Ancyridris Wheeler, 1935: 1. Type species (by monotypy): A. polyrhachioides Wheeler , 1935: 2 (Mt Misim, PAPUA NEW GUINEA).
A. polyrhachioides Wheeler , 1935: 2, fig. 1, a-c; Mt. Misim, PAPUA NEW GUINEA.
A. rupicapra (Stitz) , 1938: 99, fig. 1, a-d; 'DEUTSCH NEU-GUINEA' ( Pheidole (Pheidolacanthinus) (sic!) rupicapra ) (Combination: Bolton, 1995: 62).
Ancyridris (Figs 19, 20) is the only putatively endemic ant genus known from New Guinea. It was provisionally cited as a junior synonym of Lordomyrma by Brown (1973: 178), but subsequently listed by him with generic status (Brown, 2000: 47). The suggested synonymy was not followed by Bolton (2003, et al.), and is declined here. Recent studies investigating DNA affinities among a number of myrmicine ants could indicate that the Ancyridris species comprise a sister group to the rump of Lordomyrma (Lucky, Sarnat & Ward pers.coms). Its species could, however, be considered a lineage within the Lordomyrma clade .
The genus is singularly morphologically distinctive and surprisingly species-rich, yet its taxa are structurally only modestly interspecifically diversified. Ancyridris appears to be limited to elevations above about 1,500 m. in the New Guinean cordillera, often at altitudes above those where ants are otherwise generally well represented. It includes a compact set of at least six undescribed species ( ANIC ) in addition to L. polyrhachioides and L. rupicapra . Its members are very alike, with considerable interspecific size variation; usually largely blackish-brown in color (though the 'red goat', A. rupicapra , is reddish-brown) and generally strongly shining, with at most very weak sculpturation, sparse pilosity and strongly developed, elongate, divergent, apically hooked propodeal spines. The anterior clypeal border carries a median point, the frontal carinae and antennal scrobes are vestigial, the petiole strongly and distinctively dorsolaterally bispinose and the postpetiole usually conical above, the antennae are 12-merous and the palpal formula 3:2 in 4 examined species. The clypeal structure, hooked propodeal spines, paired petiolar spines and dorsally extended postpetiole distinguish Ancyridris from Lordomyrma . Differently configured bilateral petiolar spines are present in Lordomyrma rouxi (Figs 17, 18), but they almost certainly represent a homoplasy.
Available specimens are from scattered sites in Papua New Guinea, with very few known from Indonesian West Papua. Sets of up to four sympatric or near-sympatric species are represented, and sympatric associations with Lordomyrma species are unknown. Ancyridris species are as distinctive and bizarre as some of the derivative lowland New Guinean Lordomyrma species. Despite this, their interspecific morphological diversity is relatively low and quite different in degree from that seen among the structurally diverse lowland New Guinean and New Caledonian Lordomyrma species. The genus compares most closely in the nature of its diversity to the Fijian Lordomyrma fauna (see above).
One species from moss forest on Mt Kaindi near Edie Creek (07o21'S, 146o40'E) is a morphologically specialized workerless parasite collected from the nest of another free-living species. Two additional sympatric free-living species are found in the vicinity.
The prospects for discovery of further such sympatric assemblages of Ancyridris species, including additional undescribed taxa, could relate directly to the large number of myrmecologically unexplored high mountain blocs on New Guinea. This significant group is surely not yet well represented in collections.
Ancyridris is a small genus of myrmicine ants, with only two described species from New Guinea.
The eyes are well developed. The long and narrow mesosoma is shaped somewhat as in Aphaenogaster. The propodeum bears two long, flattened, hooked spines resembling those of Polyrhachis bihamata. On the pronotum there are long hairs. The worker of A. polyrhachioides is almost 6 mm long. Apart from the curious anchor-like spines on its propodeum, Ancyridris bears a general resemblance to Aphaenogaster or certain worker forms of Pheidole. Wheeler suspected some aberrant or archaic group, "another of the living fossils which are continually turning up in the Papuan and Australian Regions".[2] Ancyridris in fact seems close to Lordomyrma. It is the only ant genus currently thought to be endemic to the island of New Guinea.
A. rupicapra was originally described in the genus Pheidole (Pheidolacanthinus). Its workers are 4 mm long.[3] A. polyrhachioides is black, and A. rupicapra reddish-brown (as implied by its specific epithet which translates as "red goat", referring as well to the goat-horn like propodeal spines. The sole known rupicapra specimen was collected in the mountains of the Sepik River catchment by the German colonial Kaiserin Augustafluss Expedition (1912–13).
The two original type specimens of A. polyrhachioides were recovered somewhat damaged from the stomach of an eastern blue-grey robin (Peneothello cyanus subcyaneus)[4] which was caught on Mount Misim in the Morobe District of New Guinea.[2]
The genus name is derived from Ancient Greek αγκυρος "anchor" and ιδρις "the knowing/provident one", Hesiod's name for an ant,[5] probably Messor barbarus or M. structor.[2]
Ancyridris is a small genus of myrmicine ants, with only two described species from New Guinea.
