Research Article |
Corresponding author: David R. Maddison ( david.maddison@science.oregonstate.edu ) Academic editor: James Liebherr
© 2021 David R. Maddison, Nick Porch.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Maddison DR, Porch N (2021) A preliminary phylogeny and review of the genus Tasmanitachoides, with descriptions of two new species (Coleoptera, Carabidae, Bembidarenini). In: Spence J, Casale A, Assmann T, Liebherr JК, Penev L (Eds) Systematic Zoology and Biodiversity Science: A tribute to Terry Erwin (1940-2020). ZooKeys 1044: 153-196. https://doi.org/10.3897/zookeys.1044.62253
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The genus Tasmanitachoides Erwin, a genus of very small carabid beetle endemic to Australia, is reviewed. Although uncommon in collections, they can be abundant and diverse on banks of fine gravel or coarse sand next to bodies of fresh water; samples from southeastern Australia suggest numerous undescribed species. An initial phylogenetic hypothesis for the genus is presented, including 19 of the 32 known species. The inferred phylogeny, based upon one mitochondrial and four nuclear genes, shows the kingi group to be sister to remaining Tasmanitachoides, with the wattsensis group and T. lutus (Darlington) also being phylogenetically isolated. Two new species are described: T. baehri sp. nov., from the Australian Capital Territory, is a member of the kingi group; T. erwini sp. nov., from Tasmania, is a member of the wattsensis group. Identification tools for described and some undescribed species are presented, including photographs of all known species.
Australia, beetle, DNA, systematics, taxonomy, Trechinae
The genus Tasmanitachoides Erwin, 1972 (Fig.
This enigmatic group has migrated through the classification of carabids. In describing the first known species, which he called Tachys murrumbidgensis,
During the last twenty years, two threads wove together to yield the discovery, documented here, that Tasmanitachoides are likely notably more diverse than reported in the 13 papers describing the 25 known species. NP began collecting Tasmanitachoides in 1998, intrigued by their described diversity given the relatively few specimens that had been studied by Martin Baehr.
After two decades of pondering Tasmanitachoides, our first encounter together with living Tasmanitachoides was memorable. DRM had collected numerous species of the three South American genera of Bembidarenini on trips to Chile, Argentina, and Ecuador between 2006 and 2011, but had only seen preserved Tasmanitachoides. As neontological systematists we often are embedded in rooms full of dead carcasses of the organisms we study, and as beautiful as they may be, the experience of observing pinned specimens is very different than seeing alive, in nature, the biodiversity we seek to document and discover. In the early evening of 8 January 2019, we approached Uriarra Crossing of the Murrumbidgee River, not knowing whether we would find these relatively rarely collected organisms. At our first footsteps on the fine gravel banks of the river specimens of Tasmanitachoides emerged from the substrate, and in short order we had collected three species and more than 110 individuals.
These beetles are not rare in their preferred habitat (Fig.
Habitats of Tasmanitachoides A Australia: ACT: Murrumbidgee River at Angle Crossing, 35.5825°S, 149.1100°E, 598 m. This and similar areas a few meters upstream are habitat of T. murrumbidgensis, T. sp. “ Tambo R”, T. cf. gerdi, T. sp. “Angle Crossing #1”, T. wilsoni, T. maior, T. sp. “Angle Crossing #2”, and T. rufescens B Australia: Victoria: Flat Rock Creek at highway B23, 37.2835°S, 149.2223°E, 256 m. Habitat of T. lutus, T. leai, and T. angulicollis C Australia: Tasmania: mouth of Machinery Creek into the River Forth at C136, 41.4712°S, 146.1366°E, 126 m. Habitat of T. leai, T. kingi, T. erwini, and T. sp. “River Forth” D Australia: Tasmania: Lake St Clair, 42.1121°S, 146.2051°E, 741 m. Habitat of T. hobarti.
Tasmanitachoides are found on the shores of larger rivers (Fig.
In these water-shore habitats, Tasmanitachoides are concentrated in those regions with no or minimal vegetation, within 3 meters of the shoreline, with at least some moisture a centimeter or two below the surface. Most critically, though, they are found where the substrate is composed of moderately well-sorted fine gravel and coarse sand, with particles mostly approximately 1–4 mm (Fig.
Gravel from Tasmanitachoides habitat at Australia: ACT: Murrumbidgee River at Angle Crossing, 35.5803°S, 149.1109°E, 600 m. This is the substrate from an area in which T. murrumbidgensis and T. sp. “Tambo R” were abundant, with some specimens of T. maior and T. rufescens. Scale bar: 10 mm.
