摘要:

A well‐preserved portion of a body chamber of a coiled nautiloid (taxon uncertain) from the Kendrick Shale (Lower Pennsylvanian) of Floyd County, Kentucky, U.S.A., exhibits three comparatively large, nearly circular punctures and a circular indentation in the shell. These punctures are interpreted as representing an attack on the nautiloid by a cladodontid shark, most likely by the large symmoriid shark,Symmorium reniforme.We conclude that the punctures in the nautiloid body chamber were inflicted by three teeth in a single tooth file in the lower jaw of a specimen of 5.reniformethat was approximately 2.5 meters long. This nautiloid specimen is the first Paleozoic record of a chondrichthyan‐cephalopod/ predator‐prey relationship. We suggest, however, that this relationship was perhaps a common one and that other examples probably exist in collections of late Paleozoic ccphalopods. ?Paleozoic, Pennsylvanian,Symmorium reniforme,cephalopod. pred

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01613.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01614.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Specimens of inarticulate brachiopods (family Acrotrctidae) with boreholes were found in Upper Cambrian carbonates in the southern Great Basin of the United States. Some morphologic features and preferred orientation of the borings are similar to those made by predators and previously reported in the fossil and Holocene record. Such predatory activity on brachiopods is previously unknown in Cambrian rocks. Taxa associated with these specimens are not known to have been predators and identity of the predatory organism is unknown.Cambrian brachiopods, predation, paleoecology.

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01615.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Deformed fossils which originally had a regular geometric outline, such as crinoid columnals, can be restored using a scanning electron microscope technique called tilt correction. This magnifies the specimen in one direction only. It is unsuitable for specimens where deformation has occurred unevenly and can also distort small structures while restoring the whole specimen. DCrinoid columnals, scanning electron microscope, tilt correction.

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01616.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01617.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Size‐frequency and growth‐ring data have been used to calculate mortality and growth patterns in two micromorphic bivalve species from pelagic mud of Lower‐Middle Pleistocene age on Rhodes (Greece).Phaseolus ovatusSequenza, a lametilid deposit‐feeder, showed increasing mortality and a slow‐fast‐slow growth pattern accompanied by an abrupt change of shape in the fast‐growing interval. This in turn is coincident with a minimum in the size‐frequency distribution. The bimodality occurring in all distributions is interpreted as a recurrent population character, probably a non‐annual reproduction cycle, while height and spacing of the modes, which differ among the distributions, are environmentally controlled.Kelliella miliaris(Philippi), a vesicomyid suspension‐feeder, showed a near‐constant mortality and a logarithmic growth rate. The difference in mortality between the two species is related to grain‐size of the sediment and to stability of the food source.Growth pattern, mortality, foo

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01618.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

MacrothecaWaagen 1880, previously known only from the Salt Range of Pakistan and from Timor, andToxeumorphoraShimanskiy, previously known only from the Ural Mountains, have been identified in the Permian of northern East Greenland. The new specimens are assigned to the order Toxeumorphorida which is transferred to the class Hyolitha. The class Xenoconchia tentatively proposed by Shimanskiy two decades ago to include the toxeumorphorids is abandoned.Macrotheca almgreenin. sp. is described.Mollusca, Hyolitha, Toxeumorphorida, Xenoconchia, Permian, Greenland.

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01619.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01620.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

D. murchisoni(Beck 1839), the types species ofDidymograptusM'Coy, has been the subject of considerable confusion as a result of the extreme taxonomic splitting within the didymograptids. An attempt is made here to show the range of variation in this graptolite, based on the population on the original type slab, and to suggest ways in which studies on populations can lead to better understanding of the stratigraphic range of these Ordovician forms.Gruptolithina, Didymograptus murchisoni,taxonomy.

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01621.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0024-1164    

DOI:10.1111/j.1502-3931.1984.tb01622.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY