Paratendipes separata, Published, 2007

Published, First, 2007, Chironomid midges from early Eocene amber of France (Diptera: Chironomidae), Zootaxa 1404, pp. 1-66: 49-51

publication ID

1175­5334

persistent identifier

http://treatment.plazi.org/id/03CE87EB-4943-072B-FF36-FBA2FC69DDDD

treatment provided by

Felipe

scientific name

Paratendipes separata
status

n. sp.

Paratendipes separata   n. sp.

( Figs. 45 –47)

Etymology: This species is named for its separate hind tibial combs.

Diagnosis: 13 flagellomeres; antennal ratio> 0.35; scutal tubercle absent; hind tibial combs separate; mid and hind tibial combs bearing spurs; anal point present; inferior volsella elongate, apically globular; median volsella present.

Description: Head 0.3 mm long; ocelli absent; antenna 0.63 mm long, much longer than head, distinctly hairy, with 13 flagellomeres covered with long setae (shortest 0.03 mm long, longest 0.28 mm long), antennal ratio 0.75 (> 0.35), pedicel broad and short, rounded, 13 th flagellomere 0.32 mm long; eye bare but deformed, with strong dorsomedial extension, with 4 rows of ommatidia at minimum width; mouthparts lacking functional mandibles; 5 palpomeres with numerous setae; clypeus with few dorsal setae; postocular, frontal, inner vertical, and outer vertical setae absent. Thorax 0.56 mm long, 0.06 mm wide, 0.50 mm high; postnotum bare, with distinct longitudinal median groove; surface of scutellum with 3 long setae; scutal tubercle absent; prealar and supraalar setae not visible; anterior acrostichal setae present, uniserial and decumbent; series of few dorsocentral setae; preepisternum bare.

Wing macropterous, apically rounded, 1 mm long, 0.27 mm wide, hyaline, without macrotrichia but covered with microtrichia; anal vein An 2 absent; radius with 3 branches R 1, R 2+3 and R 4+5, R 2+3 not divided into R 2 and R 3, and very nearly to R 4+5; costa ending at level of insertion of last branch of radius; only M 1+2 and M 3+4 present; cross­vein MCu absent. Halter 0.16 mm long. Fore femur 0.43 mm long, tibia 0.31 mm long, tarsus 1.30 mm long; mid femur 0.46 mm long, tibia 0.35 mm long, tarsus 0.58 mm long; hind femur 0.47 mm long, tibia 0.42 mm long, tarsus 0.76 mm long; fore tibial scale bearing spine but not spur; hind tibial combs separate; mid and hind tibiae with 2 spurs, 1 on each comb; ta4 of all legs cylindrical, not cordiform; claw of all legs simple; pulvilli absent. Abdomen 1.03 mm long; gonostylus with long setae, 0.06 mm long, 0.02mm wide; fused to gonocoxite, gonocoxite 0.08 mm long, 0.05 mm wide, with long setae; anal point conical and long, 0.07 mm long, 0.05 mm wide at base; inferior volsella elongate, apically globular and with strong setae, 0.05 mm long; median volsella present.

FIGURE 46. Paratendipes separata   n. sp., holotype PA 12425, photograph of male genitalia.

FIGURE 47. Paratendipes separata   n. sp., holotype PA 12425, drawing of male genitalia (scale bar = 0.1 mm).

Discussion: The subfamilial and tribal placement of this fossil in the Chironomini   is based on features stated above. Paratendipes separata   can be placed in Paratendipes   for the following reasons, according to the key of Cranston et al. (1989): wing apically rounded, antenna with 13 flagellomeres, fore tibial scale bearing spine but not spur, antennal ratio 0.75 (> 0.35), median volsella present, mid and hind tibiae with their two combs bearing a spur, and anal point present. Paratendipes separata   differs from recent species of this genus by its hind tibial combs being clearly separated (its mid tibial combs are fused, as in recent species of Paratendipes   ). This difference would at least justify specific separation.

Based on Cranston & Hare (1995), Paratendipes   belongs to a group of genera that comprise the genera Stictochironomus Kieffer, 1919   , Omisus Townes, 1945   , Skusella Freeman, 1961   , and Conochironomus Freeman, 1961   . Omisus   and Stictochironomus   are excluded, based on the key of Cranston et al. (1989). Skusella   has fused mid and hind tibial combs, each pair with one long spur, instead of two, as in in our fossil ( Freeman 1961). The mid and hind tibial combs of Conochironomus   are slightly separated, each bearing a spur, similar to Paratendipes separata   , but the former genus has a male antennal ratio of 2.0­3.0, instead of 0.75, as in Paratendipes separata   , and it has a scutal tubercle, unlike in Paratendipes   and our fossil ( Cranston & Hare 1995). As we have no information on the female adult, larva, and pupa of our fossils, we prefer to place the specimens in Paratendipes   rather than in a new genus.

Paratendipes   has a wide distribution in the Holarctic, Oriental, and Afrotropical regions. Its presence in the Early Eocene amber of France is not surprising.

Material: Holotype PA 12425, paratype PA 4321, both males.