Habitats of Tasmanitachoides A, B Australia: Tasmania: South Esk River at Avoca, 41.7807°S, 147.7148°E, 193 m. Habitat of T. leai, T. hobarti, and T. sp. “River Forth”. We found Tasmanitachoides only in a small area noted by the arrow in A, and shown close-up in B C Australia: Victoria: Tambo River at Bruthen, 37.7111°S, 147.8369°E, 10 m. Habitat of T. murrumbidgensis, T. sp. “Tambo R”, T. maior, as well as Bembidion aterdustum, B. brullei, B. jacksoniense, and Tachyura victoriensis D Australia: Tasmania: Weld River NE Weldborough, 41.1897°S, 147.9118°E, 357 m. Habitat of T. hobarti.
This is the first in a series of planned papers about diversity within Tasmanitachoides. We infer an initial phylogeny of the genus based upon DNA sequence data, document some aspects of the diversity we found, describe two new species, and provide an improved identification key as well as images of the species. We plan a more complete revision of the genus after more focused collecting throughout Australia, and a more detailed phylogenetic analysis including more species.
Members of Tasmanitachoides were examined from or deposited in the collections listed below. Each collection’s listing begins with the code used in the text.
NPC Nick Porch Collection, Melbourne, Australia;
ZSM Zoologische Staatssammlung München, Munich, Germany.
Specimens were collected with the aid of an aspirator after splashing water on fine gravel or coarse sand, and waiting for the beetles to appear on the surface. Specimens for morphological studies were killed and preserved in Acer sawdust to which ethyl acetate was added. Specimens for DNA sequencing were collected into 95% or 100% ethanol.
General methods of specimen preparation for morphological work, and terms used, follow
Photographs of entire beetles, elytra, and heads were taken with a Leica M165C dissecting scope and a Sony NEX-7 camera, and of male genitalia with a Leica DM5500B compound microscope and DMC425C camera. Microsculpture photographs were taken with a DMC425C camera attached to a DM5500B compound scope equipped with an X-Cite 110LED light source, which provides co-axial illumination, and a 20× epi-illumination objective lens. For all photographs of specimens or body parts, a stack of images from different focal positions was merged using the PMax procedure in Zerene Systems’ Zerene Stacker; the final images thus potentially have some artefacts caused by the merging algorithm. Measurements were made using Leica Application Suite v4.9 from images acquired using these either a Leica Z6 Apo lens and DMC4500 camera or a Leica DM5500B compound microscope and DMC425C camera.
We follow
Genes studied, and abbreviations used in this paper, are:
28S 28S ribosomal DNA (D1–D3 domains);
18S 18S ribosomal DNA;
CAD4 and CAD2 carbamoyl phosphate synthetase domain of the rudimentary gene (part 4 and part 2 of
COI cytochrome c oxidase I;
wg wingless.
DNA was extracted using a Qiagen DNeasy Blood and Tissue Kit. Gene fragments were amplified using the Polymerase Chain Reaction on an Eppendorf Mastercycler ProS Thermal Cycler, using TaKaRa Ex Taq and the basic protocols recommended by the manufacturers. Primers and details of the cycling reactions used are given in
We sampled DNA from 54 specimens of 19 species of Tasmanitachoides, as well as specimens of seven outgroup species, which belonged to other genera of Bembidarenini (Table
Specimens and genes sequenced of Bembidarenini. Four-digit numbers in entries (#) are D.R. Maddison DNA voucher numbers; further information about Tasmanitachoides specimens is given in Table
Alignment was not difficult for any of the protein-coding genes. There were no insertion or deletions (indels) evident in the sampled CAD4, CAD2, wg, or COI sequences. Alignments of 28S and 18S were conducted in MAFFT version 7.130b (
Localities of capture of Tasmanitachoides specimens whose DNA was sequenced. Four-digit numbers at the start of each row are D.R. Maddison DNA voucher numbers.
