DOCSLIB.ORG

Anatomy of the Middle Ear Region of the Avian Skull: Sphenisciformes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

ANATOMY OF THE MIDDLE EAR REGION OF THE AVIAN SKULL: SPHENISCIFORMES EDWARD SAIFF WHEN I reviewedthe literature on the middle ear regionof birds (Saiff 1974), it became obvious that few anatomical studies have been made on this regionin birds, penguinsin particular. Watson's (1883) report on the anatomyof the Sphenisciformeslacks any detailson the middleear. Walker (1888) studiedquadrate morphology in a large variety of birds includingSphenisciformes. Pycraft (1898) describedthe skullof penguins but passedover the middle ear region save for a few brief statementsre- gardingthe quadrate,basitemporal platform, eustachiantube, and the trigeminalforamen. Shufeldt (1901) also failed to go into detailsof the middleear regionin his osteologicalstudy of the penguins.More recently, in a study of the evolution of penguins,Simpson (1946) describedthe skull of Paraptenodytesantarcticus, a fossilpenguin. This studytheorized a close relationship between the penguins and the Procellariiformes. Crompton (1953) made a further study on penguinsand did an extensive developmentalstudy of the chondrocranium.An analysisof middle ear anatomy of Procellariiformes,including a glossaryof avian middle ear characters,appears in Saiff (1974). Recently Frost et al. (1975) de- scribedthe circulatory systemin the head o/ Spheniscusdemersus in an effort to describeheat-exchange systems in penguins. Obviouslacunae exist in the studyof the middleear of birds,including Sphenisciformes.This study describesthe anatomyof the middle ear and basicraniaof the Sphenisciformesand where possiblemakes com- parisonswith Procellariiformes. MATERIALS AND METItODS This study is based on an analysis of charactersof specimensborrowed from the Bird Department of the American Museum of Natural History. Peters (1931) was used as the basis for the genericclassification and Wetmore (1930) for the higher taxa. I studied the following specimens: dried skull: Aptenodytes/orsteri AMNH 3745. A. patagonicaAMNH 1623, 2611, 3139, 4630, 4383, 4382. Eudyptes chrysolophus AMNH 5974. E. crestatusAMNH 3854, 5398, 5972. E. pachyrhynchusAMNH no number. E. schlegeliAMNH 5399. Eudyptula rainor AMNH 5314, 5620, 6257. Megadyptesantipodes AMNH 5613, 5615. Pygoscelisadeliae AMNH 5041. P. papua A.MNIt 3196, 4361, 5373, 5766, 5973. Spheniscusderaersus AMNH 1625, 1310, 3875, 4042, 4069, 4942. S. huraboldtiAMNH 2768, 4920, 4921. S. raendiculusAMNH 3648, 3772. Dissected: S. deraersus AMNH 4548. 749 The Auk 93: 749-759. October 1976 750 EDWARDSA• [Auk, Vol. 93 ANATOMICAL DESCRIPTIONS EXTERNAL.--Theexternal auditory meatusis on the same horizontal plane as the gape. The meatus lies on the border of a white band of feathersthat runs first over and then behind the eye and a dark feather patch that extendsposterior to the gape onto the throa region. The feathers that cover the external meatus grow only from its anterior rim. The meatus ranges between 2.4 to 3.5 mm tall and 1.9 to 2.1 mm wide (2 ears). The rim of the meatusdoes not appearto be sopliable as to close completely. The external auditory canal is directed posteroventrally.No ridges appear on the inner membranouslining of the canal. Ridges do appear with somedegree of consistencyin Procellariiformes(Saiff 1974) although the presenceor absenceof suchridges may be an effect of preservation. Upon removal of the m. depressormandibulac, the oater membrane coveringof the external auditory canal becomesvisible and when this is dissectedopen the tympanicmembrane comes into view. The tympanic membrane is roughly circular in shape, mildly protubcrant, and faces posterolaterad.It is composedof a tough, thick outer layer that is quite elastic and a thinner but equally tough inner layer. The outer layer of the tympanic membrane is a continuation of the lining of the external auditory canal while the inner layer is continuouswith the epithelium lining the middle ear cavity. The inferior processof the extra-columella, coveredby its ligament,lies embeddedwithin the inner tympaniclayer. Here the tympanic membrane is thickened. The tympanic membrane separatesthe externalauditory canal from the middle ear cavity. ANATOMY O1' THE MIDDLE EAR REGION. The middle ear of all six generaof penguinsis characterizedby a conicaltympanic cavity as seen in Fig. 1 that opensto the rear of the skull medial to the quadrate. Watson (1883) clearly figured this region but did not label it. The dorsal,ventral, and anteriorwall of the tympaniccavity is a curvedplate of bone that extendslaterally to touch the rear of the dorsalend of the quadrate; the ventral edgeof this plate is bent backwardhorizontally to form, alongwith a lateral extensionof the basitemporalplate, the ventral wall of the tympanic cavity. The tympanicmembrane (seen dried in placein