Record details

Title
    Minute Silurian oncocerid nautiloids with unusual colour patterns
Other titles
    Neobvyklý barevný vzor u silurského nautiloida
Author
    Manda, Štěpán
    Turek, Vojtěch
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Acta Palaeontologica Polonica
Vol./nr.
    Roč. 54, č. 3
Pages
    10
Year
    2009
Thesaurus term
    Cephalopoda
    Cephalopoda, Nautiloidea, taxonomy, colour pattern, shell size, shell malformation, Silurian.
    colour pattern
    Nautiloidea
    shell malformation
    shell size
    Silurian
    taxonomy
Keyword
    Colour
    Minute
    Nautiloids
    Oncocerid
    Patterns
    Silurian
    Unusual
Abstract (in czech)
   Je popsán neobvyklý barevný vzor u silurského nautiloida z pražské pánve.
Abstract (in english)
   A minute Silurian oncocerid Cyrtoceras pollux, from Bohemia is assigned here to the genus Pomerantsoceras. The only so far known species of this genus comes from Ordovician of Estonia. Pomerantsoceras thus represents, except for un-revised poorly understood taxa, the single known oncocerid genus surviving the end-Ordovician extinction events. Colour pattern characterised by a few longitudinal bands on the entire circumference of the shell is here reported in oncocerids. Longicone and only slightly curved small shells as in Pomerantsoceras are unusual among nautiloids and resemble straight shells of orthocerids and pseudorthocerids, in which the colour pattern consists of straight colour bands. Consequently the shell shape as well as the colour pattern should be regarded as adaptive convergence with orthocerids and pseudorthocerids. It supports the hypothesis that colour pattern functioned as camouflage and its evolution was under adaptive control.

   A minute Silurian oncocerid Cyrtoceras pollux, from Bohemia is assigned here to the genus Pomerantsoceras. The only so far known species of this genus comes from Ordovician of Estonia. Pomerantsoceras thus represents, except for un-revised poorly understood taxa, the single known oncocerid genus surviving the end-Ordovician extinction events. Colour pattern characterised by a few longitudinal bands on the entire circumference of the shell is here reported in oncocerids. Longicone and only slightly curved small shells as in Pomerantsoceras are unusual among nautiloids and resemble straight shells of orthocerids and pseudorthocerids, in which the colour pattern consists of straight colour bands. Consequently the shell shape as well as the colour pattern should be regarded as adaptive convergence with orthocerids and pseudorthocerids. It supports the hypothesis that colour pattern functioned as camouflage and its evolution was under adaptive control.
Contributor
    Česká geologická služba
    Národní muzeum Praha
Contributor code
    ČGS (RIV)
    NM
Source format
    R
Import date
    8. 8. 2012
    15. 10. 2014