Naturwissenschaften DOI 10.1007/s00114-014-1221-z
The oldest micropepline beetle from Cretaceous Burmese amber and its phylogenetic implications (Coleoptera: Staphylinidae) Chen-Yang Cai & Di-Ying Huang
Received: 20 May 2014 / Revised: 18 July 2014 / Accepted: 25 July 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract The staphylinid subfamily Micropeplinae includes small strongly sclerotized beetles with truncate elytra leaving the most part of abdomen exposed. Fossil micropeplines are rare and confined to Cenozoic representatives of extant genera. Here, we describe the oldest micropepline, Protopeplus cretaceus gen. and sp. n., from the Upper Cretaceous Burmese amber. Fluorescence microscope and confocal laser scanning microscopy (CLSM) were both used to reveal diagnostic features of Micropeplinae and some primitive traits that place Protopeplus very basally within Micropeplinae. Keywords Insecta . Staphylinidae . Micropeplinae . Burmese amber
Introduction Micropeplinae are small (1∼3 mm long) strongly sclerotized beetles with truncate elytra leaving five abdominal segments exposed (Campbell 1968). Although this group has been treated as a separate family (Campbell 1968; Newton 1984), it is currently widely accepted as a subfamily within Staphylinidae (Newton and Thayer 1992). They are a small group associated with moist forest floor litter, water margins,
plant debris or nests of mammals; they feed on mould spores and hyphae (Campbell 1968; Löbl and Burckhardt 1988; Newton et al. 2000; Thayer 2005). To date, 82 extant species placed in six genera have been described from the Neotropical, Nearctic, Palaearctic, Ethiopian and Oriental regions (Herman 2001; Thayer 2005). Micropeplinae are readily recognizable by antennae with nine antennomeres, the ninth being enlarged into an oval club; elytra with longitudinal ridges and prothorax with deep excavations underneath for reception of the antennae (Newton et al. 2000). The fossil record of Micropeplinae is rare and confined to Cenozoic representatives of the extant genera. Four species have been known as fossils from the very end of Tertiary. Three extinct Pliocene species are attributed to the extant genus Micropeplus Latreille, including Micropeplus hoogendorni Matthews 1970 and Micropeplus hopkinsi Matthews 1970 from the Lava Camp Mine of Alaska, the USA and Micropeplus macrofulvus Gersdorf 1976 from Willershausen of Germany. In addition, fossils of the micropeplines from the extant species Kalissus nitidus LeConte and Micropeplus tesserula Curtis are known from the Pliocene of Alaska (Matthews 1970). Here, we describe a new genus and species from the earliest Cenomanian (Late Cretaceous) Burmese amber from Myanmar.
Communicated by: Sven Thatje C.