someskulls as well as in situ in AMNH 4548) is stretchedacross the rear apertureof the tympanic cavityfrom the metoticprocess to the quadrate.On the medialwall of the tympanic cavity is the fenestraovalis, posteriorto which is a pneumatic foramen. Ventral to thesetwo structuresis the recessusscalae tympani. The seventh nerve foramen varies among the specimensexamined. A facial foramenopening within the tympaniccavity is lackingin Eudyptes, October1976] PenguinMiddle Ear Region 751 VlI FR AQF U/TRC I / / / •X !..... H PA ET BP MP CF M Fig. 1. Spi•eniscusdemersus (AMNH 4042) obliqueventral view of the left middle ear regionwith quadrateremoved: AQF, anteriorquadrate facet; BP, basitemporal platform;C, columella;CF, carotidforamen; ET, entranceto eustachiancanal; FP, foramenprooticum; H, hypoglossalforamen; IX, glossopharyngealforamen; •I, metoticprocess; MP, mammillaryprocess of basitemporalplatform; OF, foramenfor occipitalvein; P, pneumaticforamen; PA, foramenfor palatineartery; SF, stapedial arterialforamen; TC, tympaniccavity; UTR, uppertympanic recess; VCL, exit point from skullof venacapiris lateralis; VIIp, foramenfor palatinebranch of facialnerve; X, vagal foramen. Eudyptula,Megadyptes, and Spheniscus. Crompton (1953) studiedthe de- velopmentalprocess involved in this arrangementin Spheniscus.The palatinenerve enters the carotidcanal through a foramenon its dorso- medialsurface in orderto runforward along with the carotid artery. The sectionof the carotidcanal where the palatinenerve and carotidartery traveltogether represents the parabasalcanal. At the anterolateraledge of the parabasalcanal is a foramen for the forward continuationof the palatinenerve. Just anteriorto this palatinenerve foramen is a larger foramenfor the palatine artery. The hyomandibularbranch of the facial nerveexits from a foramenlocated posterodorsal and lateral to 752 Et)w^a• S^•v [Auk, Vol. 93 the fenestraovalis and then leavesthe middle ear regionwith the stapedial artery throughthe stapedialarterial foramen. One specimenof Eudyptula (AMNH 5314) I examinedhad a foramenonly on the right side of the inner wall of the tympanic cavity. This foramenis coveredover by a membraneand is probably pneumatic. Aptenodytes has a facial foramen. Dorsal and lateral to the facial foramen is an overhang of bone that is a forward continuation of the lateral wall of a canal that curvesposterodorsally above the fenestra ovalis and opensposteriorly into the middle ear cavity. The posterior openingis directed toward the foramen housingthe stapedialartery. It seemsreasonable to assumethat the hyomandibularnerve travels within this bony canal up to the stapedialcanal and leavesthe middle ear region via the stapedialcanal and the stapedial arterial foramen. Anteroventral to the facial foramena foramenenters the carotidcanal from the tympanic cavity. Presumably the palatine nerve travels along the wall of the tympanic cavity to enter the carotid canal through this foramen. The presenceof a facial foramen opening into the middle ear of Pygosceliscannot be determined without a dissection. Anterolateral to the fenestraovalis in Pygoscelisare two fossaeseparated by a vertical ridge of bone. On this ridge is a foramenthat is patent only on the left side in one of the specimensexamined here (AMNH 5766) and in none of the others. It is not possibleto tell whether this foramen is for the facial nerve, and if so, for which branch. It is doubtful, though,that the palatinebranch would exit from this foramen. If it did, it wouldhave to travel posteriorlyfor almost the entire length of the tympanic cavity in order to enter the carotid canal as there is no foramen that leads into the carotid canal from the tympaniccavity as is presentin Aptenodytes. All speciesexamined had a bony canal for the stapedial artery dorsal to the columella,deep to the tympanic cavity. Posteriorto entry into the middle ear, the stapedial canal runs medial to a vertical bar of bone (the lateral edge of the metotic process) connectingthe rear of the paroccipitalprocess to the rear of the basitemporalplatform. Running anteriorly in the ventrolateralportion of the tympanic cavity are two bony canals: a lateral canal for the eustachiantube, and a more dorsomedialcarotid canal. These two canals are separatedby a thin plate of bone referred to by Pycraft (1898) as a downgrowthfrom the alisphenoidwing of the parasphenoid.Anteriorly, the tympaniccavity is blind. The blind area presumablyrepresents the presphenoidsinus of several Procellariiformes,Pelecaniformes, and Ciconiiformes(Salff 1973). In all penguinsexamined the carotid artery enters the carotid canal throughthe carotidforamen, which is locatedventromedial to the tympanic October 1976] Penguin Middle Ear Region 753 cavity. The carotidartery is neverexposed within the tympaniccavity.
Recommended publications
  • Longevity in Little Penguins Eudyptula Minor

