Anochetus brevidentatus, new species, a second fossil Odontomachiti ant (Hymenoptera: Formicidae).

Abstract

-I describe the new species Anochetus brevidentatus from Dominican Republic amber, possibly deposited 30-40 million years before present. This species is a member of the emarginatus species group and the haytianus superspecies. It is closely related to the extant A. kempfi. I present characters for distinguishing this ant from the others in the haytianus super species. Recently we have seen a rapid growth of knowledge of ants of the Dominican Republic amber, due primarily to the work of Baroni-Urbani and Wilson (see Wilson, 1988 for references). One of these new species, Anochetus corayi, was recently de scribed by Baroni-Urbani (1980). In this paper, I describe a second species in the genus Anochetus from Dominican amber. Anochetus brevidentatus, new species Figs. 1, 2, 3, 8 Diagnosis. This species is closely related to A. kempfi. It differs in that the man dibular teeth are smaller (Figs. 2 and 6), the teeth on the petiolar node are much smaller (Figs. 3 and 4), the mandibles are enlarged in the middle (as in A. haytianus Fig. 7) and it is smaller than A. kempfi. It can be easily distinguished from A. haytianus and A. longispina as the teeth on the node of the petiole are much smaller (Figs. 3 and 5) and it has teeth on the propodeum, which are absent on the latter species. Description of worker: HL 1.34, HW 1.20, SL 1.40, ML 0.90, EL 0.2, WL 2.08 (abbreviations as in Brown, 1978, measurements in mm). Mandibles with three apical teeth (Fig. 8) in addition to six smaller teeth along mesial border (Fig. 2), mandible slightly thickened at one half length of mandible; eye appears to be relatively small (not easily seen in specimen); mesosoma similar to that of A. kempfi, anterior edge of mesonotum higher than level of pronotum; propodeum with pair of well developed spines, directed vertically (Fig. 1); anterior face of petiole almost flat (in profile), posterior face convex, node bidentate, teeth relatively small (Fig. 3). Erect hairs sparse, present on mandibles, dorsum of head, pronotum and gaster. Sculpture fine, parallel striae on most of mesosoma; gaster smooth and shining. Female and male: Unknown. Discussion. This species is a member of the emarginatus species group, defined by Brown (1978) as species of large size and slender build, mandibles serially dentate, and petiole bidentate. It shows some affinities with the inermis group of the genus, as it has relatively small eyes, teeth on the node, and the denticular configeration is This content downloaded from 207.46.13.98 on Fri, 05 Aug 2016 05:59:20 UTC All use subject to http://about.jstor.org/terms 1991 NEW FOSSIL ANOCHETUS 139