Tasmanitachoides kingi (Darlington) | |
5489 | Australia: TAS: River Forth at C136, 126 m, 41.4712°S, 146.1366°E |
5753 | Australia: TAS: Weld River NE Weldborough, 357 m, 41.1897°S, 147.9109°E |
Tasmanitachoides angulicollis Baehr | |
5515 | Australia: VIC: Flat Rock Creek at highway B23, 256 m, 37.2835°S, 149.2223°E |
Tasmanitachoides wilsoni (Sloane) | |
5514 | Australia: ACT: Murrumbidgee R. at Uriarra Crossing, 450 m, 35.2462°S, 148.9530°E |
5580 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
Tasmanitachoides baehri sp. nov. | |
2032 | Australia: ACT: Murrumbidgee River, 0.15 km u/s Uriarra Crossing (35°14.717'S, 148°57.135'E 440 m) |
5569 | Australia: ACT: Murrumbidgee River, 0.15 km u/s Uriarra Crossing (35°14.717'S, 148°57.135'E 440 m) |
Tasmanitachoides lutus (Darlington) | |
1773 | Australia: VIC: Jingalalla (Deddick) River, at Deddick Road, N. of Cobanandra, 525 m, (37.08S, 148.40E). |
5582 | Australia: VIC: Flat Rock Creek at highway B23, 256 m, 37.2835°S, 149.2223°E |
Tasmanitachoides sp. “Lerderderg R” | |
1772 | Australia: VIC: Lerderderg River, 6.8 km N. Bacchus Marsh, 135 m, (37.37'30"S, 144.25'24"E) |
2029 | Australia: VIC: Lerderderg River, 6.8 km N. Bacchus Marsh, 135 m, (37.37'30"S, 144.25'24"E) |
5584 | Australia: VIC: Lerderderg River, 6.8 km N. Bacchus Marsh, 135 m, (37.37'30"S, 144.25'24"E) |
Tasmanitachoides erwini sp. nov. | |
5509 | Australia: TAS: River Forth at C136, 126 m, 41.4712°S, 146.1366°E |
5583 | Australia: TAS: River Forth at C136, 126 m, 41.4712°S, 146.1366°E |
5679 | Australia: TAS: River Forth at C136, 126 m, 41.4712°S, 146.1366°E |
Tasmanitachoides cf. gerdi Baehr | |
2030 | Australia: ACT: Murrumbidgee River, 0.15 km u/s Uriarra Crossing (35°14.717'S, 148°57.135'E 440 m) |
5556 | Australia: ACT: Murrumbidgee R. at Uriarra Crossing, 450 m, 35.2462°S, 148.9530°E |
5575 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.11°E |
5676 | Australia: ACT: Murrumbidgee R. at Uriarra Crossing, 450 m, 35.2462°S, 148.9530°E |
Tasmanitachoides sp. “Angle Crossing #1” | |
5497 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
5578 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
5677 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
Tasmanitachoides hobarti (Blackburn) | |
5488 | Australia: TAS: Lake St Clair, 741 m, 42.1121°S, 146.2051°E |
5551 | Australia: TAS: South Esk River at Avoca, 193 m, 41.7807°S, 147.7148°E |
5552 | Australia: TAS: Weld River NE Weldborough, 357 m, 41.1897°S, 147.9118°E |
5554 | Australia: TAS: Ringarooma River at Derby, 148 m, 41.1492°S, 147.8050°E |
5579 | Australia: TAS: Ringarooma River at Derby, 148 m, 41.1492°S, 147.8050°E |
Tasmanitachoides leai (Sloane) | |
5507 | Australia: VIC: Flat Rock Creek at highway B23, 256 m, 37.2835°S, 149.2223°E |
5525 | Australia: TAS: River Forth at C136, 126 m, 41.4712°S, 146.1366°E |
5549 | Australia: TAS: Ringarooma River at Derby, 148 m, 41.1492°S, 147.805°E |
5557 | Australia: TAS: South Esk River at Avoca, 193 m, 41.7807°S, 147.7148°E |
5581 | Australia: VIC: Flat Rock Creek at highway B23, 256 m, 37.2835°S, 149.2223°E |
Tasmanitachoides rufescens Baehr | |
1993 | Australia: ACT: Murrumbidgee River, 0.15 km u/s Uriarra Crossing (35°14.717'S, 148°57.135'E 440 m) |
5577 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 600 m, 35.5803°S, 149.1109°E |
Tasmanitachoides sp. “River Forth” | |
5555 | Australia: TAS: River Forth at C136, 126 m, 41.4712°S, 146.1366°E |
Tasmanitachoides sp. “Angle Crossing #2” | |
5550 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
5678 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
Tasmanitachoides bicolor Baehr | |
5568 | Australia: QLD: Gayndah, Gray’s Waterhole |
Tasmanitachoides fitzroyi (Darlington) | |
0762 | Australia: QLD: Gayndah, Gray’s Waterhole |
1575 | Australia: QLD: Gayndah, Gray’s Waterhole |
Tasmanitachoides maior Baehr | |
5508 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 600 m, 35.5803°S, 149.1109°E |
5567 | Australia: VIC Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
Tasmanitachoides murrumbidgensis (Sloane) | |
2031 | Australia: ACT: Murrumbidgee River, 0.15 km u/s Uriarra Crossing (35°14.717'S, 148°57.135'E 440 m) |
5553 | Australia: VIC: Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
5564 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
5565 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 598 m, 35.5825°S, 149.1100°E |
5566 | Australia: VIC: Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
5571 | Australia: VIC: Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
5572 | Australia: VIC: Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
5754 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 600 m, 35.5803°S, 149.1109°E |
Tasmanitachoides sp. “Tambo R” | |
5548 | Australia: VIC: Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
5570 | Australia: VIC: Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
5573 | Australia: VIC: Tambo River at Bruthen, 10 m, 37.7111°S, 147.8369°E |
5574 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 600 m, 35.5803°S, 149.1109°E |
5576 | Australia: ACT: Murrumbidgee R. at Angle Crossing, 600 m, 35.5803°S, 149.1109°E |
Sites in 28S were chosen to be excluded from consideration using the modified GBLOCKS analysis (
Maximum likelihood (ML) analysis was conducted for each gene individually using IQ-TREE version 1.6.12 (
In addition, analyses of a matrix formed by concatenation of all six gene fragments were conducted, with the TESTMERGE option also being used, beginning with each codon position for each gene as a separate part (thus, the analysis began allowing for up to 11 parts: three for each of the three protein-coding genes, as well as one for 28S and one for 18S). Fifty searches were conducted for the ML tree for each matrix; for bootstrap analyses, 500 replicates were performed. In addition, an equivalent ML search was conducted for a matrix formed by the concatenation of all gene fragments except COI.
