Gollandia, Makranczy, Gyoergy, Yamamoto, Shuhei & Engel, Michael S., 2018

Makranczy, Gyoergy, Yamamoto, Shuhei & Engel, Michael S., 2018, Description of a Cretaceous amber fossil putatively of the tribe Coprophilini (Coleoptera, Staphylinidae, Oxytelinae), ZooKeys 782, pp. 81-94 : 82-84

Gollandia gen. n.

Type species.

Gollandia planata sp. n., (described below).

Diagnosis.

Head. Head somewhat retracted under large pronotum; head capsule rather short. Epistomal sulcus not well visible, but presence suggested by a tranvserse ‘run’ of air between amber and cuticle. Supraantennal prominences weak. Antennomeres with long tactile setae near apices (prominent on articles 3-11). Labial palp trimerous, basal two palpomeres rather stout, last palpomere thin. Labrum with two thick, forward-directed setae. Mandibles not prominent, apices acute. Maxillary palp tetramerous, basal three palpomeres moderately elongate, last palpomere much wider and long, not reduced, apex pointed. Gular sulci seemingly widely separated at base but confluent anteriorly (this area is not well visible as preserved). Neck separated by gentle constriction and (at least laterally) a groove. Thorax. Pronotum strongly explanate, margin slightly reflexed, marginal bead present, lateral edge finely serrate/sinuous. Laterally with a strong seta at each of ‘anteroangularis’ and ‘lateralis’ positions, plus strong seta on both sides well inside lateral margin at about 1/3 length, posterior edge appearing slightly concave (might be artefact of preservation). Pronotal disc with shallow impressions, with fine and dense punctation and setation. Procoxae contiguous, projecting; procoxal fissure present and open (Figure 7). Mesoscutellum (Figure 8) with apex exposed and somewhat impressed without distinct pattern. Elytra finely and randomly punctate. Mesocoxae narrowly separated by mesosternal process (Figure 9). Legs slender (metatibia especially elongate), with regular rows of tibial spines (more slender than strong), and a conspicuous mesotibial spur (and a second spur half size at half-length towards femoral joint). Tarsal formula 4-4-4, no tarsal lobes (Figure 10), but empodial setae strong (Figure 11). Elytra with epipleural ridge, seemingly with a fine and shallow dorsal groove following it from inside, epipleura strongly deflexed and rather wide but epipleural fold thin to inconspicuous. Post-scutellar area with a pair of elongate impressions along suture. Shoulders prominently developed, narrowly rounded, even slightly projecting forward in relation to anterior edge at mesoscutellar area, posterior margin slightly oblique but straight from suture to outer 3/4, slightly incurved (concave) in outer 1/4 thereby producing a somewhat sharp outer corner in dorsal view. Abdomen. Abdomen with only six visible segments (not counting segments IX–X, often retracted under VIII), second abdominal segment not developed. With two pairs of laterosclerites. Apex of tergite VII seemingly without well-developed palisade fringe (difficult to judge; an air bubble under this structure obscures almost its entire width), apex of segment conspicuously widening (not narrowing to base of next segment), surface somewhat concave. Tergite VIII with apical edge truncate medially or slightly concave. Apex of sternite VIII without modification.

Differential diagnosis.

All extant Coprophilini have a 5-5-5 tarsal formula, and even the fossil genus Mesocoprophilus has five tarsomeres, so the 4-4-4 condition in Gollandia is significant. The new genus differs greatly from Mesocoprophilus in the antennal structure, stout and short in Mesocoprophilus , slender and elongate with well-developed tactile setae on all antennomeres in the present fossil. The neck (lateral constriction, postoccipital groove) also differentiates this genus from Mesocoprophilus where these features are absent. The lack of striae or puncture rows on the elytra makes this genus distinct from all extant Coprophilini , while a distinction from Mesocoprophilus cannot be made as that fossil lacks its dorsal portion ( Cai and Huang 2013). The present fossil is also peculiar in the slender and elongate appendages. The present-day representatives of Coprophilini lack such strongly formed, almost forward-projecting shoulders and the new genus has more slender antennae and palp, more slender tibiae, a procoxal cavity far removed from the pronotal margin, a prominently explanate pronotum, and the mesosternal process extending much more posteriorly. Two unusual traits for this subfamily are the posteriorly slightly incised elytral corners and the cylindrical, wide apex of segment VII (not narrowing to the base of segment VIII), both features otherwise characteristic of the subfamily Aleocharinae.

Systematic placement.

The only feature that clearly unites the fossil with extant Coprophilini is the lack of the well-developed second sternite. Beyond that, the head shape is reminiscent of Homalotrichus , while the pronotum bears some similarity to that of some Coprophilus (e.g., Coprophilus striatulus (Fabricius, 1793) plus its close relatives) and to a lesser extent some Homalotrichus (e.g., Homalotrichus impressicollis Solier, 1849), but none of these are as explanate as in the fossil.

Etymology.

The new genus is named after Susan Golland, exhibition developer at the Field Museum of Natural History, Chicago, whom the first author met at 10:32am on 14 March 2018 in front of Crystal Maier’s office. The fossil specimen described here was shown to him by the second author later on the same day. The gender of the name is considered feminine.