Characters of a new species of the Cretaceous genus † Loeblitoides affirm affinities to the extant ‘ Syndicus group’ of Stenichnini (Coleoptera: Staphylinidae: Scydmaeninae) Author Jałoszyński, Paweł Museum of Natural History, University of Wrocław, Sienkiewicza 21, 50 - 335 Wrocław, Poland. Author Szawaryn, Karol Museum and Institute of Zoology, Polish Academy of Sciences, Twarda 51 / 55, 00 - 818 Warszawa, Poland. text Zootaxa 2024 2024-08-22 5497 1 123 132 http://dx.doi.org/10.11646/zootaxa.5497.1.7 journal article 10.11646/zootaxa.5497.1.7 1175-5326 13618054 8F0CBBEF-DA94-4A6D-B7A0-3250F31D3A87 † Loeblitoides latus Jałoszyński & Szawaryn sp. nov. ( Figs 1–19 ) Type material. Holotype : ( MYANMAR ): sex unknown, label: “ Myanmar amber / GPIH no. 5076 / (coll. Carsten Gröhn , CCHH 11930 ) / LOEBLITOIDES / latus Jałoszyński & Szawaryn, 2024 / HOLOTYPUS ” [red, printed] ( GPIH ). Diagnosis. Body stout, with pronotal length / width clearly below 1.5 and the elytral length / width below 1.7; antennomere 3 about 3 times as long as broad in lateral view; antennomeres 8‒10 each about as long as broad. FIGURES 1–7. † Loeblitoides latus sp. nov. , holotype; light micrographs. Lateral habitus ( 1 ), pronotum and elytral base in dorsal view ( 2 ), head in dorsal view ( 3 ), anterior body part in ventral view ( 4 ), distal region of maxillary palp ( 5 ), mesotarsus ( 6 ), and mesotarsomere 5 ( 7 ). Description. Body ( Figs 1 , 8–10 , 12–13 ; Supplementary animation 1) moderately slender, strongly convex, dark brown, length 2.33 mm , constriction between head and pronotum deep, between pronotum and elytra shallow but distinct. FIGURES 8–11. † Loeblitoides latus sp. nov. , holotype ( 8–10 ), and Syndicus echinatus Jałoszyński ( 11 ). Sketch of habitus in lateral view ( 8 ); μCT reconstructions of habitus in dorsal ( 9 ) and ventral ( 10 ) views; left elytral articulating lobe in dorsal view, scanning electron micrography ( 11 ). Abbreviations: a3‒11, antennomere 3‒11; bef, basal elytral fovea; ce, compound eye; fcg, frontoclypeal groove; pd, pedicel; pn, pronotum; sc, scape; scs, scutellar shield. FIGURES 12–13. † Loeblitoides latus sp. nov. , holotype; μCT reconstructions of habitus in right ( 12 ) and left ( 13 ) lateral views. Head ( Figs 3 , 14–19 ) flattened; length 0.50 mm , width 0.35 mm ; vertex strongly transverse and weakly, evenly convex; tempora weakly rounded, strongly convergent posteriorly, about as long as eye (best visible in Fig. 13 ); frons posteriorly confluent with vertex, transverse, its anterior margin with broad and short anteromedian expansion over frontoclypeal groove; supra-antennal tubercles weakly elevated; clypeus subtrapezoidal, distinctly transverse, weakly convex, weakly narrowing anterad, on entire width demarcated posteriorly by deep and sharply marked frontoclypeal groove; compound eyes large, strongly convex, moderately finely faceted. Punctures on vertex and frons poorly visible, setae on dorsal surface of head sparse and short, suberect. Maxillary palps ( Fig. 5 ) with strongly elongate, slender palpomere 3 and with strongly elongate subconical and pointed palpomere 4. Antennae ( Figs 2–4 , 8 ) slender, weakly and gradually broadening from antennomere 1 to 10, length 1.23 mm . Antennomeres 3–5 each with conspicuous mesal spine inserted on distinct projection or papilla, also antennomere 6 with similar seta; antennomeres 1–6 each distinctly elongate, with antennomere 3 longest, about 3 times as long as broad in lateral view (not counting mesal tubercle), antennomere 7 indistinctly elongate, 8–10 each