Pheidole anticua, Casadei-Ferreira, Alexandre, Chaul, Julio C. M. & Feitosa, Rodrigo M., 2019

Casadei-Ferreira, Alexandre, Chaul, Julio C. M. & Feitosa, Rodrigo M., 2019, A new species of Pheidole (Formicidae, Myrmicinae) from Dominican amber with a review of the fossil records for the genus, ZooKeys 866, pp. 117-125 : 118-120

† Pheidole anticua sp. nov. Figures 1 , 2

Holotype major worker.

Dominican Republic, "La Toca" mine (ANTWEB1038178) [DZUP].

Holotype conditions.

After treatment, the amber piece is now a 15 × 10 × 5 mm, roughly pyramidal structure, glued in a perspex card, and pinned. The specimen pre sents discrete to moderate distortions in the antennae, mesosoma (especially in the propodeum), legs, waist and gaster. Additionally, head vertexal margin and gaster present abundant compression wrinkles. The inclusion also presents several bubbles, and a smalls internal fractures on the matrix close to the right lateral margin of head which hamper prefect visualization.

Diagnosis.

Among the extant Pheidole species, † P. anticua shares some features with members of the flavens group, which is characterized by small size, short antennal scape, thick antennal club, compact body, and vestigial or absent mesonotal convexity. Some of the extant and morphologically similar species are Pheidole arhuaca Forel, Pheidole nitidicollis Emery, Pheidole flavens Roger, Pheidole jamaicensis Wheeler, W.M., Pheidole schmalzi Emery, and Pheidole tambopatae Wilson. However, all these species, except for P. jamaicensis , present shorter scapes when compared to † P. anticua . Additionally, unlike P. flavens , † P. anticua has a projecting and slightly angulate humerus (like P. arhuaca , P. nitidicollis , P. jamaicensis , P. schmalzi , and P. tambopatae ). Compared with the other five species, † P. anticua has different mesosomal sculpture, with a smooth and shiny pronotum but sculptured mesonotum. † P. anticua cannot be assigned as the major worker of † P. primigenia and † P. tethepa due to the absence of humeral spines and the comparatively small body size (considering the average size proportion between Pheidole minor and major workers).

Measurements

(holotype): HL 0.75, HW 0.71, SL 0.5, EL 0.11, ML 0.63, PSL 0.12, PTW 0.06, PPW 0.15, CI 95, SI 70.

Description.

Lateral margins of head, in full face view, slightly convex; with abundant hairs extending laterally. Dorsum of mandible with basal area costate and the remaining surface smooth and shiny. Hypostomal margin straight; with median process vestigial and broad, submedian processes conspicuous, narrow and straight, distant from outer processes. Clypeus, in frontal view, with anterior notch; surface uniformly smooth and shiny. Scape length not surpassing the mid-height between the eyes and the fronto-vertexal lobes; with decumbent to erect hairs. Malar area, in full-face view, with some curved costae near antennal fossae, gradually becoming longitudinal near lateral margins of head. Frons, in full-face view, uniformly costate longitudinally. Antennal scrobe, in full-face view, shallow, internally costate longitudinally, not delimited posteriorly by a curved costulae. Vertexal margin deep, with narrow and strongly convex lobe; surface smooth and shiny.

Humerus, in dorsal-oblique view, projected and slightly angulate; with flexuous hair as long as the adjacent ones. Pronotal profile flat; surface completely smooth and shiny; with abundant long, flexuous and dark hairs. Mesonotum, in lateral view, projected and angulate, abruptly inclined posteriorly; with surface areolate. Katepisternum surface areolate. Propodeum, in lateral view, with long, narrow inclined projections; surface entirely areolate.

Petiolar peduncle, in lateral view, with dorsal margin gradually ascending posteriorly, so that the anterior margin of the node is inconspicuous. Petiolar node, in frontal view, with dorsal margin bilobed; with abundant, long and flexuous hairs, two of which are comparatively longer than the adjacent ones. Postpetiole, in dorsal view, with lateral margins rounded, surface smooth and shiny; with abundant, long and flexuous hairs. First gastral tergum uniformly smooth and shiny; dorsally with flexuous erect to decumbent hairs, less than 1.5 × the eye length.

Etymology.

From Latin anticua meaning old.

Figures

Figure 1. † Pheidole anticua sp. nov. A Lateral view B dorsal view C full face view and D hypostomal margin. Scale bars: 0.2 mm.

Figure 2. Illustrations of † Pheidole anticua sp. nov. A Lateral view B full face view C dorsal view and D hypostomal margin. Scale bars: 0.2 mm.