    Longevity in Little Penguins Eudyptula Minor

    71 LONGEVITY IN LITTLE PENGUINS EUDYPTULA MINOR PETER DANN1, MELANIE CARRON2, BETTY CHAMBERS2, LYNDA CHAMBERS2, TONY DORNOM2, AUSTIN MCLAUGHLIN2, BARB SHARP2, MARY ELLEN TALMAGE2, RON THODAY2 & SPENCER UNTHANK2 1 Research Group, Phillip Island Nature Park, PO Box 97, Cowes, Phillip Island, Victoria, 3922, Australia ([email protected]) 2 Penguin Study Group, PO Box 97, Cowes, Phillip Island, Victoria, 3922, Australia Received 17 June 2005, accepted 18 November 2005 Little Penguins Eudyptula minor live around the mainland and Four were females, two were males and one was of unknown sex offshore islands of southern Australia and New Zealand (Marchant (Table 1). The oldest of the birds was a male that was banded by the & Higgins 1990). They are the smallest penguin species extant, Penguin Study Group as a chick before fledging on Phillip Island breeding in burrows and coming ashore only after nightfall. Most on 2 January 1976 in a part of the colony known as “the Penguin of their mortality appears to result from processes occurring at sea Parade.” This bird was not recorded again after initial banding (Dann 1992). The average life expectancy of breeding adult birds until it was five years old and was found raising two chicks at the is approximately 6.5 years (Reilly & Cullen 1979, Dann & Cullen Penguin Parade. This individual had a bill depth measurement 12% 1990, Dann et al. 1995); however, some individuals in southeastern less than the mean for male penguins from Phillip Island (Arnould Australia have lived far in excess of the average life expectancy. et al. 2004), but was classified as a male based on the sex of its mates (sexed as females from the presence of cloacal distension Approximately 44 000 birds have been flipper-banded on Phillip following egg-laying or from their bill-depth measurements).
  • Genomic Characterisation of a Novel Avipoxvirus Isolated from an Endangered Yellow-Eyed Penguin (Megadyptes Antipodes)

    Genomic Characterisation of a Novel Avipoxvirus Isolated from an Endangered Yellow-Eyed Penguin (Megadyptes Antipodes)

    viruses Article Genomic Characterisation of a Novel Avipoxvirus Isolated from an Endangered Yellow-Eyed Penguin (Megadyptes antipodes) Subir Sarker 1,* , Ajani Athukorala 1, Timothy R. Bowden 2,† and David B. Boyle 2 1 Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC 3086, Australia; [email protected] 2 CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, VIC 3220, Australia; [email protected] (T.R.B.); [email protected] (D.B.B.) * Correspondence: [email protected]; Tel.: +61-3-9479-2317; Fax: +61-3-9479-1222 † Present address: CSIRO Australian Animal Health Laboratory, Australian Centre for Disease Preparedness, Geelong, VIC 3220, Australia. Abstract: Emerging viral diseases have become a significant concern due to their potential con- sequences for animal and environmental health. Over the past few decades, it has become clear that viruses emerging in wildlife may pose a major threat to vulnerable or endangered species. Diphtheritic stomatitis, likely to be caused by an avipoxvirus, has been recognised as a signifi- cant cause of mortality for the endangered yellow-eyed penguin (Megadyptes antipodes) in New Zealand. However, the avipoxvirus that infects yellow-eyed penguins has remained uncharacterised. Here, we report the complete genome of a novel avipoxvirus, penguinpox virus 2 (PEPV2), which was derived from a virus isolate obtained from a skin lesion of a yellow-eyed penguin. The PEPV2 genome is 349.8 kbp in length and contains 327 predicted genes; five of these genes were found to be unique, while a further two genes were absent compared to shearwaterpox virus 2 (SWPV2).
  • The Ear in Mammal-Like Reptiles and Early Mammals