about as long as broad, 11 minute, tightly sitting on apex of 10. Pronotum ( Figs 2 , 9 ) distinctly but not strongly elongate, broadest near anterior 1/4, length 0.58 mm , width 0.40 mm , pronotal index (length/width) 1.44. Anterior margin and sides in anterior fourth strongly, evenly rounded, lateral margins broadly and very shallowly concave behind middle; posterior corners well-marked, nearly rightangled, blunt; posterior margin nearly straight. Basal pronotal cavity poorly visible, presumably filled with dirt, about as long as half-length of pronotum and as wide as about 1/3 of pronotal width. Lateral impressions on pronotal disc strongly elongate and sharply demarcated. Punctures on pronotal disc indiscernible, setae short and sparse, suberect. Elytra ( Figs 1, 2 , 8–10 , 12 ) together oval, broadest slightly in front of middle; length 1.25 mm , width 0.75 mm , elytral index (length/width) 1.67; elytral apices rounded together; humeral calli poorly developed, basal elytral impressions shallow, each elytron with two deep and asetose basal foveae connected by inversely U-shaped deep groove convex anteriorly ( Fig. 9 ). Punctures fine and inconspicuous; elytra covered with long, dense suberect setae. Mesoscutellar shield ( Fig. 9 ) elongate subtriangular, only its very tip projecting posteriorly beyond step-wise border between elytral articulating lobe and elytral disc. Legs slender and lacking peculiar characters except for protibiae ( Fig. 10 ; best visible in right tibia) slightly curved inwards (i.e., mesally) in distal regions; all tarsi with tarsomeres distally reducing in length ( Fig. 6 ) and with long claws ( Fig. 7 ). Etymology. The Latin adjective latus , broad, refers to the much stouter body of this species than in the previously known † Loeblites separatus . Distribution. Hukawng Valley near Tanai village, Kachin State , northern Myanmar ; late Albian-early Cenomanian, mid-Cretaceous. FIGURES 14–19. † Loeblitoides latus sp. nov. , holotype, μCT reconstructions. Body in anterior ( 14 ), anteroventral ( 15 ), posterolateral ( 16 ), anterodorsal ( 17 ), anteroventral ( 18 ), and posteroventral ( 19 ) views. Abbreviations: ce, compound eye; cl, clypeus; cx1, procoxa; cx2, mesocoxa; fcg, frontoclypeal groove; fr, frons; hr, hypostomal ridge; tm, temple; v3, metaventrite; vt, vertex. Remarks. † Loeblitoides latus can be easily distinguished from † L. separatus by its stouter pronotum and elytra, and different proportions of antennomeres. In † L. latus , the pronotal ratio length/width is merely 1.44 (vs. 2.00 in † L. separatus ), and the elytral ratio equals 1.67 (vs. 2.08 in † L. separatus ). The antennomere 3 in the new species is clearly more elongate, while antennomeres 7‒10 are much stouter, each almost as long as broad (each clearly elongate in † L. separatus ). The differences in proportions of the pronotum and elytra cannot be attributed to a different sex of the same species, as such profound differences are not known to characterize sexes in any known extant Stenichnini species. Also, the shapes of antennomeres in otherwise unmodified antennae are too different to represent sexual dimorphism (which in extant Stenichnini is either not expressed in antennal features or evident by some conspicuously modified antennomeres in males). † Loeblitoides latus has also a distinctly broader neck region than that in the slenderer † L. separatus . Still, the neck is slightly narrower than half width of the head (including eyes), and therefore the generic diagnosis does not need to be modified to include this variation.