Genus Aulacosternus Marseul, 1853


Aulacosternus** Marseul, 1853: 234 [type species: Aulacosternus zelandicus Marseul, 1853: 236, designated by Mazur, 1984: 253]; Lacordaire, 1854: 255. Erroneously homonimized by Signoret, 1861: ii, with Aulacosternum Dallas, 1852: 503.

Sternaulax*** Marseul, 1862: 705 [nomen novum for Aulacosternus Marseul, 1853]; Broun, 1880: 162; Bickhardt, 1917: 147; Mazur, 1984: 253; 1997: 83.


Broun's (1880) description.

"I have not been able to find the description of this genus, but the subjoined characters agree with those of S. zealandicus, Marseul.

Mandibles prominent, very strong, strongly dentate inwardly. Head moderately large; the epistome without any visible suture; antennal orbits angular; labrum transverse, concave and a little hollowed in front; the vertex defined by a distinct groove proceeding from the front part of the eye and continued across the back part of the head; eyes transversal, rounded in front, truncated behind. Antennae inserted in deep foveiform scrobes below their orbits immediately in front of the eyes; they are eleven-jointed, terminated by an oval, solid, indistinctly three-jointed club; the basal joint is stout, and as long as the next seven conjointly, incised at its apex, which has an outer spine-like process. Chin-piece of prosternum prominent; the prosternal process limited by the mesosternum, rather narrow, rounded at the end, and grooved at each side; antennal cavities large; mesosternum short, the metasternum large. The basal abdominal segment is as large as the next four taken together. The front tibiae are nearly straight inwardly, but curved externally, and dilated, with a long flexuose tarsal furrow, the exterior edge strongly toothed; the other two pairs are dilated, and armed with spine-like teeth. Thorax transverse, its apex emarginated, base curved outwardly, and the sides a little rounded anteriorly. Propygidium curved in front, the pygidium sub-triangular."

Notes (Ohara & Mazur, 2000).

The genus Aulacosternus Marseul is represented by two species, A. caledoniae Fauvel (New Caledonia) and A. zelandicus Marseul (New Zealand). Aulacosternus differs from Platysoma and allies in possessing the combination of the following characteristics: presence of distinct carinal striae on prosternal process, a well-developed external subhumeral stria, and outer pronotal lateral stria replaced by coarse punctures. It can not be separated from Platysoma and allied genera on the basis of the characteristics employed in the key by Bickhardt (1917), who differentiated between the two genera on the basis of the presence or absence of a frontal stria on account of the fact that A. caledoniae possesses such a stria.

According to the characteristics of the male genitalia, Aulacosternus seems to be one of primitive members of the tribe Platysomatini, having simple parameres and lacking of distinct projection on 9th tegmen. The systematic position of the genus, however, is not clear.

Distribution. New Caledonia, New Zealand.


** Notes: (i) Aulacosternus Marseul, 1853 is not a junior homonym of Aulacosternum Dallas, 1852 [ICZN. Article 56.2]. (ii) Mazur (1984: 253) stated that A. zelandicus was the type species by monotypy. This claim of monotypy is in error since A. edwardsii was also originally included. Mazurs statement nevertheless counts as a valid type species designation [Article 69.2.4] (Dr. S. Thorpe, pers. com.)

*** Notes: (i) The publication date may have been 1863. (ii) Since Aulacosternus is not a junior homonym (see above), Sternaulax is an unnecessary replacement name, and there have not been enough publications which used the name in the last fifty years to warrant conservation of it [Article 23.9.1]. (Dr. S. Thorpe, pers. com.)



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