Magnifitermes undetermined, JOUAULT, ENGEL & NEL, 2022

Jouault, Corentin, Engel, Michael S., Fls, Legendre, Frédéric, Huang, Diying, Grandcolas, Philippe & Nel, André, 2022, Incrementing and clarifying the diversity and early evolution of termites (Blattodea: Isoptera), Zoological Journal of the Linnean Society 196, pp. 608-629 : 618-620

MAGNIFITERMES KRISHNAI JOUAULT, ENGEL & NEL SP. NOV.

( FIGS 6–8 )

Z o o b a n k r e g i s t r a t i o n: h t t p: / / z o o b a n k. o r g / urn:lsid:zoobank.org:act:DCEAE642-54ED-4FEC-8AC4-CA6C23C821D8

Holotype: Specimen identifier IGR.BU-053 (a complete alate specimen preserved in a drop-shaped amber piece measuring 18 × 29 × 5 mm), housed in the amber collection of the Geological Department and Museum (IGR), Rennes, France.

Etymology: The specific epithet honours the late Dr Kumar Krishna (1928–2014), eminent termitologist and beloved friend and collaborator of MSE. Dr Krishna’s work also inspired CJ to study fossil termites. He is sorely missed. The name is treated as a noun in the genitive case.

Locality and age: Noije Bum Hill, Hukawng Valley, Kachin State, Myanmar; Upper Albian to Lower Cenomanian, ‘Mid’-Cretaceous.

Diagnosis: As for the genus (vide supra).

Description: Imago. Body c. 13.5 mm long (as preserved and measured from tip of labrum to abdomen apex). Head massive, c. 2.87 mm long (measured from posterior margin to tip of labrum) and about 1.5 mm wide excluding compound eyes (measured beyond eyes), slightly trapezoidal, prognathous, sides convex, postclypeus and anteclypeus combined length c. 0.32mm long, labrum lobe-shape, sides nearly parallel, slightly narrower basally, apical margin nearly straight, with few setae; mandibles triangular shaped, c. 0.46 mm high, covered by labrum; left mandible apical tooth sharp, two marginal teeth, LM 1 -LM 2 interdental space broad, v-shaped, LM 2 elongate; right mandible not visible; glossa (gl) and paraglossa (gl), lacinial incisor with at least one long tooth; five maxillary palpomeres visible, combined length c. 0.9 mm; three labial palpomeres present, at least 0.60 mm long; compound eyes, c. 0.52 mm long, circular, situated laterally near head midlength, and separated from posterior head margin by more than their length; ocelli present; fontanelle absent; antennae moniliform with 28(?) antennomeres. Pronotum massive, c. 1.58 mm long, trapezoidal, wider than head, anterior margin concave surrounding head, posterior margin broadly convex, with dorsal surface flatly arched in profile, sides convex.

Legs slender; profemur, c. 1.37 mm long, protibia c. 0.90 mm long, protarsus c. 0.54 mm long; protibia with three spurs f1, f2, f3, plus additional spines (see Diagnosis, supra); mesotibia c. 1.31 mm long, mesotarsus c. 0.57 mm long; mesotibia with four observable spurs m1, m2, m3, m4, additional spines (see Diagnosis, supra); metatibia c. 1.87 mm long, with four observable spurs h1, h2, h3, h4, plus additional spines (see Diagnosis, supra), mesotarsus c. 0.75 mm long; all spurs flattened with serration; all tarsi pentamerous; pretarsal arolium present. Forewing scale at least 1.50 mm long. Hindwing hidden under forewing.

Abdomen at least 6.46 mm long (damaged during fossilization), with at least nine observable segments; abdominal segments apparently slightly wider near midlength. Cerci with five cercomeres, stylus preserved but covered by a white coat.

Colour: Not preserved.

Remarks: Magnifitermes krishnai differs from most other Cretaceous Isoptera in combining a series of plesiomorphic characters in the wings (e.g. fine reticulation between veins in the scale and anal lobe present), tarsi wholly pentamerous (plesiomorphic character), a tibial spur formula of 3-4-4 and an overall massive trapezoidalshaped pronotum. The wholly pentamerous tarsi and enriched tibial spur formula suggest an earlydiverging position among Isoptera , among groups like Archotermopsidae , Hodotermitidae , Hodotermopsidae , Mastotermitidae and their various extinct relatives. Additionally, its general habitus, and particularly its large pronotum and anal lobe, suggest that M. krishnai is related to Mastotermitidae . Recently, Mastotermitidae were split into two distinct subfamilies Mastotermitinae and Idanotermitinae ( Jiang et al., 2021) . Idanotermitinae are mainly characterized by the absence of ocelli on the head of imagoes.Due to the presence of ocelli, the new fossil is placed in the subfamily Mastotermitinae . It differs from the other Mastotermitinae , in particular Mastotermes , by a distinct Y-shaped ecdysial scar. Potential paraphyly of Mastotermitinae relative to Idanotermitinae is in need of clarification.

Figures

Figure 6. Magnifitermes krishnai gen. et sp. nov., holotype IGR.BU-053. Photograph of habitus. Scale bar: 2 mm.

Figure 7. Magnifitermes krishnai gen. et sp. nov., holotype IGR.BU-053. Detailed photographs. A, head and pronotum; B, antenna; C, foreleg; D, midleg; E, hindleg. lc, lacinia; lci, lacinial incisor; Lp, labial palp; oc, ocellus. Scale bar: 1 mm (A, B, C, D); 0.5 mm (E).

Figure 8. Magnifitermes krishnai gen. et sp. nov., holotype IGR.BU-053. A, detailed photograph of mandibles; B, line drawing of forewing venation.CuA, anterior cubitus; M, media; PCu, postcubitus; RA, anterior radius; RP, posterior radius; Sc, subcosta. Scale bar: 0.5 mm (A); 2 mm (B).