Nutlet micromorphology and character evolution of Lappula species (Boraginaceae) and its systematic implications

Background The macro/micro-morphology of nutlets in 11 species (and 22 accessions) of the Boraginaceae family was investigated using stereomicroscope and scanning electron microscopy to evaluate the taxonomic relevance of the traits. To evaluate the phylogenetic significance of the character evolution, phylogenetic analysis was carried out by comparing available DNA sequence data from GenBank with selected original nutlet data. Results The Rochelieae nutlets' shape varied from ovoid (ovoid, ovoid-triangular, and ovoid-rectangular) to pyramid. Six major patterns were recognized based on the nutlet ultrastructure characters. Rocheliae is characterized by a transition from “without appendage” to “with tubercles and prickles” on the nutlet disk, and also via a shift from “lack of prickles” to “glossy prickles”. Conclusions The results show that the nutlet ultrastructure pattern of Rochelieae is systematically informative at the genus level, but not at the species level. Findings demonstrated that glochid is not an ancestral trait but is a synapomorphy and the transition to this trait occurred in the genus Lappula. The close boundary of nutlet microstructures between L. barbata and L. microcarpa has been discussed.

Adaptive function and phylogenetic significance of novel skeletal features of a new Devonian microconchid tubeworm (Tentaculita) from Wyoming, USA

A new genus and species of microconchid tubeworm, Aculeiconchus sandbergi n. gen. n. sp., is described from the Givetian (Devonian) Maywood Formation of Cottonwood Canyon, Wyoming, USA. It possesses unique hollow spines of various lengths on the tube underside, a position previously undocumented for these fossils. Like some cyclostome bryozoans possessing basal tubular extensions, the basal spines of Aculeiconchus n. gen. were presumably also used for fixation to flexible substrata, e.g., algal thalli, which is a previously undocumented adaptive strategy in microconchids. Together with other skeletal features, such basal spines could suggest that ‘lophophorate’ microconchids, unlike the other tentaculitoids, might be phylogenetically not as distant from bryozoans as previously thought. The Maywood Formation, which contains a few-millimeters thick, monospecific shell accumulation of the microconchids described herein, records deposition in an estuarine brackish setting within narrow channels that were cut into underlying strata. The microconchids were opportunistic taxa that repeatedly colonized these salinity-stressed estuarine channels, leading to a series of adaptive innovations, including colonization of plant stems during the Early Devonian (Beartooth Butte Formation) and possibly flexible, soft-algal substrata during the Middle Devonian (Maywood Formation, this study). Tectonic quiescence during the Early and Middle Devonian indicates that erosion and subsequent deposition of the Maywood and the underlying Beartooth Butte Formation channels were responses to major eustatic events. Over a span of nearly 30 Myr, channels were cut successively during lowstand conditions and a distinctive faunal assemblage with microconchids tracked marine transgressions into the channels. UUID: http://zoobank.org/394c8b32-d5e7-411e-8e56-6fb9f55bbb8a

Nutlet Micromorphology and Character Evolution of Some Species of Rochelieae (Boraginaceae) and Its Systematic Implications

Background: The macro/micro-morphology of nutlets in 11 species (and 22 accessions) of the Boraginaceae family was investigated by stereomicroscope and scanning electron microscopy to evaluate the taxonomic relevance of these traits. To evaluate the phylogenetic significance of the character evolution, available DNA sequence data from GenBank were combined with selected original nutlet data, and phylogenetic analysis was performed.Results: The Rochelieae nutlets' shape varied from ovoid (ovoid, ovoid-triangular, and ovoid-rectangular) to the pyramid. Six major patterns were recognized based on nutlet ultrastructure characters. Rocheliae is characterized by a transition from “without appendage” to “with tubercles and prickles” on the nutlet disk, and also by a shift from “lack of prickles” to “glossy prickles”.Conclusions: The results indicated that the nutlet ultrastructure pattern of Rochelieae is systematically informative at the genus level, but not at the species level. The results showed that glochid is not an ancestral trait but is a synapomorphy and the transition to this trait occurred in the genus Lappula. The Close boundary of nutlet microstructures between L. barbata and L. microcarpa was discussed.

Phylogenetic placement of the enigmatic longhorned beetle Vesperoctenus flohri Bates (Vesperidae) and a first description of its female internal structures

Taxonomic placement of the enigmatic monotypic Mexican longhorned beetle genus Vesperoctenus Bates is examined through inclusion in and reanalysis of the dataset of Haddad et al. (2018, Systematic Entomology 43: 68–89). We describe and discuss the phylogenetic significance of the internal structures of a recently collected V. flohri female from the Sierra de la Laguna mountain range in Mexico, the same specimen from which phylogenomic data was generated. Our phylogenomic analyses (469 genes) recovered Vesperoctenus with maximal statistical support within the cerambyciform family Vesperidae, sister to Vesperus Dejean (Vesperinae). Vesperus + Vesperoctenus were recovered sister to Philinae, and collectively form a clade sister to Anoplodermatinae. Thus, we place V. flohri within Vesperidae: Vesperinae: Vesperoctenini based on analyses of large-scale phylogenomic data. Finally, we propose that the conservation status of V. flohri merits assessment.

An updated generic circumscription for Cryptangieae (Cyperaceae, Poales) based on a molecular phylogeny and a morphological character reconstruction

Cryptangieae is a monophyletic tribe, as asserted in a recent molecular hypothesis, but there are questions about the circumscription and relationships of its genera. We enlarged the sampling of the tribe diversity, including about 80% of known species, and provide new analyses using single and combined matrices from two chloroplast (rbcL and trnL-F) and three nuclear ribosomal (ITS, ETS and 5S-NTS) regions with Bayesian Inference to clarify these questions. We also performed character reconstruction analyses with diagnostic morphological characters, including some traditionally applied in Cryptangieae taxonomy, using parsimony methods. The molecular analyses show Lagenocarpus in the current circumscription as polyphyletic, and the need to merge Cephalocarpus and Everardia to avoid paraphyletic genera. We propose an updated circumscription following the phylogeny, including a new name to a group at generic level (Krenakia); and discuss the phylogenetic significance of the morphological characters in Cryptangieae taxonomy. Though the relationship among some genera still needs more research, the genera we propose are strongly supported clades with clear morphological synapomorphies. Additionally, we provide an identification key, a brief description of genera and a list of accepted species including the required new combinations.