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  • Atractosteus messelensis Grande, 2010


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    • With 13cm SL a relatively small Atractosteus - the average length is probably about 26cm. Adult specimens exceed 60cm in length. Invalid names: Atractosteus strausi and A. kinkelini

       

      Quote from Grande, 2010:

      "In a redescription of the species of Atractosteus from Messel, Gaudant (2005) correctly noted that the name A. strausi (Kinkelin), 1884, based on an isolated ganoid scale "devoid of any diagnostic character" found in Miocene deposits of Frankfurt-Niederrad, cannot be applied to either of the Messel gar species because the name is inapplicable and a nomen dubium (he used nomen vanum but the International Code does not recognize this sometimes ambiguously defined term, so I follow Chorn and Whetstone (1978) and others in using nomen dubium). Gaudant (2005) offered a replacement name for A. strausi (A. kinkelini) but unfortunately, he did not clearly designate a validly diagnosable holotype for the new name. He instead chose a skull fragment (SMF P. 1676, consisting of several lacrimomaxillae and a partial dentary) to serve as a "Lectotype" (p. 131) for A. strausi, and holotype (caption for fig. 2, p. 112) for A. kinkelini. He stated that the "[reduced number of infraorbitals]" is the diagnostic feature of this specimen, but the specimen is missing its anterior end making a complete count of lacrimomaxillary bones (his "infraorbitals") impossible. The count of lacrimomaxillary bones in the Messel Atractosteus also falls completely within the ranges of A. spatula, A. tristoechus and A. simplex (Table 181). Therefore, this species is not differentiated with an applicable diagnosis. Also, the fragmentary type, like the Kinkelin scale, is "devoid of any diagnostic character." Therefore a new name is erected here for the Messel Atractosteus (Atractosteus messelensis sp. nov.) with a unique combination of characters to diagnose it and a nearly complete specimen as holotype."

       

      Lit.:

      Grande, L. (2010) An empirical synthetic pattern study of gars (Lepisosteiformes) and closely related species, based mostly on skeletal anatomy. The resurrection of Holostei. American Society of Ichthyologists and Herpetologists, Copeia, Special Publication 6, Supplementary Issue, 10(2A):1-871

    Taxonomy

    Gar

    Kingdom: Animalia
    Phylum: Chordata
    Class: Actinopterygia
    Order: Lepisosteiformes
    Family: Lepisosteidae
    Genus: Atractosteus
    Species: A. messelensis
    Author Citation Grande, 2010

    Geological Time Scale

    Eon: Phanerozoic
    Era: Cenozoic
    Period: Paleogene
    Epoch: Eocene
    International Age: Lutetian

    Stratigraphy

    Messel Formation

    Provenance

    Collector: T. Bastelberger
    Date Collected: 06/01/1973
    Acquired by: Field Collection

    Location

    Grube Messel
    Messel near Darmstadt
    Hessia
    Germany

    Comments

    With 13cm SL a relatively small Atractosteus - the average length is probably about 26cm. Adult specimens exceed 60cm in length. Invalid names: Atractosteus strausi and A. kinkelini

     

    Quote from Grande, 2010:

    "In a redescription of the species of Atractosteus from Messel, Gaudant (2005) correctly noted that the name A. strausi (Kinkelin), 1884, based on an isolated ganoid scale "devoid of any diagnostic character" found in Miocene deposits of Frankfurt-Niederrad, cannot be applied to either of the Messel gar species because the name is inapplicable and a nomen dubium (he used nomen vanum but the International Code does not recognize this sometimes ambiguously defined term, so I follow Chorn and Whetstone (1978) and others in using nomen dubium). Gaudant (2005) offered a replacement name for A. strausi (A. kinkelini) but unfortunately, he did not clearly designate a validly diagnosable holotype for the new name. He instead chose a skull fragment (SMF P. 1676, consisting of several lacrimomaxillae and a partial dentary) to serve as a "Lectotype" (p. 131) for A. strausi, and holotype (caption for fig. 2, p. 112) for A. kinkelini. He stated that the "[reduced number of infraorbitals]" is the diagnostic feature of this specimen, but the specimen is missing its anterior end making a complete count of lacrimomaxillary bones (his "infraorbitals") impossible. The count of lacrimomaxillary bones in the Messel Atractosteus also falls completely within the ranges of A. spatula, A. tristoechus and A. simplex (Table 181). Therefore, this species is not differentiated with an applicable diagnosis. Also, the fragmentary type, like the Kinkelin scale, is "devoid of any diagnostic character." Therefore a new name is erected here for the Messel Atractosteus (Atractosteus messelensis sp. nov.) with a unique combination of characters to diagnose it and a nearly complete specimen as holotype."

     

    Lit.:

    Grande, L. (2010) An empirical synthetic pattern study of gars (Lepisosteiformes) and closely related species, based mostly on skeletal anatomy. The resurrection of Holostei. American Society of Ichthyologists and Herpetologists, Copeia, Special Publication 6, Supplementary Issue, 10(2A):1-871



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