The first described turtle beetles from Eocene Baltic amber, with notes on fossil Chelonariidae (Coleoptera: Byrrhoidea)

Mauricio Barbi,Hans C. E. Larsson,Andris Bukejs,Ryan C. McKellar,Vitalii I. Alekseev,Jerit Mitchell

doi:10.5194/fr-24-19-2021

Abstract

Abstract. Chelonariidae, or turtle beetles, are rarely represented in the fossil record. Two new extinct species of this thermophilous coleopteran family, Chelonarium andabata Alekseev and Bukejs sp. nov. and Ch. dingansich Alekseev and Bukejs sp. nov., are described and illustrated from Eocene Baltic amber using X-ray micro-computed tomography (micro-CT). They are the first formally described species of turtle beetles from Eocene Baltic amber and the first known European representatives of this family. Based on modern habitats of the group, the presence of the plants with which their larvae are associated (epiphytic orchids) is proposed in the Eocene amber forest. The Eocene Florissant Formation fossil Chelonarium montanum Wickham, 1914, which was originally placed within Chelonariidae, is discussed based on its original description, and placement as incertae sedis within Byrrhoidea is proposed for this compression fossil (http://zoobank.org/References/C2EE164D-59DD-42FE-937D-B01C78DCD228, last access: 8 February 2021).

Highlights

The coleopteran superfamily Byrrhoidea consists of 12 extant families (Slipinski et al, 2011), and half of them have been reported from Eocene Baltic amber (Klebs, 1910; Larsson, 1978; Kirejtshuk and Azar, 2013; Alekseev, 2019)
Brounia Sharp is restricted to New Zealand; Pseudochelonarium Pic occurs in New Guinea, India, eastern and southeastern Asia; and Chelonarium Fabricius is mainly found in the neotropics and occurs in Asia and Australia (Leschen and Early, 2004; Beutel and Leschen, 2016)
In the present-day Palaearctic region, Chelonariidae are restricted to the southernmost periphery of eastern Asia (Afghanistan; Bhutan; China: Hainan; India; Japan; Taiwan) and represented by four species of Chelonarium and seven species of Pseudochelonarium (Satô, 2016)

Summary

Introduction

The coleopteran superfamily Byrrhoidea consists of 12 extant families (Slipinski et al, 2011), and half of them have been reported from Eocene Baltic amber (Klebs, 1910; Larsson, 1978; Kirejtshuk and Azar, 2013; Alekseev, 2019). Reports of chelonariid beetles from Eocene Baltic amber have been made in the recent literature (Kirejtshuk and Azar, 2013; Alekseev, 2019), but even generic assignment of the specimens is never mentioned in these works. The first turtle beetle species from Eocene Baltic amber of the Kaliningrad Region (western Russia) is described and illustrated using X-ray microcomputed tomography (micro-CT). Alekseev et al.: The first described turtle beetles from Eocene Baltic amber

Material and methods

Systematic palaeontology

Findings

Zoogeographical and ecological notes