Siphonophora hui Jiang, Shear, Hennen, Chen & Xie 2019

Autor: SU, YI-TONG, CAI, CHEN-YANG, HUANG, DI-YING
Rok vydání: 2021
Předmět:
DOI: 10.5281/zenodo.5507844
Popis: Siphonophora hui Jiang, Shear, Hennen, Chen & Xie, 2019 Material. Three specimens, two males (NIGP175067 and NIGP175068) and one female (NIGP175069), all completely preserved. Diagnosis (revised after Jiang et al., 2019). Rostrum moderately elongate, gradually constricted from head, extending to the 5 th antennomere. Gnathochilarium formed by incompletely fused sclerites. Two pairs of tiny macrosetae on anterior part of gnathochilarium. Anterior margin of collum deeply concave. Body setation sparse and short. Prozonites with flat tubercles, metazonites without tubercles. Anterior and posterior gonopods with six podomeres; 6 th podomere of anterior gonopods short, spoon-shaped with prominent apical projection; 6 th podomere of posterior gonopods with stout cone-shaped base and extremely elongate extension, without spines or notches. Locality and horizon. Mid-Cretaceous, Tanai Village, Hukawng Valley, northern Myanmar. Description. Adult male (Figs 1���5). Body length 14.4���14.7 mm; maximum width ca. 0.82 mm, gradually broadening from collum to ca. 32 th tergite, and gradually narrowing from ca. 40 th tergite to telson. Head: moderately to densely setose (Figs 1D, 2A), lateral-basal parts with tiny tubercles (Figs 2D, 5B). Ommatidia absent. Rostrum (beak) gradually extend from the head, slightly curved, reaching lower part of 5 th antennomere (Figs 1C, 2A). Seven antennomeres, antennomere I���VI approximately in same widths, antennomere VII slightly narrower, lengths of antennomeres VI>V���IV���III���II���I>VII, each antennomere covered with strong setae (Figs 2A, B, 3A, B, 5A). No sensory pits visible on antennomere V and VI. Four sensory cones on top of antennomere VII. Gnathochilarium strongly modified, formed by incompletely fused inner and outer sclerites, with 1���2 rows of short setae arranged sparsely along outer margins and along suture between sclerites. Two pairs of short macrosetae located on anterior part of inner sclerites, close to suture. Trunk: 69���71 tergites (including collum and telson) with 66���68 podous and three apodous (collum, penultimate and telson). Collum relatively large, more than two times longer than 2 nd metazonite; anterior margin strongly concave, posterior margin slightly concave (Figs 1D, 2A). Tergites, pleurites, and sternites free from each other, no medial suture on tergites. Prozonites without setae, narrower than metazonites. Anterior part of prozonites usually overlapped by previous metazonites, with transversely arranged scale-shaped structures; posterior edge of anterior prozonites concave medially (Figs 1F, 3C). Posterior part of prozonites with 3���8 rows of flat tubercles (Figs 1F, 2E, 4C). Metazonites apparently arched in 2 nd to 7 th tergite, and gradually flattened from 8 th tergite; tergal setae short, moderately to densely distribute on collum to 8 th metazonite, and becoming sparse on rest of metazonites (Fig. 2C, E). Ridge-shaped paranota start to develop from the 8 th tergites (Figs 1F, 2E, 4C). Ozopores starting from 5 th tergite, located on dorsal-lateral sides of tergites or upper surface of posterior parts of paranota (Figs 2E, 3C). Pleurites rounded to subangular, covered with sparse short setae and dense discoidal flat tubercles. Sternites relatively large, partially overlapped by pleurites; spiracles large, columned, often overlapped by pleurites; coxae on anterior-most part of trunk almost in touch with each other, and gradually becoming separated on following sternites; midline triangular ridges only present on sternites with closely positioning coxae. Legs consisting of six podomeres; several long setae located on middle part of each podomere; tarsus tapering, usually longer and slender than other podomeres; tarsus claw beak-shaped, moderately sharp, with an accessory claw located laterally (Figs 2B, 3E, 5B, D). A pair of cone-shaped gonopores on second pair of coxae (Figs 2F, 5A, C). Gonopods modified from 9 th and 10 th leg-pairs (Figs 1C, 4B). Anterior gonopods stout, with six podomeres; 4 th podomere the longest and bend forward; last podomere relatively short, with posterior side spoon-shaped and a prominent projection located on apex; several long and strong setae present on edge of middle part of each podomeres (Figs 3D, 5E, F). Posterior gonopods more elongate than anterior, with six podomeres; last podomere with stout cone-shaped base, strongly constricted to an extremely long and slender extension which is more than three times as long as basal part, no spines or notches can be observed (Figs 3D, 5E). The last pair of pleurites large, closely in touch with each other (Fig. 1G). Detailed structures of telson not visible in our male specimens. Adult female (Figs 6���7): body length 13.8 mm; maximum width about 0.75 mm, gradually broadening from collum to about 29 th tergite, and gradually narrowing from about 38 th tergite to telson. Trunk with 64 tergites (including collum and telson), 61 podous and three apodous (collum, penultimate, and telson). Setae on head and tergites of anterior part of trunk slightly sparser and shorter than in male (Fig. 7A). A pair of sclerite-like structures located behind second pair of coxae, each with a spine on middle (Fig. 7F); these structures may relate to vulvae. Preanal sclerite forming a complete ring, with tubercles and setae similar to pleurites; paraprocts oval, with sparse setae and tubercles; hypoproct tiny, posterior margin smooth (Fig. 6F, G).
Published as part of SU, YI-TONG, CAI, CHEN-YANG & HUANG, DI-YING, 2021, Morphological revision of Siphonophora hui (Myriapoda: Diplopoda: Siphonophoridae) from the mid-Cretaceous Burmese amber, pp. 279-288 in Palaeoentomology 4 (3) on pages 280-284, DOI: 10.11646/palaeoentomology.4.3.15, http://zenodo.org/record/5507842
{"references":["Jiang, X., Shear, W. A., Hennen, D. A., Chen, H. M. & Xie, Z. C. (2019) One hundred million years of stasis: Siphonophora hui sp. nov. the first Mesozoic sucking millipede (Diplopoda: Siphonophorida) from mid-Cretaceous Burmese amber. Cretaceous Research, 97, 34 - 39. https: // doi. org / 10.1016 / j. cretres. 2019.01.011"]}
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