Zootaxa 3981 (4): 592–596 www.mapress.com /zootaxa / Copyright © 2015 Magnolia Press
Article
ISSN 1175-5326 (print edition)
ZOOTAXA
ISSN 1175-5334 (online edition)
http://dx.doi.org/10.11646/zootaxa.3981.4.9 http://zoobank.org/urn:lsid:zoobank.org:pub:567185B9-58B0-4768-A86E-50C186439BDD
A new fossil species of the genus Coptodera Dejean, 1825 (Coleoptera: Carabidae: Lebiinae) from Baltic amber SARA GAMBOA1 & VICENTE M. ORTUÑO2,3 1
PMMV Team. Department of Paleontology, Faculty of Geology. University Complutense of Madrid (UCM). José Antonio Novais 2, E28040, Madrid, Spain. E-mail:
[email protected] 2 Research Team on Soil Biology and Subterranean Ecosystems. Department of Life Sciencies. Faculty of Biology, Chemistry and Environmental Sciences. University of Alcalá (UAH). A.P. 20. Campus Universitario. E-28805, Alcalá de Henares, Madrid, Spain 3 Corresponding author. E-mail:
[email protected]
Abstract In this paper a new species of fossil ground-beetle, Coptodera elektra n. sp. (Coleoptera: Carabidae) preserved in a piece of Baltic amber (Eocene) is described and the paleobiology of the species is studied. This new species represents the first known fossil record for the genus, as well as the first record of its presence in Europe. Key words: Arthropoda, Hexapoda, Pericalina, taxonomy, paleoentomology
Introduction Ground beetles (Carabidae) probably were originated in the Mesozoic. The oldest known fossil of carabids belong to the Triassic of Virginia (USA) (Grimaldi & Engel 2005). At present, Carabidae is a speciose family with more than 34000 described species (Lorenz 2005) widely distributed, being present in all continents but Antarctica. Althought amber carabid fossil known are from the Tertiary, only a small number of them have been described, thirty two in Baltic amber (Alekseev 2013), none of them belonging to the subfamily Lebiinae Bonelli 1810. However, there are some other mentions in classic literature (19th century) which include some references to this subfamily, but they must be regarded with caution as they were never redescribed and some type material is lost; for a complete list and further information see Larsson (1978). Several tribes are included in the subfamily Lebiinae. One of them, Lebiini Bonelli 1810, is a markedly complex worldwide tribe. The absence of a known synapomorphy has suggested that the tribe constitutes a nonmonophyletic lineage (Ober & Maddison, 2008). Herewith, the relationship of the tribe is not clearly defined and the supraspecific classification is debated. In this paper, we follow Ball & Bousquet (2000), who considered the tribe divided in 16 subtribes, being Pericalina Hope 1838 the richest in species, with 825 species distributed worldwide (Lorenz 2005: 454-464). Pericalina includes the genus Coptodera Dejean 1825 with 106 species (Lorenz 2005: 457-458; Baehr 2014) widely distributed in the tropical and subtropical regions of all continents but Europe (Baehr 2014) In this work, a new species of Coptodera, preserved in Eocene Baltic amber, is described, establishing the first known fossil record for the genus and the first reference of this genus in Europe.
592 Accepted by K. Ober: 17 Jun. 2015; published: 7 Jul. 2015
Results Order Coleoptera Linnaeus 1758 Suborder Adephaga Schellenberg 1806 Family Carabidae Latreille 1802 Subfamily Lebiinae Bonelli 1810 Tribe Lebiini Bonelli 1810 Subtribe Pericalina Hope 1838 Coptodera Dejean 1825 Coptodera elektra n. sp. (Figure 1) Description (based on a single specimen—holotype). Length (from head to elitral apex): 3.8 mm. Colour brownreddish. Body partially covered by a metallic look patina (probably due to taphonomic processes). Head: Markedly transverse, wider than long (L/W ratio: 0.43). Very large and convex compound eyes. Short tempora. Transverse microsculpture. Two superficial fossae in the anterior region of the head. Two supraocular setae, being the anterior one over the midline of eyes and the posterior one at the level of the posterior edge of eyes. Two setae on the clypeus. Labrum with six antero-marginal setae, being the lateral setae longer. Filiform antennae with eleven antennomeres, pubescent from 3th to 11th (the 3th one lacking pubescence in it basal half part), being more densely pilose in their ventral side. Antennomeres bearing a crown of distal setae except from the first one (with only one long seta in its inner face) and the second one (shorter than the rest and without setae). Mandibles trigonal and curved apically. Mentum edentate. Complete and conspicuous labial-prebasilar suture. Prebasilar bearing one pair of setae. Palpiger with a single seta. Pronotum: Subrectangular, transverse, almost twice as wide as it is long (L/W ratio: 0.61) and slightly wider than the head. Disc very slightly convex, divided lenghtways by a distinct but shallow medial sulcus. Transverse microsculpture. Anterior margin slightly convex, being its anterior angles round shaped. Basal margin slightly convex. Lateral margins curved, with its maximum width at the level of the anterior marginal setae, slightly sinuous in basal third. Posterior angles obtuse, blunt and dorsally projected. Lateral channel wide, shallow and gradually spread to the posterior angles. Bassal fossae deep but with poor defined outline. Two setae on each side, at basal angle and before the middle. Elytra: Elytra manifestly wide (L/W ratio: 2.26), somewhat convex and glabrous. Elytra and lateral channel explanated towards the apical third. Rounded shoulders. Basal ridge hardly visible but complete. Sutural angle rounded. All striae are visible and complete, from the base to