Clusiomitidae, A New Family of Eocene Fossil Acalyptratae, with Revision of Acartophthalmites Hennig and Clusiomites Gen. Nov. (Diptera)

The Eocene Baltic amber fossil flies of the genus Acartophthalmites Hennig, 1965 (Diptera: Acalyptratae) are revised. Seven species are recognized and described or redescribed. Five species, A. crassipes sp. nov., A. luridus sp. nov., A. rugosus sp. nov., A. tertiaria Hennig, 1965 (type species) and A. willii Pérez-de la Fuente, Hoffeins et Roháček, 2018 are retained in Acartophthalmites while Clusiomites gen. nov. is described for two other species, C. clusioides (Roháček, 2016) comb. nov. (type species) and C. ornatus sp. nov. Relationships of these fossil taxa are discussed and, because they cannot be confidently placed in any known family of Diptera, a new family, Clusiomitidae, is established for them. Clusiomitidae is recognized as a family of Opomyzoidea, probably most closely allied to Clusiidae. These results again confirmed that the diversity of acalyptrate flies was very high in the Mid-late Eocene amber forest.

A new fossil species of the genus Parasinalda Heiss & Golub (Hemiptera: Heteroptera: Tingidae) from Upper Eocene Rovno amber

Parasinalda sukachevae sp. nov. (Hemiptera: Heteroptera: Tingidae: Tinginae: Phatnomini) is described based on one specimen from Eocene amber of the Rovno region (Ukraine). Similarities and differences to closely related species Parasinalda baltica (Drake, 1950), P. froeschneri (Golub & Popov, 1998), and P. groehni Heiss & Golub, 2013 are discussed, and a key to the four known species of the genus is provided.

Mosquitoes (Diptera: Culicidae) in Eocene amber from the Rovno region, Ukraine

Culex ekaterinae sp. nov. is described based on an adult male embedded in amber from the Rovno region, northwestern Ukraine. The new species is compared with its presumed closest known relative, i.e. Culex erikae Szadziewski et Szadziewska, 1985 described from adults in Baltic amber. The two species exhibit distinct differences in the size of the main body parts, including the antenna, maxillary palpus and proboscis, as well as in the venation of the wing, the structure of the ungues and male genitalia—characters crucial in the diagnosis of adult mosquitoes. A redescription of Culiseta gedanica Szadziewski et Giłka, 2011, to date known from a single adult male, is presented based on a male in amber from Voronki, Rovno region. A tabulation of fossil Culicidae with their geological ages is provided.

A new species of the genus Dorytomus Germar, 1817 (Coleoptera, Curculionidae) from Rovno amber

A new species, Dorytomus mikhailovi sp. n., from late Eocene Rovno amber is described and illustrated. The new species is similar to D. groehni Bukejs et Legalov, 2019 from Baltic amber but differs in the shorter rostrum, dorsum covered with denser decumbent hairs and erect to semierect scale-like setae, and smaller body sizes. It is distinguished from D. bukejsi Legalov, 2020 from Baltic amber by the densely punctate pronotum, longer rostrum and wide elytral interstriae. The new species differs from D. vlaskini Legalov et al., 2019 from Rovno amber by the elytral interstriae covered with decumbent hairs and erect to semierect scale-like setae, shorter rostrum and coarsely punctuate pronotum. It is the first named curculionid beetle from the Olevsk amber locality, and the eleventh amber species reported from the Zhitomyr region. The presence of seven species of Dorytomus suggests a rather high diversity of Salicaceae in the late Eocene amber forests of Europe. It corresponds well with other principal Holarctic species in European amber biotas.

Fossil mosses: What do they tell us about moss evolution?

The moss fossil records from the Paleozoic age to the Eocene epoch are reviewed and their putative relationships to extant moss groups discussed. The incomplete preservation and lack of key characters that could define the position of an ancient moss in modern classification remain the problem. Carboniferous records are still impossible to refer to any of the modern moss taxa. Numerous Permian protosphagnalean mosses possess traits that are absent in any extant group and they are therefore treated here as an extinct lineage, whose descendants, if any remain, cannot be recognized among contemporary taxa. Non-protosphagnalean Permian mosses were also fairly diverse, representing morphotypes comparable with Dicranidae and acrocarpous Bryidae, although unequivocal representatives of these subclasses are known only since Cretaceous and Jurassic. Even though Sphagnales is one of two oldest lineages separated from the main trunk of moss phylogenetic tree, it appears in fossil state regularly only since Late Cretaceous, ca. 70 million years ago (Ma), while earlier they were found twice as small leaf fragments from Lower Jurassic (ca. 200 Ma) and Late Ordovician (ca. 455 Ma). Pleurocarpous mosses appear in fossil state near the border between Jurassic and Cretaceous, although most Cretaceous mosses belong to acrocarps. Only in Eocene amber pleurocarps become more numerous than acrocarps. Some Eocene mosses can be assigned to extant families and sometimes genera, although the majority of Eocene pleurocarps are difficult to identify up to the family, as their morphology often allows placement of a particular specimen into several different families.

