Neoponera vejestoria, Fiorentino & Lattke & Troya & Sosiak & Dong & Barden, 2023

Fiorentino, Gianpiero, Lattke, John, Troya, Adrian, Sosiak, Christine, Dong, Minsoo & Barden, Phillip, 2023, Deep time extinction of largest insular ant predators and the first fossil Neoponera (Formicidae: Ponerinae) from Miocene age Dominican amber, BMC Biology (26) 21 (1), pp. 1-12 : 2-6

publication ID	https://doi.org/ 10.1186/s12915-022-01488-9
DOI	https://doi.org/10.5281/zenodo.7629987
persistent identifier	https://treatment.plazi.org/id/3E13D26F-1557-313E-7D79-EC84FE89B329
treatment provided by	Felipe
scientific name	Neoponera vejestoria
status	sp. nov.

Treatment

Neoponera vejestoria sp. nov.

ZooBank LSID: urn:lsid:zoobank.org:pub:DAF246D4-5D88-4858-BDFE-6329E2507396 .

Diagnosis, worker

Neoponera vejestoria shows the typical diagnostic characters present in the genus, including well-developed, convex eyes placed at about head mid-length; welldeveloped aroliae; and slit-shaped propodeal spiracle (most species in the genus). Within Neoponera , this fossil mostly resembles species in the foetida and aenescens species groups. However, it is readily assignable to the foetida group (see more insights further below) since it shows (1) well-developed malar carinae, which are absent in the aenescens species group, and (2) eyes placed at about head mid-length, whereas in the aenescens group these are placed slightly anterad. Neoponera vejestoria may only be confused with three extant species in the genus, N. dismarginata (Mackay & Mackay), N. carbonaria (Smith) , and N. ecu39704 (undescribed, see images of MEPNINV39794 on AntWeb.org). It can be separated from these taxa by the following: N. vejestoria shows evident striae on the body dorsum, particularly on the mesonotum and on abdominal segments III and IV (no striae on N. dismarginata, showing instead microfoveae; in N. carbonaria and N. ecu39794, the cuticle is almost devoid of sculpture dorsally, instead having few, usually feebly impressed striae on the meso- and metapleuron). Neoponera vejestoria shows blunt humeral carinae (welldeveloped and sharp in N. dismarginata; blunt to absent in N. ecu39794, and N. carbonaria ). Finally, N. vejestoria has well-developed, apparently sharp, posterolateral nodal carinae on the petiole (absent in N. dismarginata; sometimes present in N. carbonaria , though always blunt; and always present but blunt in N. ecu39794). Within the foetida group, N. vejestoria is the only taxon showing a bluish-greenish iridescent cuticle. Among extant Neoponera , this trait has only been seen in some species of the aenescens group, for example, in N. carbonaria .

Description, worker

Head. Frontal view: subquadrate, slightly longer than broad (CI 95); postocular lateral margins feebly converging posterad; posterior head margin moderately concave; eye well-developed (OI 29), convex, breaking lateral head margin, located dorsolaterally near head mid-length (OMD 0.50). In frontal/lateral view: posterior head corner convex; well-developed malar carina present, almost reaching anterior eye margin; anterior mid-clypeal margin convex; mandible with 13–15 teeth on masticatory margin, basal margin edentate; frontal lobe apparently subtriangular, slightly convex anteriorly, feebly projecting over antennal insertions, so that bulbous neck is partially visible dorsally; antennal scape relatively long (SL 119), surpassing posterior head margin by approximately three apical widths.

Mesosoma. Lateral view: dorsal pronotal margin slightly convex, humeral carina present, blunt, not salient (Additional file 1: Fig. S1A View Fig ); promesonotal articulation present; mesonotum weakly convex; posterior margin sloping; notopropodeal suture present, grooved, though not deeply impressed; mesonotum broader than long (MsL = 37); dorsal propodeal margin slightly convex (Additional file 1: Fig. S1B View Fig ); propodeal declivity with concave transverse section; propodeal carina with blunt elevated lateral margin; metanotal spiracle covered by lobe, propodeal spiracle slit-shaped; metapleural gland opening with seemingly reduced posterior cuticular flap (Additional file 1: Fig. S1G View Fig ); probasisternum broad anteriorly and gradually narrowing posterad, grooved, with acute posterior process; mesosternal process present but reduced, apparently canine tooth-shaped: lobes are blunt distally as compared to those on metasternum; metasternal process present, fang-shaped, space between distally acute lobes greater than width of each lobe ( Fig. 1C View Fig , Additional file 1: Figs. S1A and B View Fig ).

Legs. Fourth metatarsus about half as long as 5th (Additional file 1: Fig. S1E View Fig ); arolium well-developed, about 1/3 of claw length (Additional file 1: Fig. S1F View Fig ).

Petiole. Lateral view: node sessile, higher than broad (LPI 66), subtriangular and robust, broad at base and slightly tapering atop, with anterior margin relatively straight, feebly inclined posterad, and posterior margin convex, both meeting anteriorly to nodal vertical midline; posterolateral nodal face with evident convex carina ( Fig. 1C View Fig ); longitudinal carina on lateral face not apparent; subpetiolar process with blunt anterior cusp. Dorsal view: subtriangular, anterior margin subacute, posterior margin straight to slightly convex.

Gaster. Prora well-developed, tooth-shaped, with subacute tip directed anteroventrad; cinctus between segments AIII–AIV well-developed (Additional file 1: Fig. S1C View Fig and Fig. S2 View Fig ); stridulitrum on pretergite of AIV not apparent.

