Antilissus makauwahi, Porch, 2020

Porch, Nick, 2020, A new and likely extinct species of Antilissus Sharp, 1879 (Coleoptera: Zopheridae Colydiinae) from Makauwahi Cave, Kauai, Hawaiian Islands, Zootaxa 4868 (1), pp. 135-141 : 137-138

Antilissus makauwahi sp. nov.

(Fig.1,2,3)

Type Locality: Hawaiian Islands , Kauai, Makauwahi Cave, NW Excavation Pit (21°53.311’N 159°25.122’W) .

Type material. Holotype ( Figure 1 ): Hawaiian Islands , Kauai , Makauwahi Cave , BAW-NW Pit, Bucket auger sample, 3.3–3.6 metres depth—articulated head and prothorax, dorsally and ventrally complete except for appendages. BPBM, Honolulu.

Paratypes (5) ( Figure 2 ): Hawaii, Kauai, Makauwahi Cave, BAW-NW Pit , 2009 square GG74, ‘ Sump’ 4.0-4.5 metres depth–prothorax, dorsally and ventrally complete except for appendages (1 BPBM, Honolulu); Hawaii, Kauai , Makauwahi Cave , BAW-NW Pit , Sump 4.0–4.5 metres depth, 4 prothoraces (3 BPBM, Honolulu; 1 Porch research collection) .

Diagnosis. Antilissus makauwahi can be distinguished from A. aper Sharp on the basis of its pronotal sculpture: A. aper has the medial channel continuous from apical to basal margin, (see Figure 4 ) whereas A. makauwahi has this channel interrupted from just before the middle of the pronotum to just anterior of the base resulting in the presence of a shield-shaped island, cleft in its base ( Figure 2 ).

Description. Colour: The Holotype is pale reddish brown; all other specimens variously piceous-black. Colour varies in part because some specimens retain internal sediment (darker), whereas others don’t (paler).

Prothorax longer than wide, subparallel, widest at approximately 1/4–1/2 length of prothorax. Lateral margins straight behind widest point to obtuse, crenulate, hind angles, weakly curved to anterior angles; on most specimens lateral margin very weakly concave adjacent to medio-lateral pits. Lateral margin narrow, but triangularly expanded inward at location of marginal pit, moderately crenulate, with very small widely separated punctures on small tubercles which presumably held setae. Anterior margin curved and slightly protuberant to medially straight, strongly bisinuate to acute produced anterior angles which remain posteriad the middle part of anterior margin; front without continuous margin. Posterior margin curved and notched to hind angles; margined with semi-continuous sulcus connecting small pits/depressions; bearing widely separated punctures on small tubercles oriented into marginal sulcus, some of which still bear yellowish setae (about the width of the sulcus in length); deepest immediately adjacent to basal angles and becoming shallower medially. Procoxal cavities circular and broadly closed, separated by just over half procoxal cavity width.

Pronotal disc divided into a series of discrete ‘islands’ by channels and associated deep pits (see Fig. 1-2 ): four quadrate islands across the anterior half of the disk, the middle two of which separated by narrow triangular channel wider and briefly divided into two at the front and becoming less well-developed posteriorly; a medial shieldshaped island mostly behind middle distinctly cleft in its base, defined by deep channels with pits at anteriolateral corners, pits laterally between marginal islands, and posteriorly behind cleft hind margin; a further two subtriangular islands baso-laterally, adjacent to the medial shield-shaped island; two very small weakly developed islands present behind medial shield-shaped island and connected to the basolateral triangular islands by a weakly defined channel. Marginal channel at least twice as wide as lateral margin and wider than discal channels, curved from anterior and posterior angles around anterior and posterior lateral islands to deep pit just behind middle. Base of channel smooth. Channel merges with basal margin becoming narrower just inside basal angle. Pronotal surfaces glossy without obvious microsculpture and with small impressed punctures separated by their width, usually much more: punctures larger and closer around margins and smaller and more widely separated medially. Punctures presumably bore setae.

Prosternum in front of coxae approximately 2.3 times length of coxae, densely punctate with large circularsemicircular seta-bearing punctures separated by less than their width across most of the prosternum, further apart in medial area where arranged in weakly diagonal transverse rows. Surface glossy in between punctures. Wide, shallowly impressed, anterior margin composed of interlocking punctures and, compared to disk, distinctly dull. Prosternal process between coxae narrower than procoxal cavity and expanded from middle of cavity to the width of procoxal cavity, margined in front of coxae and along length of procoxae with dull impressed area similar to anterior margin. Apex of prosternal process truncate to very weakly concave. Postcoxal projections less than half width of procoxal cavity. Hypomeron punctate, the punctures broad and shallow and almost confluent, areas between with distinctive reticulate microsculpture.

Head (based on holotype with head still articulated with prothorax ( Figure 1 ) and a single non-type head ( Figure 3 )) with reduced eye consisting of approximately four rows of ommatidia forming a crescent with larger ommatidia anteriorly: number of ommatidia in each row diminishing from anterior to posterior row. Ventrally, antennal groove narrow and extended well behind eye. Dorsally, with longitudinal sulcus above each eye and with two deep pits immediately mesad from this sulcus connected by anteriorly arcuate suture which is impressed at base of clypeus. Sculpture of irregular low tubercules bearing short, pale yellow, setae.

Figures

FIGURE 1. Holotype Antilissus makauwahi articulated prothorax and head, dorsal (left) and ventral (right) - (Hawaiian Islands, Kauai, Makauwahi Cave, BAW-NW Pit, Bucket auger sample, 3.3–3.6 metres depth). Scale bar = 0.5 mm.

FIGURE 2. Type series prothoraces of Antilissus makauwahi from Makauwahi Cave. All paratypes other than the holotype. A-D, F. BAW-NW Pit, 2009 square GG74, ‘Sump’ 4.0–4.5 metres depth. E. Holotype of A. makauwahi. Scale bar = 0.5 mm.

FIGURE 3. Head of non-type specimen of Antilissus makauwahi sp. nov. from BAC-NW 2009 GG74 ‘Sump’ 4.0–4.5 metres. Scale bar = 0.25 mm.

FIGURE 4. Antilissus aper, Sharp, 1879: A. Historical specimen of A. aper from Oahu (Labels: Kaumuahona, 6.17.17, Oahu; J.C. Bridwell, collector; Bobea; Antilissus aper, Sharp, 1879 det.?; BPBM ENT, 2004012430); B. Subfossil specimen of A. aper from Makauwahi Cave sequence (Sample: BAC-NW 2009 PHD).