Sequences have been deposited in GenBank with accession numbers MW291161 through MW291313. Aligned data for each gene as well as files containing inferred trees for each gene are available in Suppl. material
The ML tree for all six gene fragments combined is shown in Fig.
Maximum likelihood tree for the concatenated matrix of all gene fragments (main figure) and for the concatenated matrix of all genes except COI (inset; this shows only part of the tree). Branch length is shown proportional to relative divergence, as estimated by IQ-TREE; scale bar indicates 0.01 units. Outgroups (Bembidarenas, Argentinatochoides, and Andinodontis; Table
Based upon these analyses, the kingi group of Tasmanitachoides appears to be a clade that is sister to the remaining species. This result is supported by bootstrap values of 100%, and by ML trees for all gene fragments except for CAD4 (Figs
With one exception, for all species for which multiple specimens were sampled, the sequences of a species form a clade in the gene trees separate from specimens of other species. This is evident in the tree for 28S (Fig.
Adults of the Tasmanitachoides katherinei and obliquiceps species groups. A T. katherinei, voucher V101468 B T. elongatulus, voucher DNA5515 C T. comes, holotype D T. gerdi, holotype. E T. cf. gerdi, voucher DNA5676 F T. sp. “Angle Crossing #1”, voucher DNA5677. G T. obliquiceps, voucher V101477 H T. mandibularis, voucher V101473. Scale bars: 1.0 mm.
Adults of the wattsensis group and other Tasmanitachoides A T. wattsensis, voucher DNA5758; NSW: Leatherbarrel Creek u/s Alpine Way B T. sp. “Lerderderg R”, voucher V101049; VIC: Lerderderg River, 6.8 km N. Bacchus Marsh C T. erwini, voucher V101469 D T. leai, voucher V101467 E T. hobarti, voucher V101463 F T. glabellus, paratype. Scale bars: 1.0 mm.
The known species of Tasmanitachoides vary in shape, form, and color (Figs
Left elytron of Tasmanitachoides A T. kingi, voucher V101468 B T. angulicollis, voucher DNA5515 C T. wilsoni, voucher V101470 D T. baehri, voucher V101479 E T. lutus, voucher V101462 F T. katherinei, voucher V101475 G T. cf. gerdi, voucher DNA5676 H T. sp. “Angle Crossing #1”, voucher DNA5677 J T. obliquiceps, voucher V101477 K T. mandibularis, voucher V101473.
Left elytron of Tasmanitachoides A T. sp. “Lerderderg R”, voucher V101049 B T. erwini, voucher V101469 C T. hobarti, voucher V101463 D T. leai, voucher V101467 E T. rufescens, voucher V101478 F T. sp. “River Forth”, voucher DNA5555 G T. sp. “Angle Crossing #2”, voucher DNA5678 H T. flindersianus, paratype J T. bicolor, voucher V101472 K T. fitzroyi, voucher V101471 L T. maior, voucher DNA5508 M T. arnhemensis, voucher V101476. N T. murrumbidgensis, voucher V101464 P T. minor, voucher V101474 Q T. sp. “Tambo R”, voucher V101465.