the apex, and barely punctate. Scutellary striole faintly marked on the base of the first interstria. Lateral umbilical series with 13 setigerous pores as follows: humeral area with five equidistant setae, four medial setae and subapical area with four equidistant setae. Interstriae flat and with micropunctures. Two visible discal setae in the third interstria of each elytron, beside the third stria. One apical seta over both elytra. Scutellar pores located at the base of first stria. Last visible abdominal sternite with four setae close to posterior margin. Metaepisternum elongate, twice longer than wide Metepimeron obliquely truncate at posterior margin, as is common in Lebiini. Wings well developed. Legs: Fore-tibia with markedly developed upper spur on inner surface. Tarsomeres with dorsal surface setose. First tarsomere as long as second, third and fourth tarsomeres together on all legs. Fourth tarsomere slightly biolbated. Tarsal claws pectinates. Type series. Holotype: 1 female, preserved in a piece of Baltic amber (1.5 cm x 0.54 cm x 0.35 cm) (Eocene) deposited in Department of Life Sciencies. Faculty of Biology, Chemistry and Environmental Sciences. University of Alcalá (UAH) (Collection V.M. Ortuño). Etymology: Specific epithet refers to Elektra, derivated from the Greek Ἠλέκτρα, which derives from ηλεκτρον (elektron), meaning "amber”. State of preservation. Although the specimen is slightly damaged, the state of preservation good, so morphological and taxonomic studies are possible. Dorsal side of the fossil, specially the elytra, appears slightly deformed due to polishing process. The curved surface, as a result of amber preparation, produces some optical distortions. Left elytron shows a slight fracture in its apical portion. The genitalia and other soft tissues are not
NEW FOSSIL OF COPTODERA (CARABIDAE)
Zootaxa 3981 (4) © 2015 Magnolia Press ·
593
FIGURE 1. Coptodera elektra n. sp. Photographs: a) piece of amber (scale bar: 1 cm); b) dorsal view; c) ventral view. Drawings: d) specimen in dorsal view; e) specimen in ventral view (scale bar: 1 mm).
594 · Zootaxa 3981 (4) © 2015 Magnolia Press
GAMBOA & ORTUÑO
FIGURE 2. Global known distribution map for Coptodera subgenera. Red: Coptodera Dejean 1825; yellow: Coptoderina Jeannel 1949; blue: Coptoderinella Hansen 1968; green: Haplocrepis Jeannel 1949. Distribution data obtained from Hansen (1968), Habu (1982), Shpeley & Ball (1993), Park et al. (2006), Park et al. (2011) and Baehr (2014). Star: Location of ancient Baltic forest.
observed, but the specimen has been determinated as female, regarding the fact protarsi are not swollen and as four abdominal apex setae are presented.
Discussion The studied specimen belongs to genus Coptodera Dejean 1825 according to Dejean (1825: 273-278; 1826: 458459) and Darlington (1968) as it shows a combination of diagnostic features highlighting a markedly wide pronotum, discal setae located on the 3th interstriae, a mentum without a medial tooth, labial palpiger setose and pectinate tarsal claws. This set of characteristics makes possible the identification of the genus among other taxa with morphological similitudes, such as Horniulus Jedlika 1932, which presents a toothed mentum and smooth claws or Minuthodes Andrewes 1941, showing also a medial tooth in the mentum. In the same way, morphological features stablish conspicuous differences between Coptodera and its adelphotaxon (Shpeley & Ball, 1993) Pericalus MacLeay 1825, standing out the presence of distally incised labrum, as well as smooth claws and dissimilar tagma proportions. Furthermore, an unambiguous subgenus attribution is unlikely. The species of the genus are arranged in four subgenera (Coptodera Dejean 1825; Coptoderina Jeannel 1949; Coptoderinella Hansen 1968; Haplocrepis Jeannel 1949), mainly attending genital features. The impossibility to study the genitalia, as well as the lack of references about the genus presence in Europe and the temporal difference between the studied specimen and current species, make it difficult the setting of the individual in any stablished subgenus. In terms of paleobiology, Coptodera elektra n. sp. shows some morphological features, most notably the presence of a rather depressed body and pectinate claws, corresponding to the corticiculous habits, characteristic of the present day genus. This way of life is widely represented in other Carabidae from Baltic amber including Agatoides carinulatus Motschulsky 1856; Cymindoides sculptipennis Motschulsky 1856 and Dromius backeri Abdullah 1969. Furthermore, the markedly developments of eyes and mandibles suggests an active predator behaviour during the day. On the other hand, the fully developed wings correspond to a great dispersal capability along the ancient Baltic forest. All known present day species of Coptodera are forests inhabitants, intimately associated with tropical and warm temperate humid climates (Figure 2), which agrees with the climate inferred for the (Early) Eocene Baltic
NEW FOSSIL OF COPTODERA (CARABIDAE)
Zootaxa 3981 (4) © 2015 Magnolia Press ·
595
forest. (Weitschat & Wichard 2010; Selden & Nudds 2012). The presence of Coptodera in Baltic amber suggests that the genus has retreated from a former broader distribution to the present pantropical distribution, presumably as a result of Tertiary climate cooling. Finally, this new species is not just the first representative of this genus in the fossil record, but also the first known species ever recorded in Europe. The discovery constitutes a piece of great value in order to understand the evolutionary process of this group.
