Anoplius planeta Rodriguez and Pitts, 2016

Rodriguez, Juanita, Waichert, Cecilia, Von Dohlen, Carol D., Jr., George Poinar & Pitts, James P., 2016, Eocene and not Cretaceous origin of spider wasps: Fossil evidence from amber, Acta Palaeontologica Polonica 61 (1), pp. 89-96 : 90-91

Anoplius planeta Rodriguez and Pitts sp. nov.

Fig. 1 .

Etymology: From Latin planeta , planet (noun in apposition), a nickname used by the first author’s parents (Iomara Arrieta and Francisco Manuel Rodriguez).

Holotype: Complete male inclusion, OSAC Hy-10-45.

Type locality: Cordillera Septentrional , between Puerto Plata and Santiago, Dominican Republic.

Type horizon: Dominican amber, Early Miocene.

Diagnosis. — Wings hyaline; maximum width 0.18× its length; 2Rs cell as long as 1Rs; 2m-cu vein slightly curved, meeting 2Rs cell 0.70× distance from base to apex of cell; and 2M cell with an inflection at the base of the vein Cu.

Description. — Male. Body length 6.20 mm. Forewing 4.80 mm. Integument dark on head and mesosoma, light on metasoma. Body pubescence short and scattered on entire body. Mandible glabrous. Erect, long setae, present on second half of mandible. Pygidium bare, polished. Punctation inconspicuous. Antenna elongate; ratio of length of segments two to four 6:15:16; WA3 0.40× LA3; WA4 0.26× LA4. Pronotum short, width 2.35× length, posterior margin slightly angulate; pronotal disc well defined. Length of 2 R 1 cell 0.71× distance from its margin to wing apex; 2Rs cell as long as 1Rs; 2m-cu slightly curved, meeting 2Rs cell 0.70× distance from base to apex of cell. Tibiae and tarsi with few spines present, short, acute, sparse; pulvillar comb strong; metasoma 1.33× as long as mesosoma.

Remarks. — This is the first species of Anoplius described from Dominican amber. We are confident about the placement of this species into Anoplius due to the good preservation of the specimen. The characters that place this specimen in Anoplius are: the postnotum is a transverse band with parallel anterior and posterior margins, the 2m-cu vein arises on the Cu less than half the distance from the base of the 2M cell to the outer wing margin, the clypeus is emarginated, the strong pulvillar comb, and the claws bifid. The only other genus with which it could be confused is Arachnospila Kincaid, 1900 , which occurs in the Nearctic region, but Arachnospila does not have a strong pulvillar comb. Anoplius planeta does not fit the diagnosis of any of the Anoplius subgenera; on the contrary, it shows a combination of characters that belong to many of them. The two subgenera that Anoplius planeta best fits are Anoplioides Banks, 1939 and Arachnophroctonus Howard, 1901 . In the first case, members of the subgenus have a 2Rs cell wider anteriorly than 1Rs, but A. planeta lacks this character. Also, extant members of Anoplioides do not show light colouration on the metasoma as does A. planeta . The light orange colouration on the metasoma could place A. planeta in the subgenus Arachnoprochtonus . Nevertheless, members of this subgenus have a fifth tarsomere in the front leg with the inner margin slightly produced, while in A. planeta it is parallel sided. Given these reasons, we are not placing this species in an extant subgenus, rather, this is considered a desiomorph species, i.e., a fossil that possesses morphological characters found in two or more fossil or extant groups. Desiomorphs have been found in amber, and are known in species of Coleoptera, Diptera, Hemiptera , Hymenoptera , and Neuroptera ( Poinar 2012).

The age of Dominican amber is controversial, with various published dates: 54–40 Ma ( Landis and Snee 1991), 45–30 Ma (Cepek in Schlee 1990), 23–30 ( Grimaldi 1995), and 20–15 Ma ( Iturralde-Vinent and MacPhee 1996) (for a comprehensive review see Penney 2010). Amber from the northern region of Dominican Republic has been found to be from 40 to 26 Ma ( Lambert et al. 1985), but Iturralde-Vinent and MacPhee (1996) argue that all Dominican amber should be dated to the same age as the deposits bearing it, because evidence suggests that the fragments have not been emplaced by re-deposition. Therefore, Iturralde-Vinent and MacPhee (1996) proposed an age of 20–15 Ma for all Dominican amber, based on biostratigraphic and palaeogeographic data from Hispaniola. Later, Iturralde-Vinent (2001) constrained the age of Amber to approximately 16 Ma ( Penney 2010).

Insect inclusions have also been observed in Dominican copal ( Brown 1999). This material is similar to amber in appearance and composition, and for this reason has sometimes been mistakenly reported as Pliocene–Pleistocene amber. Radiocarbon dating has suggested ages of less than 50 000 years for copal, while ambers are out of the radiocarbon age range ( Burleigh and Whalley 1983).

Stratigraphic and geographic range.—Early Miocene of the northern of Dominican Republic.

Figures

Fig. 1. Spider wasp Anoplius planeta Rodriguez and Pitts sp. nov., holotype, OSAC Hy-10-45, male specimen, from Early Miocene Dominican amber, Cordillera Septentrional, between Puerto Plata and Santiago, Dominican Republic. A. Habitus in lateral view. B. Mesosoma in dorsal view. C. Forewing. D. Pulvillus. E. Hindwing. Photographs (A1, B1), camera lucida illustrations (A2, B2, C–E).