Cratokalotermes Bechly, 2007

Grimaldi, David A., Engel, Michael S. & Krishna, Kumar, 2008, The Species of Isoptera (Insecta) from the Early Cretaceous Crato Formation: A Revision, American Museum Novitates 3626 (1), pp. 1-32 : 18-21

Genus Cratokalotermes Bechly

Cratokalotermes Bechly, 2007: 260 . Type species: Cratokalotermes santanensis Bechly, 2007 . By original designation.

DIAGNOSIS (REVISED): Imago: Head ovoid, posterior border apparently gently rounded, lateral borders greatly convex. Antenna moniliform (total number of articles unknown), scape apparently short, scarcely longer than following article. Compound eye circular or semicircular, moderate-sized, separated from posterior border of head by slightly more than compound eye length. Ocelli, fontanelle, and Y-shaped coronal ecdysial line absent. Pronotum flat and subtrapezoidal, distinctly narrower than head (0.6 X head width); anterior margin relatively straight, with anterolateral corners broadly rounded but not pronounced, lateral margins gently curved and slightly converging posteriorly in posterior halves, posterolateral margins broadly rounded, posterior margin relatively straight medially. Forewing relatively long and broad; basal scale relatively large, with apices of basal suture and CuP not converged; CuP relatively straight (not strongly arched); radial field narrow, confined to costal third of wing, terminating prior to the wing apex; R 1 simple, terminating on costal margin near wing base; five superior branches of Rs in forewing, most are simple (fewer branches in hind wing). Area between C and Rs significantly sclerotized. M with basal branch near midlength of forewing, two shorter branches in distal third of wing, which reach to wing apex (similar in hind wing). Seven parallel branches of Cu in forewing (hind wing obscured). Abdomen broad, well sclerotized, apical margin of each tergite with row of minute striae. Cerci short, apex conical, with two segments; cuticular microsculpture with coarse imbrication.

Cratokalotermes santanensis Bechly

Figures 14–16

Cratokalotermes santenensis Bechly, 2007: 261 .

DIAGNOSIS: As for the genus (see above).

DESCRIPTION: Imago: The above diagnosis characterizes the genus and species (ICZN, 1999: Art. 13.4). To the generic diagnosis can be added the metrics provided in table 1.

HOLOTYPE: Imago, SMNS 66195 . Other material examined: ROM 1764 . Both specimens from Early Cretaceous (Aptian), Crato Formation, Brazil .

COMMENTS: The head, pronotum, and cerci of the ROM specimen are very well preserved; this specimen has just portions of the costal half of the forewing preserved. The SMNS specimen (holotype) has beautifully preserved fore- and hind wings (including the basal scale), as well as the thorax and cerci, but the head and pronotum are not well preserved. The reconstruction (fig. 16) is thus combined from the best-preserved features of both specimens .

Based on the apparent lack of a coronal ecdysial line, the rounded head shape, a twosegmented cercus, and the relatively small pronotum, this species appears to be the most derived in the Crato fauna and from the Early Cretaceous in general. Kalotermitidae and all more recently derived families of Isoptera have only two cercomeres. Cratokalotermes shares with living Kalotermitidae the crowded radial field and long cubital field (extends to near the apex of the wing). Cratokalotermes differs from living kalotermitids by the wing membrane lacking small nodules/pimpules, and by having a larger field of M veins (specifically, the apices of M veins encompass the wing tip, and there is a basal fork of M near the distal third of the wing). These features suggest a possible basal position in Kalotermitidae or else a stem group to this family or the kalotermitid + higher termite lineage. Unfortunately, the two specimens are each missing the legs (i.e., tarsomere number), which compromises an estimate of its phylogenetic position.

Genus Cretorhinotermes Bechly

Figure 17

Cretorhinotermes Bechly, 2007: 262. Type species: C. novaolindense Bechly, 2007: 262 . By original designation. Monotypic.

DIAGNOSIS: Very partial remains with primarily just the apical half of the forewing: Radial field narrow, apparently simple (with few superior branches), Rs comprised of at least 4 long branches, most ventral one of which nearly extends to wing apex. M field large, extending from wing apex to anal margin, with series of at least nine long, parallel branches. Longitudinal veins with extensive, well-developed, and coarse reticulations among them.

COMMENTS: Without doubt, this genus does not belong to the Rhinotermitidae as originally classified ( Bechly, 2007), though the M field was probably originally interpreted as Cu. One definitive rhinotermitid exists from the Cretaceous, preserved in 100 myo amber from Myanmar (Krishna and Grimaldi, 2003), and it possesses most of the features of modern Rhinotermitidae : a fontanelle, four tarsomeres, a simple R vein, a simple M, and a pectinate series of Cu veins with very sparse and faint reticulations between them. Unfortunately, the bodies of both Crato specimens are very poorly preserved (details of the head and tarsi are not preserved), and in light of such limited features we can only suggest that this species belongs to a basal grade of termites near Hodotermitidae and Termopsidae s.l.

Figures

Fig. 14. Cratokalotermes santanensis Bechly, photomicrographs. A. ROM 1764. B. Holotype, SMNS 66195.

Fig. 15. Cratokalotermes santanensis. Scanning electronmicrographs of ROM 1764. A. Anterior portion of head (composite of several images). B. Detail of right cercus, showing the coarsely imbricate cuticular microsculpture of the distal segment. Cuticle on the tip is lost, but the cercus appears to be two-segmented.

Fig. 16. Cratokalotermes santanensis, reconstruction. Venation and abdomen are largely based on the holotype (SMNS 66195); head and pronotum on ROM 1764; the two-segmented cerci are preserved in both specimens.

Fig. 17. Cretorhinotermes novaolindense Bechly. A. Photomicrograph of holotype, SMNS 66196. B. Venation of preserved section of forewing of holotype. C. Venation of preserved section of forewing of paratype, SMNS 66197, oriented to match that of the holotype wing.