Aknowledgements We want to express our gratitude to Dr. Danny Shpeley, Department of Biological Sciences, University of Alberta, for his taxonomic and bibliography assistance, as well as his kindness. We want also to thank Dr. Manuel Hernández Fernández, Department of Paleontology, University Complutense of Madrid, for his help in this study.
References Alekseev, V.I. (2013) The beetles (Insecta: Coleoptera) of Baltic amber: the checklist of described species and preliminary analysis of biodiversity. Zoology and Ecology, 23 (1), 5‒12. http://dx.doi.org/10.1080/21658005.2013.769717 Baehr, M. (2014) A new species of the genus Coptodera Dejean, 1825 from Tanimbar Islands (Coleoptera: Carabidae: Lebiini). Studies and Reports: Taxonomical Series, 10 (2), 249‒256. Ball, G.E. & Bousquet, Y. (2000) Carabidae Latreille, 1810. In: Arnett, R.H. & Thomas, M.C. (Eds.), American beetles: Archostemata, Myxophaga, Adephaga, Polyphaga: Staphyliniformia. Vol. 1. CRC Press, Florida, pp. 32‒132. Darlington, P. J. (1968) The Carabid beetles of New Guinea. Part III. Harpalinae continued. Perigonini to Pseudomorphini. Bulletin of the Museum of Comparative Zoology, 139, 1–253. Dejean, P. (1825) Species général des coléoptères, de la collection de M. le Comte Dejean. Tome premier. Mequignon-Marvis. 463 pp. Dejean, P. (1826) Species général des coléoptères de la collection de M. le Comte Dejean. Tome second. Mequignon-Marvis. 501 pp. Grimaldi, D.A. & Engel, M.S. (2005) Evolution of the Insects. Cambridge University Press, New York, 755 pp. Habu, A. (1982) Revised and supplementary notes on and descriptions of the Truncatipennes group of Japan (I). Entomological Review of Japan, 32 (2), 85–142. Hansen, W. (1968) Revision des Coptoderines d’Afrique. Bulletin et annales de la Société royale d’entomologie de Belgique, 104, 277‒363. Larsson, S.G. (1978) Baltic amber – a paleobiological study. In: Lyneborg, L. (Ed.), Entomonograph. Vol. 1. Scandinavian Science Press Ltd., Klampenborg, pp. 1–192. Lorenz, W. (2005) A Systematic List of Extant Ground Beetles of the World (Coleoptera "Geadephaga": Trachypachidae and Carabidae, incl. Paussinae, Cicindelinae, Rhysodinae). 2nd Edition. Edited by author, Tutzing, 528 pp. Ober, K.A. & Maddison, D.R. (2008) Phylogenetic relationships of tribes within Harpalinae (Coleoptera: Carabidae) as inferred from 28S ribosomal DNA and the wingless gene. Journal of Insect Science, 8, 63. http://dx.doi.org/10.1673/031.008.6301 Park, J.K., Lee, C.M., Kwon, T.S., Park, J.Y. & Lee, J.E. (2011) Korean species of the genus Coptodera Dejean (Coleoptera: Carabidae: Lebiinae). Entomological research. 41 (3), 103‒105. http://dx.doi.org/10.1111/j.1748-5967.2011.00324.x Park, J.K., Trac, D.H. & Will, K. (2006) Carabidae from Vietnam (Coleoptera). Journal of Asia-Pacific Entomology, 9 (2), 85‒105. http://dx.doi.org/10.1016/S1226-8615(08)60280-0 Selden, P. & Nudds, J. (2012) Evolution of fossil ecosistems. 2nd Edition. Academic Press, Massachusetts, 288 pp. http://dx.doi.org/10.1201/b15128 Shpeley, D. & Ball, G.E. (1993) Classification, reconstructed phylogeny and geographical history of the New World species of Coptodera Dejean (Coleoptera: Carabidae: Lebiini). Proceedings of the Entomological Society of Ontario, 124, 1‒182. Weitschat, W. & Wichard, W. (2010) Baltic Amber. In: Penney, D. (Ed.), Biodiversity of fossils in amber from the mayor world deposits. Siri Scientific Press, Rochdale, pp. 1–304.
596 · Zootaxa 3981 (4) © 2015 Magnolia Press
GAMBOA & ORTUÑO
