Cratomastotermes 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 : 5-18

Genus Cratomastotermes Bechly

Cratomastotermes Bechly, 2007: 253 . Type species: M. wolfschwenningeri Bechly. By original designation. Monotypic.

DIAGNOSIS (REVISED): The largest and most robust of the Crato Formation termites: pronotum distinctly broader than head, length of pronotum approximately one-half the width, with strongly concave anterior margin and convex posterior margin; head not round- ed, with large clypeus; tarsi pentamerous; wing with extensive, well-developed reticulation, like crossveins.

DESCRIPTION: Imago: Head robust, round- ed, significantly longer than wide, lateral borders convex, gently rounded; clypeus and postclypeus large. Compound eye circular to semicircular, moderate-sized, separated from posterior border of head by distance slightly less than diameter of eye. Ocelli and fontanelle apparently absent. Y-shaped coronal ecdysial line not visible, if at all present. Pronotum very broad, transverse, subrectangular, distinctly wider than head; length about one-half the width; anterior margin gently concave and wrapping around posterior portion of head; anterolateral corners pronounced, acute and rounded, slightly angled along border of head; lateral margins relatively straight and parallel; posterolateral corners rounded, posterior margin gently convex. Tibiae stout, width approximately 3 X the width of tarsi; tibial macrosetae (‘‘spines’’) not preserved/exposed. All tarsi completely pentamerous, tarsomeres 2–4 compact; tibial spur formula with 1-2-2 visible, but probably more; arolium small. Wings relatively long and broad, membrane (where evident) with well-developed reticulations throughout, which connect like crossveins to longitudinal veins; basal scale of forewing possibly large, with humeral (anterior) margin arched; bases of fore- and hind wings well separated from each other, but overlap of basal scales difficult to discern; venation of forewing largely obscured (best seen in SMNS 66186, holotype), with at least four major Rs branches, last branch with series of five lightly sclerotized, parallel, inferior branches that connect to M. Apex of Rs field encompassing wing apex in fore- and hind wings. Hind wing with distinctive merging of Rs veins with inferior Rs vein near apex. Cerci and abdominal styli not evident (latter presumably absent, but terminal structures observable only in a single specimen).

COMMENTS: The body proportions of this termite suggest that Cratomastotermes is extremely basal in the Isoptera . In particular, the size of the pronotum is enormous, matched in size only by that of the recently described Garmitermes succineus in mid- Eocene Baltic amber ( Engel et al., 2007b), and the pronota of both are similar in size to that in the most basal living termite, Mastotermes darwiniensis Froggat. Specifically , the ratio of the width of the head to the width of the pronotum in Cratomastotermes is 0.80: 1, in Garmitermes it is 0.65: 1, and in the one living species of Mastotermes and three extinct ones it is 0.7–0.9 (Krishna and Grimaldi, 1991: table 1). Because Garmitermes succineus is so well preserved, its phylogenetic position near the Mastotermitidae is well established. Also, all three genera are among the largest termites known. Unfortunately, phylogenetically important details of Cratomastotermes are not preserved, such as ocelli, bases of the wings, details of the forecoxae, and cercal segmentation. In the original description of the species ( Bechly, 2007), the tarsomere number was unknown, but a ‘‘well-developed anal fan’’ was report- ed, which is a primitive, dictyopteran feature retained only in Mastotermes . Study of the SMNS material by the senior author revealed no anal fan, though the portion of the hind wing that is preserved is slightly broader than the forewing. Hopefully, continued excavations of Crato Formation insects will yield complete specimens of this fascinating species.

Cratomastotermes wolfschwenningeri Bechly

Figures 5–7

Cratomastotermes wolfschwenningeri Bechly, 2007: 254 . By original designation.

DIAGNOSIS: As for the genus.

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 66186 , Paratypes SMNS 66187 , 66188 . Early Cretaceous (Aptian), Crato Formation, Brazil, Araripe Basin .

Other material examined: AMNH Sa-I1, ROM 1746, 1755, 1756, SMNS 66189.

Genus Meiatermes Lacasa-Ruiz and Martínez-Delclòs

Meiatermes Lacasa-Ruiz and Martínez-Delclòs, 1986: 56 . Type species: M. bertrani Lacasa-Ruiz and Martínez-Delclòs, 1986 , Early Cretaceous , Montsec, Spain. By original designation.

Nordestinatermes Martins-Neto et al., 2006: 129 ; Bechly, 2007: 256. NEW SYNONYMY.

