Niels P Kristensen

Publications (3)3.32 Total impact

• Source

  Available from: Rolf Beutel

  Article: Morphology and insect systematics in the era of phylogenomics.

  Rolf G Beutel, Niels P Kristensen
  Arthropod structure & development 05/2012; 41(4):303-5. · 1.11 Impact Factor
• Article: Derived morphology in a basal moth: The uniquely specialized sternum V glands of Agathiphaga (Lepidoptera: Agathiphagidae).

  Marie Djernæs, Niels P Kristensen
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  ABSTRACT: The sternum V gland is a notable specialization shared by basal Lepidoptera and most Trichoptera; it is generally present in both sexes or in females only. In both orders the secretory cells usually discharge into a sac-like reservoir from which a duct leads to the opening on sternum V. In contrast, the gland in agathiphagid moths is only present in males and it exhibits several unique specialisations: the glandular portion being the apical (morphologically anterior) part of a long tubular cuticular invagination covered with contiguous 'type-3' glandular units; together with the following part of the efferent duct it is coiled like a ball of yarn; the duct expands into a fusiform reservoir, and a separate small sac surrounded by a complex muscular coat is present just inside the gland opening. The principal opener muscle of each gland originates on the contralateral side of sternum VI, hence crossing its counterpart in the midline. Characters of the agathiphagid sternum V gland, the function of which remains unclear (though sex pheromone production may appear most likely), add significantly to the suite of autapomorphies exhibited by this otherwise overall remarkably generalized moth taxon.
  Arthropod structure & development 09/2011; 40(6):559-69. · 1.11 Impact Factor
• Source

  Available from: Rolf Beutel

  Article: Resolving insect phylogeny: The significance of cephalic structures of the Nannomecoptera in understanding endopterygote relationships.

  Rolf G Beutel, Niels P Kristensen, Hans Pohl
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  ABSTRACT: The Nannomecoptera are among the most enigmatic and controversial taxa of endopterygote insects, the phylogenetic resolution of which is crucial to understanding the evolution of neopteran insects. Once considered a subordinate lineage within the Mecoptera, renewed interest in nannochoristids has been prompted by evidence that the Nannomecoptera are not admissible to the clade of extant scorpion flies but are more likely to belong to the clade Siphonaptera + Nannomecoptera + Diptera. The overarching purpose of the present account is to provide novel and extensive morphological character traits in addition to those already existing for adult structures. The aim is to determine if these traits support molecular data sets that have been suggested elsewhere to clarify the phyletic position of Nannochoristidae. This account focuses on nannomecopteran larvae, which unlike those of other mecopterans have received little attention. Thus, the thrust of this investigation is to provide detailed anatomical data on nannochoristid larvae for a targeted inquiry into their phylogenetic affinities. The described characters are discussed and presented in a data matrix comprising representatives of all endopterygote orders. While the study is based primarily on the New Zealand species Nannochorista philpotti, it is proposed that all nannomecopteran larvae will prove to be similar to this taxon in most if not all structural features of significance to a higher-level phylogenetic context.
  Arthropod structure & development 07/2009; 38(5):427-60. · 1.11 Impact Factor