• Medientyp: E-Artikel
  • Titel: Early Evolution of the Adephaga: Some Locomotor Speculations
  • Erschienen: The Coleopterists' Society, 1982
  • Erschienen in: The Coleopterists Bulletin, 36 (1982) 4, Seite 597-607
  • Sprache: Englisch
  • ISSN: 0010-065X; 1938-4394
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  • Beschreibung: Evolution of Mesozoic adephaga (described by Ponomarenko) is considered in relation to their possible locomotor habits. The adephagan ancestor may have been a fairly large, fast running archostematan which hunted over the open ground surface during early Triassic time. It could have given rise to a caraboid stock of ground beetles in the mid-Triassic which, by Upper Triassic, had differentiated to produce the superficially similar Carabidae-Protorabinae and Trachypachidae-Eodromiinae. These appear to be faster runners but weaker wedge-pushers which were adapted to the open ground conditions. Trachypachid specializations include immobilised metacoxae which possibly evolved as an anti-crushing device, but which were pre-adapted to aquatic life. Dytiscomorphs evolved from trachypachids in the Lower Jurassic, but Haliplidae (Triaplidae) and possibly Gyrinidae may be distinct lines which separated in Triassic time. Both carabid and trachypachid ground beetles were drastically affected by the angiosperm revolution of the mid-Cretaceous which provided widespread deciduous litter. This allowed stronger wedge-pushers but slightly slower running stocks of Carabidae to become dominant, and may have caused the major decline of the Trachypachidae.