DIAGNOSIS (REVISED): Imago: Head robust, rounded, posterior border apparently gently rounded, lateral borders convex, gently rounded. Antenna moniliform, with more than 23 segments, first article (scape) slightly longer than combined lengths of second and third articles or second through fourth articles. Compound eye semicircular, of moderate size, separated from posterior border of head by more than compound eye length. Ocelli and fontanelle absent. Y-shaped coronal ecdysial cleavage line present. Pronotum flat and transverse, slightly wider than head, anterior margin gently concave, with anterolateral corners acutely rounded, lateral margins gently convex and converging in posterior halves, posterolateral corners broadly round- ed, posterior margin medially relatively straight (in bertrani ) or weakly concave (in araripena ). All tarsi completely pentamerous; tibial spur formula at least 2-2-2 (but probably at least 3-3-3 because of insufficient preservation), tibiae with subapical macroseta (‘‘spines’’); arolium minute. Forewing relatively long and broad, membrane with coarse reticulations throughout; scale quite large, with humeral (anterior) margin gently but distinctly arched (not figured by Lacasa-Ruiz and Martínez-Delclòs, 1986, but present [personal obs.]), basal suture weakly and gently convex, claval fissure (CuP) apparently meeting posterior margin before basal suture, all veins originating within wing scale; Sc simple, terminating on costal margin near one-third ( araripena ) to one-half the wing length ( bertrani , but some individuals closer to onethird); radial field relatively broad, width relatively consistent until about wing midpoint ( araripena ) or apical third ( bertrani ) then expanding to encompass wing apex; R 1 simple ( araripena ) or with a single branch ( bertrani ), terminating on costal margin prior to wing midlength ( araripena ) or just beyond ( bertrani ); R 2 present or absent, when present then simple along its length; Rs branching near wing midlength, branches with some secondary branches and with at least a couple of inferior branches encompassing wing apex; M branching near or just beyond wing midlength, with two primary branches, sometimes with secondary branches, terminating slightly posterior to wing apex; CuA with numerous branches along posterior margin of wing, some with secondary branches, terminating in apical half to third of wing length.

COMMENTS: We have here returned araripena Krishna to Meiatermes . Fontes and Vulcano (1998, 2004) transferred the species to Cretatermes , and Martins-Neto et al. (2006) classified the species in their new genus Nordestinatermes , but these transfers are unfounded. Venation of the monotypic genus Cretatermes ( carpenteri Emerson, 1967 : Late Cretaceous, Labrador) is significantly reduced, with merely two branches to CuA terminating before or at the wing midlength. The pattern and numerous branches in M. araripena are nearly identical to that of M. bertrani Lacasa-Ruiz and Martínez-Delclòs from the Early Cretaceous of Spain, and in this respect it is important to note that these two large limestone Lagerstätte were not far removed from each other when they were deposited in the Early Cretaceous. Differences between M. araripena and M. hariolus , n.sp., are significant, namely, the former having three (vs. five) cercal segments, but there are no obvious venational differences. The apparent lack of abdominal styli in M. araripena could simply be due to the biased preservation of females (in modern species alates of this sex lack styli), and the preservation of a unique male for M. hariolus . Given the similar venation of these two species, and the incomplete nature of the two specimens of M. hariolus , it is probably prudent to avoid classifying them in different genera.

Meiatermes araripena Krishna , reinstated combination Figures 8–11 , 19 , 20

Meiatermes araripena Krishna, 1990: 76 .

Cretatermes araripena (Krishna) ; Fontes and Vulcano, 1998: 246.

Cretatermes pereirai Fontes and Vulcano, 1998: 265 . NEW SYNONYMY.

Nordestinatermes araripena (Krishna) ; Martins- Neto et al., 2006: 130.

DIAGNOSIS: Distinguished from M. bertrani by M. araripena having the pronotal hind margin with a slight median concavity, and by its radial field encompassing less of the apical margin of the wing. Distinguished from M. hariolus , n.sp., as diagnosed below.

DESCRIPTION: Imago: Besides venational features discussed above, other features are the following: Abdominal styli not evident, possibly absent. Cerci short, trimerous (contra Krishna, 1990), basal segment transverse, length of second one slightly shorter than its width; distal cercal segment distinctly longer than preceding segments, 2.5 X the length of second segment, conical in form. Metrics provided in table 1. Otherwise, as described for the genus.

MATERIAL EXAMINED: Holotype imago, AMNH 43902 , two paratype imagoes ( AMNH 43901–43903 ), and 28 additional, newly studied imagoes ( AMNH Sa-I7, 8, 11, 12, 14, 15, 16, 21, 25, 27, 28, 29, 30; ROM 1747 a, b, 1748a, 1750, 1751a, b, 1759, 1761, 1762, 1765, 1766, 1770, 1774, 1777; SMNS 66191 , 66192 ; ZMHB MBI.2061). All Early Cretaceous (Aptian), Crato Formation, Brazil.

COMMENTS: Cretatermes perarai Fontes and Vulcano appears to be a synonym of M. araripena , based on the similar body size, wing length, pronotal shape (i.e., figs. 29 and 30 in Fontes and Vulcano, 1998), number of tarsomeres, and venation. Unfortunately, none of the three specimens were preserved well enough that each one could be measured for head width, pronotal length, and wing length. As discussed below (under nomina dubia), we suspect that the three new genera and species proposed by Martins-Neto et al. (2006) are synonyms of M. araripena , but unfortunately the descriptions do not allow definitive identification.

Meiatermes hariolus Grimaldi , new species

Figures 12 , 13

Nordestinatermes araripena: Bechly, 2007: 255 , fig. 11.25c, d.

