Project 2657: Lars Ramsköld. 1991. Pattern and process in the evolution of the Odontopleuridae (Trilobita). The Selenopeltinae and Ceratocephalinae. Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 82 (2):143-181.
Specimen: † Koneprusia (unvouchered)
View: fossil

Abstract

The systematics of parts of the Odontopleuridae are revised using character analyses tracing homologous structures, and a computerised cladistic analysis. The choice of outgroup is shown to affect the result of the analysis. Several synapomorphies place Selenopeltis, the type genus of the Selenopeltinae Hawle & Corda, 1847 as sister genus to Dicranurus. The latter's close relationship to Miraspis, type genus of the Miraspidinae Richter & Richter, 1917 is confirmed. The Selenopeltinae therefore becomes a senior subjective synonym of the Miraspidinae. The Selenopeltinae includes about 90 of the over 380 named odontopleurid species known to date (excluding accepted synonyms). The Ceratocephalinae is recognised, including about 30 species. The paired, large pygidial border spines present in most odontopleurids are in some species not homologous, and a falsifiable hypothesis is proposed for the homology of the ‘true major border spines’. This structure is the posterior pleural spine of the tenth postcephalic segment in selenopeltines, ceratocephalines and odontopleurines, and in acidaspidines and apianurines it is the serially homologous spine of the eleventh postcephalic segment. The spine belongs to the first pygidial segment in all taxa except ceratocephalines, where it is on the last thoracic segment. The homology in selenopeltines of the progressive restructuring of the cheek border is reviewed, explaining the supramarginal appearance of the genal spine. The presence and homology of the sublobation of L1 in odontopleurids is discussed, and it may be homologous with the sublobation in lichids. The strongly differentiated thoracic segmental lengths (exsag.), with maximum length reached in the anterior part of thorax, and the much reduced length of the posterior segments, are aspects of a single character-complex, uniquely derived within the Selenopeltinae. The ontogenetic origin of the anterior and posterior pleural spines is reviewed. The presence in Ceratocephala of two instars in one meraspid degree is discussed. A cladistic analysis of selenopeltine and ceratocephaline genera does not entirely resolve the topology of the phylogenetic tree of these taxa, but it confirms Selenopeltis as sister taxon to Dicranurus. These two genera belong in a clade also including Miraspis, Selenopeltoides, and Ceratonurus. Two new genera are erected, Ceratocara and Archaeopleura, the latter with type species A. kazakhensis sp. nov.


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Article DOI: https://doi.org/10.1017/S0263593300007616

Project DOI: 10.7934/P2657, http://dx.doi.org/10.7934/P2657
This project containsMatrices
  • 1 Media
  • 1 Matrix
  • 20 Taxa
  • 1 Specimen
  • 22 Characters
Total size of project's media files: 1 MB

Download Project SDD File
Total scored cells: 344
Total media associated with cells: 0
Total labels associated with cell media: 0
Characters
Total characters: 22
Total characters with associated media: 0
Total characters with media with labels: 0
Total character states: 54
Total character states with associated media: 0
Total character states with media with labels:0
Total unordered/ordered characters:22/0
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MorphoBank Project 2657


    Members

    member name taxa specimens media chars character
    media
    labels
    cell scorings
    (scored, NPA, "-")
    cell
    medialabels
    rules
    Michael Pankowski
    Project Administrator
    Last logged in 06/15/17
    20002200344
    (344, 0, 0)
    000
    Thomas Hegna
    Full membership
    Last logged in 05/18/17
    0000000
    (0, 0, 0)
    000


    Taxonomic Overview for Matrix 'M24554' (20 Taxa)

    taxon unscored
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    no cell
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    "-" cellscell images labels on
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    [1] † Ceratocara
    Last Modified in 04/07/17
    3191900002
    [2] † Ceratocephala
    Last Modified in 08/06/18
    0222200002
    [3] † Ceratocephalina
    Last Modified in 04/08/17
    2202000002
    [4] † Ceratonurus
    Last Modified in 04/08/17
    1212100002
    [5] † Dicranurus
    Last Modified in 04/08/17
    0222200002
    [6] † Elbaspis
    Last Modified in 08/06/18
    175500002
    [7] † Isoprusia
    Last Modified in 04/08/17
    2202000002
    [8] † Koneprusia
    Last Modified in 08/06/18
    184400002
    [9] † Laethoprusia
    Last Modified in 04/08/17
    3191900002
    [10] † Miraspis
    Last Modified in 04/08/17
    0222200002
    [11] † Orphanaspis
    Last Modified in 04/08/17
    157700002
    [12] † Proceratocephala
    Last Modified in 04/08/17
    1212100002
    [13] † Selenopeltis
    Last Modified in 04/08/17
    0222200002
    [14] † Selenopeltoides
    Last Modified in 04/08/17
    2202000002
    [15] † Hypanc
    Last Modified in 04/08/17
    3191900002
    [16] † Diacanthaspis
    Last Modified in 04/08/17
    0222200002
    [17] † Boedaspis
    Last Modified in 08/06/18
    0222200002
    [18] † Meadowtownella
    Last Modified in 04/09/17
    0222200002
    [19] † Archaeopleura
    Last Modified in 04/08/17
    157700002
    [20] † Lichakephalidae
    Last Modified in 04/08/17
    148800002


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