Kachincambala distorta, Moritz & Wesener, 2021

Moritz, Leif & Wesener, Thomas, 2021, Electrocambalidae fam. nov., a new family of Cambalidea from Cretaceous Burmese amber (Diplopoda, Spirostreptida), European Journal of Taxonomy 755 (1), pp. 22-46 : 35-37

Kachincambala distorta gen. et sp. nov.

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Fig. 5

Diagnosis

Forty-two ommatidia arranged in circular patch ( Fig. 5A ). Anal valve with 8 marginal setae. Male leg pair 1 well-developed ( Fig 5D ). Kachincambala distorta gen. et sp. nov. differs from the only other species of the genus, K. muelleri gen. et sp. nov., in gonopod characters: unlike in K. distorta gen. et sp. nov., the posterior gonopod of K. muelleri gen. et sp. nov. does not possess a lateral lobe apically. On the anterior gonopod, the outer lobe of the anterior gonopod’s coxite is nearly as long as the inner lobe in K distorta gen. et sp. nov., while the outer lobe is short and broad, oriented more laterally in K. muelleri gen. et sp. nov. Furthermore, the anterior gonopod’s telopodite is in K. distorta gen. et sp. nov. apically pointed and not rounded as in K. muelleri gen. et sp. nov. ( Fig. 5F–G ).

Etymology

From the Latin word ʻ distortus ʼ, meaning ʻdistortedʼ or ʻdeformedʼ, referring to the strong deformation of the specimen and especially its gonopods. Noun in the adjective case.

Type material

Holotype MYANMAR • ♂; Kachin State, Hukawng Valley, Mid-Cretaceous Burmese amber inclusion; formerly in the collection of Patrick Müller ( BuB1839 ); ZFMK-MYR7368 .

Description

HABITUS. 56 + 4 body rings. Body cylindrical, slender, up to at least 20.8 mm in length, 0.4 mm in diameter. Colour grey to brown ( Fig 5A ).

HEAD. As wide as collum and body ring 6 onwards, wider than body rings 2–5. 42/39 ommatidia arranged in circular patch ( Fig. 5C ). Incisura lateralis present, closed. Antennae with 7 antennomeres, reaching to posterior margin of body ring 4, 6 =3>4>5>2>1> 7, with 4 apical sensory cones ( Fig. 5D ). Labrum tridentate, with setae. Mandibular base divided in small cardo and large stipes ( Fig. 5D ). Gnathochilarium with eumentum and promentum. Lamella lingualis reaching to lower third of promentum, not touching eumentum. Promentum not completely separating the lamellae lingualis. Stipes of gnathochilarium along whole length of gnathochilarium touching gula laterally.

TRUNK. Collum only slightly curved, projecting over posterior margin of head, reaching laterally to height of mandibular base ( Fig. 5C ). Collum ventrally with 6 grooves on posterior margin ( Fig. 5D ). Body rings totally fused from body ring 5 onwards. Metazonite from body ring 5 onwards distinctly arched, wider than prozonite. Metazonite ventrally with 6 to 9 striae ( Fig. 5C ). Posterior margin dorsally with few setae ( Fig. 5D ). Ozopores start on body ring 6. Midbody rings (9) ca 0.8 times as long as diameter ( Fig. 5C ).

LEGS. First two leg pairs surrounded by first pleuro-tergite (collum), leg pair 3 surrounded by 2 nd pleurotergite, body rings 3 and 4 legless, from body ring 5 onwards 2 leg pairs per body ring ( Fig. 5C ). Midbody legs with coxa, prefemur, femur, postfemur, tibia, tarsus. Podomeres with few setae. Tarsus with one claw, no apical spine ( Fig. 5E ). Tarsus> prefemur> postfemur> femur = tibia> coxa. Coxa of 2 nd leg pair inserted medial of coxa of 1 st leg pair.

POSTERIOR BODY RINGS. Preanal ring without epiproct projecting, with few setae. Valves with at least 8 marginal setae. Subanal scale not projecting over valve.

MALE SEXUAL CHARACTERS. In males leg pairs 1 and 2 slightly reduced in size but not in segmentation. In leg pair 2 femur> tarsus> tibia = postfemur = prefemur> coxa. Except leg pair 1 with tarsal claw. Coxa of leg pair 2 inserted medial of coxa of leg pair 1. Paired penis located behind leg pair 2, within pouch. Anterior and posterior gonopods on body ring 7 well-developed, retracted into body. Left gonopods highly deformed ( Fig. 5F–G ). Anterior gonopod with telopodite slightly longer than coxite, apically pointed. Coxite long, slender, with two lobes, outer lobe pointed and nearly as long as inner lobe. Inner lobe apically rounded. Presence of flagellum unknown. Posterior gonopod longer than anterior gonopod, anterior surface of posterior gonopod with possible seminal groove ( Fig. 5F–G ).

Measurements and taphonomy

MEASUREMENTS. 20.8 mm long, 0.4 mm in diameter ( Fig. 5A ).

AMBER DESCRIPTION.Amber flat, elliptical, 19.7 × 14.8 × 3.9 mm. Polished, yellow transparent ( Fig. 5A ).

SYNINCLUSIONS. Soil particles, plant parts, pollen, antennae, leg parts and cuticle of arthropods.

TAPHONOMIC FEATURES. Specimen bend dorsally. Front of specimen laterally flattened (compressed, cuticle partially broken) ( Fig. 5A ). Left antenna missing ( Fig. 5B ). Preanal segment damaged.

Figures

Fig. 5. Kachincambala distorta gen. et sp. nov., holotype, ♂ (ZFMK-MYR7368). A. Amber piece, photograph. B. Head and anterior body rings, lateral view, photograph. C. Head and anterior body rings, lateral view, volume rendering. D. Head, lateral view, drawing. E. Tarsus, drawing. F. Gonopods, anterior view, segmentation. G. Gonopods, lateral view, segmentation. Abbreviations: ag = anterior gonopod; at = antennae; cl = claw; co = collum; cx = coxite; L = leg; la = labrum; md = mandible; om = ommatidia; oz = ozopore; pg = posterior gonopod; ta = tarsus; te = telopodite.