The ground beetle genus Bembidion Latreille in Baltic amber: Review of preserved specimens and first 3D reconstruction of endophallic structures using X-ray microscopy (Coleoptera, Carabidae, Bembidiini)

• Published in: ZooKeys Vol. 662; no. 662; pp. 101 - 126
• Main Authors: Schmidt, Joachim, Michalik, Peter
• Format: Journal Article
• Language: English
• Published: Bulgaria Pensoft Publishers 01-01-2017
• Subjects: Amber; Baltic amber; Beetles; Bembidion; Endangered & extinct species; Fossils; Identification and classification; Microscopy; Natural history; New species; Physical characteristics; Predators; Zoology; new species; Archaeophilochthus; 3D reconstruction; Christian Gottfried Giebel collection; Ground beetles; Eodontium new subgenus; Eocene
• ISSN: 1313-2989; 1313-2970
• DOI: 10.3897/zookeys.662.12124

The ground beetle genus
is a highly diverse group of small predators with more than 1.200 described extant species. In contrast, only two representatives of
are known from the amber fossil record and their position within this mega-diverse genus is dubious. Here, we address the taxonomic position of these two extinct
species (
Giebel, 1856 and
Ortuño & Arillo, 2010). Based on the insufficient description and the missing type specimen,
, nomen dubium, cannot be assigned to the genus
and/or to the tribe Bembidiini with certainty. The subgenus Archaeophilochthus Ortuño & Arillo, 2010 was erected for the second extinct species,
, based on external characters. However, this species seems indistinguishable to members of the earlier described subgenus Philochthemphanes Netolitzky, 1943 which comprises about extant 10 species distributed in East and Southeast Asia. Furthermore, we describe two new species,
and
, from the Eocene Baltic amber using X-ray microscopy. Based on external and genital morphology including endophallic structures, we erected the monotypic subgenus Eodontium
for
, which is probably related to the subgenera
Netolitzky, 1931, the
complex, or the
series sensu Maddison (2012). On the other hand,
can be assigned to the subgenus Eupetedromus Netolitzky, 1911. The occurrence of representatives of at least two species groups adapted to a temperate climate suggests the presence of at least locally temperate climates in Baltic amber forests.