Diagnoses and descriptions of the genus are provided by
kingi group
T. kingi (Darlington)
T. angulicollis Baehr
T. hendrichi Baehr
T. wilsoni (Sloane)
T. baehri sp. nov.
wattsensis group
T. wattsensis (Blackburn)
T. sp. “Lerderderg R”
T. erwini sp. nov.
lutus group
T. lutus (Darlington)
katherinei group
T. katherinei Erwin
T. elongatulus Baehr
T. comes Baehr
T. gerdi Baehr
T. sp. “Angle Crossing #1”
obliquiceps group
T. obliquiceps (Sloane)
T. mandibularis Baehr
fitzroyi group
T. fitzroyi (Darlington)
T. maior Baehr
T. arnhemensis Erwin
T. murrumbidgensis (Sloane)
T. minor Baehr
T. sp. “Tambo R”
T. bicolor Baehr
unplaced to group
T. hobarti (Blackburn)
T. glabellus Baehr
T. leai (Sloane)
T. hackeri Baehr [likely a synonym of T. leai]
T. balli Baehr
T. rufescens Baehr
T. sp. “River Forth”
T. sp. “Angle Crossing #2”
T. flindersianus Baehr
The placement of species into groups may change once more species are better known, including those we have not sampled for DNA.
Species of Tasmanitachoides are currently very difficult to identify using morphological characteristics, in part because they are small, and as the known external differences between many species are subtle. In addition, although the internal sac of the male aedeagus has a complex pattern of sclerites, and thus could be a very valuable source of characters for identification, genitalic variation is not well documented or understood. One difficulty with comparing male genitalia is that the internal sac sclerites are oriented in a plane that is nearly edge-on in the standard left lateral view. This causes them to appear very differently as a function of slight differences in the orientation of the genitalia (compare, for example, Fig.
The key we present below is only an incremental improvement on
Based upon our examination of specimens of all known species, we have removed some of the inconsistencies in the key, simplified it, and changed its structure somewhat. However, we view this as a provisional key. Although we have previously seen specimens of all known species, for some of them (e.g., T. glabellus, T. comes, T. gerdi) we modified the key without those specimens at hand, and depended upon our notes and photographs of the primary types, as well as Martin Baehr’s papers. In addition, the variation within many species is not yet known, as there is limited material available (ten of the described species are known from fewer than five specimens). For example, Baehr’s key uses size to separate T. maior from other species, noting that the only specimen he knew was 2.9 mm in length; however, based upon our somewhat larger sample (we have measured seven specimens) the holotype is at the upper end of the size range, with some specimens as small as 2.44 mm in length, overlapping in length with related species. We suspect that the sizes given in the key for many species will need to be modified once more material is examined. The same will likely be true for color, as we have seen more variation in color in our large samples of some species than Martin Baehr had seen in his smaller samples. In addition, the geographic distributions mentioned in the key should be viewed with suspicion, as the ranges of species are very poorly known.
In Baehr’s keys, the couplet which divides Tasmanitachoides into the largest two groups is that which focuses on whether or not the clypeus is “distinctly impressed anteriorly”. We find this character difficult to ascertain, with many specimens appearing ambiguous, in part because of the more or less continuous variation in this trait across Tasmanitachoides species. For this reason we have replaced this couplet with one that focuses instead on a related trait, the presence or absence of tubercles on the anterior lateral corners of the clypeus, with associated modifications to other regions of the clypeus; this latter character is easier to judge.
1 | Only the sutural stria distinct, others completely effaced or almost so (Fig. |
(lutus group) T. lutus (Darlington) |
– | Elytra with at least stria 5 impressed anteriorly, other striae superficial to deeply impressed | 2 |
2 | Anterior lateral corners of the clypeus raised, tuberculate, such that the central region of the anterior half of the clypeus is distinctly lower than the lateral regions (Fig. |
fitzroyi group, 3 |
– | Anterior lateral regions of clypeus not obviously tuberculate; the central region is thus convex, flat, or only slightly concave (Fig. |
8 |
3 | Body larger and wider (Fig. |
4 |
– | Body smaller and narrower (Fig. |
5 |
4 | Color uniformly rufous or rufo-piceous; apical antennomeres infuscated. ACT, NSW, VIC | T. maior Baehr |
– | Color pale with rufo-testaceous forebody, elytra at apex testaceous (Fig. |
T. fitzroyi (Darlington) |
5 | Forebody reddish to reddish-testaceous, elytra testaceous. NT, WA | 6 |
– | Either completely piceous or dark reddish, or forebody dark piceous and elytra dark reddish with piceous borders, suture, base, and apex. VIC, ACT, NSW | 7 |