DIAGNOSIS: The new species can be distinguished from M. araripena most readily by the five cercal articles (three in araripena , although the distal segment in araripena can appear subdivided and be easily misinterpret- ed as four total). Wing venation with four to five dorsal branches of Rs.

DESCRIPTION: Imago: Body length slightly smaller than M. araripena (6.5 mm, vs. 7.5– 8.5 mm). Venation without long ventral branch of Rs (arising from near middle of wing in araripena , and occasionally absent); four to five (vs. five) dorsal branches of Rs. Abdominal styli present (male?); cerci short, pentamerous, of approximately same length and shape, individual lengths subequal to individual widths. Metrics provided in table 1.

HOLOTYPE: Imago, AMNH Sa-I22; Early Cretaceous (Aptian), Crato Formation , Brazil. Deposited in the Division of Invertebrate Zoology, American Museum of Natural History . Paratype: SMNS 66190 . The holotype specimen is ventrally exposed; the pronotum is obscured, though its exposed lateral edges suggest a width equal to that of the head. Forelegs are lost; coxae, trochanters, and femora of mid- and hind legs are preserved; all tarsi are lost. Forewing is well preserved, but veins preserved only as impressions and must be observed with a raking light . Paratype is well preserved, with details of cerci and tarsi observable, and costal portions of fore- and hind wings. Paratype with dorsal surface of head and pronotum largely crushed.

ETYMOLOGY: The specific epithet is Latin for ‘‘prophet’’.

COMMENTS: It is critical when observing the cerci to use an oblique, raking light positioned at one end, which is directed along the axis of the cercus, in order to observe the faint suture between cercomeres four and five (i.e., fig. 13, cf: fig. 9 E, F). The photomicrograph of the cercus in Bechly (2007: 255: fig. 11.25d) indicates four cercomeres of SMNS 66190, but when this specimen was observed by the senior author using the lighting described above, the faint, distalmost suture was apparent.

Figures

Fig. 5. Cratomastotermes wolfschwenningeri Bechly, photomicrographs. A. ROM 1746. B. AMNHSaI-1. C. Detail of wing apex, AMNHSaI-1. D. Detail of hind tarsus, AMNHSaI-1. E. Holotype, SMNS 66186.

Fig. 6. Cratomastotermes wolfschwenningeri, venation of left hind wing of SMNS 66186.

Fig. 7. Cratomastotermes wolfschwenningeri. A. Reconstruction. Presence of the Y-shaped epicranial ecdysial line and cerci are conjectural, based on their consistent presence in basal termites. B. Distal portion of left hind leg of AMNHSaI-1. C. Pretarsus and portion of distal tarsomere of left foreleg of same.

Fig. 8. Meiatermes araripena Krishna. Photomicrographs of well-preserved specimens. A. AMNHSaI- 1749. B. AMNHSaI-1749 head. C. AMNHSaI-1749 wing base. D. ROM 1746. E. ZMHB 2061 head. F. ZMHB 2061. G. SMNS 66192.

Fig. 9. Meiatermes araripena. Scanning electron micrographs of select details of AMNHSaI-13. A, B, D: Distal portions of legs. A. Mid left tarsus and tibial apex (dorsal view). B. Portion of mid right tarsus (most of distal tarsomere is lost). C. Detail of wing surface, showing faintly imbricate microsculpture. D. Midtibial apical spurs (serrations are not discernable). E, F: Cerci (E, right; F, left).

Fig. 10. Intraspecific variation in wing venation in Meiatermes araripena, all to the same scale and arranged in the same orientation to facilitate comparisons. A. AMNHSaI-10, left forewing; B. AMNHSaI- 12, right forewing; C. ROM 1762, right forewing; D. AMNHSaI-23, left forewing; E. AMNHSaI-16, left forewing; F–G: AMNHSaI-20 (F, forewing; G, hind wing); H, I: AMNHSaI-11 (H, right forewing; I, right hind wing). J: SMNS 66192, fore- and hind wings.

Fig. 11. Meiatermes araripena. Reconstructed habitus, as based on a series of specimens. Venation is generalized to accommodate the variation seen in this species (see fig. 10).

Fig. 19. Photomicrographs of midguts of Meiatermes araripena. A. ROM 1762 (cf. fig. 16C–F). B. ROM 1770.

Fig. 20. Scanning electronmicrographs of the details of digestive tract preserved in Meiatermes araripena. A, B: Midgut (ROM 1770, AMNHSaI-30, respectively). C–F: ROM 1762. C, Midgut. D, Proventriculus. E, Detail of midgut shown in fig. C. F, Detail of the base of Malpighian tubules, where they connect to the end of the midgut and showing the branched bases.

Fig. 12. Meiatermes hariolus, n. sp. A. Wing, AMNH SaI-22. B-C. Wings, SMNS 66190. D. Drawing of cercus of SMNS 66190. E. Photomicrograph, same (to same scale).

Fig. 13. Meiatermes hariolus, n. sp. Scanning electron micrographs of holotype, AMNHSaI-22. A. Abdominal apex, showing right cercus and bases of styli (broken off distally). B. Detail of right cercus showing the five cercomeres.