    The Ear in Mammal-Like Reptiles and Early Mammals

    Acta Palaeontologica Polonica Vol. 28, No. 1-2 pp, 147-158 Warszawa, 1983 Second Symposium on Mesozoic T erre stial Ecosystems, Jadwisin 1981 KENNETH A. KERMACK and FRANCES MUSSETT THE EAR IN MAMMAL-LIKE REPTILES AND EARLY MAMMALS KERMACK, K . A. a nd MUSS ETT, F.: The ear in mammal-like r eptiles an d early mammals. Acta Palaeont. P olonica , 28, 1-2, 147-158, 1983. Th e early m embers of the Theropsida lacked a tympanic membrane. In the later theropslds, the Therapsid a, a tym p an ic membrane develop ed from thc skin on the lateral side of th e lower jaw. The tympanum is not homologous In the Therapsida and ' t he Sauropslda. The ther apsid ea r w as a poor receiver of airborne sound, both In hi gh frequency r esp onse and In the r ange of frequencies encompassed. With the radiation of the Sauropsida in the Triassic the large therapsids became extinct, the small therap si ds evolv ed In to the mammal s and became nocturnal. High frequency hearin g w as essen tial for the nocturn al mode of life; quadrate and arttcutar became diss ociated from the jaw hinge to become the m ammali an au di tory ossi cles . I n the Theria the cochlea became coil ed. The spiral cochlea could n ot have existed until there w as a middle ear w ith the n ec essary h ig h f re q uency r esp onse. This m ay n ot have been until the Cretace ous.
  • Declining Eastern Rockhopper (Eudyptes Filholi) and Erect-Crested (E

    Declining Eastern Rockhopper (Eudyptes Filholi) and Erect-Crested (E

    124 AvailableNew on-lineZealand at: Journal http://www.newzealandecology.org/nzje/ of Ecology, Vol. 38, No. 1, 2014 Declining eastern rockhopper (Eudyptes filholi) and erect-crested (E. sclateri) penguins on the Antipodes Islands, New Zealand Johanna A. Hiscock1 and B. Louise Chilvers2* 1Southern Islands, Department of Conservation, PO Box 743, Invercargill, New Zealand 2Marine Species and Threats, Department of Conservation, PO Box 10 420, Wellington, New Zealand *Author for correspondence (Email: [email protected]) Published online: 7 November 2013 Abstract: New Zealand’s subantarctic Antipodes Islands are of international significance for breeding seabirds. However, penguin populations on the islands are declining. Uncertainty about the extent of this decline has been accentuated by a lack of accurate information on the population size and nest distribution of the penguin species, and the absence of an appropriate methodology for their long-term monitoring. We surveyed the nest abundance and distribution of eastern rockhopper penguins (Eudyptes filholi) and erect-crested penguins (E. sclateri) on the Antipodes Islands from 22 October to 6 November 2011 and compared counts with historical censuses from 1978 to 1995. Presence or absence of colonies previously known to have existed was recorded and counts of all nests within colonies around the islands were undertaken. In total, 42 689 nests of both species were counted over 103 colonies. Of these, 86% of nests (2475 rockhopper and 34 226 erect-crested) were counted accurately from on land. Overall, 24 entire colonies have ceased to exist since 1978, and there was an estimated 23% decline in the number of penguin nests between 1995 and 2011.
  • The Skull O Neurocranium, Form and Function O Dermatocranium, Form