6 | Pronotum broader, lateral margin of pronotum strongly rounded, with short, straight region just in front of the projected hind angle; second to fourth elytral striae less impressed. Body larger and wider, 1.9–2.15 mm long. Central and northern NT, northern WA. | T. arnhemensis Erwin |
– | Lateral border of pronotum distinctly sinuate in front of the right-angled, but non-projected hind angle; second to fourth elytral striae more impressed. Body smaller and narrower, 1.65–1.95 mm long. Northern WA, north of Great Sandy Desert. | T. minor Baehr |
7 | Body more convex, broader, especially the pronotum, which is more evidently wider than the head (maximum width of prothorax/width of head across eyes 1.12–1.15, n = 5). Lateral margins of pronotum more rounded, especially around anterior lateral seta. Body size in general larger, 1.87–2.17 mm, most specimens > 1.90 mm. | T. murrumbidgensis (Sloane) |
– | Body flatter, narrower; pronotum only very slightly wider than head (maximum width of prothorax/width of head across eyes 1.04–1.08, n 5). Lateral margins of pronotum less rounded, straighter. Body size in general smaller, 1.64–1.97 mm, most specimens < 1.90 mm | T. sp. “Tambo R” |
8 | Head very large, with large, elongate mandibles (Fig. |
obliquiceps group, 9 |
– | Head of a relative size more typical for a carabid, with shorter, less protruding mandibles; eyes larger, more protruded, temples, if evident, small; posterior supraorbital seta situated immediately at posterior border of eye; pronotum laterally more rounded, widest far behind anterior angles; color variable | 10 |
9 | Larger species, body length > 2 mm; pronotum wider, ratio width/length > 1.35; elytra longer, ratio length/width > 1.75; pronotum impunctate; pilosity on pronotum and elytra barely visible even at high magnification. NSW, QLD | T. obliquiceps (Sloane) |
– | Smaller species, body length < 1.85 mm; pronotum narrower, ratio width/length < 1.32; elytra shorter, ratio length/width < 1.68; pronotum finely punctate; pilosity on pronotum and elytra distinct, erect. WA | T. mandibularis Baehr |
10 | Third and fourth elytral striae absent, or barely recognizable (except in some species as shallow, broad, impunctate grooves, Fig. |
kingi group, 11 |
– | Third and fourth elytral striae present, with at least small punctures, although sometimes superficial. Frontal furrows variable | 15 |
11 | Pronotum narrow, much narrower than the elytra at the shoulders (Fig. |
T. baehri sp. nov. |
– | Pronotum closer to the width of the elytra at the shoulders (Fig. |
12 |
12 | Body short and convex (Fig. |
T. wilsoni (Sloane) |
– | Body longer and narrower, less convex; elytra more than 1.5 × longer than wide; pronotum narrower, base (at hind angles) considerably narrower than apex, hind angle acute, laterally projected. Body orange-brown or darker. Second stria effaced or present | 13 |
13 | Eyes less protruded, temples perceptible; hind angle of pronotum approximately 90°, less acute and projected. Most specimens with body infuscated. TAS | T. kingi (Darlington) |
– | Eyes more protruded, temples reduced; hind angle of pronotum acute, < 90°, laterally distinctly projected. Most specimens with body orange or orange-brown. VIC, NSW | 14 |
14 | Prothorax wider, ratio width/length > 1.25; elytra shorter and wider, ratio length/width 1.55; finest traces of striae still visible between first and fifth stria | T. angulicollis Baehr |
– | Prothorax narrower, ratio width/length <1.15; elytra longer and narrower, ratio length/width l.70; virtually no traces of striae visible between first and fifth striae | T. hendrichi Baehr |
15 | Frontal furrows short (Fig. |
katherinei group, 16 |
– | Frontal furrows longer (Fig. |
19 |
16 | Entire dorsal surface with distinct isodiametric microsculpture; color testaceous, in some specimens head and prothorax slightly darker than elytra; elytra generally shorter, ratio length/width of elytra < l.65. Northern NT, northern WA, northern QLD, northeastern NSW | T. katherinei Erwin |
– | Dorsal surface with at most indistinct, superficial microsculpture, in particular elytra which are shiny with microsculpture almost effaced; color various; elytra generally longer, ratio length/width > 1.70. Northern WA, northern QLD | 17 |
17 | Frontal furrows attaining but the anterior third of the eyes, ended abruptly (Fig. |
T. gerdi Baehr |
– | Frontal furrows attaining mid-level of the eyes, ended less abruptly (Fig. |
18 |
18 | Color darker, head and pronotum dark reddish to reddish-piceous, elytra reddish (Fig. |
T. comes Baehr |
– | Color paler, head and pronotum pale reddish, elytra pale yellow (Fig. |
T. elongatulus Baehr |
19 | Pronotum constricted posteriad such that the hind margin is notably narrower than width at widest point, with lateral margin distinctly sinuate (Fig. |
T. flindersianus Baehr |
– | Pronotum less constricted, with sides less sinuate (Figs |
20 |