The first described turtle beetles from Eocene Baltic amber, with notes on fossil Chelonariidae (Coleoptera: Byrrhoidea)

Chelonariidae, or turtle beetles, are rarely represented in the fossil record. Two new extinct species of this thermophilous coleopteran family, Chelonarium andabata Alekseev and Bukejs sp. nov. and Ch. dingansich Alekseev and Bukejs sp. nov., are described and illustrated from Eocene Baltic amber using X-ray micro-computed tomography (micro-CT). They are the first formally described species of turtle beetles from Eocene Baltic amber and the first known European representatives of this family. Based on modern habitats of the group, the presence of the plants with which their larvae are associated (epiphytic orchids) is proposed in the Eocene amber forest. The Eocene Florissant Formation fossil Chelonarium montanum Wickham, 1914, which was originally placed within Chelonariidae, is discussed based on its original description, and placement as incertae sedis within Byrrhoidea is proposed for this compression fossil (http://zoobank.org/References/C2EE164D-59DD-42FE-937D-B01C78DCD228, last access: 8 February 2021).

The first fossil Phloeocharinae Erichson, 1839 (Coleoptera, Staphylinidae) from the Baltic Eocene amber

A new species of the genus Charhyphus Sharp, 1887 (Phloeocharinae) from the Eocene Baltic amber is described and illustrated: Ch. balticus Shavrin, sp. nov. The specimen was studied by using X-ray micro-computed tomography (μCT); images of the habitus, body parts and aedeagus were obtained. Based on external morphology, the new species is related to Nearctic Ch. picipennis (LeConte, 1863) and East Palaearctic Ch. paradoxus (Bernhauer, 1933), from which it differs by the smaller body, shape of the head, and other details.

The oldest fungus gnat of the tribe Exechiini in the lowermost Eocene Oise amber (Diptera: Mycetophilidae)

Eoexechia gallica gen. n. and sp. n., oldest record of the fungus gnat tribe Exechiini, is described from the Lowermost Eocene amber of France. It falls as sister group of all the extant Exechiini after its addition to the morphological phylogenetic analysis of the tribe. Its discovery suggests a Paleocene age for the Exechiini, in accordance with the current phylogenetic dating. This new discovery will help to date the whole clade in future phylogenies.

Minute and diverse in fossil sticky stuff: Tanytarsini (Diptera: Chironomidae) from early Eocene Indian Cambay amber

We here present a pioneering systematic review of fossil dipterans of the tribe Tanytarsini (family Chironomidae) discovered in Indian amber from Cambay. The specimens examined belong to five species: Gujaratomyia miripes,Stempellina stebneri sp. nov., Stempellinella pollex sp. nov., Tanytarsus forfex sp. nov. andTanytarsus ramus sp. nov., which are described. All species belong to the oldest known Tanytarsini and come from the Cambay shale formation in Tadkeshwar, dated to the early Eocene (~54 Mya). Displaying unusual characters/structures of diagnostic and phylogenetic importance, the specimens studied are discussed against the background of the evolution and systematics of the oldest fossil (Eocene) and extant representatives in the tribe. An updated checklist and key to the identification of genera and species of Tanytarsini from Eocene amber is also provided. The spectral characteristics and physical properties of Cambay amber are similar to those of glessite resins, which are discussed in detail in order to substantiate the identity of the amber and the origin of the inclusions studied.

A new species of Ampulicomorpha Ashmead from Eocene French amber, with a list of fossil and extant Embolemidae (Insecta: Hymenoptera) of the world

Embolemidae is a cosmopolitan but species-poor group of chrysidoid wasps with a scarce fossil record, despite a long evolutionary history since at least the Early Cretaceous. Here, the new species, Ampulicomorpha quesnoyensis sp. nov., is illustrated and described based on a single female found in Early Eocene amber of Oise (France). The new species is compared with the three other known fossil species of the genus, and a key to all fossil species of Ampulicomorpha is provided. This is the third European fossil species of Ampulicomorpha, which suggests that the genus was once well established in Western Europe while it is more widely distributed in the Eastern Palaearctic region today. A list of all fossil and extant Embolemidae of the world, as well as a map of their geographical distribution map, are provided.