taxonID	type	description	language	source
03C887FBFFD92E44FF13F8FAFA83F9DD.taxon	materials_examined	Type species: † Eoractocetus storozhenkoi sp. nov.; Upper Eocene Baltic amber.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD92E44FF13F8FAFA83F9DD.taxon	diagnosis	Diagnosis. The list of the diagnostic characters represent mostly those that can be used for the comparison of the genus † Eoractocetus gen. nov. within other seven genera currently defined in fossils, for which lists with corresponding characters are also compiled with the same numeration of characters for more convenience. List of diagnostic characters of the genus † Eoractocetus gen. nov. (type species: † Eoractocetus storozhenkoi sp. nov., Eocene Baltic amber): 1. Body moderately narrow. 2. Head with strongly reduced postocular portion and with very short temples. 3. Antennae moniliform with antennomeres 3 – 6 thickest. 4. Apical maxillary palpomeres simple and palpomere 3 modified into maxillary palporgan; 5. Pronotum elongate and convex along the middle and with a narrow median depression along entire length, about 1.5 times as long as wide and widest at base, anterior angles not to scarcely expressed, anterior edge strongly convex, gently rounded and far projecting anteriorly, posterior angles strongly projecting posteriorly. 6. Scutellum transversely subtriangular to subpentangular and widely rounded at apex, with subcordiform median plate narrowed at base, slightly longer than wide and not reaching scutellar apex. 7. Prosternum along its middle about a third as long as mesoventrite. 8. Metaventrite more than 1.5 times as long as wide, with posterior edge strongly projecting posteriorly. 9. Metacoxae rather “ narrow ” (distance between anterior and posterior edges), strongly obliquely declined to apices, their subcontiguous parts comprising a third of entire metacoxal length. 10. Abdominal ventrite 1 between metacoxal apices and its posterior edge markedly shorter than each of other abdominal ventrites (2 – 5). 11. Female pygidium slightly narrowing posteriorly, more than 1.5 times as long as wide, subpentagonal and subacute at apex. 12. Female hypopygidium (ventrite 5) less than 1.5 times as long as wide, widely rounded at posterior edge. Notes. This new genus seems to be rather closely related to Cretoquadratus Chen 2019, Eoractocetinus gen. nov., Lymexylopsis gen. nov. and Paratractocerus Nazarenko et Perkovsky in Nazarenko et al. 2020 differering from all of them in the comparatively short postocular portion of epicranium, convex anterior part of pronotum far projecting anteriorly and covering the head base (Fig. 5), and also subcordiform plate on basal part of scutellum. The short prosternum along the middle in Eoractocetus storozhenkoi sp. nov. (Fig. 10) (something like that in Atractocerus Palisot de Beauvois, 1801) is a very distinct character from that in species of Eoractocetinus gen. nov., Lymexylopsis gen. nov. and Paratractocerus with rather long prosternum, while the prosternum of Cretoquadratus remains unknown. Besides, Cretoquadratus is very distinct from Eoractocetus gen. nov. in its very large head in comparison with prothorax, very narrow antennae, pronotum widest at the tips of the anterior angles and without narrow median depression, larger and clearly pentagonal scutellum with distinct median stripe along its entire length. In addition to the mentioned characters, the genus Eoractocetinus gen. nov. differs from Eoractocetus gen. nov. in the compressed antennomeres, subquadrangular pronotum without narrow median depression, and also in the posterior edges of metaventrite slightly oblique mesally, while the genus Lymexylopsis gen. nov. — in more or less arcuate pronotal sides, subquadrate scutellum with a wide median subparallel-sided stripe and abdominal ventrite 1 markedly longer than each of ventrites 2 – 4. Finally, the genus Paratractocerus is distinct from other fossil atractocerine genera in simple maxillary palpi with comparatively short palpomeres, and also, in addition to the above-mentioned features, the latter genus is distinguished from Eoractocetus gen. nov. in the pronotum without narrow median depression, and also in the abdominal ventrite 1 markedly longer than each of ventrites 2 – 4.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFDD2E4FFF13FBE7FAAAFC55.taxon	description	(Figs 1 – 12)	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFDD2E4FFF13FBE7FAAAFC55.taxon	materials_examined	Type material. Holotype “ 8761 ” (KAM); adult, female. A rather complete beetle with completely exposed ovipositor included in a transparent, yellow amber flat piece with black number “ 8761 ”, which has a subtrapezoid shape with somewhat arcuate greatest side (15 mm) becoming thinner, while other sides (6.8 x 7.7 x 7.7 mm) are straight nearly vertically cut. Along the beetle body plan some flat cracks mixed with traces of resin layers, having whitish color and opaque and making examination of the beetle difficult and some details almost impossible. Besides, there are many brownish to yellowish small pieces of organic matter with different shape and size, and also with very small gas bubbles disorderly spread in amber. Type locality. Yantarny settlement (formerly Palmnicken), Sambian (Samland) Peninsula, Kaliningrad Region, Russia. Type stratum. Late Eocene, Priabonian (probably 36.8 – 36.4 Ma).	