligator gar has flexible and overlapping cycloid scales which consist of a tough Bouligand-type arrangement of collagen Coelacanth layers in the base and a hard external mineralized surface, protecting it from piranha, a predator with extremely Arapaima sharp teeth. The coelacanth has overlapping elasmoid scales that consist of adjacent Bouligand-type pairs, forming a double-twisted Bouligand-type structure. The collagenous layers are connected by collagen fibril struts which significantly contribute to the energy dissipation, so that the scales have the capability to defend from predators such as sharks.
    [Show full text]
  • I Ecomorphological Change in Lobe-Finned Fishes (Sarcopterygii
    Ecomorphological change in lobe-finned fishes (Sarcopterygii): disparity and rates by Bryan H. Juarez A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science (Ecology and Evolutionary Biology) in the University of Michigan 2015 Master’s Thesis Committee: Assistant Professor Lauren C. Sallan, University of Pennsylvania, Co-Chair Assistant Professor Daniel L. Rabosky, Co-Chair Associate Research Scientist Miriam L. Zelditch i © Bryan H. Juarez 2015 ii ACKNOWLEDGEMENTS I would like to thank the Rabosky Lab, David W. Bapst, Graeme T. Lloyd and Zerina Johanson for helpful discussions on methodology, Lauren C. Sallan, Miriam L. Zelditch and Daniel L. Rabosky for their dedicated guidance on this study and the London Natural History Museum for courteously providing me with access to specimens. iii TABLE OF CONTENTS ACKNOWLEDGEMENTS ii LIST OF FIGURES iv LIST OF APPENDICES v ABSTRACT vi SECTION I. Introduction 1 II. Methods 4 III. Results 9 IV. Discussion 16 V. Conclusion 20 VI. Future Directions 21 APPENDICES 23 REFERENCES 62 iv LIST OF TABLES AND FIGURES TABLE/FIGURE II. Cranial PC-reduced data 6 II. Post-cranial PC-reduced data 6 III. PC1 and PC2 Cranial and Post-cranial Morphospaces 11-12 III. Cranial Disparity Through Time 13 III. Post-cranial Disparity Through Time 14 III. Cranial/Post-cranial Disparity Through Time 15 v LIST OF APPENDICES APPENDIX A. Aquatic and Semi-aquatic Lobe-fins 24 B. Species Used In Analysis 34 C. Cranial and Post-Cranial Landmarks 37 D. PC3 and PC4 Cranial and Post-cranial Morphospaces 38 E. PC1 PC2 Cranial Morphospaces 39 1-2.
    [Show full text]