Sphecomyrmodes, ENGEL & GRIMALDI, 2005

ENGEL, MICHAEL S. & GRIMALDI, DAVID A., 2005, Primitive New Ants in Cretaceous Amber from Myanmar, New Jersey, and Canada (Hymenoptera: Formicidae), American Museum Novitates 3485, pp. 1-24 : 5-7

† Sphecomyrmodes , new genus

TYPE SPECIES: † Sphecomyrmodes orientalis , new species .

DIAGNOSIS: Distinguished from all other species of the tribe Sphecomyrmini by the minute, peglike denticles running along the entirety of the anterior margin of the clypeus and from † Sphecomyrma by the absence of a medial extension or process on the clypeal margin.

ETYMOLOGY: The new genus­group name is a combination of † Sphecomyrma , type genus of the subfamily, and the suffix– odes, meaning ‘‘with the form of’’. The name is masculine.

† Sphecomyrmodes orientalis , new species

Figures 3–4

DIAGNOSIS: As for the genus (vide supra).

DESCRIPTION: Head. Relatively large, height of head slightly less than length of alitrunk. Length of head 1.23 mm (with mandibles closed). No apparent microsculpture on cuticle of head. Clypeus setose; setae of moderate length and widely separated. Mandible simple, with only two teeth; outer surface with numerous, widely scattered, fine setae. Antenna of moderate length, with scape short, funicular article I (pedicel) shortest antennal article, funicular article II the longest article of funiculus. Lengths of antennal articles (in mm): scape 0.23, pedicel (funicular article [fa] I) 0.13, faII 0.32, faIII 0.15, faIV 0.15, faV 0.15, faVI 0.15, faVII 0.17, faVIII 0.17, faIX 0.17, faX 0.17, faXI 0.27. Mesosoma. Mesosomal length 1.33 mm; without apparent microsculpturing, with scattered fine, short setae on all visible surfaces, those on propodeum about twice as long as other setae. Coxae large, slightly inflated, ventrally setose, setae numerous and fine. Legs moderate length. Foreleg with tarsomere I distinctly longer than combined lengths of more distal tarsomeres; tarsomere I with ‘‘antennal cleaner’’ (strigil) a velvety notch on ventral margin of proximal end; calcar present, length slightly longer than greatest width of profemur, ventral margin with row of fine teeth and (apically) setae. Patch of dense, elongate setae opposite strigil on profemur; inner posterior surface of protibial apex with three stout, spinelike setae minutely curved inward at their extreme apices (visible on left foreleg). Pairs of stiff setae on ventral surface of protarsomeres: tarsomeres I­III with three pairs, IV with two small pairs. Pretarsal claw with minute subapical tooth. Metasoma. Attachment of petiole to propodeum not particularly thick; thickness (measured in lateral view) of anterior end of petiolar peduncle 0.33 greatest depth of propodeum. Petiole length 0.38 mm, height 0.37 mm. Preserved portion of gaster 1.73 mm in length. Integument without apparent microsculpturing, with scattered, fine setae. Distalmost metasomal segments torn apart, although sting bulb and sting well preserved beneath metasoma (fig. 4).

TYPE MATERIAL: Holotype. AMNH Bu­ 351, an incompletely preserved worker in a piece of reddish­orange amber, from Myanmar. Collected in Kachin state, Tanai village, on Ledo Road , 105 km NW Myitkyna, via Leeward Capital Corp., 1999.

ETYMOLOGY: The specific epithet is the Latin word orientalis , meaning ‘‘of the east’’ and is a reference to this being the first species of the tribe † Sphecomyrmini (sensu Bolton, 2003) recorded from Myanmar.

Figures

Figs. 1–3. Three Cretaceous amber ants. 1. †Myanmyrma gracilis, new genus and species (AMNH Bu­014) in Burmese amber. 2. †Cananeuretus occidentalis, new genus and species (TMP 8.89.7) in Canadian amber. 3. †Sphecomyrmodes orientalis, new genus and species (AMNH Bu­351) in Burmese amber.

Fig. 4. Holotype worker of †Sphecomyrmodes orientalis, new genus and species (AMNH Bu­351); general habitus, sting, clypeal margin and mandibles, and antenna.