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFDD2E4FFF13FBE7FAAAFC55.taxon	description	Description. Body length with head somewhat declined down 7.6 mm, width 1.5 mm, height 1.2 mm. Body elongate and narrow, rather convex as dorsally as ventrally. Integument rather dark, nearly blackish, dorsal surface densely and shortly pubescent with fine subrecumbent hairs about as long as or somewhat longer than distance between their insertions, punctures about as coarse as third to fifth of eye facets and interspaces between them extremely finely microreticulated; metaventrite, metacoxae and first abdominal ventrites with almost inconspicuous hairs, more finely and sparsely punctured than dorsal ones, interspaces between punctures alutaceous; other parts of underside integument and femora with pubescence similar to that on dorsal sclerites, other sclerites of legs more densely pubescent with longer hairs and antennomeres particularly densely pubescent with rather long hairs. Head declined and visible mostly from below, rather large with very large eyes of coarse facets, narrowly separated dorsally, their rather deeply incised around antennal insertions and postocular portion of epicranium rather reduced and partly covered with anterior part of pronotum. Labrum rather large, trapezoid and widening anteriorly. Maxillary palps with moderately raised elongate palpomere 4 and unclearly observable maxillary palporgan due to “ milky ” opaqueness. Antennae moniliform, consisting of antennomeres 2 – 10 thickening apically and with largest (thickest) antennomeres 3 – 6, antennomere 11 fusiform and markedly longer and narrower than each of antennomeres 2 – 10. Pronotum elongate and gently convex along middle of anterior part, with one pair of shallow paramedian depressions at middle and with narrow depression along entire length, about 1.5 times as long as wide and subparallel-sided at base, anterior angles not expressed not at all, anterior edge strongly convex and gently rounded, posterior angles strongly projecting posteriorly (markedly surpassing level of convexity of posterior edge of pronotum). Scutellum transversely subtriangular to subpentangular and widely rounded at apex, with subcordiform median plate narrowed at base, slightly longer than wide and not reaching scutellar apex. Elytra about 2.5 times as long as pronotum, each elytron almost fifth as wide as long, without trace of venation. Exposed tergites somewhat longer than wide and laterosternites rather narrow. Pygidium slightly narrowing posteriorly, more than 1.5 times as long as wide, subpentagonal and subacute at apex. Prosternum along middle about third as long as mesoventrite, with anterior sclerotized edge deeply excised and extermely short precoxal portion (something like that in Atractocerus). Procoxae about twice as long as wide and with gently convex posterior edge. Mesocoxae very long, with subparallel anterior and posterior edges, three times as long as wide, their inner edges subparallel to each other (but not closely). Metaventrite more than 1.5 times as long as wide, with posterior edge strongly projecting posteriorly. Metacoxae rather “ narrow ” (distance between anterior and posterior edges), strongly obliquely declined to apices, their subcontiguous parts comprising third of entire metacoxal length, subtruncate at apex. Abdominal ventrite 1 between metacoxal apices and its posterior edge markedly shorter than each of other abdominal ventrites (2 – 5), ventrites 2 – 4 somewhat transverse. Hypopygidium (ventrite 5) less than 1.5 times as long as wide, widely rounded at posterior edge. Legs with very long and thin femora, tibiae and tarsomeres. Considerable part of hind wings visible, somewhat folded and spread along posterior edge, fused C-Sc-R vein rather stout, distal part of hind wind observable and showing two long anal veins reaching posterior edge, M and Cu distinctly separated, wedge-cell well raised and r-m crossvein very distinct, but radial cell not traced. Ovipositor moderately sclerotized and with styli as long as width of ovipositor apex.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFDD2E4FFF13FBE7FAAAFC55.taxon	etymology	Etymology. The epithet of the new species is devoted to the seventieth birthday of Sergey Yu. Storozhenko (Vladivostok, Russia). Notes. This species has apparently rather short postocular portion of epicranium which is covered with the anterior part of pronotum. The lymexylid head is moving thanks to a more or less considerable reduction of anterior sclerotized part of the prosternum, as a result, a large membranous window is formed, facilitating significant head mobility. Having looked through thousands of named and unnamed specimens in the Zoological Institute of RAS collection, the author did not find any specimen with the head retracted into the prothoracic segment, because the anterior pronotal edge is usually much narrower than the head. Another peculiarity of the examined specimen is some convexity of pronotum along the middle, while other examined lymexylid specimens are characterized by more or less straight pronotum in lateral view or even concave at anterior edge (probably for an additional fixation of the posterior part of epicranium). The next peculiar feature of this specimen is its posterior pronotal angles strongly projecting posteriorly, as is known in fossil Cretoquadratus and modern Hymaloxylon Kurosawa, 1985, while other lymexylids have at most slightly projecting posterior angles or frequently obtuse to rounded ones.