20 | First elytral stria straighter, less abruptly sinuate (Fig. |
21 |
– | First elytral stria abruptly sinuate, very close to the suture in the anterior fifth or fourth, at which point it abruptly bends away from the suture (Fig. |
24 |
21 | Eyes large, more protruded, temples almost wanting (Fig. |
22 |
– | Eyes smaller, less protruded, temples more evident, oblique (Fig. |
T. rufescens Baehr |
22 | Body more convex, especially the pronotum. Pronotum with lateral margins more rounded. Apical antennomeres darker, such that antennomere 9 is much darker than antennomere 4. QLD | 23 |
– | Body flatter. Pronotum with lateral margins straighter. Apical antennomeres only slightly darker than basal antennomeres, such that antennomere 9 is only slightly darker than antennomere 4. ACT | T. sp. “Angle Crossing #2” |
23 | Color uniformly dark piceous; elytra slightly shorter and wider, ratio length/width approximately 1.65; microsculpture on pronotum and elytra much more superficial; punctation of intervals very fine, less distinct. Northern QLD, Iron Range, mid Cape York Peninsula | T. balli Baehr |
– | Forebody piceous, elytra distinctly lighter on disk; elytra slightly longer and narrower, ratio length/width approximately 1.75; microsculpture on pronotum and elytra much more distinct; punctation of intervals coarser, distinct. Northeastern QLD, south of Cape York Peninsula | T. bicolor Baehr |
24 | Fifth elytral stria abruptly ended behind anterior third (Fig. |
T. leai (Sloane) and T. hackeri Baehr |
– | Fifth elytral stria distinct even in apical half (Fig. |
25 |
25 | Third and fourth elytral striae at halfway point of elytra much less impressed than second and fifth; sixth stria absent or extremely faint | wattsensis group, 26 |
– | Third and fourth elytral striae more less as impressed as second; sixth stria distinct, consisting of evident punctures | 27 |
26 | Legs darker, with femur piceous, tibia at least mostly piceous, and tarsi at least infuscated if not piceous; all antennomeres piceous, including first antennomere. Body less convex, dorsal surface flatter. TAS | T. erwini sp. nov. |
– | Legs paler, with femur rufo-testaceous or infuscated, tibia at most slightly infuscated, and tibia rufo-testaceous or testaceous; first antennomere distinctly paler than others. Body relatively convex. VIC, southern NSW | T. wattsensis (Blackburn) |
27 | Occurring in TAS | T. hobarti (Blackburn) |
– | Occurring in QLD | T. glabellus Baehr |
Below we provide notes about some of the species of Tasmanitachoides, as well as descriptions of T. baehri, sp. nov., and T. erwini, sp. nov.
Holotype. Male (
Paratypes
(26). Same label data as holotype (8;
We have seen an addition specimen labeled “Paddy’s River, 1 mi. S. of Cotter Dam, ACT, 17.iv.1969. S. Misko” (
Australia: ACT: Murrumbidgee River, 0.15 km u/s Uriarra Crossing (35°14.717'S, 148°57.135'E 440 m).
We are honored to name this species after the late Martin Baehr, who discovered and documented many of the carabid species of Australia, and who described 14 of the known species of Tasmanitachoides.
Very small, length 1.59–1.63 mm (n = 4). A pale species, body mostly orange, with the front half of the elytra and head a darker reddish orange. Antennae pale testaceous, with antennomeres 5–11 slightly infuscated. Head with moderately long but shallow frontal furrows, reaching approximately the center of the eye, and at least to the anterior supraorbital seta (Fig.
Dorsal view of head of Tasmanitachoides adults A T. wilsoni, voucher V101470 B T. baehri, voucher V101479 C T. lutus, voucher V101462 D T. cf. gerdi, voucher DNA5676 E T. sp. “Angle Crossing #1”, voucher DNA5677 F T. obliquiceps, voucher V101477 G T. erwini, voucher V101469 H T. hobarti, voucher V101463 J T. leai, voucher V101467 K T. rufescens, voucher V101478 L T. fitzroyi, voucher V101471 M T. murrumbidgensis, voucher V101464.
Likely to be confused only with similarly small and compact T. wilsoni, from which it can be distinguished by the narrower pronotum with less rounded lateral margins, and narrower, less rounded elytra. In addition, T. wilsoni has much shorter frontal furrows, which do not reach the anterior supraorbital seta (Fig.
Only known from the Australian Capital Territory (Fig.
Collected from pockets of gravelly cobble at the edge of still water of the Murrumbidgee River. The collection locality was amongst riverbank sheoaks (Allocasuarina) and relatively protected. Specimens were recovered by splashing the gravel bank after removal of cobbles. The species was collected with T. murrumbidgensis, T. rufescens, and a single specimen of T. leai.
This species belongs to the kingi species group and appears to be sister to T. wilsoni among the sampled species (Figs
This species was called “Tasmanitachoides cf. rufescens” in
Holotype. Male (
Paratypes
(23). Same label data as holotype (20;
Australia: Tasmania: at the mouth of Machinery Creek into the River Forth at road C136, 41.4712°S, 146.1366°E, 126 m.
