Bembidion christelae Ortuno & Arillo

Schmidt, Joachim & Michalik, Peter, 2017, The ground beetle genus Bembidion Latreille in Baltic amber: Review of preserved specimens and first 3 D reconstruction of endophallic structures using X-ray microscopy (Coleoptera, Carabidae, Bembidiini), ZooKeys 662, pp. 101-126 : 103

publication ID

https://dx.doi.org/10.3897/zookeys.662.12124

publication LSID

lsid:zoobank.org:pub:0250ADB4-740A-4DB2-83FA-92E3BA0363D2

persistent identifier

https://treatment.plazi.org/id/EE50980C-EEC8-49CA-5971-55CA1DAF485D

treatment provided by

ZooKeys by Pensoft

scientific name

Bembidion christelae Ortuno & Arillo
status

 

Bembidion christelae Ortuno & Arillo View in CoL

Bembidion (Archaeophilochthus) christelae Ortuño & Arillo, 2010: 190.

Remarks on taxonomic position.

A monotypic subgenus Archaeophilochthus Ortuño & Arillo, 2010 was established for the fossil B. christelae . In the subgeneric diagnosis, the authors mentioned the following six features to be important for assigning the taxon: (i) elytral discal setae each are inserted in the third interval separated from the third stria; (ii) the groove of the rounded humeral margin ends "close to the 4th or 5th striae" ( Ortuño and Arillo, 2010: 191, subgeneric diagnosis) and "at the base of 6th interstriae" (p. 190, species diagnosis), respectively; (iii) humeral setae of the elytral umbilicate series grouped and +/- equidistant; (iv) pronotal basolateral fovea poorly delimited; (v) pronotal laterobasal angles with carina well developed; vi) pronotal laterobasal angles formed oblique.

Because the first five of these features are similarly developed in Philochthus Stephens, 1828, Ortuño and Arillo (2010) assume a close relationship of the fossil with this Bembidion subgenus. Character state (vi) was considered plesiomorphic by the authors, and because the apomorphic state 'pedunculated pronotal basal margin’ is developed in Philochthus the authors proposed a separate subgenus for the B. christelae .

Two extant Bembidion subgenera have been identified to be closely related to Philochthus ( Maddison 2012) and which should be therefore considered when discussing the probable relationships of B. christelae : Lindrochthus Maddison, 2012, and Philochthemphanes Netolitzky, 1943. The former is monotypic and only includes B. wickhami Hayward, 1897, a species endemic to north-western North America. Lindrochthus is distinguished from Philochthus "by the less abruptly sinuate hind margin of the prothorax, and the reduced number of elytral striae" ( Maddison 2012: 570). The pronotal margin is, however, more markedly sinuate in B. wickhami than in the fossil B. christelae , and the latter possesses eight completely developed elytral striae ( Ortuño and Arillo 2010), which represents the plesiomorphic state. Philochthemphanes Netolitzky, 1943 (type species: B. exquisitum Andrewes, 1923 from the Central Himalaya) is a Bembidion subgenus containing little more than ten species distributed in East and Southeast Asia ( Lorenz 2005, Toledano 2008, database of J.S.) and is considered to be the sister group of Philochthus based on molecular data ( Maddison 2012). Species of Philochthemphanes possess a moderately sinuate pronotal basal margin as developed in B. christelae . Most noteworthy, B. christelae shows all diagnostic features of the exoskeleton compared to Philochthemphanes . It is thus very likely that the fossil taxon Archaeophilochthus is a junior synonym of Philochthemphanes . This assumption is further supported biogeographically as the flora and fauna of the Baltic amber forests is very similar to the modern biota of Indo-Malaya where Philochthemphanes is distributed nowadays ( Wolfe 1975, Schmidt 2015). Here, extant species of Philochthemphanes inhabit cloud forests and forest’s edges and the adults can be found on the ground as well as on the mossy branches of shrubs and trees, even though these species lack the common features present among most of the arboreal ground beetles. Therefore and in contrast to the suggestion of Ortuño and Arillo (2010), B. christelae maybe had a semi-arboreal life style very similar to extant Philochthemphanes species. On the other hand, Philochthemphanes is not defined by clear synapomorphies. Thus, a careful revision and character analysis of Philochthemphanes is needed before a well-funded taxonomic conclusions regarding the synonymization of Archaeophilochthus and Philochthemphanes can be drawn.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Carabidae

Genus

Bembidion