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD22E4DFF13FAF0FBCDFE95.taxon	materials_examined	Type species: Raractocetus fossilis Yamamoto, 2019; Albian / Cenomanian Burmese amber.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD22E4DFF13FAF0FBCDFE95.taxon	diagnosis	Diagnosis. The list of the diagnostic characters of this new genus is given in the comparison of the genus Eoractocetus gen. nov. (see above). Notes. This new genus seems to be rather closely related to Cretoquadratus, Eoractocetus gen. nov., Lymexylopsis gen. nov. and Paratractocerus differering from all of them in the compressed cordiform antennomeres. Besides, it differs from: — Cretoquadratus in the shorter pronotum with stump to subrounded anterior and posterior angles;	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD22E4DFF13FAF0FBCDFE95.taxon	description	— Eoractocetus gen. nov. in the longer postocular portion of epicranium, pronotum with more expressed tips of anterior angles and not projecting posterior ones, also with anterior edge not strongly anteriorly and not covered the head base, moderately long prosternum and metacoxae slightly oblique mesally; — Lymexylopsis gen. nov. in the pronotum with subrectilinear sides, scutellum subtriangular to subpentagonal (not trapezoid with short median process), abdominal ventrite 1 between metacoxal apices and its posterior edge distinctly longer than each of ventrites 2 – 4; — Paratractocerus in the presence of palporgan and abdominal ventrite 1 markedly longer than each of ventrites 2 – 4.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD22E4DFF13FAF0FBCDFE95.taxon	etymology	Etymology. The name of this new genus is formed from the combination of the Greek “ εοσ ” (dawn) and a part of the generic name Raractocetus and a suffix “ etinus ”. Gender masculine. Composition. In addition to the type species, the second congener is Raractocetus extinctus Yamamoto, 2019; Albian / Cenomanian Burmese amber; distinct from the type species in the different prothorax and shape of sclerites of ultimate abdominal segment. Li et al. (2022) erroneously put it into the genus Cretoquadratus (see above). The two considered species of the genus should get the following combinations: Eoractocetinus extinctus (Yamamoto, 2019), comb. nov. and Eoractocetinus fossilis (Yamamoto, 2019), comb. nov.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD32E4DFF13FE62FADBFAFF.taxon	materials_examined	Type species Raractocetus balticus Yamamoto, 2019; Eocene Baltic amber.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD32E4DFF13FE62FADBFAFF.taxon	diagnosis	Diagnosis. The list of the diagnostic characters of this new genus is given in the comparison of the genus Eoractocetus gen. nov. (see above). Notes. This new genus seems to be rather closely related to Cretoquadratus, Eoractocetinus gen. nov., Eoractocetus gen. nov. and Paratractocerus differering from all of them in the subquadrate scutellum and metacoxal subcontiguous parts comprising about half of entire metacoxal length (last character is not applicable for Cretoquadratus). Besides, it differs from: — Cretoquadratus in the pronotum with more or less widely arcuate sides and widely rounded anterior and posterior angles;	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD32E4DFF13FE62FADBFAFF.taxon	description	— Eoractocetinus gen. nov. in the not compressed antennomeres, pronotum with more or less arcuate sides, metacoxae slightly obliquely declined to apices, abdominal ventrite 1 between metacoxal apices and its posterior edge shorter than each of ventrites 2 – 4; — Eoractocetus gen. nov. in the longer postocular portion of epicranium, pronotum with more expressed tips of anterior angles and not projecting posterior ones, also with anterior edge not strongly anteriorly and not covered the head base, moderately long prosternum; — Paratractocerus in the presence of palporgan.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
03C887FBFFD32E4DFF13FE62FADBFAFF.taxon	etymology	Etymology. The name of this new genus is formed from the combination of the generic name Lymexylon and Greek “ ΟΨΙϚ ” meaning “ resembling a (specified) thing ”. Gender feminine. Composition. In addition to the type species, the second congener is Raractocetus sverlilo Nazarenko, Perkovsky et Yamamoto in Yamamoto et al., 2022; Eocene Rovno amber; distinct from the type species at least in structure of prothorax, antennae and pubescence. Li et al. (2022) erroneously placed it into the genus Cretoquadratus (see above). The two considered species of the genus should get the following combination: Lymexylopsis baltica (Yamamoto, 2019), comb. nov. and Lymexylopsis sverlilo (Nazarenko, Perkovsky et Yamamoto, 2021), comb. nov.	en	Kirejtshuk, Alexander G. (2025): Taxonomic notes on fossils of the subfamily Atractocerinae (Coleoptera: Lymexylidae) with description of a new species from Eocene Baltic amber and proposal of three new genera for fossil lymexylids. Zootaxa 5715 (1): 204-217, DOI: 10.11646/zootaxa.5715.1.18, URL: https://doi.org/10.11646/zootaxa.5715.1.18
