T y p e m a t e r i a l: Holotype ♂: "GR – Samothraki [21], Therma, 40°29'49''N, 25°36'31''E, 30 m, soil washing near stream, 10.IV.2019, V. Assing / Tychobythinus assingi spec.nov. ♂, det. Brachat / Holotypus " (cBra).
E t y m o l o g y: This species is dedicated to Volker Assing, who collected the holotype.
D e s c r i p t i o n: Body length 1.15 mm. Body brownish with yellowish appendages, glossy, and smooth with scattered and mostly indistinct (more distinct and somewhat rugose on head) punctation. Pubescence sparse, relatively long ( 0.08 mm) on elytra, shorter on head and pronotum.
Head indistinctly transverse (length 0.22 mm; width 0.23 mm). Eye strongly reduced, reduced to only a single ommatidium. Frontal lobe 0.13 mm broad. Antenna 0.54 mm long; antennomeres I slender and elongate (length 0.15 mm; width 0.04 mm), II oval (length 0.06 mm; width 0.04 mm) III minute (length 0.03 mm; width 0.025 mm), IV-VII globular (length and width 0.025), VIII weakly transverse (length 0.020 mm; width 0.025 mm); IX (length 0.03 mm; width 0.04 mm) transverse and distinctly broader than VIII, X (length 0.03 mm; width 0.05 mm) more distinctly transverse, broader than IX, and XI large, as long as the combined length of VIII-X (length 0.11 mm; width 0.08 mm). Maxillary palpi slender; palpomeres II and III with numerous small tubercles; palpomere III oblong; palpomere IV approximately 2.5 times as long as broad (length 0.16 mm; width 0.07 mm). Pronotum transverse, longer and broader than head (length 0.27 mm; width 0.31 mm), without lateral carina. Elytra 0.39 mm long, 0.48 mm broad, and 1.25 times as broad as long; humeral angles weakly marked. Hind wings completely reduced.
♂: head ventrally with transverse gular impression with slightly elevated anterior and lateral margins, anterior margin medially with short and erect lamella; profemur dilated and with scattered tubercles on inner face; protrochanter with small tooth; mesofemur slightly dilated; metafemur simple, not dilated; meso- and metatrochanter with fine carina on inner side; metaventrite weakly convex; aedeagus ( Fig. 28) 0.26 mm long; internal sac with a pair of sclerotized structures of distinctive shape; paramere with long seta in apical third.
♀: unknown.
C o m p a r a t i v e n o t e s: Two anophthalmous, troglobiontic Tychobythinus species are known from Greece: T. naxius BESUCHET, 1993 from Naxos and T. brachati BESUCHET, 2008 from Samos. The new species is distinguished from both of them by distinctly shorter antennae and by the shapes of the internal structures of the aedeagus. All other Tychobythinus species known from Greece are winged and have eyes of normal size.
D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Tychobythinus assingi is most likely endemic to Samothraki. The holotype was collected by washing soil beneath old Platanus orientalis near a stream at an altitude of 30 m ( Fig. 34). Cyrtotyphlus samothracicus was found in the same sample.