Evolutionary morphology of the antennal heart in stick and leaf insects (Phasmatodea) and webspinners (Embioptera) (Insecta: Eukinolabia)

The morphology of the antennal hearts in the head of Phasmatodea and Embioptera was investigated with particular reference to phylogenetically relevant key taxa. The antennal circulatory organs of all examined species have the same basic construction: they consist of antennal vessels that are connected to ampullae located in the head near the antenna base. The ampullae are pulsatile due to associated muscles, but the points of attachment differ between the species studied. All examined Phasmatodea species have a Musculus (M.) interampullaris which extends between the two ampullae plus a M. ampulloaorticus that runs from the ampullae to the anterior end of the aorta; upon contraction, all these muscles dilate the lumina of both ampullae at the same time. In Embioptera, only the australembiid Metoligotoma has an M. interampullaris. All other studied webspinners instead have a M. ampullofrontalis which extends between the ampullae and the frontal region of the head capsule; these species do not have M. ampulloaorticus. Outgroup comparison indicates that an antennal heart with a M. interampullaris is the plesiomorphic character state among Embioptera and the likely ground pattern of the taxon Eukinolabia. Antennal hearts with a M. ampullofrontalis represent a derived condition that occurs among insects only in some embiopterans. These findings help to further clarify the controversially discussed internal phylogeny of webspinners by supporting the view that Australembiidae are the sister group of the remaining Embioptera.

Primotrapa gen. nov., an extinct transitional genus bridging the evolutionary gap between Lythraceae and Trapoideae, from the early Miocene of North China

Background Although Trapa is a well-defined genus of distinctive freshwater plants with accumulations of extensive morphological and embryological autapomorphies, its phylogenetic relationships have long been unclear. Formerly placed in the monotypic family Trapaceae, Trapa is now recognized as sister to Sonneratia within Lythraceae s.l., although both genera lack morphological synapomorphies. Thus, a split between the two taxa must have occurred in deep evolutionary time, which raises the possibility of finding transitional forms in the fossil record. Results Here we describe a new genus and species, Primotrapa weichangensis Y. Li et C.-S. Li (Lythraceae s.l.: Trapoideae), based on three-dimensionally preserved floral cups, fruits, and seeds from the early Miocene of Weichang County, Hebei Province, China. Primotrapa is characterized by a shallow, saucer-shaped floral cup, four distally barbellate sepals, four intersepal appendages alternating with the sepals at the rim of cup, a superior to basally inferior ovary, a fusiform or ovoid, one-seeded fruit with a ribbed surface, and a long persistent peduncle. Two fossil species of Hemitrapa are proposed as new combinations of Primotrapa, namely P. alpina (T. Su et Z.-K. Zhou) Y. Li et C.-S. Li comb. nov. and P. pomelii (Boulay) Y. Li et C.-S. Li comb. nov. Our phylogenetic analysis based on fifteen flower and fruit characters supports the placement of Primotrapa, Hemitrapa and Trapa in a monophyletic clade, which comprise subfamily Trapoideae. The phylogenetic analysis places Primotrapa at the base of Trapoideae. Conclusions In view of its superior ovary, which is a plesiomorphic character of Lythraceae s.l., the newly recognized genus Primotrapa and its three species likely represent transitional forms that bridge the evolutionary gap between the basal taxa of Lythraceae s.l., i.e. Lythrum, and the highly derived taxon Trapa.

A new species of Succinoraphidia Aspöck & Aspöck, 2004 (Raphidioptera: Raphidiidae) from the late Eocene Rovno amber, with venation characteristics of the genus

Succinoraphidia radioni sp. nov. (Raphidiidae) is described from the late Eocene Rovno amber, Ukraine. The genus also includes two species from contemporaneous Baltic amber, i.e., S. exhibens Aspöck & Aspöck, 2004 and S. baltica (Carpenter, 1957), comb. nov. The venation of Succinoraphidia is analysed. It possesses several plesiomorphic character states at the family level, and the monotypic subfamily Succinoraphidinae represents a basal group within the family or possibly even a potential stem group of Raphidiidae. All diagnostic character states of Succinoraphidia (except the structure of the pterostigma) are found in a few Cretaceous species of the paraphyletic Mesoraphidiidae, but some of these are not found in the extant Raphidiidae.

Cytogenetics of Gymnogeophagus setequedas (Cichlidae: Geophaginae), with comments on its geographical distribution

ABSTRACT We provide cytogenetic data for the threatened species Gymnogeophagus setequedas, and the first record of that species collected in the Iguaçu River, within the Iguaçu National Park’s area of environmental preservation, which is an unexpected occurrence for that species. We verified a diploid number of 2n = 48 chromosomes (4sm + 24st + 20a) and the presence of heterochromatin in centromeric and pericentromeric regions, which are conserved characters in the Geophagini. The multiple nucleolar organizer regions observed in G. setequedas are considered to be apomorphic characters in the Geophagini, whereas the simple 5S rDNA cistrons located interstitially on the long arm of subtelocentric chromosomes represent a plesiomorphic character. Because G. setequedas is a threatened species that occurs in lotic waters, we recommend the maintenance of undammed environments within its known area of distribution.

A laid-­back trip through the Hennigian forests (Notes from Naturalists)

Binary matrix with a priori defined plesiomorphic character‐state may be re-­written as a simple set of branching diagrams (as a “Hennigian forest”). The last might be analyzed by the average consensus method. This procedure eventually avoids the taxon-­‐character matrix from the analysis of the data. Within this framework, the criteria of the best topologies based on the character-­‐state changes are unnecessary. The solely ‘reversal’-­based groups are always appear within the average consensus topologies despite the lack of evidence from the primary data.

A laid-­back trip through the Hennigian forests (Notes from Naturalists)

Binary matrix with a priori defined plesiomorphic character‐state may be re-­written as a simple set of branching diagrams (as a “Hennigian forest”). The last might be analyzed by the average consensus method. This procedure eventually avoids the taxon-­‐character matrix from the analysis of the data. Within this framework, the criteria of the best topologies based on the character-­‐state changes are unnecessary. The solely ‘reversal’-­based groups are always appear within the average consensus topologies despite the lack of evidence from the primary data.

A laid-­back trip through the Hennigian forests (Notes from Naturalists)

Binary matrix with a priori defined plesiomorphic character-­state may be re-­written as a set of branching diagrams (as a “Hennigian forest”). The last might be analyzed by the average consensus method. This procedure eventually avoids the taxon-­character matrix from the analysis of the data. Within this framework, the criteria of the best topologies based on the character-­state changes are unnecessary. The solely ‘reversal’‐based groups are always appear within the average consensus topologies despite the lack of direct evidence from the primary data.

A laid-­back trip through the Hennigian forests (Notes from naturalists)

Binary matrix with an a priori defined plesiomorphic character-­state may be re-­written as a set of branching diagrams (as a “Hennigian forest”). The last might be analyzed by the average consensus method. This procedure eventually avoids the taxon-­character matrix from the analysis of the data. Within this framework, the criteria of the best topologies based on the character-­state changes are unnecessary. The solely ‘reversal’‐based groups are always appear within the average consensus topologies despite the lack of direct evidence from the primary data.