    The Skull O Neurocranium, Form and Function O Dermatocranium, Form

    Lesson 15 ◊ Lesson Outline: ♦ The Skull o Neurocranium, Form and Function o Dermatocranium, Form and Function o Splanchnocranium, Form and Function • Evolution and Design of Jaws • Fate of the Splanchnocranium ♦ Trends ◊ Objectives: At the end of this lesson, you should be able to: ♦ Describe the structure and function of the neurocranium ♦ Describe the structure and function of the dermatocranium ♦ Describe the origin of the splanchnocranium and discuss the various structures that have evolved from it. ♦ Describe the structure and function of the various structures that have been derived from the splanchnocranium ♦ Discuss various types of jaw suspension and the significance of the differences in each type ◊ References: ♦ Chapter: 9: 162-198 ◊ Reading for Next Lesson: ♦ Chapter: 9: 162-198 The Skull: From an anatomical perspective, the skull is composed of three parts based on the origins of the various components that make up the final product. These are the: Neurocranium (Chondocranium) Dermatocranium Splanchnocranium Each part is distinguished by its ontogenetic and phylogenetic origins although all three work together to produce the skull. The first two are considered part of the Cranial Skeleton. The latter is considered as a separate Visceral Skeleton in our textbook. Many other morphologists include the visceral skeleton as part of the cranial skeleton. This is a complex group of elements that are derived from the ancestral skeleton of the branchial arches and that ultimately gives rise to the jaws and the skeleton of the gill
  • Behavior and Nesting Success Relative to Nest Location in Adslie Penguins (Pygoscelis Adeliae)

    Behavior and Nesting Success Relative to Nest Location in Adslie Penguins (Pygoscelis Adeliae)

    BEHAVIOR AND NESTING SUCCESS RELATIVE TO NEST LOCATION IN ADSLIE PENGUINS (PYGOSCELIS ADELIAE) RICHARD TENAZAl Department of Zoology University of Wisconsin Madison, Wisconsin This study is an experimental evaluation of the predictions for three reasons: (1) it is much hypothesis that differences in nest positions less disturbed in the presence of man than within and outside Ad&e Penguin colonies are most colonial sea birds, (2) it is subject influence behavior, egg loss rates, and nest to predation upon eggs and chicks, and (3) characteristics. “Colony” and “rookery” are theft of nest material from neighbors is con- used in this report as defined for Ad&lies by spicuous and frequent. Also, the breeding Penney (X365:85): “A colony is a geograph- behavior and ecology of the Ad&lie is the ically continuous group of breeding birds best known of the Antarctic penguins. whose territorial boundaries are contiguous,” and a rookery is a “geographical area . that METHODS contains one or more colonies.” The study was conducted at Cape Hallet (72” 18 ’ 50” The actions of predators and conspecifics S, 170” 13 ’ 00” E ), Victoria Land, Antarctica, during within a dense nesting colony of Ad&es or the 1967-1968 austral summer. The Cape Hallet other sea birds are highly predictable. Nests Ad&e Penguin rookery occupies about 40 ha of a are regularly spaced, just far enough apart to low lying spit (“Seabee Spit”), approximately 1000 m long and 200-650 m wide, projecting into the Moubray allow owners of adjacent territories to touch Bay inlet of the Ross Sea (fig.
  • Eudyptula Minor) Picture of Bird Full Life History Info: H�P://Nzbirdsonline.Org.Nz/Species/Li�Le-Penguin

    Eudyptula Minor) Picture of Bird Full Life History Info: HP://Nzbirdsonline.Org.Nz/Species/LiLe-Penguin

    Lile Blue Penguin (Eudyptula minor) Picture of bird Full life history info: h@p://nzbirdsonline.org.nz/species/li@le-penguin Introduc>on Ecology and life history The Li@le Blue Penguin (also known as li@le penguin, Normal adult weight range: Male 925-1650g blue penguin, fairy penguin, or kororā) is the smallest Female 765-1250g of all the penguin species in the world. They are found Moult: Synchronous moult i.e. moults all feathers at the on the main islands and coastal islands of New Zealand same ,me. In January-March for a 2 week duraon. and along the southern Australian coastline. Recent During this period LBPs stay in the burrow and do not go gene,c analysis strongly suggests that the NZ and swimming to forage for food. They can loose up to 50% of Australian li@le penguins are two separate species. body weight during this period. Although they are the most common penguins in their Breeding: July to February. range, the populaon is declining due to several Monogamous. threatening processes including introduced predators Egg laying between Jul to Nov. (dogs and cats, ferrets in NZ and foxes in Australia), Incubaon 30-39 days. human disturbance or destruc,on of nes,ng habitat Age at fledging 54-56 days. and decreased food supplies through overfishing. Age at first breeding 2-3 years. LBPs are a robust and resilient species that copes well Lifespan: up to 25 years. in the rehabilitaon environment, making them the Diet: Piscivorous ideal candidate for wash, rehabilitaon and release Conserva>on status (NZ Threat Classifica>on): Declining during an oil spill.
  • Foraging Behaviour of the Chinstrap Penguin 85