Sculpture, pilosity, and color. Whole-body iridescent and shiny, with green/blue metallic coloration (similar to N. carbonaria ); head with sparse erect hairs and somewhat dense short pubescence, antenna mostly devoid of pubescence, sparse erect setae present on scape and antennomeres; malar and genal regions punctate to rugulose, clypeus mostly punctate; mandibles finely punctate, covered by thick, long pilosity (mostly ventrally); dorsoposterior head surface with fine longitudinal striae; propleuron with abundant (> 10) erect hairs; mesonotum densely punctate, longitudinally striate, covered with sparse long, erect hairs (mostly dorsally); dorsal face of propodeum densely punctate, transversely striate, with sparse short erect setae and long erect setae laterally; declivity of propodeum transversely striate, with long erect setae on the lateral border. Legs with long erect and dense short appressed setae; arolium whitish; anterior face of the node with fine longitudinal striae, posterior face sparsely punctate, anterior and posterior margins with long erect setae; subpetiolar process distinctly rugulose and finely punctate; abdominal tergites III and IV longitudinally striate; gaster sparsely covered with long erect setae, lacking appressed pubescence; prora distinctly smooth and shiny; hypopygium and epipygium with long erect hairs; distinctly smooth and shiny, lacking short tooth-like setae.

Worker measurements: HW 2.39, Hl 2.54, EL 0.63, SL 2.87, OMD 0.50, ProW 1.5, WL 3.71, MsW 0.91, MsL 2.46, MfL 3.51, PW 1.08, PH 1.44, PL 0.9, AIIIL 1.41, AIIIW 1.94, AIVL 1.23, AIVW 1.77, TL 12.3; CI 95, OI 26, SI 119, MsI 37, LPI 66, DPI 120.

Etymology. The name is derived from the Spanish vernacular word “vejestorio,” an informal way to refer to an old person or object. The specific epithet is a feminized, non- Latinized adjective placed in apposition, thus invariant.

Type material. Holotype. MNHNSD FOS 18.01 worker, deposited in the Museo Nacional de Historia Natural “Prof. Eugenio de Jesús Marcano,” Santo Domingo , Dominican Republic ( Figs. 1 View Fig and 2 View Fig , Additional file 1: Figs. S1 View Fig and S 3 View Fig ). Preserved within a 60 mm by 40 mm section of transparent, yellow amber with abundant bubbles. Syninclusions include a long-jawed spider ( Tetragnathidae ), a staphylinid beetle (Paederinae), and a fungus gnat ( Mycetophilidae ).

Horizon and locality. Early Miocene, Burdigalian (ca. 16 Ma; [ 11]); in amber from the Northern mines of the Santiago Providence, Dominican Republic.

Comments. Neoponera vejestoria is the first fossil species in the genus and also the first confidently assigned to the genus level in the Pachycondyla genus group from the Neotropics. Morphometric analysis of 12 traits across 47 of the 58 valid Neoponera placed the novel species within the morphospace comprising the aenescens and apicalis species groups, but also

close to the morphospace of the foetida group ( Fig. 3 View Fig ). However, from a taxonomic perspective, this species is morphologically assignable to the foetida group, mainly due to (1) the presence of malar carinae. Though this trait presents some variation, it is a re-occurring, welldistinguished feature in all lineages of this species group. Perhaps the only exception to this rule is N. dismarginata where these carinae are rudimentary and hard to distinguish, but still present. As cited before, the malar carina is absent in all known lineages of the aenescens group (Additional file 1: Fig. S2A View Fig ). (2) The eyes placed approximately on the head mid-length. This feature is among the easiest to discern in the foetida group and is also quite similar to the arrangement found in virtually all species in the crenata group, which is its putative sister clade sensu Troya et al. (unpublished). Except perhaps for N. aenescens (Mayr) , from the nominotypical species-group, the eyes of all taxa in the aenescens group are placed slightly anterad on the head. Again, this feature is clearly discernible, thus easy to diagnose. (3) The humeral carinae are well-impressed in N. vejestoria , though somewhat blunt and not salient. This character is variable in the foetida group, from strongly salient and acute as in N. foetida , to acute but not salient as in N. zuparkoi (Mackay & Mackay), to blunt and feebly impressed as in N. fisheri (Mackay & Mackay). Nevertheless, a humeral angle is always present in all members of the foetida group, and it could be considered apomorphic for it, as well for all species in the crenata group. In contrast, the humeral carina in species of the aenescens group, although feebly impressed in some lineages, like in N. aenescens or N. carbonaria , is overall absent in the form of an acute border in all its members. (4) Abundant pilosity, both appressed and erect, is another remarkable feature in most members of the foetida group, with the exception of N. fisheri and N. solisi (Mackay & Mackay) which show much less appressed pilosity mainly on the nodal dorsum as compared to their group partners. In a similar fashion, all species in the aenescens group are setose, many of them show abundant appressed setae like N. eleonorae (Forel) , but none shows abundant long setae as in members of the foetida group. (5) A conspicuous and grooved notopropodeal suture (Additional file 1: Fig S1A View Fig ) is also present in all members of the aenescens and apicalis groups but is absent in almost all members of the crenata group.

Besides the three possible similar species mentioned in the diagnosis, N. vejestoria is perhaps also similar to N. insignis (Mackay and Mackay), but the petiolar node of the latter is somewhat block-shaped, approximately symmetric in lateral view. The longitudinal striae on the dorsum of the head is a putative autapomorphy in N. vejestoria . Only N. foetida (Linnaeus) and N. theresiae (Forel) show a similar sculpture, but this is restricted to the node and laterally on the propodeum in those species. Finally, N. vejestoria is easily distinguished by its notable iridescence which has been observed only in some species of the aenescens group, for example, in N. carbonaria , but in the foetida group it is, thus far, a novelty which warrants further research.