摘要:

An intact and well‐preserved biota of cavity‐dwelling organisms (coelobionts) of early Cambrian age is found within growth‐framework cavities in archaeocyathid patch reefs of the lower Forteau Formation (upperBonnia‐OlenellusZone) of southern Labrador. The biota was diverse, and consisted of encrusting and vagrant organisms.Renalcis, aRenalcis‐likeform,Epiphyton, Girvanella, andSerligia, all lived attached to walls and roofs of the cavities; other attached formswere Bija, Archaeotrypa, and two types ofWetheredella, an agglutinated foraminifer. Other organisms, including trilobites, probable calcareous ostracodes, brachiopods, echinoderms, and worms, as well as fungi, are also found preserved within the cavities. The structure of the coelobiontic community is surprisingly modern; it indicates that as early as the Lower Cambrian coelobiontic organisms were well‐established in reefs, and were an important part of the reef community

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb00997.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Enrollment is not as fundamental a character complex for the classification of Trilobita as Bergstrom (1973,Fossils and Strata 2;1977.Lethaia 10) has claimed. Different enrollment styles occur within accepted monophyletic taxa, which cut across Bergstrom's (1973) classification and which support the concept of the Order Proetida Fortey&Owens, 1975. False phylogenetic relationships are deduced from unjustifieda prior;assumptions about the nature of primitive and derived character states.Einrollung ist kein so grundlegendes Merkmal für die Klassifizierung der Trilobiten, wie dies Bergström (1973,Fossils and Strata 2;1977,Lethaia 10) gefordert hat. Das Auftreten verschiedener Einrollungs‐weisen innerhalb anerkannter monophyletischer Taxa durchkreuzt nämlich seine Klassifizierung (1973), stützt aber die der Aufstellung der Ordnung Proetida Fortey&Owens 1975 zugrundeliegende Auf‐fassung. Unrichtige apriori‐Antworten auf die Frage, was primitive und was sekundäre Merkmale sind, führen zu irrigen Folgerungen über phylogenetische Zusammenhänge.L'enroulement n'est pas, pour la classification des Trilobites, un ensemble de caracteres aussi fonda‐mental que Bergström(1973,Fossils and Strata 2; 1977. Lethaia 10)abien voulu le dire. Différents styles d'enroulement sont présents chez des taxa reconnus comme monophylétiques ce qui ne correspond pas á la classification de Bergström (1973) mais vient à I'appui de I'Ordre Proetida Fortey&Owens 1975. Des distinctionsa prior;et insuffisamment fondées entre caractères primitifs et caractères évolués conduisent á l'establissement de relati

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb00998.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb00999.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Representatives of the disjunct element conodont genusGnathodusdescribed from lower Mississippian strata (Kinderhookian and Osagean Series) in the Midcontinent of North America illustrate a phylogenetic association composed of ten species. The lineage of G.delicatus — G. punctatus‐G. semiglaber, of late Kinderhookian to early Osagean age, has been documented previously. Three distinct forms, G. cf.bilineatus, G. anfetexanus, and G.bulbosus, descended from G.semiglaberin early Osagean time. The latter two continued as parallel lineages;G. bulbosus‐G. pseudosemiglaberandG. antetexanus‐G. taxanus. In addition, two dead‐end lineages, represented by G.typicusand G.cuneiformis, were separately derived from G.antetexanus. Comparison with gnathodont faunas described from Great Britain, Europe, and Australia indicates worldwide distribution of this lineage. The apparent homotaxis ofGnathodusillustrates the value that has been placed on conodonts as tools for regional and intercontinental co

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb01000.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb01001.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Evolutionary lineages of conodont elements and of some apparatuses are gradually being documented to increase the value of these fossils in stratigraphic interpretation and to further our understanding of conodont taxonomy. The well‐documented faunas from Mississippian strata of the Illinois Basin and type Mississippian beds provide a great deal of information for the recognition of phylogenies. The disjunct element genusSpathognathodusis part of a basic and long‐ranging type of conodont apparatus from which a number of other forms have been derived, and some of its Mississippian disjunct element species can now be placed in multielement species. A lineage involving spathognathodont Pa elements recognized in the Mississippian, then, is the basis of the present study. The phylogeny recognized started withSynprioniodina? crassidentata, and includesS.? regularis, S.? pulchra, S.? coalescens, S.? spicula, Hinduodus cristula, andH. minutusin the Mississippian.Aputiignathus scitulusandA. penrscitulusapparently represent a separate line, which also might include disjunct elementSpathognathodus rexro

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb01002.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb01003.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Sample populations ofSolenastrea fairbanksi, collected from different environments in the Pliocene Imperial Formation, can be distinguished by measurements of linear dimensions of the coenosteum and thickness of septal structures. In these characters, magnitudes of intercolony variance components are lower than interpopulation or intracolony components, suggesting that the variation is largely caused by environmental factors. Three patterns of mean variation exist between populations: (1) Highest means occur in shallow, offshore (high energy) environments. (2) Highest means occur in shallow environments with low turbidity (high light intensity). (3) Highest means occur in clear, deeper offshore environments (favorable nutrient supply). The distance between adjacent corallites and the inverse of coenosteal porosity follow the first pattern, measures of thickness of vertical corallite structures follow the second, whereas estimates of annual growth rate follow the third. Corallite diameters and columella thicknesses do not vary between populations. Comparisons with modern species show that many characters inS. fairbanksirespond to environmental factors in a manner different from similar characters in other scleractinian species. In fact, some inflexible characters inS. fairbunksiare highly flexible in other species.

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb01004.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb01005.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Supraorbital bones inSaurolophus angustirostrisare described, and their presence in all hadrosaurs is suggested. Frontal‐nasal and premaxillar‐nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginousdiverticulum nasiwithin the circumnarial depression inSaurobphus ongustirostrisare presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is propo

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1979.tb01006.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY