Eoractocetinus, Kirejtshuk, 2025

Genus Eoractocetinus gen. nov.

Type species: Raractocetus fossilis Yamamoto, 2019 ; Albian/Cenomanian Burmese amber.

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;

— 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.

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.