    Foraging Behaviour of the Chinstrap Penguin 85

    1999 Wilson & Peters: Foraging behaviour of the Chinstrap Penguin 85 FORAGING BEHAVIOUR OF THE CHINSTRAP PENGUIN PYGOSCELIS ANTARCTICA AT ARDLEY ISLAND, ANTARCTICA RORY P. WILSON & GERRIT PETERS Institut für Meereskunde an der Universität Kiel, Düsternbrooker Weg 20, D-24105 Kiel, Germany ([email protected]) SUMMARY WILSON, R.P. & PETERS, G. 1999. Foraging behaviour of the Chinstrap Penguin Pygoscelis antarctica at Ardley Island, Antarctica. Marine Ornithology 27: 85–95. The foraging behaviour of 20 Chinstrap Penguins Pygoscelis antarctica breeding at Ardley Island, King George Island, Antarctica was studied during the austral summers of 1991/2 and 1995/6 using stomach tem- perature loggers (to determine feeding patterns), depth recorders and multiple channel loggers. The multi- ple channel loggers recorded dive depth, swim speed and swim heading which could be integrated using vectors to determine the foraging tracks. Half the birds left the island to forage between 02h00 and 10h00. Mean time at sea was 10.6 h. Birds generally executed a looping type course with most individuals foraging within 20 km of the island. Maximum foraging range was 33.5 km. Maximum dive depth was 100.7 m although 80% of all dives had depth maxima less than 30 m. The following dive parameters were positively related to maximum depth reached during the dive: total dive duration, descent duration, duration at the bottom of the dive, ascent duration, descent angle, ascent angle, rate of change of depth during descent and rate of change of depth during ascent. Swim speed was unrelated to maximum dive depth and had mean values of 2.6, 2.5 and 2.2 m/s for the descent, bottom and ascent phases of the dive.
  • Mammalogy Lecture 2 - Origin of Mammals I

    Mammalogy Lecture 2 - Origin of Mammals I

    Mammalogy Lecture 2 - Origin of Mammals I. There are three major living (extant) groups of mammals A. Monotremes - egg laying mammals B. Metatherians - marsupial mammals C. Eutherians - Placental mammals These are related by the following evolutionary tree or phylogeny Monotremes Metatherians (Marsupials) Eutherians (Placentals) Node - Divergence Event Branch - Common Ancestor Marsupials and placentals share an ancestor not shared by monotremes. II. A. In order to understand the origin of mammals, we have to look farther back, into the Paleozoic (350 MYA), and look at relationships among the tetrapod vertebrates. So we’ll start by going deeper in time, and work our way back up to this level in the phylogeny. Amp hibians Mamm als Tur tles Squ amates Crocodylians Dino1 Birds Dino 2 Synaps ida Stem Rep tiles - Captor hino mo rp hs Am n ion Trans ition to land We can mark evolutionary changes along this phylogeny; the evolution of limbs, the evolution of the amnion, etc. It’s this lineage labeled Synapsida that we’ll examine in order to understand the origin of mammals. We need to understand the situation just prior to this in the “stem reptiles,” the ancestors to mammals, birds, turtles, and other reptiles. Captorhinomorphs. B. In the Carboniferous, ca. 350 MYBP, the captorhinomorphs evolved, and the synapsid lineage diverged from the stem reptiles 30 MY later 320 MYA, and it’s this lineage that will eventually lead the modern mammals. Synapsid - “together arch” describes a skull condition that is unique to this lineage. The word “synapsid” is also used to refer to the group of organisms that exhibit this condition.
  • Birds of the Snares Islands, New Zealand