We are honored to name this species after the late Terry Lee Erwin, for his many contributions to carabidology and systematics in general, and to our knowledge of Tasmanitachoides and other bembidarenines in particular.
Length 2.25–2.75 mm (n = 7); most specimens less than 2.6 mm. One of the darker species of Tasmanitachoides (Fig.
As with other members of the wattsensis group, this species has a relatively unmodified clypeus, without anterior lateral tubercles, and with the third and fourth elytral striae nearly effaced. Its darker color (including the entirely piceous antenna) and flatness distinguish it from other members of the group. It is the only known species of the group from Tasmania. From the other two large and dark Tasmanitachoides from Tasmania, T. hobarti and T. leai, T. erwini is distinguished by having a darker antennomere 1 and flatter body. From T. hobarti it is further distinguished by the much weaker striae 3 and 4; from T. leai by the longer stria 5.
At the type locality, members of this species were found during daylight hours in fine gravel on the banks of Mineral Creek at its mouth into the River Forth (Fig.
This species belongs to the wattsensis species group, and appears to be the sister to T. sp. “Lerderderg R” among the sampled species (Figs
This is the species illustrated by
We have examined the holotype of T. hendrichi and a paratype of T. angulicollis, and found them to be extremely similar; it is possible that they are synonyms.
There is only one known specimen of T. comes and only one of T. gerdi (
We have examined a photograph of the type (or syntype – see
Baehr’s mixed concept of T. hobarti may be relevant to understand the history of T. glabellus. We have examined high-quality photographs of the paratype of T. glabellus (in ZSM, courtesy of Michael Balke), and it looks extremely similar, if not identical, to true T. hobarti. We could see no evident differences. As it seems very unlikely that a species would be known from only Tasmania and one mountain top in North Queensland, even given how poorly Tasmanitachoides is collected, it seems more likely that these are distinct species or that the label data for the two T. glabellus specimens is in error. We leave it to further field work and closer examination of the types to resolve the status of T. glabellus.
In his description of T. hackeri, Baehr (2008) notes that this species has “Stria 5 near base deeply sulcate, abruptly ended behind basal third”, and indeed, the paratype from the type locality that we have examined (ZSM) has this trait. This is the character by which he separates this species from, for example, T. leai in the dichotomous key he presents. However, in this regard T. hackeri exactly matches all specimens of T. leai we have examined, including the lectotype (
The only specimen
The specimens we have in hand of the T. wattsensis group from Victoria and New South Wales show a great deal of variation, hinting at a complex of closely related species. The specimens from the Lerderderg River (T. sp. “Lerderderg R”) are distinctly broader than the remainder, and appear to be a separate species. This is the species that was called “Tasmanitachoides cf. leai” in
George Eugene Ball died on 12 January 2019, as the two authors of this current paper were travelling on the ferry from Melbourne, Victoria to Devonport, Tasmania, in the midst of the field work that produced the bulk of the specimens on which this paper was based. In less than two years since that day, the world has lost most of the remaining senior figures in carabid systematics, and in the process a tremendous amount of knowledge about carabid beetles that had never been written down. George’s death was followed by that of Martin Baehr, who knew the Australian carabid fauna better than anyone. We lost Augusto Vigna Taglianti and Ross Taylor Bell later in 2019. In the early spring of 2020 we lost Terry Lee Erwin, and in early October, Shun-Ichi Uéno. To have lost six of our grand masters in less than two years is stunning. Our naming a species after Terry and one after Martin are but small gestures to help us honor and remember these two carabidologists, and all the others, like George, Augusto, Ross, and Shun-Ichi, who have devoted their lives to uncover the hidden diversity in the small organisms with which we share our planet.
This paper is dedicated to the memory of Terry Lee Erwin, who contributed to biodiversity studies in general in so many ways, including his role in creating the seminal journal ZooKeys, and who contributed to carabid systematics in particular, including naming the genus Tasmanitachoides.
Specimens were collected under permit FA19258 issued by the Tasmanian Department of Primary Industries, Parks, Water and Environment and permit 10008992 issued by the Victorian Department of Environment, Land, Water, and Planning. As with most biodiversity projects, this work could not have been completed without the people who are stewards of insect collections at museums around the world. We thank Cate Lemann (
This project was supported by the Harold E. and Leona M. Rice Endowment Fund at Oregon State University.
Mesquite NEXUS file containing the DNA sequence data and resulting phylogenetic trees from maximum likelihood analyses for Tasmanitachoides and other Bembidarenini
Data type: NEXUS file (DNA sequences, phylogenetic trees)