    Birds of the Snares Islands, New Zealand

    Notornis, 2001, Vol. 48: 1-40 0029-4470 0 The Ornithological Society of New Zealand, Inc. 2001 Birds of the Snares Islands, New Zealand COLIN M. MISKELLY Department of Zoology, University of Canterbury, Private Bag 4800, Christchurch, New Zealand Current address: Wellington Conservancy, Department of Conservation, PO. Box 5086, Wellington, New Zealand [email protected] PAUL M. SAGAR National Institute of Water &Atmospheric Research, PO. Box 8602, Christchurch ALAN J.D. TENNYSON Museum of New Zealand Te Papa Tongarewa, PO. Box 467, Wellington R. PAUL SCOFIELD Department of Zoology, University of Otago, PO. Box 56, Dunedin Abstract Bird records from the Snares Islands between Dec 1982 and Oct 2000 are summarised. Population estimates and distributions are given for the 29 breeding species. Bird species recorded breeding on the Snares Is for the first time since 1982 were southern black-browed albatross (Diomedea melanophtys), Chatham Island albatross (D. eremita), mallard (Anasplatyrhynchos), southern black-backed gull (Larus dominicanus), fantail (Rhipidura Juliginosa), and starling (Sturnus vulyaris). Fantails are now abundant on the Snares Is. Published work on the breeding chronology and breeding success of 8 intensively studied species is summarised, and new information on breeding ecology is presented for all breeding species. Sighting of 70 non-breeding and vagrant species are summarised;34 of these were new records from the Snares Is since 1980. The total bird list for the Snares Is is now 99 species, with a further 8 species reported from boats offshore. Miskelly, C.M.; Sagar, EM.; Tennyson, A.J.D;Scofield, R.l? 2001. Birds of the Snares Islands, New Zealand.Notornis 48(1): 1-40.
  • Endangered Species Research 39:293

    Endangered Species Research 39:293

    Vol. 39: 293–302, 2019 ENDANGERED SPECIES RESEARCH Published August 22 https://doi.org/10.3354/esr00970 Endang Species Res OPENPEN ACCESSCCESS Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean Antje Steinfurth1,2,*,**, Jenny M. Booth3,**, Jeff White4, Alexander L. Bond5,6, Christopher D. McQuaid3 1FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7700, South Africa 2RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, David Attenborough Building, Cambridge, Cambridgeshire CB2 3QZ, UK 3Coastal Research Group, Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa 4Marshall University, Huntington, WV 25755, USA 5RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire SG19 2DL, UK 6Bird Group, Department of Life Sciences, The Natural History Museum, Tring, Hertfordshire HP23 6AP, UK ABSTRACT: The Endangered northern rockhopper penguin Eudyptes moseleyi, like all pen- guins, is monomorphic, making sex determination of individuals in the field challenging. We examined the degree of sexual size dimorphism of adult birds across the species’ breeding range in the Atlantic Ocean and developed discriminant functions (DF) to predict individuals’ sex using morphometric measurements. We found significant site-specific differences in both bill length and bill depth, with males being the larger sex on each island. Across all islands, bill length contri - buted 78% to dissimilarity between sexes. Penguins on Gough Island had significantly longer bills, whilst those from Tristan da Cunha had the deepest. Island-specific DFs correctly classified 82−94% of individuals, and all functions performed significantly better than chance.
  • Department of the Interior Fish and Wildlife Service

    Department of the Interior Fish and Wildlife Service

    Thursday, December 18, 2008 Part III Department of the Interior Fish and Wildlife Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; 12-Month Findings on Petitions To List Penguin Species as Threatened or Endangered Under the Endangered Species Act; Proposed Rules VerDate Aug<31>2005 18:06 Dec 17, 2008 Jkt 217001 PO 00000 Frm 00001 Fmt 4717 Sfmt 4717 E:\FR\FM\18DEP2.SGM 18DEP2 rwilkins on PROD1PC63 with PROPOSALS2 77264 Federal Register / Vol. 73, No. 244 / Thursday, December 18, 2008 / Proposed Rules DEPARTMENT OF THE INTERIOR • Federal eRulemaking Portal: http:// within 12 months following receipt of www.regulations.gov. Follow the the petition on whether the requested Fish and Wildlife Service instructions for submitting comments. action is warranted, not warranted, or • U.S. mail or hand-delivery: Public warranted but precluded by higher- 50 CFR Part 17 Comments Processing, Attn: [FWS–R9– priority listing actions (this finding is [FWS–R9–IA–2008–0069; 96000–1671– IA–2008–0069]; Division of Policy and referred to as the ‘‘12-month finding’’). 0000–B6] Directives Management; U.S. Fish and Section 4(b)(3)(C) of the Act requires Wildlife Service; 4401 N. Fairfax Drive, that a finding of warranted but RIN 1018–AV73 Suite 222; Arlington, VA 22203. precluded for petitioned species should We will not accept comments by be treated as having been resubmitted Endangered and Threatened Wildlife e-mail or fax. We will post all comments on the date of the warranted but and Plants; 12-Month Finding on a on http://www.regulations.gov.